Merge pull request #5161 from Disservin/cluster

Merge SF master in the cluster branch

.clang-format

@@ -0,0 +1,44 @@
+AccessModifierOffset: -1
+AlignAfterOpenBracket: Align
+AlignConsecutiveAssignments: Consecutive
+AlignConsecutiveDeclarations: Consecutive
+AlignEscapedNewlines: DontAlign
+AlignOperands: AlignAfterOperator
+AlignTrailingComments: true
+AllowAllParametersOfDeclarationOnNextLine: true
+AllowShortCaseLabelsOnASingleLine: false
+AllowShortEnumsOnASingleLine: false
+AllowShortIfStatementsOnASingleLine: false
+AlwaysBreakTemplateDeclarations: Yes
+BasedOnStyle: WebKit
+BitFieldColonSpacing: After
+BinPackParameters: false
+BreakBeforeBinaryOperators: NonAssignment
+BreakBeforeBraces: Custom
+BraceWrapping:
+  AfterFunction: false 
+  AfterClass: false
+  AfterControlStatement: true
+  BeforeElse: true
+BreakBeforeTernaryOperators: true
+BreakConstructorInitializers: AfterColon
+BreakStringLiterals: false
+ColumnLimit: 100
+ContinuationIndentWidth: 2
+Cpp11BracedListStyle: true
+IndentGotoLabels: false
+IndentPPDirectives: BeforeHash
+IndentWidth: 4
+MaxEmptyLinesToKeep: 2
+NamespaceIndentation: None
+PackConstructorInitializers: Never
+ReflowComments: false
+SortIncludes: false
+SortUsingDeclarations: false
+SpaceAfterCStyleCast: true
+SpaceAfterTemplateKeyword: false
+SpaceBeforeCaseColon: true
+SpaceBeforeCpp11BracedList: false
+SpaceBeforeInheritanceColon: false
+SpaceInEmptyBlock: false
+SpacesBeforeTrailingComments: 2

.git-blame-ignore-revs

@@ -0,0 +1,7 @@
+# .git-blame-ignore-revs
+# Ignore commit which added clang-format
+2d0237db3f0e596fb06e3ffbadba84dcc4e018f6
+
+# Post commit formatting fixes
+0fca5605fa2e5e7240fde5e1aae50952b2612231
+08ed4c90db31959521b7ef3186c026edd1e90307

.github/ISSUE_TEMPLATE/BUG-REPORT.yml

@@ -0,0 +1,65 @@
+name: Report issue
+description: Create a report to help us fix issues with the engine
+body:
+- type: textarea
+  attributes:
+    label: Describe the issue
+    description: A clear and concise description of what you're experiencing.
+  validations:
+    required: true
+
+- type: textarea
+  attributes:
+    label: Expected behavior
+    description: A clear and concise description of what you expected to happen.
+  validations:
+    required: true
+
+- type: textarea
+  attributes:
+    label: Steps to reproduce
+    description: |
+      Steps to reproduce the behavior.
+      You can also use this section to paste the command line output.
+    placeholder: |
+      ```
+      position startpos moves g2g4 e7e5 f2f3
+      go mate 1
+      info string NNUE evaluation using nn-6877cd24400e.nnue enabled
+      info depth 1 seldepth 1 multipv 1 score mate 1 nodes 33 nps 11000 tbhits 0 time 3 pv d8h4
+      bestmove d8h4
+      ```
+  validations:
+    required: true
+
+- type: textarea
+  attributes:
+    label: Anything else?
+    description: |
+      Anything that will give us more context about the issue you are encountering.
+      You can also use this section to propose ideas on how to solve the issue. 
+  validations:
+    required: false
+
+- type: dropdown
+  attributes:
+    label: Operating system
+    options:
+      - All
+      - Windows
+      - Linux
+      - MacOS
+      - Android
+      - Other or N/A
+  validations:
+    required: true
+
+- type: input
+  attributes:
+    label: Stockfish version
+    description: |
+      This can be found by running the engine.
+      You can also use the commit ID.
+    placeholder: Stockfish 15 / e6e324e
+  validations:
+    required: true

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,8 @@
+blank_issues_enabled: false
+contact_links:
+  - name: Discord server
+    url: https://discord.gg/GWDRS3kU6R
+    about: Feel free to ask for support or have a chat with us on our Discord server!
+  - name: Discussions, Q&A, ideas, show us something...
+    url: https://github.com/official-stockfish/Stockfish/discussions/new
+    about: Do you have an idea for Stockfish? Do you want to show something that you made? Please open a discussion about it!

.github/ci/arm_matrix.json

@@ -0,0 +1,51 @@
+{
+  "config": [
+    {
+      "name": "Android NDK aarch64",
+      "os": "ubuntu-22.04",
+      "simple_name": "android",
+      "compiler": "aarch64-linux-android21-clang++",
+      "emu": "qemu-aarch64",
+      "comp": "ndk",
+      "shell": "bash",
+      "archive_ext": "tar"
+    },
+    {
+      "name": "Android NDK arm",
+      "os": "ubuntu-22.04",
+      "simple_name": "android",
+      "compiler": "armv7a-linux-androideabi21-clang++",
+      "emu": "qemu-arm",
+      "comp": "ndk",
+      "shell": "bash",
+      "archive_ext": "tar"
+    }
+  ],
+  "binaries": ["armv8-dotprod", "armv8", "armv7", "armv7-neon"],
+  "exclude": [
+    {
+      "binaries": "armv8-dotprod",
+      "config": {
+        "compiler": "armv7a-linux-androideabi21-clang++"
+      }
+    },
+    {
+      "binaries": "armv8",
+      "config": {
+        "compiler": "armv7a-linux-androideabi21-clang++"
+      }
+    },
+    {
+      "binaries": "armv7",
+      "config": {
+        "compiler": "aarch64-linux-android21-clang++"
+      }
+    },
+    {
+      "binaries": "armv7-neon",
+      "config": {
+        "compiler": "aarch64-linux-android21-clang++"
+      }
+    }
+  ]
+}

.github/ci/libcxx17.imp

@@ -0,0 +1,21 @@
+[
+    # Mappings for libcxx's internal headers
+    { include: [ "<__fwd/fstream.h>", private, "<iosfwd>", public ] },
+    { include: [ "<__fwd/ios.h>", private, "<iosfwd>", public ] },
+    { include: [ "<__fwd/istream.h>", private, "<iosfwd>", public ] },
+    { include: [ "<__fwd/ostream.h>", private, "<iosfwd>", public ] },
+    { include: [ "<__fwd/sstream.h>", private, "<iosfwd>", public ] },
+    { include: [ "<__fwd/streambuf.h>", private, "<iosfwd>", public ] },
+    { include: [ "<__fwd/string_view.h>", private, "<string_view>", public ] },
+
+    # Mappings for includes between public headers
+    { include: [ "<ios>", public, "<iostream>", public ] },
+    { include: [ "<streambuf>", public, "<iostream>", public ] },
+    { include: [ "<istream>", public, "<iostream>", public ] },
+    { include: [ "<ostream>", public, "<iostream>", public ] },
+    { include: [ "<iosfwd>", public, "<iostream>", public ] },
+
+    # Missing mappings in include-what-you-use's libcxx.imp
+    { include: ["@<__condition_variable/.*>", private, "<condition_variable>", public ] },
+    { include: ["@<__mutex/.*>", private, "<mutex>", public ] },
+]

.github/ci/matrix.json

@@ -0,0 +1,160 @@
+{
+  "config": [
+    {
+      "name": "Ubuntu 20.04 GCC",
+      "os": "ubuntu-20.04",
+      "simple_name": "ubuntu",
+      "compiler": "g++",
+      "comp": "gcc",
+      "shell": "bash",
+      "archive_ext": "tar",
+      "sde": "/home/runner/work/Stockfish/Stockfish/.output/sde-temp-files/sde-external-9.27.0-2023-09-13-lin/sde -future --"
+    },
+    {
+      "name": "MacOS 13 Apple Clang",
+      "os": "macos-13",
+      "simple_name": "macos",
+      "compiler": "clang++",
+      "comp": "clang",
+      "shell": "bash",
+      "archive_ext": "tar"
+    },
+    {
+      "name": "MacOS 14 Apple Clang M1",
+      "os": "macos-14",
+      "simple_name": "macos-m1",
+      "compiler": "clang++",
+      "comp": "clang",
+      "shell": "bash",
+      "archive_ext": "tar"
+    },
+    {
+      "name": "Windows 2022 Mingw-w64 GCC x86_64",
+      "os": "windows-2022",
+      "simple_name": "windows",
+      "compiler": "g++",
+      "comp": "mingw",
+      "msys_sys": "mingw64",
+      "msys_env": "x86_64-gcc",
+      "shell": "msys2 {0}",
+      "ext": ".exe",
+      "sde": "/d/a/Stockfish/Stockfish/.output/sde-temp-files/sde-external-9.27.0-2023-09-13-win/sde.exe -future --",
+      "archive_ext": "zip"
+    }
+  ],
+  "binaries": [
+    "x86-64",
+    "x86-64-sse41-popcnt",
+    "x86-64-avx2",
+    "x86-64-bmi2",
+    "x86-64-avxvnni",
+    "x86-64-avx512",
+    "x86-64-vnni256",
+    "x86-64-vnni512",
+    "apple-silicon"
+  ],
+  "exclude": [
+    {
+      "binaries": "x86-64",
+      "config": {
+        "os": "macos-14"
+      }
+    },
+    {
+      "binaries": "x86-64-sse41-popcnt",
+      "config": {
+        "os": "macos-14"
+      }
+    },
+    {
+      "binaries": "x86-64-avx2",
+      "config": {
+        "os": "macos-14"
+      }
+    },
+    {
+      "binaries": "x86-64-bmi2",
+      "config": {
+        "os": "macos-14"
+      }
+    },
+    {
+      "binaries": "x86-64-avxvnni",
+      "config": {
+        "os": "macos-14"
+      }
+    },
+    {
+      "binaries": "x86-64-avxvnni",
+      "config": {
+        "os": "macos-14"
+      }
+    },
+    {
+      "binaries": "x86-64-avx512",
+      "config": {
+        "os": "macos-14"
+      }
+    },
+    {
+      "binaries": "x86-64-vnni256",
+      "config": {
+        "os": "macos-14"
+      }
+    },
+    {
+      "binaries": "x86-64-vnni512",
+      "config": {
+        "os": "macos-14"
+      }
+    },
+    {
+      "binaries": "x86-64-avxvnni",
+      "config": {
+        "ubuntu-20.04": null
+      }
+    },
+    {
+      "binaries": "x86-64-avxvnni",
+      "config": {
+        "os": "macos-13"
+      }
+    },
+    {
+      "binaries": "x86-64-avx512",
+      "config": {
+        "os": "macos-13"
+      }
+    },
+    {
+      "binaries": "x86-64-vnni256",
+      "config": {
+        "os": "macos-13"
+      }
+    },
+    {
+      "binaries": "x86-64-vnni512",
+      "config": {
+        "os": "macos-13"
+      }
+    },
+    {
+      "binaries": "apple-silicon",
+      "config": {
+        "os": "windows-2022"
+      }
+    },
+    {
+      "binaries": "apple-silicon",
+      "config": {
+        "os": "macos-13"
+      }
+    },
+    {
+      "binaries": "apple-silicon",
+      "config": {
+        "os": "ubuntu-20.04"
+      }
+    }
+  ]
+}

.github/workflows/arm_compilation.yml

@@ -0,0 +1,94 @@
+name: Compilation
+on:
+  workflow_call:
+    inputs:
+      matrix:
+        type: string
+        required: true
+jobs:
+  Compilation:
+    name: ${{ matrix.config.name }} ${{ matrix.binaries }}
+    runs-on: ${{ matrix.config.os }}
+    env:
+      COMPILER: ${{ matrix.config.compiler }}
+      COMP: ${{ matrix.config.comp }}
+      EMU: ${{ matrix.config.emu }}
+      EXT: ${{ matrix.config.ext }}
+      BINARY: ${{ matrix.binaries }}
+    strategy:
+      fail-fast: false
+      matrix: ${{ fromJson(inputs.matrix) }}
+    defaults:
+      run:
+        working-directory: src
+        shell: ${{ matrix.config.shell }}
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Download required linux packages
+        if: runner.os == 'Linux'
+        run: |
+          sudo apt update
+          sudo apt install qemu-user
+
+      - name: Install NDK
+        if: runner.os == 'Linux'
+        run: |
+          if [ $COMP == ndk ]; then
+            NDKV="21.4.7075529"
+            ANDROID_ROOT=/usr/local/lib/android
+            ANDROID_SDK_ROOT=$ANDROID_ROOT/sdk
+            SDKMANAGER=$ANDROID_SDK_ROOT/cmdline-tools/latest/bin/sdkmanager
+            echo "y" | $SDKMANAGER "ndk;$NDKV"
+            ANDROID_NDK_ROOT=$ANDROID_SDK_ROOT/ndk/$NDKV
+            ANDROID_NDK_BIN=$ANDROID_NDK_ROOT/toolchains/llvm/prebuilt/linux-x86_64/bin
+            echo "ANDROID_NDK_BIN=$ANDROID_NDK_BIN" >> $GITHUB_ENV
+          fi
+
+      - name: Extract the bench number from the commit history
+        run: |
+          for hash in $(git rev-list -100 HEAD); do
+            benchref=$(git show -s $hash | tac | grep -m 1 -o -x '[[:space:]]*\b[Bb]ench[ :]\+[1-9][0-9]\{5,7\}\b[[:space:]]*' | sed 's/[^0-9]//g') && break || true
+          done
+          [[ -n "$benchref" ]] && echo "benchref=$benchref" >> $GITHUB_ENV && echo "From commit: $hash" && echo "Reference bench: $benchref" || echo "No bench found"
+
+      - name: Download the used network from the fishtest framework
+        run: make net
+
+      - name: Check compiler
+        run: |
+          if [ $COMP == ndk ]; then
+            export PATH=${{ env.ANDROID_NDK_BIN }}:$PATH
+          fi
+          $COMPILER -v
+
+      - name: Test help target
+        run: make help
+
+      - name: Check git
+        run: git --version
+
+      # Compile profile guided builds
+
+      - name: Compile ${{ matrix.binaries }} build
+        run: |
+          if [ $COMP == ndk ]; then
+            export PATH=${{ env.ANDROID_NDK_BIN }}:$PATH
+            export LDFLAGS="-static -Wno-unused-command-line-argument"
+          fi
+          make clean
+          make -j4 profile-build ARCH=$BINARY COMP=$COMP WINE_PATH=$EMU
+          make strip ARCH=$BINARY COMP=$COMP
+          WINE_PATH=$EMU ../tests/signature.sh $benchref
+          mv ./stockfish$EXT ../stockfish-android-$BINARY$EXT
+
+      - name: Remove non src files
+        run: git clean -fx
+
+      - name: Upload artifact for (pre)-release
+        uses: actions/upload-artifact@v4
+        with:
+          name: ${{ matrix.config.simple_name }} ${{ matrix.binaries }}
+          path: .

.github/workflows/clang-format.yml

@@ -0,0 +1,51 @@
+# This workflow will run clang-format and comment on the PR.
+# Because of security reasons, it is crucial that this workflow
+# executes no shell script nor runs make.
+# Read this before editing: https://securitylab.github.com/research/github-actions-preventing-pwn-requests/
+
+name: Clang-Format
+on:
+  pull_request_target:
+    branches:
+      - "master"
+    paths:
+      - "**.cpp"
+      - "**.h"
+jobs:
+  Clang-Format:
+    name: Clang-Format
+    runs-on: ubuntu-20.04
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}
+
+      - name: Run clang-format style check
+        uses: jidicula/clang-format-action@f62da5e3d3a2d88ff364771d9d938773a618ab5e # @v4.11.0
+        id: clang-format
+        continue-on-error: true
+        with:
+          clang-format-version: "17"
+          exclude-regex: "incbin"
+
+      - name: Comment on PR
+        if: steps.clang-format.outcome == 'failure'
+        uses: thollander/actions-comment-pull-request@fabd468d3a1a0b97feee5f6b9e499eab0dd903f6 # @v2.5.0
+        with:
+          message: |
+            clang-format 17 needs to be run on this PR.
+            If you do not have clang-format installed, the maintainer will run it when merging.
+            For the exact version please see https://packages.ubuntu.com/mantic/clang-format-17.
+
+            _(execution **${{ github.run_id }}** / attempt **${{ github.run_attempt }}**)_
+          comment_tag: execution
+
+      - name: Comment on PR
+        if: steps.clang-format.outcome != 'failure'
+        uses: thollander/actions-comment-pull-request@fabd468d3a1a0b97feee5f6b9e499eab0dd903f6 # @v2.5.0
+        with:
+          message: |
+            _(execution **${{ github.run_id }}** / attempt **${{ github.run_attempt }}**)_
+          create_if_not_exists: false
+          comment_tag: execution
+          mode: delete

.github/workflows/codeql.yml

@@ -0,0 +1,53 @@
+name: "CodeQL"
+
+on:
+  push:
+    branches: ["master"]
+  pull_request:
+    # The branches below must be a subset of the branches above
+    branches: ["master"]
+  schedule:
+    - cron: "17 18 * * 1"
+
+jobs:
+  analyze:
+    name: Analyze
+    runs-on: ubuntu-latest
+    permissions:
+      actions: read
+      contents: read
+      security-events: write
+
+    strategy:
+      fail-fast: false
+      matrix:
+        language: ["cpp"]
+        # CodeQL supports [ 'cpp', 'csharp', 'go', 'java', 'javascript', 'python', 'ruby' ]
+        # Use only 'java' to analyze code written in Java, Kotlin, or both
+        # Use only 'javascript' to analyze code written in JavaScript, TypeScript or both
+        # Learn more about CodeQL language support at https://aka.ms/codeql-docs/language-support
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      # Initializes the CodeQL tools for scanning.
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@v3
+        with:
+          languages: ${{ matrix.language }}
+          # If you wish to specify custom queries, you can do so here or in a config file.
+          # By default, queries listed here will override any specified in a config file.
+          # Prefix the list here with "+" to use these queries and those in the config file.
+
+          # For more details on CodeQL's query packs, refer to: https://docs.github.com/en/code-security/code-scanning/automatically-scanning-your-code-for-vulnerabilities-and-errors/configuring-code-scanning#using-queries-in-ql-packs
+          # queries: security-extended,security-and-quality
+
+      - name: Build
+        working-directory: src
+        run: make -j build ARCH=x86-64-modern
+
+      - name: Perform CodeQL Analysis
+        uses: github/codeql-action/analyze@v3
+        with:
+          category: "/language:${{matrix.language}}"

.github/workflows/compilation.yml

@@ -0,0 +1,89 @@
+name: Compilation
+on:
+  workflow_call:
+    inputs:
+      matrix:
+        type: string
+        required: true
+jobs:
+  Compilation:
+    name: ${{ matrix.config.name }} ${{ matrix.binaries }}
+    runs-on: ${{ matrix.config.os }}
+    env:
+      COMPILER: ${{ matrix.config.compiler }}
+      COMP: ${{ matrix.config.comp }}
+      EXT: ${{ matrix.config.ext }}
+      NAME: ${{ matrix.config.simple_name }}
+      BINARY: ${{ matrix.binaries }}
+      SDE: ${{ matrix.config.sde }}
+    strategy:
+      fail-fast: false
+      matrix: ${{ fromJson(inputs.matrix) }}
+    defaults:
+      run:
+        working-directory: src
+        shell: ${{ matrix.config.shell }}
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install fixed GCC on Linux
+        if: runner.os == 'Linux'
+        uses: egor-tensin/setup-gcc@eaa888eb19115a521fa72b65cd94fe1f25bbcaac # @v1.3
+        with:
+          version: 11
+
+      - name: Setup msys and install required packages
+        if: runner.os == 'Windows'
+        uses: msys2/setup-msys2@v2
+        with:
+          msystem: ${{ matrix.config.msys_sys }}
+          install: mingw-w64-${{ matrix.config.msys_env }} make git zip
+
+      - name: Download SDE package
+        if: runner.os == 'Linux' || runner.os == 'Windows'
+        uses: petarpetrovt/setup-sde@91a1a03434384e064706634125a15f7446d2aafb # @v2.3
+        with:
+          environmentVariableName: SDE_DIR
+          sdeVersion: 9.27.0
+
+      - name: Download the used network from the fishtest framework
+        run: make net
+
+      - name: Check compiler
+        run: $COMPILER -v
+
+      - name: Test help target
+        run: make help
+
+      - name: Check git
+        run: git --version
+
+      - name: Check compiler
+        run: $COMPILER -v
+
+      - name: Show g++ cpu info
+        if: runner.os != 'macOS'
+        run: g++ -Q -march=native --help=target
+
+      - name: Show clang++ cpu info
+        if: runner.os == 'macOS'
+        run: clang++ -E - -march=native -###
+
+      # x86-64 with newer extensions tests
+
+      - name: Compile ${{ matrix.config.binaries }} build
+        run: |
+          make clean
+          make -j4 profile-build ARCH=$BINARY COMP=$COMP WINE_PATH="$SDE"
+          make strip ARCH=$BINARY COMP=$COMP
+          WINE_PATH="$SDE" ../tests/signature.sh $benchref
+          mv ./stockfish$EXT ../stockfish-$NAME-$BINARY$EXT
+
+      - name: Remove non src files
+        run: git clean -fx
+
+      - name: Upload artifact for (pre)-release
+        uses: actions/upload-artifact@v4
+        with:
+          name: ${{ matrix.config.simple_name }} ${{ matrix.binaries }}
+          path: .

.github/workflows/iwyu.yml

@@ -0,0 +1,47 @@
+name: IWYU
+on:
+  workflow_call:
+jobs:
+  Analyzers:
+    name: Check includes
+    runs-on: ubuntu-22.04
+    defaults:
+      run:
+        working-directory: Stockfish/src
+        shell: bash
+    steps:
+      - name: Checkout Stockfish
+        uses: actions/checkout@v4
+        with:
+          path: Stockfish
+
+      - name: Checkout include-what-you-use
+        uses: actions/checkout@v4
+        with:
+          repository: include-what-you-use/include-what-you-use
+          ref: f25caa280dc3277c4086ec345ad279a2463fea0f
+          path: include-what-you-use
+
+      - name: Download required linux packages
+        run: |
+          sudo add-apt-repository 'deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy-17 main'
+          wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
+          sudo apt update
+          sudo apt install -y libclang-17-dev clang-17 libc++-17-dev
+
+      - name: Set up include-what-you-use
+        run: |
+          mkdir build && cd build
+          cmake -G "Unix Makefiles" -DCMAKE_PREFIX_PATH="/usr/lib/llvm-17" ..
+          sudo make install
+        working-directory: include-what-you-use
+
+      - name: Check include-what-you-use
+        run: include-what-you-use --version
+
+      - name: Check includes
+        run: >
+          make analyze
+          COMP=clang
+          CXX=include-what-you-use
+          CXXFLAGS="-stdlib=libc++ -Xiwyu --comment_style=long -Xiwyu --mapping='${{ github.workspace }}/Stockfish/.github/ci/libcxx17.imp' -Xiwyu --error"

.github/workflows/sanitizers.yml

@@ -0,0 +1,65 @@
+name: Sanitizers
+on:
+  workflow_call:
+jobs:
+  Test-under-sanitizers:
+    name: ${{ matrix.sanitizers.name }}
+    runs-on: ${{ matrix.config.os }}
+    env:
+      COMPILER: ${{ matrix.config.compiler }}
+      COMP: ${{ matrix.config.comp }}
+      CXXFLAGS: "-Werror"
+    strategy:
+      fail-fast: false
+      matrix:
+        config:
+          - name: Ubuntu 22.04 GCC
+            os: ubuntu-22.04
+            compiler: g++
+            comp: gcc
+            shell: bash
+        sanitizers:
+          - name: Run with thread sanitizer
+            make_option: sanitize=thread
+            instrumented_option: sanitizer-thread
+          - name: Run with UB sanitizer
+            make_option: sanitize=undefined
+            instrumented_option: sanitizer-undefined
+          - name: Run under valgrind
+            make_option: ""
+            instrumented_option: valgrind
+          - name: Run under valgrind-thread
+            make_option: ""
+            instrumented_option: valgrind-thread
+    defaults:
+      run:
+        working-directory: src
+        shell: ${{ matrix.config.shell }}
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Download required linux packages
+        run: |
+          sudo apt update
+          sudo apt install expect valgrind g++-multilib
+
+      - name: Download the used network from the fishtest framework
+        run: make net
+
+      - name: Check compiler
+        run: $COMPILER -v
+
+      - name: Test help target
+        run: make help
+
+      - name: Check git
+        run: git --version
+
+      # Sanitizers
+
+      - name: ${{ matrix.sanitizers.name }}
+        run: |
+          export CXXFLAGS="-O1 -fno-inline"
+          make clean
+          make -j4 ARCH=x86-64-sse41-popcnt ${{ matrix.sanitizers.make_option }} debug=yes optimize=no build > /dev/null
+          ../tests/instrumented.sh --${{ matrix.sanitizers.instrumented_option }}

.github/workflows/stockfish.yml

@@ -0,0 +1,104 @@
+name: Stockfish
+on:
+  push:
+    tags:
+      - "*"
+    branches:
+      - master
+      - tools
+      - github_ci
+  pull_request:
+    branches:
+      - master
+      - tools
+jobs:
+  Prerelease:
+    if: github.repository == 'official-stockfish/Stockfish' && (github.ref == 'refs/heads/master' || (startsWith(github.ref_name, 'sf_') && github.ref_type == 'tag'))
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      # returns null if no pre-release exists
+      - name: Get Commit SHA of Latest Pre-release
+        run: |
+          # Install required packages
+          sudo apt-get update
+          sudo apt-get install -y curl jq
+
+          echo "COMMIT_SHA_TAG=$(jq -r 'map(select(.prerelease)) | first | .tag_name' <<< $(curl -s https://api.github.com/repos/${{ github.repository_owner }}/Stockfish/releases))" >> $GITHUB_ENV
+
+      # delete old previous pre-release and tag
+      - run: gh release delete ${{ env.COMMIT_SHA_TAG }} --cleanup-tag
+        if: env.COMMIT_SHA_TAG != 'null'
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      # Make sure that an old ci that still runs on master doesn't recreate a prerelease
+      - name: Check Pullable Commits
+        id: check_commits
+        run: |
+          git fetch
+          CHANGES=$(git rev-list HEAD..origin/master --count)
+          echo "CHANGES=$CHANGES" >> $GITHUB_ENV
+
+      - name: Get last commit SHA
+        id: last_commit
+        run: echo "COMMIT_SHA=$(git rev-parse HEAD | cut -c 1-8)" >> $GITHUB_ENV
+
+      - name: Get commit date
+        id: commit_date
+        run: echo "COMMIT_DATE=$(git show -s --date=format:'%Y%m%d' --format=%cd HEAD)" >> $GITHUB_ENV
+
+      # Create a new pre-release, the other upload_binaries.yml will upload the binaries
+      # to this pre-release.
+      - name: Create Prerelease
+        if: github.ref_name == 'master' && env.CHANGES == '0'
+        uses: softprops/action-gh-release@4634c16e79c963813287e889244c50009e7f0981
+        with:
+          name: Stockfish dev-${{ env.COMMIT_DATE }}-${{ env.COMMIT_SHA }}
+          tag_name: stockfish-dev-${{ env.COMMIT_DATE }}-${{ env.COMMIT_SHA }}
+          prerelease: true
+
+  Matrix:
+    runs-on: ubuntu-latest
+    outputs:
+      matrix: ${{ steps.set-matrix.outputs.matrix }}
+      arm_matrix: ${{ steps.set-arm-matrix.outputs.arm_matrix }}
+    steps:
+      - uses: actions/checkout@v4
+      - id: set-matrix
+        run: |
+          TASKS=$(echo $(cat .github/ci/matrix.json) )
+          echo "MATRIX=$TASKS" >> $GITHUB_OUTPUT
+      - id: set-arm-matrix
+        run: |
+          TASKS_ARM=$(echo $(cat .github/ci/arm_matrix.json) )
+          echo "ARM_MATRIX=$TASKS_ARM" >> $GITHUB_OUTPUT
+  Compilation:
+    needs: [Matrix]
+    uses: ./.github/workflows/compilation.yml
+    with:
+      matrix: ${{ needs.Matrix.outputs.matrix }}
+  ARMCompilation:
+    needs: [Matrix]
+    uses: ./.github/workflows/arm_compilation.yml
+    with:
+      matrix: ${{ needs.Matrix.outputs.arm_matrix }}
+  IWYU:
+    uses: ./.github/workflows/iwyu.yml
+  Sanitizers:
+    uses: ./.github/workflows/sanitizers.yml
+  Tests:
+    uses: ./.github/workflows/tests.yml
+  Binaries:
+    if: github.repository == 'official-stockfish/Stockfish'
+    needs: [Matrix, Prerelease, Compilation]
+    uses: ./.github/workflows/upload_binaries.yml
+    with:
+      matrix: ${{ needs.Matrix.outputs.matrix }}
+  ARM_Binaries:
+    if: github.repository == 'official-stockfish/Stockfish'
+    needs: [Matrix, Prerelease, ARMCompilation]
+    uses: ./.github/workflows/upload_binaries.yml
+    with:
+      matrix: ${{ needs.Matrix.outputs.arm_matrix }}

.github/workflows/tests.yml

@@ -0,0 +1,365 @@
+name: Tests
+on:
+  workflow_call:
+jobs:
+  Test-Targets:
+    name: ${{ matrix.config.name }}
+    runs-on: ${{ matrix.config.os }}
+    env:
+      COMPILER: ${{ matrix.config.compiler }}
+      COMP: ${{ matrix.config.comp }}
+      CXXFLAGS: "-Werror"
+    strategy:
+      fail-fast: false
+      matrix:
+        config:
+          - name: Ubuntu 20.04 GCC
+            os: ubuntu-20.04
+            compiler: g++
+            comp: gcc
+            run_32bit_tests: true
+            run_64bit_tests: true
+            shell: bash
+          - name: Ubuntu 20.04 Clang
+            os: ubuntu-20.04
+            compiler: clang++
+            comp: clang
+            run_32bit_tests: true
+            run_64bit_tests: true
+            shell: bash
+          - name: Android NDK aarch64
+            os: ubuntu-22.04
+            compiler: aarch64-linux-android21-clang++
+            comp: ndk
+            run_armv8_tests: true
+            shell: bash
+          - name: Android NDK arm
+            os: ubuntu-22.04
+            compiler: armv7a-linux-androideabi21-clang++
+            comp: ndk
+            run_armv7_tests: true
+            shell: bash
+          - name: Linux GCC riscv64
+            os: ubuntu-22.04
+            compiler: g++
+            comp: gcc
+            run_riscv64_tests: true
+            base_image: "riscv64/alpine:edge"
+            platform: linux/riscv64
+            shell: bash
+          - name: Linux GCC ppc64
+            os: ubuntu-22.04
+            compiler: g++
+            comp: gcc
+            run_ppc64_tests: true
+            base_image: "ppc64le/alpine:latest"
+            platform: linux/ppc64le
+            shell: bash
+          - name: MacOS 13 Apple Clang
+            os: macos-13
+            compiler: clang++
+            comp: clang
+            run_64bit_tests: true
+            shell: bash
+          - name: MacOS 14 Apple Clang M1
+            os: macos-14
+            compiler: clang++
+            comp: clang
+            run_64bit_tests: false
+            run_m1_tests: true
+            shell: bash
+          - name: MacOS 13 GCC 11
+            os: macos-13
+            compiler: g++-11
+            comp: gcc
+            run_64bit_tests: true
+            shell: bash
+          - name: Windows 2022 Mingw-w64 GCC x86_64
+            os: windows-2022
+            compiler: g++
+            comp: mingw
+            run_64bit_tests: true
+            msys_sys: mingw64
+            msys_env: x86_64-gcc
+            shell: msys2 {0}
+          - name: Windows 2022 Mingw-w64 GCC i686
+            os: windows-2022
+            compiler: g++
+            comp: mingw
+            run_32bit_tests: true
+            msys_sys: mingw32
+            msys_env: i686-gcc
+            shell: msys2 {0}
+          - name: Windows 2022 Mingw-w64 Clang x86_64
+            os: windows-2022
+            compiler: clang++
+            comp: clang
+            run_64bit_tests: true
+            msys_sys: clang64
+            msys_env: clang-x86_64-clang
+            shell: msys2 {0}
+    defaults:
+      run:
+        working-directory: src
+        shell: ${{ matrix.config.shell }}
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Download required linux packages
+        if: runner.os == 'Linux'
+        run: |
+          sudo apt update
+          sudo apt install expect valgrind g++-multilib qemu-user-static
+
+      - name: Install NDK
+        if: runner.os == 'Linux'
+        run: |
+          if [ $COMP == ndk ]; then
+            NDKV="21.4.7075529"
+            ANDROID_ROOT=/usr/local/lib/android
+            ANDROID_SDK_ROOT=$ANDROID_ROOT/sdk
+            SDKMANAGER=$ANDROID_SDK_ROOT/cmdline-tools/latest/bin/sdkmanager
+            echo "y" | $SDKMANAGER "ndk;$NDKV"
+            ANDROID_NDK_ROOT=$ANDROID_SDK_ROOT/ndk/$NDKV
+            ANDROID_NDK_BIN=$ANDROID_NDK_ROOT/toolchains/llvm/prebuilt/linux-x86_64/bin
+            echo "ANDROID_NDK_BIN=$ANDROID_NDK_BIN" >> $GITHUB_ENV
+          fi
+
+      - name: Set up QEMU
+        if: matrix.config.base_image
+        uses: docker/setup-qemu-action@v3
+
+      - name: Set up Docker Buildx
+        if: matrix.config.base_image
+        uses: docker/setup-buildx-action@v3
+
+      - name: Build Docker container
+        if: matrix.config.base_image
+        run: |
+          docker buildx build --load -t sf_builder - << EOF
+          FROM ${{ matrix.config.base_image }}
+          WORKDIR /app
+          RUN apk update && apk add make g++
+          CMD ["sh", "script.sh"]
+          EOF
+
+      - name: Download required macOS packages
+        if: runner.os == 'macOS'
+        run: brew install coreutils
+
+      - name: Setup msys and install required packages
+        if: runner.os == 'Windows'
+        uses: msys2/setup-msys2@v2
+        with:
+          msystem: ${{ matrix.config.msys_sys }}
+          install: mingw-w64-${{ matrix.config.msys_env }} make git expect
+
+      - name: Download the used network from the fishtest framework
+        run: make net
+
+      - name: Extract the bench number from the commit history
+        run: |
+          for hash in $(git rev-list -100 HEAD); do
+            benchref=$(git show -s $hash | tac | grep -m 1 -o -x '[[:space:]]*\b[Bb]ench[ :]\+[1-9][0-9]\{5,7\}\b[[:space:]]*' | sed 's/[^0-9]//g') && break || true
+          done
+          [[ -n "$benchref" ]] && echo "benchref=$benchref" >> $GITHUB_ENV && echo "From commit: $hash" && echo "Reference bench: $benchref" || echo "No bench found"
+
+      - name: Check compiler
+        run: |
+          if [ -z "${{ matrix.config.base_image }}" ]; then
+            if [ $COMP == ndk ]; then
+              export PATH=${{ env.ANDROID_NDK_BIN }}:$PATH
+            fi
+            $COMPILER -v
+          else
+            echo "$COMPILER -v" > script.sh
+            docker run --rm --platform ${{ matrix.config.platform }} -v ${{ github.workspace }}/src:/app sf_builder
+          fi
+
+      - name: Test help target
+        run: make help
+
+      - name: Check git
+        run: git --version
+
+      # x86-32 tests
+
+      - name: Test debug x86-32 build
+        if: matrix.config.run_32bit_tests
+        run: |
+          export CXXFLAGS="-Werror -D_GLIBCXX_DEBUG"
+          make clean
+          make -j4 ARCH=x86-32 optimize=no debug=yes build
+          ../tests/signature.sh $benchref
+
+      - name: Test x86-32 build
+        if: matrix.config.run_32bit_tests
+        run: |
+          make clean
+          make -j4 ARCH=x86-32 build
+          ../tests/signature.sh $benchref
+
+      - name: Test x86-32-sse41-popcnt build
+        if: matrix.config.run_32bit_tests
+        run: |
+          make clean
+          make -j4 ARCH=x86-32-sse41-popcnt build
+          ../tests/signature.sh $benchref
+
+      - name: Test x86-32-sse2 build
+        if: matrix.config.run_32bit_tests
+        run: |
+          make clean
+          make -j4 ARCH=x86-32-sse2 build
+          ../tests/signature.sh $benchref
+
+      - name: Test general-32 build
+        if: matrix.config.run_32bit_tests
+        run: |
+          make clean
+          make -j4 ARCH=general-32 build
+          ../tests/signature.sh $benchref
+
+      # x86-64 tests
+
+      - name: Test debug x86-64-avx2 build
+        if: matrix.config.run_64bit_tests
+        run: |
+          export CXXFLAGS="-Werror -D_GLIBCXX_DEBUG"
+          make clean
+          make -j4 ARCH=x86-64-avx2 optimize=no debug=yes build
+          ../tests/signature.sh $benchref
+
+      - name: Test x86-64-bmi2 build
+        if: matrix.config.run_64bit_tests
+        run: |
+          make clean
+          make -j4 ARCH=x86-64-bmi2 build
+          ../tests/signature.sh $benchref
+
+      - name: Test x86-64-avx2 build
+        if: matrix.config.run_64bit_tests
+        run: |
+          make clean
+          make -j4 ARCH=x86-64-avx2 build
+          ../tests/signature.sh $benchref
+
+      # Test a deprecated arch
+      - name: Test x86-64-modern build
+        if: matrix.config.run_64bit_tests
+        run: |
+          make clean
+          make -j4 ARCH=x86-64-modern build
+          ../tests/signature.sh $benchref
+
+      - name: Test x86-64-sse41-popcnt build
+        if: matrix.config.run_64bit_tests
+        run: |
+          make clean
+          make -j4 ARCH=x86-64-sse41-popcnt build
+          ../tests/signature.sh $benchref
+
+      - name: Test x86-64-ssse3 build
+        if: matrix.config.run_64bit_tests
+        run: |
+          make clean
+          make -j4 ARCH=x86-64-ssse3 build
+          ../tests/signature.sh $benchref
+
+      - name: Test x86-64-sse3-popcnt build
+        if: matrix.config.run_64bit_tests
+        run: |
+          make clean
+          make -j4 ARCH=x86-64-sse3-popcnt build
+          ../tests/signature.sh $benchref
+
+      - name: Test x86-64 build
+        if: matrix.config.run_64bit_tests
+        run: |
+          make clean
+          make -j4 ARCH=x86-64 build
+          ../tests/signature.sh $benchref
+
+      - name: Test general-64 build
+        if: matrix.config.run_64bit_tests
+        run: |
+          make clean
+          make -j4 ARCH=general-64 build
+          ../tests/signature.sh $benchref
+
+      - name: Test apple-silicon build
+        if: matrix.config.run_m1_tests
+        run: |
+          make clean
+          make -j4 ARCH=apple-silicon build
+          ../tests/signature.sh $benchref
+
+      # armv8 tests
+
+      - name: Test armv8 build
+        if: matrix.config.run_armv8_tests
+        run: |
+          export PATH=${{ env.ANDROID_NDK_BIN }}:$PATH
+          export LDFLAGS="-static -Wno-unused-command-line-argument"
+          make clean
+          make -j4 ARCH=armv8 build
+          ../tests/signature.sh $benchref
+
+      - name: Test armv8-dotprod build
+        if: matrix.config.run_armv8_tests
+        run: |
+          export PATH=${{ env.ANDROID_NDK_BIN }}:$PATH
+          export LDFLAGS="-static -Wno-unused-command-line-argument"
+          make clean
+          make -j4 ARCH=armv8-dotprod build
+          ../tests/signature.sh $benchref
+
+      # armv7 tests
+
+      - name: Test armv7 build
+        if: matrix.config.run_armv7_tests
+        run: |
+          export PATH=${{ env.ANDROID_NDK_BIN }}:$PATH
+          export LDFLAGS="-static -Wno-unused-command-line-argument"
+          make clean
+          make -j4 ARCH=armv7 build
+          ../tests/signature.sh $benchref
+
+      - name: Test armv7-neon build
+        if: matrix.config.run_armv7_tests
+        run: |
+          export PATH=${{ env.ANDROID_NDK_BIN }}:$PATH
+          export LDFLAGS="-static -Wno-unused-command-line-argument"
+          make clean
+          make -j4 ARCH=armv7-neon build
+          ../tests/signature.sh $benchref
+
+      # riscv64 tests
+
+      - name: Test riscv64 build
+        if: matrix.config.run_riscv64_tests
+        run: |
+          echo "export LDFLAGS='-static' && make clean && make -j4 ARCH=riscv64 build" > script.sh
+          docker run --rm --platform ${{ matrix.config.platform }} -v ${{ github.workspace }}/src:/app sf_builder
+          ../tests/signature.sh $benchref
+
+      # ppc64 tests
+
+      - name: Test ppc64 build
+        if: matrix.config.run_ppc64_tests
+        run: |
+          echo "export LDFLAGS='-static' && make clean && make -j4 ARCH=ppc-64 build" > script.sh
+          docker run --rm --platform ${{ matrix.config.platform }} -v ${{ github.workspace }}/src:/app sf_builder
+          ../tests/signature.sh $benchref
+
+      # Other tests
+
+      - name: Check perft and search reproducibility
+        if: matrix.config.run_64bit_tests
+        run: |
+          make clean
+          make -j4 ARCH=x86-64-avx2 build
+          ../tests/perft.sh
+          ../tests/reprosearch.sh

.github/workflows/upload_binaries.yml

@@ -0,0 +1,106 @@
+name: Upload Binaries
+on:
+  workflow_call:
+    inputs:
+      matrix:
+        type: string
+        required: true
+
+jobs:
+  Artifacts:
+    name: ${{ matrix.config.name }} ${{ matrix.binaries }}
+    runs-on: ${{ matrix.config.os }}
+    env:
+      COMPILER: ${{ matrix.config.compiler }}
+      COMP: ${{ matrix.config.comp }}
+      EXT: ${{ matrix.config.ext }}
+      NAME: ${{ matrix.config.simple_name }}
+      BINARY: ${{ matrix.binaries }}
+      SDE: ${{ matrix.config.sde }}
+    strategy:
+      fail-fast: false
+      matrix: ${{ fromJson(inputs.matrix) }}
+    defaults:
+      run:
+        shell: ${{ matrix.config.shell }}
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Download artifact from compilation
+        uses: actions/download-artifact@v4
+        with:
+          name: ${{ matrix.config.simple_name }} ${{ matrix.binaries }}
+          path: ${{ matrix.config.simple_name }} ${{ matrix.binaries }}
+
+      - name: Setup msys and install required packages
+        if: runner.os == 'Windows'
+        uses: msys2/setup-msys2@v2
+        with:
+          msystem: ${{ matrix.config.msys_sys }}
+          install: mingw-w64-${{ matrix.config.msys_env }} make git zip
+
+      - name: Create Package
+        run: |
+          mkdir stockfish
+
+      - name: Download wiki
+        run: |
+          git clone https://github.com/official-stockfish/Stockfish.wiki.git wiki
+          rm -rf wiki/.git
+          mv wiki stockfish/
+
+      - name: Copy files
+        run: |
+          mv "${{ matrix.config.simple_name }} ${{ matrix.binaries }}" stockfish-workflow
+          cd stockfish-workflow
+          cp -r src ../stockfish/
+          cp stockfish-$NAME-$BINARY$EXT ../stockfish/
+          cp "Top CPU Contributors.txt" ../stockfish/
+          cp Copying.txt ../stockfish/
+          cp AUTHORS ../stockfish/
+          cp CITATION.cff ../stockfish/
+          cp README.md ../stockfish/
+          cp CONTRIBUTING.md ../stockfish/
+
+      - name: Create tar
+        if: runner.os != 'Windows'
+        run: |
+          chmod +x ./stockfish/stockfish-$NAME-$BINARY$EXT
+          tar -cvf stockfish-$NAME-$BINARY.tar stockfish
+
+      - name: Create zip
+        if: runner.os == 'Windows'
+        run: |
+          zip -r stockfish-$NAME-$BINARY.zip stockfish
+
+      - name: Release
+        if: startsWith(github.ref_name, 'sf_') && github.ref_type == 'tag'
+        uses: softprops/action-gh-release@4634c16e79c963813287e889244c50009e7f0981
+        with:
+          files: stockfish-${{ matrix.config.simple_name }}-${{ matrix.binaries }}.${{ matrix.config.archive_ext }}
+
+      - name: Get last commit sha
+        id: last_commit
+        run: echo "COMMIT_SHA=$(git rev-parse HEAD | cut -c 1-8)" >> $GITHUB_ENV
+
+      - name: Get commit date
+        id: commit_date
+        run: echo "COMMIT_DATE=$(git show -s --date=format:'%Y%m%d' --format=%cd HEAD)" >> $GITHUB_ENV
+
+      # Make sure that an old ci that still runs on master doesn't recreate a prerelease
+      - name: Check Pullable Commits
+        id: check_commits
+        run: |
+          git fetch
+          CHANGES=$(git rev-list HEAD..origin/master --count)
+          echo "CHANGES=$CHANGES" >> $GITHUB_ENV
+
+      - name: Prerelease
+        if: github.ref_name == 'master' && env.CHANGES == '0'
+        continue-on-error: true
+        uses: softprops/action-gh-release@4634c16e79c963813287e889244c50009e7f0981
+        with:
+          name: Stockfish dev-${{ env.COMMIT_DATE }}-${{ env.COMMIT_SHA }}
+          tag_name: stockfish-dev-${{ env.COMMIT_DATE }}-${{ env.COMMIT_SHA }}
+          prerelease: true
+          files: stockfish-${{ matrix.config.simple_name }}-${{ matrix.binaries }}.${{ matrix.config.archive_ext }}

.travis.yml

@@ -1,101 +0,0 @@
-language: cpp
-dist: bionic
-
-matrix:
-  include:
-    - os: linux
-      compiler: gcc
-      addons:
-        apt:
-          packages: ['g++-8', 'g++-8-multilib', 'g++-multilib', 'valgrind', 'expect', 'curl']
-      env:
-        - COMPILER=g++-8
-        - COMP=gcc
-
-    - os: linux
-      compiler: clang
-      addons:
-        apt:
-          packages: ['clang-10', 'llvm-10-dev', 'g++-multilib', 'valgrind', 'expect', 'curl']
-      env:
-        - COMPILER=clang++-10
-        - COMP=clang
-
-    - os: osx
-      osx_image: xcode12
-      compiler: gcc
-      env:
-        - COMPILER=g++
-        - COMP=gcc
-
-    - os: osx
-      osx_image: xcode12
-      compiler: clang
-      env:
-        - COMPILER=clang++
-        - COMP=clang
-
-branches:
-  only:
-   - master
-
-before_script:
-  - cd src
-
-script:
-  # Download net
-  - make net
-
-  # Obtain bench reference from git log
-  - git log HEAD | grep "\b[Bb]ench[ :]\+[0-9]\{7\}" | head -n 1 | sed "s/[^0-9]*\([0-9]*\).*/\1/g" > git_sig
-  - export benchref=$(cat git_sig)
-  - echo "Reference bench:" $benchref
-
-  # Compiler version string
-  - $COMPILER -v
-
-  # test help target
-  - make help
-
-  # Verify bench number against various builds
-  - export CXXFLAGS="-Werror -D_GLIBCXX_DEBUG"
-  - make clean && make -j2 ARCH=x86-64-modern optimize=no debug=yes build && ../tests/signature.sh $benchref
-  - export CXXFLAGS="-Werror"
-  - make clean && make -j2 ARCH=x86-64-modern build && ../tests/signature.sh $benchref
-  - make clean && make -j2 ARCH=x86-64-ssse3 build && ../tests/signature.sh $benchref
-  - make clean && make -j2 ARCH=x86-64-sse3-popcnt build && ../tests/signature.sh $benchref
-  - make clean && make -j2 ARCH=x86-64 build && ../tests/signature.sh $benchref
-  - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then make clean && make -j2 ARCH=general-64 build && ../tests/signature.sh $benchref; fi
-  - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then make clean && make -j2 ARCH=x86-32 optimize=no debug=yes build && ../tests/signature.sh $benchref; fi
-  - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then make clean && make -j2 ARCH=x86-32-sse41-popcnt build && ../tests/signature.sh $benchref; fi
-  - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then make clean && make -j2 ARCH=x86-32-sse2 build && ../tests/signature.sh $benchref; fi
-  - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then make clean && make -j2 ARCH=x86-32 build && ../tests/signature.sh $benchref; fi
-  - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then make clean && make -j2 ARCH=general-32 build && ../tests/signature.sh $benchref; fi
-  # workaround: exclude a custom version of llvm+clang, which doesn't find llvm-profdata on ubuntu
-  - if [[ "$TRAVIS_OS_NAME" != "linux" || "$COMP" == "gcc" ]]; then make clean && make -j2 ARCH=x86-64-modern profile-build && ../tests/signature.sh $benchref; fi
-
-  # compile only for some more advanced architectures (might not run in travis)
-  - make clean && make -j2 ARCH=x86-64-avx2 build
-  - make clean && make -j2 ARCH=x86-64-bmi2 build
-  - make clean && make -j2 ARCH=x86-64-avx512 build
-  - make clean && make -j2 ARCH=x86-64-vnni512 build
-  - make clean && make -j2 ARCH=x86-64-vnni256 build
-
-  #
-  # Check perft and reproducible search
-  - make clean && make -j2 ARCH=x86-64-modern build
-  - ../tests/perft.sh
-  - ../tests/reprosearch.sh
-
-  #
-  # Valgrind
-  #
-  - export CXXFLAGS="-O1 -fno-inline"
-  - if [ -x "$(command -v valgrind )" ]; then make clean && make -j2 ARCH=x86-64-modern debug=yes optimize=no build > /dev/null && ../tests/instrumented.sh --valgrind; fi
-  - if [ -x "$(command -v valgrind )" ]; then ../tests/instrumented.sh --valgrind-thread; fi
-
-  #
-  # Sanitizer
-  #
-  - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then make clean && make -j2 ARCH=x86-64-modern sanitize=undefined optimize=no debug=yes build > /dev/null && ../tests/instrumented.sh --sanitizer-undefined; fi
-  - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then make clean && make -j2 ARCH=x86-64-modern sanitize=thread    optimize=no debug=yes build > /dev/null && ../tests/instrumented.sh --sanitizer-thread; fi

AUTHORS

@@ -1,19 +1,18 @@
-# List of authors for Stockfish, as of August 4, 2020
-
-# Founders of the Stockfish project and fishtest infrastructure
+# Founders of the Stockfish project and Fishtest infrastructure
 Tord Romstad (romstad)
 Marco Costalba (mcostalba)
 Joona Kiiski (zamar)
 Gary Linscott (glinscott)
 
-# Authors and inventors of NNUE, training, NNUE port
+# Authors and inventors of NNUE, training, and NNUE port
 Yu Nasu (ynasu87)
 Motohiro Isozaki (yaneurao)
 Hisayori Noda (nodchip)
 
-# all other authors of the code in alphabetical order
+# All other authors of Stockfish code (in alphabetical order)
 Aditya (absimaldata)
 Adrian Petrescu (apetresc)
+Ahmed Kerimov (wcdbmv)
 Ajith Chandy Jose (ajithcj)
 Alain Savard (Rocky640)
 Alayan Feh (Alayan-stk-2)
@@ -21,28 +20,42 @@ Alexander Kure
 Alexander Pagel (Lolligerhans)
 Alfredo Menezes (lonfom169)
 Ali AlZhrani (Cooffe)
+Andreas Matthies (Matthies)
+Andrei Vetrov (proukornew)
 Andrew Grant (AndyGrant)
 Andrey Neporada (nepal)
 Andy Duplain
+Antoine Champion (antoinechampion)
 Aram Tumanian (atumanian)
 Arjun Temurnikar
+Artem Solopiy (EntityFX)
 Auguste Pop
+Balazs Szilagyi
 Balint Pfliegel
+Ben Chaney (Chaneybenjamini)
 Ben Koshy (BKSpurgeon)
 Bill Henry (VoyagerOne)
 Bojun Guo (noobpwnftw, Nooby)
+borg323
+Boštjan Mejak (PedanticHacker)
 braich
 Brian Sheppard (SapphireBrand, briansheppard-toast)
 Bruno de Melo Costa (BM123499)
+Bruno Pellanda (pellanda)
 Bryan Cross (crossbr)
 candirufish
 Chess13234
 Chris Cain (ceebo)
+clefrks
+Clemens L. (rn5f107s2)
+Cody Ho (aesrentai)
 Dale Weiler (graphitemaster)
-Dan Schmidt (dfannius)
 Daniel Axtens (daxtens)
 Daniel Dugovic (ddugovic)
+Daniel Monroe (Ergodice)
+Dan Schmidt (dfannius)
 Dariusz Orzechowski (dorzechowski)
+David (dav1312)
 David Zar
 Daylen Yang (daylen)
 Deshawn Mohan-Smith (GoldenRare)
@@ -50,59 +63,71 @@ Dieter Dobbelaere (ddobbelaere)
 DiscanX
 Dominik Schlösser (domschl)
 double-beep
+Douglas Matos Gomes (dsmsgms)
+Dubslow
 Eduardo Cáceres (eduherminio)
 Eelco de Groot (KingDefender)
 Elvin Liu (solarlight2)
 erbsenzaehler
 Ernesto Gatti
-Linmiao Xu (linrock)
 Fabian Beuke (madnight)
 Fabian Fichter (ianfab)
 Fanael Linithien (Fanael)
 fanon
-Fauzi Akram Dabat (FauziAkram)
+Fauzi Akram Dabat (fauzi2)
 Felix Wittmann
 gamander
+Gabriele Lombardo (gabe)
+Gahtan Nahdi
 Gary Heckman (gheckman)
 George Sobala (gsobala)
 gguliash
+Giacomo Lorenzetti (G-Lorenz)
 Gian-Carlo Pascutto (gcp)
+Goh CJ (cj5716)
 Gontran Lemaire (gonlem)
 Goodkov Vasiliy Aleksandrovich (goodkov)
 Gregor Cramer
 GuardianRM
-Günther Demetz (pb00067, pb00068)
 Guy Vreuls (gvreuls)
+Günther Demetz (pb00067, pb00068)
 Henri Wiechers
 Hiraoka Takuya (HiraokaTakuya)
 homoSapiensSapiens
 Hongzhi Cheng
 Ivan Ivec (IIvec)
 Jacques B. (Timshel)
+Jake Senne (w1wwwwww)
 Jan Ondruš (hxim)
-Jared Kish (Kurtbusch)
+Jared Kish (Kurtbusch, kurt22i)
 Jarrod Torriero (DU-jdto)
-Jean Gauthier (OuaisBla)
+Jasper Shovelton (Beanie496)
 Jean-Francois Romang (jromang)
+Jean Gauthier (OuaisBla)
 Jekaa
 Jerry Donald Watson (jerrydonaldwatson)
 jjoshua2
-Jonathan Calovski (Mysseno)
 Jonathan Buladas Dumale (SFisGOD)
+Jonathan Calovski (Mysseno)
+Jonathan McDermid (jonathanmcdermid)
 Joost VandeVondele (vondele)
-Jörg Oster (joergoster)
 Joseph Ellis (jhellis3)
 Joseph R. Prostko
+Jörg Oster (joergoster)
+Julian Willemer (NightlyKing)
 jundery
 Justin Blanchard (UncombedCoconut)
 Kelly Wilson
 Ken Takusagawa
+Kian E (KJE-98)
 kinderchocolate
 Kiran Panditrao (Krgp)
 Kojirion
 Krystian Kuzniarek (kuzkry)
 Leonardo Ljubičić (ICCF World Champion)
 Leonid Pechenik (lp--)
+Liam Keegan (lkeegan)
+Linmiao Xu (linrock)
 Linus Arver (listx)
 loco-loco
 Lub van den Berg (ElbertoOne)
@@ -116,6 +141,8 @@ marotear
 Matt Ginsberg (mattginsberg)
 Matthew Lai (matthewlai)
 Matthew Sullivan (Matt14916)
+Max A. (Disservin)
+Maxim Masiutin (maximmasiutin)
 Maxim Molchanov (Maxim)
 Michael An (man)
 Michael Byrne (MichaelB7)
@@ -125,38 +152,47 @@ Michael Whiteley (protonspring)
 Michel Van den Bergh (vdbergh)
 Miguel Lahoz (miguel-l)
 Mikael Bäckman (mbootsector)
+Mike Babigian (Farseer)
 Mira
 Miroslav Fontán (Hexik)
 Moez Jellouli (MJZ1977)
 Mohammed Li (tthsqe12)
+Muzhen J (XInTheDark)
 Nathan Rugg (nmrugg)
-Nick Pelling (nickpelling)
+Nguyen Pham (nguyenpham)
 Nicklas Persson (NicklasPersson)
+Nick Pelling (nickpelling)
 Niklas Fiekas (niklasf)
 Nikolay Kostov (NikolayIT)
-Nguyen Pham (nguyenpham)
 Norman Schmidt (FireFather)
 notruck
+Ofek Shochat (OfekShochat, ghostway)
 Ondrej Mosnáček (WOnder93)
+Ondřej Mišina (AndrovT)
 Oskar Werkelin Ahlin
 Pablo Vazquez
 Panthee
 Pascal Romaret
 Pasquale Pigazzini (ppigazzini)
 Patrick Jansen (mibere)
-pellanda
+Peter Schneider (pschneider1968)
 Peter Zsifkovits (CoffeeOne)
+PikaCat
 Praveen Kumar Tummala (praveentml)
+Prokop Randáček (ProkopRandacek)
 Rahul Dsilva (silversolver1)
 Ralph Stößer (Ralph Stoesser)
 Raminder Singh
 renouve
-Reuven Peleg
-Richard Lloyd
+Reuven Peleg (R-Peleg)
+Richard Lloyd (Richard-Lloyd)
+Robert Nürnberg (robertnurnberg)
 Rodrigo Exterckötter Tjäder
-Ron Britvich (Britvich)
+Rodrigo Roim (roim)
 Ronald de Man (syzygy1, syzygy)
+Ron Britvich (Britvich)
 rqs
+Rui Coelho (ruicoelhopedro)
 Ryan Schmitt
 Ryan Takker
 Sami Kiminki (skiminki)
@@ -165,28 +201,42 @@ Sergei Antonov (saproj)
 Sergei Ivanov (svivanov72)
 Sergio Vieri (sergiovieri)
 sf-x
+Shahin M. Shahin (peregrine)
 Shane Booth (shane31)
 Shawn Varghese (xXH4CKST3RXx)
+Shawn Xu (xu-shawn)
+Siad Daboul (Topologist)
 Stefan Geschwentner (locutus2)
 Stefano Cardanobile (Stefano80)
+Stefano Di Martino (StefanoD)
 Steinar Gunderson (sesse)
 Stéphane Nicolet (snicolet)
+Stephen Touset (stouset)
+Syine Mineta (MinetaS)
+Taras Vuk (TarasVuk)
 Thanar2
 thaspel
 theo77186
+TierynnB
+Ting-Hsuan Huang (fffelix-huang)
+Tobias Steinmann
+Tomasz Sobczyk (Sopel97)
 Tom Truscott
 Tom Vijlbrief (tomtor)
-Tomasz Sobczyk (Sopel97)
 Torsten Franz (torfranz, tfranzer)
+Torsten Hellwig (Torom)
 Tracey Emery (basepr1me)
 tttak
 Unai Corzo (unaiic)
 Uri Blass (uriblass)
 Vince Negri (cuddlestmonkey)
+Viren
+windfishballad
+xefoci7612
+Xiang Wang (KatyushaScarlet)
 zz4032
 
-
 # Additionally, we acknowledge the authors and maintainers of fishtest,
-# an amazing and essential framework for the development of Stockfish!
+# an amazing and essential framework for Stockfish development!
 #
-# https://github.com/glinscott/fishtest/blob/master/AUTHORS
+# https://github.com/official-stockfish/fishtest/blob/master/AUTHORS

CITATION.cff

@@ -0,0 +1,23 @@
+# This CITATION.cff file was generated with cffinit.
+# Visit https://bit.ly/cffinit to generate yours today!
+
+cff-version: 1.2.0
+title: Stockfish
+message: >-
+  Please cite this software using the metadata from this
+  file.
+type: software
+authors:
+  - name: The Stockfish developers (see AUTHORS file)
+repository-code: 'https://github.com/official-stockfish/Stockfish'
+url: 'https://stockfishchess.org/'
+repository-artifact: 'https://stockfishchess.org/download/'
+abstract: Stockfish is a free and strong UCI chess engine.
+keywords:
+  - chess
+  - artificial intelligence (AI)
+  - tree search
+  - alpha-beta search
+  - neural networks (NN)
+  - efficiently updatable neural networks (NNUE)
+license: GPL-3.0

CONTRIBUTING.md

@@ -0,0 +1,97 @@
+# Contributing to Stockfish
+
+Welcome to the Stockfish project! We are excited that you are interested in
+contributing. This document outlines the guidelines and steps to follow when
+making contributions to Stockfish.
+
+## Table of Contents
+
+- [Building Stockfish](#building-stockfish)
+- [Making Contributions](#making-contributions)
+  - [Reporting Issues](#reporting-issues)
+  - [Submitting Pull Requests](#submitting-pull-requests)
+- [Code Style](#code-style)
+- [Community and Communication](#community-and-communication)
+- [License](#license)
+
+## Building Stockfish
+
+In case you do not have a C++ compiler installed, you can follow the
+instructions from our wiki.
+
+- [Ubuntu][ubuntu-compiling-link]
+- [Windows][windows-compiling-link]
+- [macOS][macos-compiling-link]
+
+## Making Contributions
+
+### Reporting Issues
+
+If you find a bug, please open an issue on the
+[issue tracker][issue-tracker-link]. Be sure to include relevant information
+like your operating system, build environment, and a detailed description of the
+problem.
+
+_Please note that Stockfish's development is not focused on adding new features.
+Thus any issue regarding missing features will potentially be closed without
+further discussion._
+
+### Submitting Pull Requests
+
+- Functional changes need to be tested on fishtest. See
+  [Creating my First Test][creating-my-first-test] for more details.
+  The accompanying pull request should include a link to the test results and
+  the new bench.
+
+- Non-functional changes (e.g. refactoring, code style, documentation) do not
+  need to be tested on fishtest, unless they might impact performance.
+
+- Provide a clear and concise description of the changes in the pull request
+  description.
+
+_First time contributors should add their name to [AUTHORS](../AUTHORS)._
+
+_Stockfish's development is not focused on adding new features. Thus any pull
+request introducing new features will potentially be closed without further
+discussion._
+
+## Code Style
+
+Changes to Stockfish C++ code should respect our coding style defined by
+[.clang-format](.clang-format). You can format your changes by running
+`make format`. This requires clang-format version 17 to be installed on your system.
+
+## Navigate
+
+For experienced Git users who frequently use git blame, it is recommended to
+configure the blame.ignoreRevsFile setting.
+This setting is useful for excluding noisy formatting commits.
+
+```bash
+git config blame.ignoreRevsFile .git-blame-ignore-revs
+```
+
+## Community and Communication
+
+- Join the [Stockfish discord][discord-link] to discuss ideas, issues, and
+  development.
+- Participate in the [Stockfish GitHub discussions][discussions-link] for
+  broader conversations.
+
+## License
+
+By contributing to Stockfish, you agree that your contributions will be licensed
+under the GNU General Public License v3.0. See [Copying.txt][copying-link] for
+more details.
+
+Thank you for contributing to Stockfish and helping us make it even better!
+
+
+[copying-link]:           https://github.com/official-stockfish/Stockfish/blob/master/Copying.txt
+[discord-link]:           https://discord.gg/GWDRS3kU6R
+[discussions-link]:       https://github.com/official-stockfish/Stockfish/discussions/new
+[creating-my-first-test]: https://github.com/official-stockfish/fishtest/wiki/Creating-my-first-test#create-your-test
+[issue-tracker-link]:     https://github.com/official-stockfish/Stockfish/issues
+[ubuntu-compiling-link]:  https://github.com/official-stockfish/Stockfish/wiki/Developers#user-content-installing-a-compiler-1
+[windows-compiling-link]: https://github.com/official-stockfish/Stockfish/wiki/Developers#user-content-installing-a-compiler
+[macos-compiling-link]:   https://github.com/official-stockfish/Stockfish/wiki/Developers#user-content-installing-a-compiler-2

Copying.txt

@@ -1,7 +1,7 @@
                     GNU GENERAL PUBLIC LICENSE
                        Version 3, 29 June 2007
 
- Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
+ Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/>
  Everyone is permitted to copy and distribute verbatim copies
  of this license document, but changing it is not allowed.
 
@@ -645,7 +645,7 @@ the "copyright" line and a pointer to where the full notice is found.
     GNU General Public License for more details.
 
     You should have received a copy of the GNU General Public License
-    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 Also add information on how to contact you by electronic and paper mail.
 
@@ -664,11 +664,11 @@ might be different; for a GUI interface, you would use an "about box".
   You should also get your employer (if you work as a programmer) or school,
 if any, to sign a "copyright disclaimer" for the program, if necessary.
 For more information on this, and how to apply and follow the GNU GPL, see
-<http://www.gnu.org/licenses/>.
+<https://www.gnu.org/licenses/>.
 
   The GNU General Public License does not permit incorporating your program
 into proprietary programs.  If your program is a subroutine library, you
 may consider it more useful to permit linking proprietary applications with
 the library.  If this is what you want to do, use the GNU Lesser General
 Public License instead of this License.  But first, please read
-<http://www.gnu.org/philosophy/why-not-lgpl.html>.
+<https://www.gnu.org/licenses/why-not-lgpl.html>.

README.md

@@ -1,300 +1,181 @@
+<div align="center">
+
+  [![Stockfish][stockfish128-logo]][website-link]
+
+  <h3>Stockfish</h3>
+
+  A free and strong UCI chess engine.
+  <br>
+  <strong>[Explore Stockfish docs »][wiki-link]</strong>
+  <br>
+  <br>
+  [Report bug][issue-link]
+  ·
+  [Open a discussion][discussions-link]
+  ·
+  [Discord][discord-link]
+  ·
+  [Blog][website-blog-link]
+
+  [![Build][build-badge]][build-link]
+  [![License][license-badge]][license-link]
+  <br>
+  [![Release][release-badge]][release-link]
+  [![Commits][commits-badge]][commits-link]
+  <br>
+  [![Website][website-badge]][website-link]
+  [![Fishtest][fishtest-badge]][fishtest-link]
+  [![Discord][discord-badge]][discord-link]
+
+</div>
+
 ## Overview
 
-[![Build Status](https://travis-ci.org/official-stockfish/Stockfish.svg?branch=master)](https://travis-ci.org/official-stockfish/Stockfish)
-[![Build Status](https://ci.appveyor.com/api/projects/status/github/official-stockfish/Stockfish?branch=master&svg=true)](https://ci.appveyor.com/project/mcostalba/stockfish/branch/master)
+[Stockfish][website-link] is a **free and strong UCI chess engine** derived from
+Glaurung 2.1 that analyzes chess positions and computes the optimal moves.
 
-[Stockfish](https://stockfishchess.org) is a free, powerful UCI chess engine
-derived from Glaurung 2.1. Stockfish is not a complete chess program and requires a
-UCI-compatible graphical user interface (GUI) (e.g. XBoard with PolyGlot, Scid,
-Cute Chess, eboard, Arena, Sigma Chess, Shredder, Chess Partner or Fritz) in order
-to be used comfortably. Read the documentation for your GUI of choice for information
-about how to use Stockfish with it.
-
-The Stockfish engine features two evaluation functions for chess, the classical
-evaluation based on handcrafted terms, and the NNUE evaluation based on efficiently
-updatable neural networks. The classical evaluation runs efficiently on almost all
-CPU architectures, while the NNUE evaluation benefits from the vector
-intrinsics available on most CPUs (sse2, avx2, neon, or similar).
+Stockfish **does not include a graphical user interface** (GUI) that is required
+to display a chessboard and to make it easy to input moves. These GUIs are
+developed independently from Stockfish and are available online. **Read the
+documentation for your GUI** of choice for information about how to use
+Stockfish with it.
 
+See also the Stockfish [documentation][wiki-usage-link] for further usage help.
 
 ## Files
 
 This distribution of Stockfish consists of the following files:
 
-  * Readme.md, the file you are currently reading.
+  * [README.md][readme-link], the file you are currently reading.
 
-  * Copying.txt, a text file containing the GNU General Public License version 3.
+  * [Copying.txt][license-link], a text file containing the GNU General Public
+    License version 3.
 
-  * AUTHORS, a text file with the list of authors for the project
+  * [AUTHORS][authors-link], a text file with the list of authors for the project.
 
-  * src, a subdirectory containing the full source code, including a Makefile
-    that can be used to compile Stockfish on Unix-like systems.
+  * [src][src-link], a subdirectory containing the full source code, including a
+    Makefile that can be used to compile Stockfish on Unix-like systems.
 
   * a file with the .nnue extension, storing the neural network for the NNUE
     evaluation. Binary distributions will have this file embedded.
 
-## UCI options
+## Stockfish on distributed memory systems
 
-Currently, Stockfish has the following UCI options:
-
-  * #### Threads
-    The number of CPU threads used for searching a position. For best performance, set
-    this equal to the number of CPU cores available.
-
-  * #### Hash
-    The size of the hash table in MB. It is recommended to set Hash after setting Threads.
-
-  * #### Clear Hash
-    Clear the hash table.
-
-  * #### Ponder
-    Let Stockfish ponder its next move while the opponent is thinking.
-
-  * #### MultiPV
-    Output the N best lines (principal variations, PVs) when searching.
-    Leave at 1 for best performance.
-
-  * #### Use NNUE
-    Toggle between the NNUE and classical evaluation functions. If set to "true",
-    the network parameters must be available to load from file (see also EvalFile),
-    if they are not embedded in the binary.
-
-  * #### EvalFile
-    The name of the file of the NNUE evaluation parameters. Depending on the GUI the
-    filename might have to include the full path to the folder/directory that contains the file.
-    Other locations, such as the directory that contains the binary and the working directory,
-    are also searched.
-
-  * #### UCI_AnalyseMode
-    An option handled by your GUI.
-
-  * #### UCI_Chess960
-    An option handled by your GUI. If true, Stockfish will play Chess960.
-
-  * #### UCI_ShowWDL
-    If enabled, show approximate WDL statistics as part of the engine output.
-    These WDL numbers model expected game outcomes for a given evaluation and
-    game ply for engine self-play at fishtest LTC conditions (60+0.6s per game).
-
-  * #### UCI_LimitStrength
-    Enable weaker play aiming for an Elo rating as set by UCI_Elo. This option overrides Skill Level.
-
-  * #### UCI_Elo
-    If enabled by UCI_LimitStrength, aim for an engine strength of the given Elo.
-    This Elo rating has been calibrated at a time control of 60s+0.6s and anchored to CCRL 40/4.
-
-  * #### Skill Level
-    Lower the Skill Level in order to make Stockfish play weaker (see also UCI_LimitStrength).
-    Internally, MultiPV is enabled, and with a certain probability depending on the Skill Level a
-    weaker move will be played.
-
-  * #### SyzygyPath
-    Path to the folders/directories storing the Syzygy tablebase files. Multiple
-    directories are to be separated by ";" on Windows and by ":" on Unix-based
-    operating systems. Do not use spaces around the ";" or ":".
-
-    Example: `C:\tablebases\wdl345;C:\tablebases\wdl6;D:\tablebases\dtz345;D:\tablebases\dtz6`
-
-    It is recommended to store .rtbw files on an SSD. There is no loss in storing
-    the .rtbz files on a regular HD. It is recommended to verify all md5 checksums
-    of the downloaded tablebase files (`md5sum -c checksum.md5`) as corruption will
-    lead to engine crashes.
-
-  * #### SyzygyProbeDepth
-    Minimum remaining search depth for which a position is probed. Set this option
-    to a higher value to probe less aggressively if you experience too much slowdown
-    (in terms of nps) due to tablebase probing.
-
-  * #### Syzygy50MoveRule
-    Disable to let fifty-move rule draws detected by Syzygy tablebase probes count
-    as wins or losses. This is useful for ICCF correspondence games.
-
-  * #### SyzygyProbeLimit
-    Limit Syzygy tablebase probing to positions with at most this many pieces left
-    (including kings and pawns).
-
-  * #### Contempt
-    A positive value for contempt favors middle game positions and avoids draws,
-    effective for the classical evaluation only.
-
-  * #### Analysis Contempt
-    By default, contempt is set to prefer the side to move. Set this option to "White"
-    or "Black" to analyse with contempt for that side, or "Off" to disable contempt.
-
-  * #### Move Overhead
-    Assume a time delay of x ms due to network and GUI overheads. This is useful to
-    avoid losses on time in those cases.
-
-  * #### Slow Mover
-    Lower values will make Stockfish take less time in games, higher values will
-    make it think longer.
-
-  * #### nodestime
-    Tells the engine to use nodes searched instead of wall time to account for
-    elapsed time. Useful for engine testing.
-
-  * #### Debug Log File
-    Write all communication to and from the engine into a text file.
-
-## A note on classical evaluation versus NNUE evaluation
-
-Both approaches assign a value to a position that is used in alpha-beta (PVS) search
-to find the best move. The classical evaluation computes this value as a function
-of various chess concepts, handcrafted by experts, tested and tuned using fishtest.
-The NNUE evaluation computes this value with a neural network based on basic
-inputs (e.g. piece positions only). The network is optimized and trained
-on the evaluations of millions of positions at moderate search depth.
-
-The NNUE evaluation was first introduced in shogi, and ported to Stockfish afterward.
-It can be evaluated efficiently on CPUs, and exploits the fact that only parts
-of the neural network need to be updated after a typical chess move.
-[The nodchip repository](https://github.com/nodchip/Stockfish) provides additional
-tools to train and develop the NNUE networks. On CPUs supporting modern vector instructions
-(avx2 and similar), the NNUE evaluation results in much stronger playing strength, even
-if the nodes per second computed by the engine is somewhat lower (roughly 80% of nps
-is typical).
-
-Notes:
-
-1) the NNUE evaluation depends on the Stockfish binary and the network parameter
-file (see the EvalFile UCI option). Not every parameter file is compatible with a given
-Stockfish binary, but the default value of the EvalFile UCI option is the name of a network
-that is guaranteed to be compatible with that binary.
-
-2) to use the NNUE evaluation, the additional data file with neural network parameters
-needs to be available. Normally, this file is already embedded in the binary or it 
-can be downloaded. The filename for the default (recommended) net can be found as the default
-value of the `EvalFile` UCI option, with the format `nn-[SHA256 first 12 digits].nnue`
-(for instance, `nn-c157e0a5755b.nnue`). This file can be downloaded from
+The cluster branch allows for running Stockfish on a cluster of servers (nodes)
+that are connected with a high-speed and low-latency network, using the message
+passing interface (MPI). In this case, one MPI process should be run per node,
+and UCI options can be used to set the number of threads/hash per node as usual.
+Typically, the engine will be invoked as
 ```
-https://tests.stockfishchess.org/api/nn/[filename]
+mpirun -np N /path/to/stockfish
 ```
-replacing `[filename]` as needed.
-
-## What to expect from the Syzygy tablebases?
-
-If the engine is searching a position that is not in the tablebases (e.g.
-a position with 8 pieces), it will access the tablebases during the search.
-If the engine reports a very large score (typically 153.xx), this means 
-it has found a winning line into a tablebase position.
-
-If the engine is given a position to search that is in the tablebases, it
-will use the tablebases at the beginning of the search to preselect all
-good moves, i.e. all moves that preserve the win or preserve the draw while
-taking into account the 50-move rule.
-It will then perform a search only on those moves. **The engine will not move
-immediately**, unless there is only a single good move. **The engine likely
-will not report a mate score, even if the position is known to be won.**
-
-It is therefore clear that this behaviour is not identical to what one might
-be used to with Nalimov tablebases. There are technical reasons for this
-difference, the main technical reason being that Nalimov tablebases use the
-DTM metric (distance-to-mate), while the Syzygy tablebases use a variation of the
-DTZ metric (distance-to-zero, zero meaning any move that resets the 50-move
-counter). This special metric is one of the reasons that the Syzygy tablebases are
-more compact than Nalimov tablebases, while still storing all information
-needed for optimal play and in addition being able to take into account
-the 50-move rule.
-
-## Large Pages
-
-Stockfish supports large pages on Linux and Windows. Large pages make
-the hash access more efficient, improving the engine speed, especially
-on large hash sizes. Typical increases are 5..10% in terms of nodes per
-second, but speed increases up to 30% have been measured. The support is
-automatic. Stockfish attempts to use large pages when available and
-will fall back to regular memory allocation when this is not the case.
-
-### Support on Linux
-
-Large page support on Linux is obtained by the Linux kernel
-transparent huge pages functionality. Typically, transparent huge pages
-are already enabled, and no configuration is needed.
-
-### Support on Windows
-
-The use of large pages requires "Lock Pages in Memory" privilege. See
-[Enable the Lock Pages in Memory Option (Windows)](https://docs.microsoft.com/en-us/sql/database-engine/configure-windows/enable-the-lock-pages-in-memory-option-windows)
-on how to enable this privilege, then run [RAMMap](https://docs.microsoft.com/en-us/sysinternals/downloads/rammap)
-to double-check that large pages are used. We suggest that you reboot
-your computer after you have enabled large pages, because long Windows
-sessions suffer from memory fragmentation, which may prevent Stockfish
-from getting large pages: a fresh session is better in this regard.
-
-## Compiling Stockfish yourself from the sources
-
-Stockfish has support for 32 or 64-bit CPUs, certain hardware
-instructions, big-endian machines such as Power PC, and other platforms.
-
-On Unix-like systems, it should be easy to compile Stockfish
-directly from the source code with the included Makefile in the folder
-`src`. In general it is recommended to run `make help` to see a list of make
-targets with corresponding descriptions.
-
+where ```N``` stands for the number of MPI processes used (alternatives to ```mpirun```,
+include ```mpiexec```, ```srun```). Use 1 mpi rank per node, and employ threading
+according to the cores per node. To build the cluster
+branch, it is sufficient to specify ```COMPCXX=mpicxx``` (or e.g. CC depending on the name
+of the compiler providing MPI support) on the make command line, and do a clean build:
 ```
-    cd src
-    make help
-    make net
-    make build ARCH=x86-64-modern
+make -j ARCH=x86-64-modern clean build COMPCXX=mpicxx mpi=yes
 ```
+Make sure that the MPI installation is configured to support ```MPI_THREAD_MULTIPLE```,
+this might require adding system specific compiler options to the Makefile. Stockfish employs
+non-blocking (asynchronous) communication, and benefits from an MPI
+implementation that efficiently supports this. Some MPI implentations might benefit
+from leaving 1 core/thread free for these asynchronous communications, and might require
+setting additional environment variables. ```mpirun``` should forward stdin/stdout
+to ```rank 0``` only (e.g. ```srun --input=0 --output=0```).
+Refer to your MPI documentation for more info.
 
-When not using the Makefile to compile (for instance, with Microsoft MSVC) you
-need to manually set/unset some switches in the compiler command line; see
-file *types.h* for a quick reference.
+## Contributing
 
-When reporting an issue or a bug, please tell us which version and
-compiler you used to create your executable. These informations can
-be found by typing the following commands in a console:
-
-```
-    ./stockfish compiler
-```
-
-## Understanding the code base and participating in the project
-
-Stockfish's improvement over the last couple of years has been a great
-community effort. There are a few ways to help contribute to its growth.
+__See [Contributing Guide](CONTRIBUTING.md).__
 
 ### Donating hardware
 
-Improving Stockfish requires a massive amount of testing. You can donate
-your hardware resources by installing the [Fishtest Worker](https://github.com/glinscott/fishtest/wiki/Running-the-worker:-overview)
-and view the current tests on [Fishtest](https://tests.stockfishchess.org/tests).
+Improving Stockfish requires a massive amount of testing. You can donate your
+hardware resources by installing the [Fishtest Worker][worker-link] and viewing
+the current tests on [Fishtest][fishtest-link].
 
 ### Improving the code
 
-If you want to help improve the code, there are several valuable resources:
-
-* [In this wiki,](https://www.chessprogramming.org) many techniques used in
+In the [chessprogramming wiki][programming-link], many techniques used in
 Stockfish are explained with a lot of background information.
+The [section on Stockfish][programmingsf-link] describes many features
+and techniques used by Stockfish. However, it is generic rather than
+focused on Stockfish's precise implementation.
 
-* [The section on Stockfish](https://www.chessprogramming.org/Stockfish)
-describes many features and techniques used by Stockfish. However, it is
-generic rather than being focused on Stockfish's precise implementation.
-Nevertheless, a helpful resource.
-
-* The latest source can always be found on [GitHub](https://github.com/official-stockfish/Stockfish).
-Discussions about Stockfish take place these days mainly in the [FishCooking](https://groups.google.com/forum/#!forum/fishcooking)
-group and on the [Stockfish Discord channel](https://discord.gg/nv8gDtt).
-The engine testing is done on [Fishtest](https://tests.stockfishchess.org/tests).
-If you want to help improve Stockfish, please read this [guideline](https://github.com/glinscott/fishtest/wiki/Creating-my-first-test)
+The engine testing is done on [Fishtest][fishtest-link].
+If you want to help improve Stockfish, please read this [guideline][guideline-link]
 first, where the basics of Stockfish development are explained.
 
+Discussions about Stockfish take place these days mainly in the Stockfish
+[Discord server][discord-link]. This is also the best place to ask questions
+about the codebase and how to improve it.
+
+## Compiling Stockfish
+
+Stockfish has support for 32 or 64-bit CPUs, certain hardware instructions,
+big-endian machines such as Power PC, and other platforms.
+
+On Unix-like systems, it should be easy to compile Stockfish directly from the
+source code with the included Makefile in the folder `src`. In general, it is
+recommended to run `make help` to see a list of make targets with corresponding
+descriptions. An example suitable for most Intel and AMD chips:
+
+```
+cd src
+make -j profile-build ARCH=x86-64-avx2
+```
+
+Detailed compilation instructions for all platforms can be found in our
+[documentation][wiki-compile-link]. Our wiki also has information about
+the [UCI commands][wiki-uci-link] supported by Stockfish.
 
 ## Terms of use
 
-Stockfish is free, and distributed under the **GNU General Public License version 3**
-(GPL v3). Essentially, this means you are free to do almost exactly
-what you want with the program, including distributing it among your
-friends, making it available for download from your website, selling
-it (either by itself or as part of some bigger software package), or
-using it as the starting point for a software project of your own.
+Stockfish is free and distributed under the
+[**GNU General Public License version 3**][license-link] (GPL v3). Essentially,
+this means you are free to do almost exactly what you want with the program,
+including distributing it among your friends, making it available for download
+from your website, selling it (either by itself or as part of some bigger
+software package), or using it as the starting point for a software project of
+your own.
 
-The only real limitation is that whenever you distribute Stockfish in
-some way, you MUST always include the full source code, or a pointer
-to where the source code can be found, to generate the exact binary
-you are distributing. If you make any changes to the source code,
-these changes must also be made available under the GPL.
+The only real limitation is that whenever you distribute Stockfish in some way,
+you MUST always include the license and the full source code (or a pointer to
+where the source code can be found) to generate the exact binary you are
+distributing. If you make any changes to the source code, these changes must
+also be made available under GPL v3.
 
-For full details, read the copy of the GPL v3 found in the file named
-*Copying.txt*.
+
+[authors-link]:       https://github.com/official-stockfish/Stockfish/blob/master/AUTHORS
+[build-link]:         https://github.com/official-stockfish/Stockfish/actions/workflows/stockfish.yml
+[commits-link]:       https://github.com/official-stockfish/Stockfish/commits/master
+[discord-link]:       https://discord.gg/GWDRS3kU6R
+[issue-link]:         https://github.com/official-stockfish/Stockfish/issues/new?assignees=&labels=&template=BUG-REPORT.yml
+[discussions-link]:   https://github.com/official-stockfish/Stockfish/discussions/new
+[fishtest-link]:      https://tests.stockfishchess.org/tests
+[guideline-link]:     https://github.com/official-stockfish/fishtest/wiki/Creating-my-first-test
+[license-link]:       https://github.com/official-stockfish/Stockfish/blob/master/Copying.txt
+[programming-link]:   https://www.chessprogramming.org/Main_Page
+[programmingsf-link]: https://www.chessprogramming.org/Stockfish
+[readme-link]:        https://github.com/official-stockfish/Stockfish/blob/master/README.md
+[release-link]:       https://github.com/official-stockfish/Stockfish/releases/latest
+[src-link]:           https://github.com/official-stockfish/Stockfish/tree/master/src
+[stockfish128-logo]:  https://stockfishchess.org/images/logo/icon_128x128.png
+[uci-link]:           https://backscattering.de/chess/uci/
+[website-link]:       https://stockfishchess.org
+[website-blog-link]:  https://stockfishchess.org/blog/
+[wiki-link]:          https://github.com/official-stockfish/Stockfish/wiki
+[wiki-compile-link]:  https://github.com/official-stockfish/Stockfish/wiki/Compiling-from-source
+[wiki-uci-link]:      https://github.com/official-stockfish/Stockfish/wiki/UCI-&-Commands
+[wiki-usage-link]:    https://github.com/official-stockfish/Stockfish/wiki/Download-and-usage
+[worker-link]:        https://github.com/official-stockfish/fishtest/wiki/Running-the-worker
+
+[build-badge]:        https://img.shields.io/github/actions/workflow/status/official-stockfish/Stockfish/stockfish.yml?branch=master&style=for-the-badge&label=stockfish&logo=github
+[commits-badge]:      https://img.shields.io/github/commits-since/official-stockfish/Stockfish/latest?style=for-the-badge
+[discord-badge]:      https://img.shields.io/discord/435943710472011776?style=for-the-badge&label=discord&logo=Discord
+[fishtest-badge]:     https://img.shields.io/website?style=for-the-badge&down_color=red&down_message=Offline&label=Fishtest&up_color=success&up_message=Online&url=https%3A%2F%2Ftests.stockfishchess.org%2Ftests%2Ffinished
+[license-badge]:      https://img.shields.io/github/license/official-stockfish/Stockfish?style=for-the-badge&label=license&color=success
+[release-badge]:      https://img.shields.io/github/v/release/official-stockfish/Stockfish?style=for-the-badge&label=official%20release
+[website-badge]:      https://img.shields.io/website?style=for-the-badge&down_color=red&down_message=Offline&label=website&up_color=success&up_message=Online&url=https%3A%2F%2Fstockfishchess.org

Top CPU Contributors.txt

@@ -1,189 +1,286 @@
-Contributors to Fishtest with >10,000 CPU hours, as of Feb 15, 2021.
+Contributors to Fishtest with >10,000 CPU hours, as of 2024-02-24.
 Thank you!
 
-Username                CPU Hours       Games played
-----------------------------------------------------
-noobpwnftw               23930906         1560559941
-dew                       1169948           70333008
-mlang                      957168           61657446
-mibere                     703840           46867607
-tvijlbrief                 517888           33379462
-JojoM                      515404           30334272
-cw                         443276           29385549
-crunchy                    427035           27344275
-grandphish2                425794           26347253
-fastgm                     414133           24519696
-gvreuls                    377843           24708884
-CSU_Dynasty                338718           23030006
-Fisherman                  326795           21820747
-TueRens                    313730           19490246
-ctoks                      298442           20052551
-velislav                   270519           17355456
-bcross                     241064           17196165
-glinscott                  217799           13780820
-nordlandia                 211692           13484886
-bking_US                   198894           11876016
-drabel                     191096           13129722
-leszek                     189170           11446821
-mgrabiak                   187153           12013300
-robal                      181389           11539242
-Thanar                     179852           12365359
-vdv                        175274            9889046
-spams                      157128           10319326
-marrco                     150292            9401741
-sqrt2                      147963            9724586
-CoffeeOne                  137086            5022516
-vdbergh                    137041            8926915
-malala                     136182            8002293
-mhoram                     132780            8398229
-xoto                       124729            8652088
-davar                      122092            7960001
-dsmith                     122059            7570238
-Data                       113305            8220352
-BrunoBanani                112960            7436849
-pemo                       109598            5036441
-Dantist                    106768            6431396
-MaZePallas                 102741            6630419
-ElbertoOne                  99028            7023771
-brabos                      92118            6186135
-linrock                     90903            6708639
-psk                         89957            5984901
-sunu                        88614            6020673
-sterni1971                  86948            5613788
-Vizvezdenec                 83761            5344740
-BRAVONE                     81239            5054681
-nssy                        76497            5259388
-cuistot                     76366            4370584
-racerschmacer               75753            5442626
-teddybaer                   75125            5407666
-Pking_cda                   73776            5293873
-0x3C33                      73133            4670293
-jromang                     72117            5054915
-solarlight                  70517            5028306
-dv8silencer                 70287            3883992
-Bobo1239                    68515            4652287
-manap                       66273            4121774
-tinker                      64321            4268390
-robnjr                      57262            4053117
-Freja                       56938            3733019
-ttruscott                   56010            3680085
-rkl                         54986            4150767
-renouve                     53811            3501516
-finfish                     51360            3370515
-eva42                       51272            3599691
-rap                         49985            3219146
-pb00067                     49727            3298270
-amicic                      49691            3042481
-ronaldjerum                 47654            3240695
-bigpen0r                    47278            3291647
-biffhero                    46564            3111352
-VoyagerOne                  45476            3452465
-eastorwest                  45033            3071805
-speedycpu                   43842            3003273
-jbwiebe                     43305            2805433
-Antihistamine               41788            2761312
-mhunt                       41735            2691355
-homyur                      39893            2850481
-gri                         39871            2515779
-oryx                        38282            2944400
-Spprtr                      38157            2470529
-SC                          37290            2731014
-csnodgrass                  36207            2688994
-jmdana                      36157            2210661
-strelock                    34716            2074055
-Garf                        33800            2747562
-skiminki                    33515            2055584
-EthanOConnor                33370            2090311
-slakovv                     32915            2021889
-yurikvelo                   32600            2255966
-Prcuvu                      30377            2170122
-manapbk                     30326            1770143
-anst                        30301            2190091
-jkiiski                     30136            1904470
-hyperbolic.tom              29840            2017394
-Pyafue                      29650            1902349
-qurashee                    27758            1509620
-OuaisBla                    27636            1578800
-chriswk                     26902            1868317
-achambord                   26582            1767323
-Fifis                       26376            1776853
-Patrick_G                   26276            1801617
-yorkman                     26193            1992080
-SFTUser                     25182            1675689
-nabildanial                 24942            1519409
-Sharaf_DG                   24765            1786697
-ncfish1                     24411            1520927
-agg177                      23890            1395014
-JanErik                     23408            1703875
-Isidor                      23388            1680691
-Norabor                     23164            1591830
-cisco2015                   22895            1762069
-Zirie                       22542            1472937
-team-oh                     22272            1636708
-MazeOfGalious               21978            1629593
-sg4032                      21945            1643065
-ianh2105                    21725            1632562
-xor12                       21628            1680365
-dex                         21612            1467203
-nesoneg                     21494            1463031
-jjoshua2                    20997            1422689
-horst.prack                 20878            1465656
-0xB00B1ES                   20590            1208666
-sphinx                      20515            1352368
-j3corre                     20405            941444
-Adrian.Schmidt123           20316            1281436
-Ente                        20017            1432602
-wei                         19973            1745989
-rstoesser                   19569            1293588
-eudhan                      19274            1283717
-jundery                     18445            1115855
-iisiraider                  18247            1101015
-ville                       17883            1384026
-chris                       17698            1487385
-purplefishies               17595            1092533
-DMBK                        17357            1279152
-DragonLord                  17014            1162790
-dju                         16515             929427
-IgorLeMasson                16064            1147232
-ako027ako                   15671            1173203
-Nikolay.IT                  15154            1068349
-Andrew Grant                15114             895539
-OssumOpossum                14857            1007129
-enedene                     14476             905279
-bpfliegel                   14298             884523
-jpulman                     13982             870599
-joster                      13794             950160
-Nesa92                      13786            1114691
-crocogoat                   13753            1114622
-Hjax                        13535             915487
-Dark_wizzie                 13422            1007152
-mpx86                       12941             693640
-mabichito                   12903             749391
-thijsk                      12886             722107
-AdrianSA                    12860             804972
-Flopzee                     12698             894821
-fatmurphy                   12547             853210
-scuzzi                      12511             845761
-Karby                       12429             735880
-SapphireBrand               12416             969604
-modolief                    12386             896470
-pgontarz                    12151             848794
-stocky                      11954             699440
-mschmidt                    11941             803401
-infinity                    11470             727027
-torbjo                      11395             729145
-Thomas A. Anderson          11372             732094
-d64                         11263             789184
-Maxim                       11129             804704
-snicolet                    11106             869170
-MooTheCow                   11008             694942
-savage84                    10965             641068
-Rudolphous                  10915             741268
-Wolfgang                    10809             580032
-rpngn                       10712             688203
-basepi                      10637             744851
-michaelrpg                  10409             735127
-dzjp                        10343             732529
-ali-al-zhrani               10324             726502
-ols                         10259             570669
-lbraesch                    10252             647825
+Username                                CPU Hours     Games played
+------------------------------------------------------------------
+noobpwnftw                               39302472       3055513453
+technologov                              20845762        994893444
+linrock                                   8616428        560281417
+mlang                                     3026000        200065824
+okrout                                    2332151        222639518
+pemo                                      1800019         60274069
+dew                                       1689162        100033738
+TueRens                                   1474943         75121774
+grandphish2                               1463002         91616949
+JojoM                                     1109702         72927902
+olafm                                      978631         71037944
+sebastronomy                               939955         44920556
+tvijlbrief                                 796125         51897690
+gvreuls                                    711320         49142318
+mibere                                     703840         46867607
+oz                                         646268         46293638
+rpngn                                      572571         38928563
+leszek                                     531858         39316505
+cw                                         518116         34894291
+fastgm                                     503862         30260818
+CSU_Dynasty                                468784         31385034
+ctoks                                      434591         28520597
+maximmasiutin                              429983         27066286
+crunchy                                    427414         27371625
+bcross                                     415724         29061187
+velislav                                   342588         22140902
+mgrabiak                                   338763         23999170
+Fisherman                                  327231         21829379
+robal                                      299836         20213182
+Dantist                                    296386         18031762
+ncfish1                                    267604         17881149
+nordlandia                                 249322         16420192
+marrco                                     234581         17714473
+tolkki963                                  233490         19773930
+glinscott                                  208125         13277240
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+Thanar                                     179852         12365359
+Fifis                                      176209         10638245
+vdv                                        175544          9904472
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+sschnee                                    118107          7389266
+Wolfgang                                   114616          8070494
+Data                                       113305          8220352
+BrunoBanani                                112960          7436849
+Wencey                                     111502          5991676
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+Maxim                                       90818          3283364
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+AGI                                         58195          4329580
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+Freja                                       56938          3733019
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+rap                                         49985          3219146
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+GPUex                                       48686          3684998
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+gri                                         39871          2515779
+Garf                                        37741          2999686
+SC                                          37299          2731694
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+csnodgrass                                  36207          2688994
+Gaster319                                   35655          3149442
+strelock                                    34716          2074055
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+Gelma                                       31771          1551204
+kdave                                       31157          2198362
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+Ente                                        23752          1678188
+jojo2357                                    23479          2061238
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+Isidor                                      23388          1680691
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+cisco2015                                   22920          1763301
+Zirie                                       22542          1472937
+Nullvalue                                   22490          1970374
+AndreasKrug                                 22485          1769491
+team-oh                                     22272          1636708
+Roady                                       22220          1465606
+MazeOfGalious                               21978          1629593
+sg4032                                      21947          1643353
+ianh2105                                    21725          1632562
+xor12                                       21628          1680365
+dex                                         21612          1467203
+nesoneg                                     21494          1463031
+user213718                                  21454          1404128
+sphinx                                      21211          1384728
+qoo_charly_cai                              21135          1514907
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+Zake9298                                    20938          1565848
+horst.prack                                 20878          1465656
+0xB00B1ES                                   20590          1208666
+Serpensin                                   20487          1729674
+Dinde                                       20440          1292390
+j3corre                                     20405           941444
+Adrian.Schmidt123                           20316          1281436
+wei                                         19973          1745989
+fishtester                                  19617          1257388
+rstoesser                                   19569          1293588
+eudhan                                      19274          1283717
+vulcan                                      18871          1729392
+Karpovbot                                   18766          1053178
+WoodMan777                                  18556          1628264
+jundery                                     18445          1115855
+ville                                       17883          1384026
+chris                                       17698          1487385
+purplefishies                               17595          1092533
+dju                                         17414           981289
+ols                                         17291          1042003
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+Skiff84                                     17111           950248
+DragonLord                                  17014          1162790
+redstone59                                  16842          1461780
+Karby                                       16839          1010124
+Alb11747                                    16787          1213990
+pirt                                        16493          1237199
+Naven94                                     16414           951718
+wizardassassin                              16392          1148672
+IgorLeMasson                                16064          1147232
+scuzzi                                      15757           968735
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+Nikolay.IT                                  15154          1068349
+Andrew Grant                                15114           895539
+OssumOpossum                                14857          1007129
+LunaticBFF57                                14525          1190310
+enedene                                     14476           905279
+IslandLambda                                14393           958196
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+YELNAMRON                                   14230          1128094
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+jpulman                                     13982           870599
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+joster                                      13710           946160
+mbeier                                      13650          1044928
+Hjax                                        13535           915487
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+Garruk                                      10365           706465
+dzjp                                        10343           732529

appveyor.yml

@@ -1,88 +0,0 @@
-version: 1.0.{build}
-clone_depth: 50
-
-branches:
-  only:
-    - master
-
-# Operating system (build VM template)
-os: Visual Studio 2019
-
-# Build platform, i.e. x86, x64, AnyCPU. This setting is optional.
-platform:
-  - x86
-  - x64
-
-# build Configuration, i.e. Debug, Release, etc.
-configuration:
-  - Debug
-  - Release
-
-matrix:
-  # The build fail immediately once one of the job fails
-  fast_finish: true
-
-# Scripts that are called at very beginning, before repo cloning
-init:
-  - cmake --version
-  - msbuild /version
-
-before_build:
-  - ps: |
-      # Get sources
-      $src = get-childitem -Path *.cpp -Recurse | select -ExpandProperty FullName
-      $src = $src -join ' '
-      $src = $src.Replace("\", "/")
-
-      # Build CMakeLists.txt
-      $t = 'cmake_minimum_required(VERSION 3.17)',
-           'project(Stockfish)',
-           'set(CMAKE_CXX_STANDARD 17)',
-           'set(CMAKE_CXX_STANDARD_REQUIRED ON)',
-           'set (CMAKE_CXX_EXTENSIONS OFF)',
-           'set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_SOURCE_DIR}/src)',
-           'set(source_files', $src, ')',
-           'add_executable(stockfish ${source_files})'
-
-      # Write CMakeLists.txt withouth BOM
-      $MyPath = (Get-Item -Path "." -Verbose).FullName + '\CMakeLists.txt'
-      $Utf8NoBomEncoding = New-Object System.Text.UTF8Encoding $False
-      [System.IO.File]::WriteAllLines($MyPath, $t, $Utf8NoBomEncoding)
-
-      # Obtain bench reference from git log
-      $b = git log HEAD | sls "\b[Bb]ench[ :]+[0-9]{7}" | select -first 1
-      $bench = $b -match '\D+(\d+)' | % { $matches[1] }
-      Write-Host "Reference bench:" $bench
-      $g = "Visual Studio 16 2019"
-      If (${env:PLATFORM} -eq 'x64') { $a = "x64" }
-      If (${env:PLATFORM} -eq 'x86') { $a = "Win32" }
-      cmake -G "${g}" -A ${a} .
-      Write-Host "Generated files for: " $g $a
-
-build_script:
-  - cmake --build . --config %CONFIGURATION% -- /verbosity:minimal
-  - ps: |
-      # Download default NNUE net from fishtest
-      $nnuenet = Get-Content -Path src\evaluate.h | Select-String -CaseSensitive -Pattern "EvalFileDefaultName" | Select-String -CaseSensitive -Pattern "nn-[a-z0-9]{12}.nnue"
-      $dummy = $nnuenet -match "(?<nnuenet>nn-[a-z0-9]{12}.nnue)"
-      $nnuenet = $Matches.nnuenet
-      Write-Host "Default net:" $nnuenet
-      $nnuedownloadurl = "https://tests.stockfishchess.org/api/nn/$nnuenet"
-      $nnuefilepath = "src\${env:CONFIGURATION}\$nnuenet"
-      if (Test-Path -Path $nnuefilepath) {
-            Write-Host "Already available."
-      } else {
-            Write-Host "Downloading $nnuedownloadurl to $nnuefilepath"
-            Invoke-WebRequest -Uri $nnuedownloadurl -OutFile $nnuefilepath
-      }
-
-before_test:
-  - cd src/%CONFIGURATION%
-  - stockfish bench 2> out.txt >NUL
-  - ps: |
-      # Verify bench number
-      $s = (gc "./out.txt" | out-string)
-      $r = ($s -match 'Nodes searched \D+(\d+)' | % { $matches[1] })
-      Write-Host "Engine bench:" $r
-      Write-Host "Reference bench:" $bench
-      If ($r -ne $bench) { exit 1 }

scripts/get_native_properties.sh

@@ -0,0 +1,120 @@
+#!/bin/sh
+
+#
+# Returns properties of the native system.
+# best architecture as supported by the CPU
+# filename of the best binary uploaded as an artifact during CI
+#
+
+# Check if all the given flags are present in the CPU flags list
+check_flags() {
+  for flag; do
+    printf '%s\n' "$flags" | grep -q -w "$flag" || return 1
+  done
+}
+
+# Set the CPU flags list
+# remove underscores and points from flags, e.g. gcc uses avx512vnni, while some cpuinfo can have avx512_vnni, some systems use sse4_1 others sse4.1
+get_flags() {
+  flags=$(awk '/^flags[ \t]*:|^Features[ \t]*:/{gsub(/^flags[ \t]*:[ \t]*|^Features[ \t]*:[ \t]*|[_.]/, ""); line=$0} END{print line}' /proc/cpuinfo)
+}
+
+# Check for gcc march "znver1" or "znver2" https://en.wikichip.org/wiki/amd/cpuid
+check_znver_1_2() {
+  vendor_id=$(awk '/^vendor_id/{print $3; exit}' /proc/cpuinfo)
+  cpu_family=$(awk '/^cpu family/{print $4; exit}' /proc/cpuinfo)
+  [ "$vendor_id" = "AuthenticAMD" ] && [ "$cpu_family" = "23" ] && znver_1_2=true
+}
+
+# Set the file CPU x86_64 architecture
+set_arch_x86_64() {
+  if check_flags 'avx512vnni' 'avx512dq' 'avx512f' 'avx512bw' 'avx512vl'; then
+    true_arch='x86-64-vnni256'
+  elif check_flags 'avx512f' 'avx512bw'; then
+    true_arch='x86-64-avx512'
+  elif [ -z "${znver_1_2+1}" ] && check_flags 'bmi2'; then
+    true_arch='x86-64-bmi2'
+  elif check_flags 'avx2'; then
+    true_arch='x86-64-avx2'
+  elif check_flags 'sse41' && check_flags 'popcnt'; then
+    true_arch='x86-64-sse41-popcnt'
+  else
+    true_arch='x86-64'
+  fi
+}
+
+# Check the system type
+uname_s=$(uname -s)
+uname_m=$(uname -m)
+case $uname_s in
+  'Darwin') # Mac OSX system
+    case $uname_m in
+      'arm64')
+        true_arch='apple-silicon'
+        file_arch='x86-64-sse41-popcnt' # Supported by Rosetta 2
+        ;;
+      'x86_64')
+        flags=$(sysctl -n machdep.cpu.features machdep.cpu.leaf7_features | tr '\n' ' ' | tr '[:upper:]' '[:lower:]' | tr -d '_.')
+        set_arch_x86_64
+        if [ "$true_arch" = 'x86-64-vnni256' ] || [ "$true_arch" = 'x86-64-avx512' ]; then
+           file_arch='x86-64-bmi2'
+        fi
+        ;;
+    esac
+    file_os='macos'
+    file_ext='tar'
+    ;;
+  'Linux') # Linux system
+    get_flags
+    case $uname_m in
+      'x86_64')
+        file_os='ubuntu'
+        check_znver_1_2
+        set_arch_x86_64
+        ;;
+      'i686')
+        file_os='ubuntu'
+        true_arch='x86-32'
+        ;;
+      'aarch64')
+        file_os='android'
+        true_arch='armv8'
+        if check_flags 'asimddp'; then
+          true_arch="$true_arch-dotprod"
+        fi
+        ;;
+      'armv7'*)
+        file_os='android'
+        true_arch='armv7'
+        if check_flags 'neon'; then
+          true_arch="$true_arch-neon"
+        fi
+        ;;
+      *) # Unsupported machine type, exit with error
+        printf 'Unsupported machine type: %s\n' "$uname_m"
+        exit 1
+        ;;
+    esac
+    file_ext='tar'
+    ;;
+  'CYGWIN'*|'MINGW'*|'MSYS'*) # Windows system with POSIX compatibility layer
+    get_flags
+    check_znver_1_2
+    set_arch_x86_64
+    file_os='windows'
+    file_ext='zip'
+    ;;
+  *)
+    # Unknown system type, exit with error
+    printf 'Unsupported system type: %s\n' "$uname_s"
+    exit 1
+    ;;
+esac
+
+if [ -z "$file_arch" ]; then
+  file_arch=$true_arch
+fi
+
+file_name="stockfish-$file_os-$file_arch.$file_ext"
+
+printf '%s %s\n' "$true_arch" "$file_name"

src/benchmark.cpp

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -16,18 +16,19 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include "benchmark.h"
+
+#include <cstdlib>
 #include <fstream>
 #include <iostream>
-#include <istream>
 #include <vector>
 
 #include "position.h"
 
-using namespace std;
-
 namespace {
 
-const vector<string> Defaults = {
+// clang-format off
+const std::vector<std::string> Defaults = {
   "setoption name UCI_Chess960 value false",
   "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1",
   "r3k2r/p1ppqpb1/bn2pnp1/3PN3/1p2P3/2N2Q1p/PPPBBPPP/R3K2R w KQkq - 0 10",
@@ -87,84 +88,78 @@ const vector<string> Defaults = {
   // Chess 960
   "setoption name UCI_Chess960 value true",
   "bbqnnrkr/pppppppp/8/8/8/8/PPPPPPPP/BBQNNRKR w HFhf - 0 1 moves g2g3 d7d5 d2d4 c8h3 c1g5 e8d6 g5e7 f7f6",
+  "nqbnrkrb/pppppppp/8/8/8/8/PPPPPPPP/NQBNRKRB w KQkq - 0 1",
   "setoption name UCI_Chess960 value false"
 };
+// clang-format on
 
-} // namespace
+}  // namespace
 
-/// setup_bench() builds a list of UCI commands to be run by bench. There
-/// are five parameters: TT size in MB, number of search threads that
-/// should be used, the limit value spent for each position, a file name
-/// where to look for positions in FEN format, the type of the limit:
-/// depth, perft, nodes and movetime (in millisecs), and evaluation type
-/// mixed (default), classical, NNUE.
-///
-/// bench -> search default positions up to depth 13
-/// bench 64 1 15 -> search default positions up to depth 15 (TT = 64MB)
-/// bench 64 4 5000 current movetime -> search current position with 4 threads for 5 sec
-/// bench 64 1 100000 default nodes -> search default positions for 100K nodes each
-/// bench 16 1 5 default perft -> run a perft 5 on default positions
+namespace Stockfish {
 
-vector<string> setup_bench(const Position& current, istream& is) {
+// Builds a list of UCI commands to be run by bench. There
+// are five parameters: TT size in MB, number of search threads that
+// should be used, the limit value spent for each position, a file name
+// where to look for positions in FEN format, and the type of the limit:
+// depth, perft, nodes and movetime (in milliseconds). Examples:
+//
+// bench                            : search default positions up to depth 13
+// bench 64 1 15                    : search default positions up to depth 15 (TT = 64MB)
+// bench 64 1 100000 default nodes  : search default positions for 100K nodes each
+// bench 64 4 5000 current movetime : search current position with 4 threads for 5 sec
+// bench 16 1 5 blah perft          : run a perft 5 on positions in file "blah"
+std::vector<std::string> setup_bench(const Position& current, std::istream& is) {
 
-  vector<string> fens, list;
-  string go, token;
+    std::vector<std::string> fens, list;
+    std::string              go, token;
 
-  // Assign default values to missing arguments
-  string ttSize    = (is >> token) ? token : "16";
-  string threads   = (is >> token) ? token : "1";
-  string limit     = (is >> token) ? token : "13";
-  string fenFile   = (is >> token) ? token : "default";
-  string limitType = (is >> token) ? token : "depth";
-  string evalType  = (is >> token) ? token : "mixed";
+    // Assign default values to missing arguments
+    std::string ttSize    = (is >> token) ? token : "16";
+    std::string threads   = (is >> token) ? token : "1";
+    std::string limit     = (is >> token) ? token : "13";
+    std::string fenFile   = (is >> token) ? token : "default";
+    std::string limitType = (is >> token) ? token : "depth";
 
-  go = limitType == "eval" ? "eval" : "go " + limitType + " " + limit;
+    go = limitType == "eval" ? "eval" : "go " + limitType + " " + limit;
 
-  if (fenFile == "default")
-      fens = Defaults;
+    if (fenFile == "default")
+        fens = Defaults;
 
-  else if (fenFile == "current")
-      fens.push_back(current.fen());
+    else if (fenFile == "current")
+        fens.push_back(current.fen());
 
-  else
-  {
-      string fen;
-      ifstream file(fenFile);
+    else
+    {
+        std::string   fen;
+        std::ifstream file(fenFile);
 
-      if (!file.is_open())
-      {
-          cerr << "Unable to open file " << fenFile << endl;
-          exit(EXIT_FAILURE);
-      }
+        if (!file.is_open())
+        {
+            std::cerr << "Unable to open file " << fenFile << std::endl;
+            exit(EXIT_FAILURE);
+        }
 
-      while (getline(file, fen))
-          if (!fen.empty())
-              fens.push_back(fen);
+        while (getline(file, fen))
+            if (!fen.empty())
+                fens.push_back(fen);
 
-      file.close();
-  }
+        file.close();
+    }
 
-  list.emplace_back("setoption name Threads value " + threads);
-  list.emplace_back("setoption name Hash value " + ttSize);
-  list.emplace_back("ucinewgame");
+    list.emplace_back("setoption name Threads value " + threads);
+    list.emplace_back("setoption name Hash value " + ttSize);
+    list.emplace_back("ucinewgame");
 
-  size_t posCounter = 0;
+    for (const std::string& fen : fens)
+        if (fen.find("setoption") != std::string::npos)
+            list.emplace_back(fen);
+        else
+        {
+            list.emplace_back("position fen " + fen);
+            list.emplace_back(go);
+        }
 
-  for (const string& fen : fens)
-      if (fen.find("setoption") != string::npos)
-          list.emplace_back(fen);
-      else
-      {
-          if (evalType == "classical" || (evalType == "mixed" && posCounter % 2 == 0))
-              list.emplace_back("setoption name Use NNUE value false");
-          else if (evalType == "NNUE" || (evalType == "mixed" && posCounter % 2 != 0))
-              list.emplace_back("setoption name Use NNUE value true");
-          list.emplace_back("position fen " + fen);
-          list.emplace_back(go);
-          ++posCounter;
-      }
-
-  list.emplace_back("setoption name Use NNUE value true");
-
-  return list;
+    return list;
 }
+
+}  // namespace Stockfish

src/benchmark.h

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -16,23 +16,19 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#ifndef BENCHMARK_H_INCLUDED
+#define BENCHMARK_H_INCLUDED
 
-#ifndef PSQT_H_INCLUDED
-#define PSQT_H_INCLUDED
+#include <iosfwd>
+#include <string>
+#include <vector>
 
+namespace Stockfish {
 
-#include "types.h"
+class Position;
 
+std::vector<std::string> setup_bench(const Position&, std::istream&);
 
-namespace PSQT
-{
+}  // namespace Stockfish
 
-extern Score psq[PIECE_NB][SQUARE_NB];
-
-// Fill psqt array from a set of internally linked parameters
-extern void init();
-
-} // namespace PSQT
-
-
-#endif // PSQT_H_INCLUDED
+#endif  // #ifndef BENCHMARK_H_INCLUDED

src/bitbase.cpp

@@ -1,170 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
-
-  Stockfish is free software: you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation, either version 3 of the License, or
-  (at your option) any later version.
-
-  Stockfish is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-#include <cassert>
-#include <vector>
-#include <bitset>
-
-#include "bitboard.h"
-#include "types.h"
-
-namespace {
-
-  // There are 24 possible pawn squares: files A to D and ranks from 2 to 7.
-  // Positions with the pawn on files E to H will be mirrored before probing.
-  constexpr unsigned MAX_INDEX = 2*24*64*64; // stm * psq * wksq * bksq = 196608
-
-  std::bitset<MAX_INDEX> KPKBitbase;
-
-  // A KPK bitbase index is an integer in [0, IndexMax] range
-  //
-  // Information is mapped in a way that minimizes the number of iterations:
-  //
-  // bit  0- 5: white king square (from SQ_A1 to SQ_H8)
-  // bit  6-11: black king square (from SQ_A1 to SQ_H8)
-  // bit    12: side to move (WHITE or BLACK)
-  // bit 13-14: white pawn file (from FILE_A to FILE_D)
-  // bit 15-17: white pawn RANK_7 - rank (from RANK_7 - RANK_7 to RANK_7 - RANK_2)
-  unsigned index(Color stm, Square bksq, Square wksq, Square psq) {
-    return int(wksq) | (bksq << 6) | (stm << 12) | (file_of(psq) << 13) | ((RANK_7 - rank_of(psq)) << 15);
-  }
-
-  enum Result {
-    INVALID = 0,
-    UNKNOWN = 1,
-    DRAW    = 2,
-    WIN     = 4
-  };
-
-  Result& operator|=(Result& r, Result v) { return r = Result(r | v); }
-
-  struct KPKPosition {
-    KPKPosition() = default;
-    explicit KPKPosition(unsigned idx);
-    operator Result() const { return result; }
-    Result classify(const std::vector<KPKPosition>& db);
-
-    Color stm;
-    Square ksq[COLOR_NB], psq;
-    Result result;
-  };
-
-} // namespace
-
-
-bool Bitbases::probe(Square wksq, Square wpsq, Square bksq, Color stm) {
-
-  assert(file_of(wpsq) <= FILE_D);
-
-  return KPKBitbase[index(stm, bksq, wksq, wpsq)];
-}
-
-
-void Bitbases::init() {
-
-  std::vector<KPKPosition> db(MAX_INDEX);
-  unsigned idx, repeat = 1;
-
-  // Initialize db with known win / draw positions
-  for (idx = 0; idx < MAX_INDEX; ++idx)
-      db[idx] = KPKPosition(idx);
-
-  // Iterate through the positions until none of the unknown positions can be
-  // changed to either wins or draws (15 cycles needed).
-  while (repeat)
-      for (repeat = idx = 0; idx < MAX_INDEX; ++idx)
-          repeat |= (db[idx] == UNKNOWN && db[idx].classify(db) != UNKNOWN);
-
-  // Fill the bitbase with the decisive results
-  for (idx = 0; idx < MAX_INDEX; ++idx)
-      if (db[idx] == WIN)
-          KPKBitbase.set(idx);
-}
-
-
-namespace {
-
-  KPKPosition::KPKPosition(unsigned idx) {
-
-    ksq[WHITE] = Square((idx >>  0) & 0x3F);
-    ksq[BLACK] = Square((idx >>  6) & 0x3F);
-    stm        = Color ((idx >> 12) & 0x01);
-    psq        = make_square(File((idx >> 13) & 0x3), Rank(RANK_7 - ((idx >> 15) & 0x7)));
-
-    // Invalid if two pieces are on the same square or if a king can be captured
-    if (   distance(ksq[WHITE], ksq[BLACK]) <= 1
-        || ksq[WHITE] == psq
-        || ksq[BLACK] == psq
-        || (stm == WHITE && (pawn_attacks_bb(WHITE, psq) & ksq[BLACK])))
-        result = INVALID;
-
-    // Win if the pawn can be promoted without getting captured
-    else if (   stm == WHITE
-             && rank_of(psq) == RANK_7
-             && ksq[WHITE] != psq + NORTH
-             && (    distance(ksq[BLACK], psq + NORTH) > 1
-                 || (distance(ksq[WHITE], psq + NORTH) == 1)))
-        result = WIN;
-
-    // Draw if it is stalemate or the black king can capture the pawn
-    else if (   stm == BLACK
-             && (  !(attacks_bb<KING>(ksq[BLACK]) & ~(attacks_bb<KING>(ksq[WHITE]) | pawn_attacks_bb(WHITE, psq)))
-                 || (attacks_bb<KING>(ksq[BLACK]) & ~attacks_bb<KING>(ksq[WHITE]) & psq)))
-        result = DRAW;
-
-    // Position will be classified later
-    else
-        result = UNKNOWN;
-  }
-
-  Result KPKPosition::classify(const std::vector<KPKPosition>& db) {
-
-    // White to move: If one move leads to a position classified as WIN, the result
-    // of the current position is WIN. If all moves lead to positions classified
-    // as DRAW, the current position is classified as DRAW, otherwise the current
-    // position is classified as UNKNOWN.
-    //
-    // Black to move: If one move leads to a position classified as DRAW, the result
-    // of the current position is DRAW. If all moves lead to positions classified
-    // as WIN, the position is classified as WIN, otherwise the current position is
-    // classified as UNKNOWN.
-    const Result Good = (stm == WHITE ? WIN   : DRAW);
-    const Result Bad  = (stm == WHITE ? DRAW  : WIN);
-
-    Result r = INVALID;
-    Bitboard b = attacks_bb<KING>(ksq[stm]);
-
-    while (b)
-        r |= stm == WHITE ? db[index(BLACK, ksq[BLACK] , pop_lsb(&b), psq)]
-                          : db[index(WHITE, pop_lsb(&b),  ksq[WHITE], psq)];
-
-    if (stm == WHITE)
-    {
-        if (rank_of(psq) < RANK_7)      // Single push
-            r |= db[index(BLACK, ksq[BLACK], ksq[WHITE], psq + NORTH)];
-
-        if (   rank_of(psq) == RANK_2   // Double push
-            && psq + NORTH != ksq[WHITE]
-            && psq + NORTH != ksq[BLACK])
-            r |= db[index(BLACK, ksq[BLACK], ksq[WHITE], psq + NORTH + NORTH)];
-    }
-
-    return result = r & Good  ? Good  : r & UNKNOWN ? UNKNOWN : Bad;
-  }
-
-} // namespace

src/bitboard.cpp

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -16,17 +16,21 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include "bitboard.h"
+
 #include <algorithm>
 #include <bitset>
+#include <initializer_list>
 
-#include "bitboard.h"
 #include "misc.h"
 
+namespace Stockfish {
+
 uint8_t PopCnt16[1 << 16];
 uint8_t SquareDistance[SQUARE_NB][SQUARE_NB];
 
-Bitboard SquareBB[SQUARE_NB];
 Bitboard LineBB[SQUARE_NB][SQUARE_NB];
+Bitboard BetweenBB[SQUARE_NB][SQUARE_NB];
 Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB];
 Bitboard PawnAttacks[COLOR_NB][SQUARE_NB];
 
@@ -35,115 +39,111 @@ Magic BishopMagics[SQUARE_NB];
 
 namespace {
 
-  Bitboard RookTable[0x19000];  // To store rook attacks
-  Bitboard BishopTable[0x1480]; // To store bishop attacks
+Bitboard RookTable[0x19000];   // To store rook attacks
+Bitboard BishopTable[0x1480];  // To store bishop attacks
 
-  void init_magics(PieceType pt, Bitboard table[], Magic magics[]);
+void init_magics(PieceType pt, Bitboard table[], Magic magics[]);
 
-}
-
-
-/// safe_destination() returns the bitboard of target square for the given step
-/// from the given square. If the step is off the board, returns empty bitboard.
-
-inline Bitboard safe_destination(Square s, int step) {
+// Returns the bitboard of target square for the given step
+// from the given square. If the step is off the board, returns empty bitboard.
+Bitboard safe_destination(Square s, int step) {
     Square to = Square(s + step);
     return is_ok(to) && distance(s, to) <= 2 ? square_bb(to) : Bitboard(0);
 }
+}
 
+// Returns an ASCII representation of a bitboard suitable
+// to be printed to standard output. Useful for debugging.
+std::string Bitboards::pretty(Bitboard b) {
 
-/// Bitboards::pretty() returns an ASCII representation of a bitboard suitable
-/// to be printed to standard output. Useful for debugging.
+    std::string s = "+---+---+---+---+---+---+---+---+\n";
 
-const std::string Bitboards::pretty(Bitboard b) {
+    for (Rank r = RANK_8; r >= RANK_1; --r)
+    {
+        for (File f = FILE_A; f <= FILE_H; ++f)
+            s += b & make_square(f, r) ? "| X " : "|   ";
 
-  std::string s = "+---+---+---+---+---+---+---+---+\n";
+        s += "| " + std::to_string(1 + r) + "\n+---+---+---+---+---+---+---+---+\n";
+    }
+    s += "  a   b   c   d   e   f   g   h\n";
 
-  for (Rank r = RANK_8; r >= RANK_1; --r)
-  {
-      for (File f = FILE_A; f <= FILE_H; ++f)
-          s += b & make_square(f, r) ? "| X " : "|   ";
-
-      s += "| " + std::to_string(1 + r) + "\n+---+---+---+---+---+---+---+---+\n";
-  }
-  s += "  a   b   c   d   e   f   g   h\n";
-
-  return s;
+    return s;
 }
 
 
-/// Bitboards::init() initializes various bitboard tables. It is called at
-/// startup and relies on global objects to be already zero-initialized.
-
+// Initializes various bitboard tables. It is called at
+// startup and relies on global objects to be already zero-initialized.
 void Bitboards::init() {
 
-  for (unsigned i = 0; i < (1 << 16); ++i)
-      PopCnt16[i] = uint8_t(std::bitset<16>(i).count());
+    for (unsigned i = 0; i < (1 << 16); ++i)
+        PopCnt16[i] = uint8_t(std::bitset<16>(i).count());
 
-  for (Square s = SQ_A1; s <= SQ_H8; ++s)
-      SquareBB[s] = (1ULL << s);
+    for (Square s1 = SQ_A1; s1 <= SQ_H8; ++s1)
+        for (Square s2 = SQ_A1; s2 <= SQ_H8; ++s2)
+            SquareDistance[s1][s2] = std::max(distance<File>(s1, s2), distance<Rank>(s1, s2));
 
-  for (Square s1 = SQ_A1; s1 <= SQ_H8; ++s1)
-      for (Square s2 = SQ_A1; s2 <= SQ_H8; ++s2)
-          SquareDistance[s1][s2] = std::max(distance<File>(s1, s2), distance<Rank>(s1, s2));
+    init_magics(ROOK, RookTable, RookMagics);
+    init_magics(BISHOP, BishopTable, BishopMagics);
 
-  init_magics(ROOK, RookTable, RookMagics);
-  init_magics(BISHOP, BishopTable, BishopMagics);
+    for (Square s1 = SQ_A1; s1 <= SQ_H8; ++s1)
+    {
+        PawnAttacks[WHITE][s1] = pawn_attacks_bb<WHITE>(square_bb(s1));
+        PawnAttacks[BLACK][s1] = pawn_attacks_bb<BLACK>(square_bb(s1));
 
-  for (Square s1 = SQ_A1; s1 <= SQ_H8; ++s1)
-  {
-      PawnAttacks[WHITE][s1] = pawn_attacks_bb<WHITE>(square_bb(s1));
-      PawnAttacks[BLACK][s1] = pawn_attacks_bb<BLACK>(square_bb(s1));
+        for (int step : {-9, -8, -7, -1, 1, 7, 8, 9})
+            PseudoAttacks[KING][s1] |= safe_destination(s1, step);
 
-      for (int step : {-9, -8, -7, -1, 1, 7, 8, 9} )
-         PseudoAttacks[KING][s1] |= safe_destination(s1, step);
+        for (int step : {-17, -15, -10, -6, 6, 10, 15, 17})
+            PseudoAttacks[KNIGHT][s1] |= safe_destination(s1, step);
 
-      for (int step : {-17, -15, -10, -6, 6, 10, 15, 17} )
-         PseudoAttacks[KNIGHT][s1] |= safe_destination(s1, step);
+        PseudoAttacks[QUEEN][s1] = PseudoAttacks[BISHOP][s1] = attacks_bb<BISHOP>(s1, 0);
+        PseudoAttacks[QUEEN][s1] |= PseudoAttacks[ROOK][s1]  = attacks_bb<ROOK>(s1, 0);
 
-      PseudoAttacks[QUEEN][s1]  = PseudoAttacks[BISHOP][s1] = attacks_bb<BISHOP>(s1, 0);
-      PseudoAttacks[QUEEN][s1] |= PseudoAttacks[  ROOK][s1] = attacks_bb<  ROOK>(s1, 0);
-
-      for (PieceType pt : { BISHOP, ROOK })
-          for (Square s2 = SQ_A1; s2 <= SQ_H8; ++s2)
-              if (PseudoAttacks[pt][s1] & s2)
-                  LineBB[s1][s2] = (attacks_bb(pt, s1, 0) & attacks_bb(pt, s2, 0)) | s1 | s2;
-  }
+        for (PieceType pt : {BISHOP, ROOK})
+            for (Square s2 = SQ_A1; s2 <= SQ_H8; ++s2)
+            {
+                if (PseudoAttacks[pt][s1] & s2)
+                {
+                    LineBB[s1][s2] = (attacks_bb(pt, s1, 0) & attacks_bb(pt, s2, 0)) | s1 | s2;
+                    BetweenBB[s1][s2] =
+                      (attacks_bb(pt, s1, square_bb(s2)) & attacks_bb(pt, s2, square_bb(s1)));
+                }
+                BetweenBB[s1][s2] |= s2;
+            }
+    }
 }
 
-
 namespace {
 
-  Bitboard sliding_attack(PieceType pt, Square sq, Bitboard occupied) {
+Bitboard sliding_attack(PieceType pt, Square sq, Bitboard occupied) {
 
-    Bitboard attacks = 0;
-    Direction   RookDirections[4] = {NORTH, SOUTH, EAST, WEST};
+    Bitboard  attacks             = 0;
+    Direction RookDirections[4]   = {NORTH, SOUTH, EAST, WEST};
     Direction BishopDirections[4] = {NORTH_EAST, SOUTH_EAST, SOUTH_WEST, NORTH_WEST};
 
     for (Direction d : (pt == ROOK ? RookDirections : BishopDirections))
     {
         Square s = sq;
-        while(safe_destination(s, d) && !(occupied & s))
+        while (safe_destination(s, d) && !(occupied & s))
             attacks |= (s += d);
     }
 
     return attacks;
-  }
+}
 
 
-  // init_magics() computes all rook and bishop attacks at startup. Magic
-  // bitboards are used to look up attacks of sliding pieces. As a reference see
-  // www.chessprogramming.org/Magic_Bitboards. In particular, here we use the so
-  // called "fancy" approach.
-
-  void init_magics(PieceType pt, Bitboard table[], Magic magics[]) {
+// Computes all rook and bishop attacks at startup. Magic
+// bitboards are used to look up attacks of sliding pieces. As a reference see
+// www.chessprogramming.org/Magic_Bitboards. In particular, here we use the so
+// called "fancy" approach.
+void init_magics(PieceType pt, Bitboard table[], Magic magics[]) {
 
     // Optimal PRNG seeds to pick the correct magics in the shortest time
-    int seeds[][RANK_NB] = { { 8977, 44560, 54343, 38998,  5731, 95205, 104912, 17020 },
-                             {  728, 10316, 55013, 32803, 12281, 15100,  16645,   255 } };
+    int seeds[][RANK_NB] = {{8977, 44560, 54343, 38998, 5731, 95205, 104912, 17020},
+                            {728, 10316, 55013, 32803, 12281, 15100, 16645, 255}};
 
     Bitboard occupancy[4096], reference[4096], edges, b;
-    int epoch[4096] = {}, cnt = 0, size = 0;
+    int      epoch[4096] = {}, cnt = 0, size = 0;
 
     for (Square s = SQ_A1; s <= SQ_H8; ++s)
     {
@@ -156,8 +156,8 @@ namespace {
         // the number of 1s of the mask. Hence we deduce the size of the shift to
         // apply to the 64 or 32 bits word to get the index.
         Magic& m = magics[s];
-        m.mask  = sliding_attack(pt, s, 0) & ~edges;
-        m.shift = (Is64Bit ? 64 : 32) - popcount(m.mask);
+        m.mask   = sliding_attack(pt, s, 0) & ~edges;
+        m.shift  = (Is64Bit ? 64 : 32) - popcount(m.mask);
 
         // Set the offset for the attacks table of the square. We have individual
         // table sizes for each square with "Fancy Magic Bitboards".
@@ -166,7 +166,8 @@ namespace {
         // Use Carry-Rippler trick to enumerate all subsets of masks[s] and
         // store the corresponding sliding attack bitboard in reference[].
         b = size = 0;
-        do {
+        do
+        {
             occupancy[size] = b;
             reference[size] = sliding_attack(pt, s, b);
 
@@ -184,9 +185,9 @@ namespace {
 
         // Find a magic for square 's' picking up an (almost) random number
         // until we find the one that passes the verification test.
-        for (int i = 0; i < size; )
+        for (int i = 0; i < size;)
         {
-            for (m.magic = 0; popcount((m.magic * m.mask) >> 56) < 6; )
+            for (m.magic = 0; popcount((m.magic * m.mask) >> 56) < 6;)
                 m.magic = rng.sparse_rand<Bitboard>();
 
             // A good magic must map every possible occupancy to an index that
@@ -201,7 +202,7 @@ namespace {
 
                 if (epoch[idx] < cnt)
                 {
-                    epoch[idx] = cnt;
+                    epoch[idx]     = cnt;
                     m.attacks[idx] = reference[i];
                 }
                 else if (m.attacks[idx] != reference[i])
@@ -209,5 +210,7 @@ namespace {
             }
         }
     }
-  }
 }
+}
+
+}  // namespace Stockfish

src/bitboard.h

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -19,26 +19,23 @@
 #ifndef BITBOARD_H_INCLUDED
 #define BITBOARD_H_INCLUDED
 
+#include <algorithm>
+#include <cassert>
+#include <cmath>
+#include <cstdint>
+#include <cstdlib>
 #include <string>
 
 #include "types.h"
 
-namespace Bitbases {
-
-void init();
-bool probe(Square wksq, Square wpsq, Square bksq, Color us);
-
-}
+namespace Stockfish {
 
 namespace Bitboards {
 
-void init();
-const std::string pretty(Bitboard b);
+void        init();
+std::string pretty(Bitboard b);
 
-}
-
-constexpr Bitboard AllSquares = ~Bitboard(0);
-constexpr Bitboard DarkSquares = 0xAA55AA55AA55AA55ULL;
+}  // namespace Stockfish::Bitboards
 
 constexpr Bitboard FileABB = 0x0101010101010101ULL;
 constexpr Bitboard FileBBB = FileABB << 1;
@@ -58,376 +55,317 @@ constexpr Bitboard Rank6BB = Rank1BB << (8 * 5);
 constexpr Bitboard Rank7BB = Rank1BB << (8 * 6);
 constexpr Bitboard Rank8BB = Rank1BB << (8 * 7);
 
-constexpr Bitboard QueenSide   = FileABB | FileBBB | FileCBB | FileDBB;
-constexpr Bitboard CenterFiles = FileCBB | FileDBB | FileEBB | FileFBB;
-constexpr Bitboard KingSide    = FileEBB | FileFBB | FileGBB | FileHBB;
-constexpr Bitboard Center      = (FileDBB | FileEBB) & (Rank4BB | Rank5BB);
-
-constexpr Bitboard KingFlank[FILE_NB] = {
-  QueenSide ^ FileDBB, QueenSide, QueenSide,
-  CenterFiles, CenterFiles,
-  KingSide, KingSide, KingSide ^ FileEBB
-};
-
 extern uint8_t PopCnt16[1 << 16];
 extern uint8_t SquareDistance[SQUARE_NB][SQUARE_NB];
 
-extern Bitboard SquareBB[SQUARE_NB];
+extern Bitboard BetweenBB[SQUARE_NB][SQUARE_NB];
 extern Bitboard LineBB[SQUARE_NB][SQUARE_NB];
 extern Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB];
 extern Bitboard PawnAttacks[COLOR_NB][SQUARE_NB];
 
 
-/// Magic holds all magic bitboards relevant data for a single square
+// Magic holds all magic bitboards relevant data for a single square
 struct Magic {
-  Bitboard  mask;
-  Bitboard  magic;
-  Bitboard* attacks;
-  unsigned  shift;
+    Bitboard  mask;
+    Bitboard  magic;
+    Bitboard* attacks;
+    unsigned  shift;
 
-  // Compute the attack's index using the 'magic bitboards' approach
-  unsigned index(Bitboard occupied) const {
+    // Compute the attack's index using the 'magic bitboards' approach
+    unsigned index(Bitboard occupied) const {
 
-    if (HasPext)
-        return unsigned(pext(occupied, mask));
+        if (HasPext)
+            return unsigned(pext(occupied, mask));
 
-    if (Is64Bit)
-        return unsigned(((occupied & mask) * magic) >> shift);
+        if (Is64Bit)
+            return unsigned(((occupied & mask) * magic) >> shift);
 
-    unsigned lo = unsigned(occupied) & unsigned(mask);
-    unsigned hi = unsigned(occupied >> 32) & unsigned(mask >> 32);
-    return (lo * unsigned(magic) ^ hi * unsigned(magic >> 32)) >> shift;
-  }
+        unsigned lo = unsigned(occupied) & unsigned(mask);
+        unsigned hi = unsigned(occupied >> 32) & unsigned(mask >> 32);
+        return (lo * unsigned(magic) ^ hi * unsigned(magic >> 32)) >> shift;
+    }
 };
 
 extern Magic RookMagics[SQUARE_NB];
 extern Magic BishopMagics[SQUARE_NB];
 
-inline Bitboard square_bb(Square s) {
-  assert(is_ok(s));
-  return SquareBB[s];
+constexpr Bitboard square_bb(Square s) {
+    assert(is_ok(s));
+    return (1ULL << s);
 }
 
 
-/// Overloads of bitwise operators between a Bitboard and a Square for testing
-/// whether a given bit is set in a bitboard, and for setting and clearing bits.
+// Overloads of bitwise operators between a Bitboard and a Square for testing
+// whether a given bit is set in a bitboard, and for setting and clearing bits.
 
-inline Bitboard  operator&( Bitboard  b, Square s) { return b &  square_bb(s); }
-inline Bitboard  operator|( Bitboard  b, Square s) { return b |  square_bb(s); }
-inline Bitboard  operator^( Bitboard  b, Square s) { return b ^  square_bb(s); }
+inline Bitboard  operator&(Bitboard b, Square s) { return b & square_bb(s); }
+inline Bitboard  operator|(Bitboard b, Square s) { return b | square_bb(s); }
+inline Bitboard  operator^(Bitboard b, Square s) { return b ^ square_bb(s); }
 inline Bitboard& operator|=(Bitboard& b, Square s) { return b |= square_bb(s); }
 inline Bitboard& operator^=(Bitboard& b, Square s) { return b ^= square_bb(s); }
 
-inline Bitboard  operator&(Square s, Bitboard b) { return b & s; }
-inline Bitboard  operator|(Square s, Bitboard b) { return b | s; }
-inline Bitboard  operator^(Square s, Bitboard b) { return b ^ s; }
+inline Bitboard operator&(Square s, Bitboard b) { return b & s; }
+inline Bitboard operator|(Square s, Bitboard b) { return b | s; }
+inline Bitboard operator^(Square s, Bitboard b) { return b ^ s; }
 
-inline Bitboard  operator|(Square s1, Square s2) { return square_bb(s1) | s2; }
+inline Bitboard operator|(Square s1, Square s2) { return square_bb(s1) | s2; }
 
-constexpr bool more_than_one(Bitboard b) {
-  return b & (b - 1);
-}
+constexpr bool more_than_one(Bitboard b) { return b & (b - 1); }
 
 
-constexpr bool opposite_colors(Square s1, Square s2) {
-  return (s1 + rank_of(s1) + s2 + rank_of(s2)) & 1;
-}
+// rank_bb() and file_bb() return a bitboard representing all the squares on
+// the given file or rank.
+
+constexpr Bitboard rank_bb(Rank r) { return Rank1BB << (8 * r); }
+
+constexpr Bitboard rank_bb(Square s) { return rank_bb(rank_of(s)); }
+
+constexpr Bitboard file_bb(File f) { return FileABB << f; }
+
+constexpr Bitboard file_bb(Square s) { return file_bb(file_of(s)); }
 
 
-/// rank_bb() and file_bb() return a bitboard representing all the squares on
-/// the given file or rank.
-
-constexpr Bitboard rank_bb(Rank r) {
-  return Rank1BB << (8 * r);
-}
-
-constexpr Bitboard rank_bb(Square s) {
-  return rank_bb(rank_of(s));
-}
-
-constexpr Bitboard file_bb(File f) {
-  return FileABB << f;
-}
-
-constexpr Bitboard file_bb(Square s) {
-  return file_bb(file_of(s));
-}
-
-
-/// shift() moves a bitboard one or two steps as specified by the direction D
-
+// Moves a bitboard one or two steps as specified by the direction D
 template<Direction D>
 constexpr Bitboard shift(Bitboard b) {
-  return  D == NORTH      ?  b             << 8 : D == SOUTH      ?  b             >> 8
-        : D == NORTH+NORTH?  b             <<16 : D == SOUTH+SOUTH?  b             >>16
-        : D == EAST       ? (b & ~FileHBB) << 1 : D == WEST       ? (b & ~FileABB) >> 1
-        : D == NORTH_EAST ? (b & ~FileHBB) << 9 : D == NORTH_WEST ? (b & ~FileABB) << 7
-        : D == SOUTH_EAST ? (b & ~FileHBB) >> 7 : D == SOUTH_WEST ? (b & ~FileABB) >> 9
-        : 0;
+    return D == NORTH         ? b << 8
+         : D == SOUTH         ? b >> 8
+         : D == NORTH + NORTH ? b << 16
+         : D == SOUTH + SOUTH ? b >> 16
+         : D == EAST          ? (b & ~FileHBB) << 1
+         : D == WEST          ? (b & ~FileABB) >> 1
+         : D == NORTH_EAST    ? (b & ~FileHBB) << 9
+         : D == NORTH_WEST    ? (b & ~FileABB) << 7
+         : D == SOUTH_EAST    ? (b & ~FileHBB) >> 7
+         : D == SOUTH_WEST    ? (b & ~FileABB) >> 9
+                              : 0;
 }
 
 
-/// pawn_attacks_bb() returns the squares attacked by pawns of the given color
-/// from the squares in the given bitboard.
-
+// Returns the squares attacked by pawns of the given color
+// from the squares in the given bitboard.
 template<Color C>
 constexpr Bitboard pawn_attacks_bb(Bitboard b) {
-  return C == WHITE ? shift<NORTH_WEST>(b) | shift<NORTH_EAST>(b)
-                    : shift<SOUTH_WEST>(b) | shift<SOUTH_EAST>(b);
+    return C == WHITE ? shift<NORTH_WEST>(b) | shift<NORTH_EAST>(b)
+                      : shift<SOUTH_WEST>(b) | shift<SOUTH_EAST>(b);
 }
 
 inline Bitboard pawn_attacks_bb(Color c, Square s) {
 
-  assert(is_ok(s));
-  return PawnAttacks[c][s];
+    assert(is_ok(s));
+    return PawnAttacks[c][s];
 }
 
-
-/// pawn_double_attacks_bb() returns the squares doubly attacked by pawns of the
-/// given color from the squares in the given bitboard.
-
-template<Color C>
-constexpr Bitboard pawn_double_attacks_bb(Bitboard b) {
-  return C == WHITE ? shift<NORTH_WEST>(b) & shift<NORTH_EAST>(b)
-                    : shift<SOUTH_WEST>(b) & shift<SOUTH_EAST>(b);
-}
-
-
-/// adjacent_files_bb() returns a bitboard representing all the squares on the
-/// adjacent files of a given square.
-
-constexpr Bitboard adjacent_files_bb(Square s) {
-  return shift<EAST>(file_bb(s)) | shift<WEST>(file_bb(s));
-}
-
-
-/// line_bb() returns a bitboard representing an entire line (from board edge
-/// to board edge) that intersects the two given squares. If the given squares
-/// are not on a same file/rank/diagonal, the function returns 0. For instance,
-/// line_bb(SQ_C4, SQ_F7) will return a bitboard with the A2-G8 diagonal.
-
+// Returns a bitboard representing an entire line (from board edge
+// to board edge) that intersects the two given squares. If the given squares
+// are not on a same file/rank/diagonal, the function returns 0. For instance,
+// line_bb(SQ_C4, SQ_F7) will return a bitboard with the A2-G8 diagonal.
 inline Bitboard line_bb(Square s1, Square s2) {
 
-  assert(is_ok(s1) && is_ok(s2));
-  return LineBB[s1][s2];
+    assert(is_ok(s1) && is_ok(s2));
+    return LineBB[s1][s2];
 }
 
 
-/// between_bb() returns a bitboard representing squares that are linearly
-/// between the two given squares (excluding the given squares). If the given
-/// squares are not on a same file/rank/diagonal, we return 0. For instance,
-/// between_bb(SQ_C4, SQ_F7) will return a bitboard with squares D5 and E6.
-
+// Returns a bitboard representing the squares in the semi-open
+// segment between the squares s1 and s2 (excluding s1 but including s2). If the
+// given squares are not on a same file/rank/diagonal, it returns s2. For instance,
+// between_bb(SQ_C4, SQ_F7) will return a bitboard with squares D5, E6 and F7, but
+// between_bb(SQ_E6, SQ_F8) will return a bitboard with the square F8. This trick
+// allows to generate non-king evasion moves faster: the defending piece must either
+// interpose itself to cover the check or capture the checking piece.
 inline Bitboard between_bb(Square s1, Square s2) {
-  Bitboard b = line_bb(s1, s2) & ((AllSquares << s1) ^ (AllSquares << s2));
-  return b & (b - 1); //exclude lsb
+
+    assert(is_ok(s1) && is_ok(s2));
+    return BetweenBB[s1][s2];
 }
 
+// Returns true if the squares s1, s2 and s3 are aligned either on a
+// straight or on a diagonal line.
+inline bool aligned(Square s1, Square s2, Square s3) { return line_bb(s1, s2) & s3; }
 
-/// forward_ranks_bb() returns a bitboard representing the squares on the ranks
-/// in front of the given one, from the point of view of the given color. For instance,
-/// forward_ranks_bb(BLACK, SQ_D3) will return the 16 squares on ranks 1 and 2.
 
-constexpr Bitboard forward_ranks_bb(Color c, Square s) {
-  return c == WHITE ? ~Rank1BB << 8 * relative_rank(WHITE, s)
-                    : ~Rank8BB >> 8 * relative_rank(BLACK, s);
+// distance() functions return the distance between x and y, defined as the
+// number of steps for a king in x to reach y.
+
+template<typename T1 = Square>
+inline int distance(Square x, Square y);
+
+template<>
+inline int distance<File>(Square x, Square y) {
+    return std::abs(file_of(x) - file_of(y));
 }
 
-
-/// forward_file_bb() returns a bitboard representing all the squares along the
-/// line in front of the given one, from the point of view of the given color.
-
-constexpr Bitboard forward_file_bb(Color c, Square s) {
-  return forward_ranks_bb(c, s) & file_bb(s);
+template<>
+inline int distance<Rank>(Square x, Square y) {
+    return std::abs(rank_of(x) - rank_of(y));
 }
 
-
-/// pawn_attack_span() returns a bitboard representing all the squares that can
-/// be attacked by a pawn of the given color when it moves along its file, starting
-/// from the given square.
-
-constexpr Bitboard pawn_attack_span(Color c, Square s) {
-  return forward_ranks_bb(c, s) & adjacent_files_bb(s);
+template<>
+inline int distance<Square>(Square x, Square y) {
+    return SquareDistance[x][y];
 }
 
-
-/// passed_pawn_span() returns a bitboard which can be used to test if a pawn of
-/// the given color and on the given square is a passed pawn.
-
-constexpr Bitboard passed_pawn_span(Color c, Square s) {
-  return pawn_attack_span(c, s) | forward_file_bb(c, s);
-}
-
-
-/// aligned() returns true if the squares s1, s2 and s3 are aligned either on a
-/// straight or on a diagonal line.
-
-inline bool aligned(Square s1, Square s2, Square s3) {
-  return line_bb(s1, s2) & s3;
-}
-
-
-/// distance() functions return the distance between x and y, defined as the
-/// number of steps for a king in x to reach y.
-
-template<typename T1 = Square> inline int distance(Square x, Square y);
-template<> inline int distance<File>(Square x, Square y) { return std::abs(file_of(x) - file_of(y)); }
-template<> inline int distance<Rank>(Square x, Square y) { return std::abs(rank_of(x) - rank_of(y)); }
-template<> inline int distance<Square>(Square x, Square y) { return SquareDistance[x][y]; }
-
 inline int edge_distance(File f) { return std::min(f, File(FILE_H - f)); }
-inline int edge_distance(Rank r) { return std::min(r, Rank(RANK_8 - r)); }
-
-
-/// attacks_bb(Square) returns the pseudo attacks of the give piece type
-/// assuming an empty board.
 
+// Returns the pseudo attacks of the given piece type
+// assuming an empty board.
 template<PieceType Pt>
 inline Bitboard attacks_bb(Square s) {
 
-  assert((Pt != PAWN) && (is_ok(s)));
-
-  return PseudoAttacks[Pt][s];
+    assert((Pt != PAWN) && (is_ok(s)));
+    return PseudoAttacks[Pt][s];
 }
 
 
-/// attacks_bb(Square, Bitboard) returns the attacks by the given piece
-/// assuming the board is occupied according to the passed Bitboard.
-/// Sliding piece attacks do not continue passed an occupied square.
-
+// Returns the attacks by the given piece
+// assuming the board is occupied according to the passed Bitboard.
+// Sliding piece attacks do not continue passed an occupied square.
 template<PieceType Pt>
 inline Bitboard attacks_bb(Square s, Bitboard occupied) {
 
-  assert((Pt != PAWN) && (is_ok(s)));
+    assert((Pt != PAWN) && (is_ok(s)));
 
-  switch (Pt)
-  {
-  case BISHOP: return BishopMagics[s].attacks[BishopMagics[s].index(occupied)];
-  case ROOK  : return   RookMagics[s].attacks[  RookMagics[s].index(occupied)];
-  case QUEEN : return attacks_bb<BISHOP>(s, occupied) | attacks_bb<ROOK>(s, occupied);
-  default    : return PseudoAttacks[Pt][s];
-  }
+    switch (Pt)
+    {
+    case BISHOP :
+        return BishopMagics[s].attacks[BishopMagics[s].index(occupied)];
+    case ROOK :
+        return RookMagics[s].attacks[RookMagics[s].index(occupied)];
+    case QUEEN :
+        return attacks_bb<BISHOP>(s, occupied) | attacks_bb<ROOK>(s, occupied);
+    default :
+        return PseudoAttacks[Pt][s];
+    }
 }
 
+// Returns the attacks by the given piece
+// assuming the board is occupied according to the passed Bitboard.
+// Sliding piece attacks do not continue passed an occupied square.
 inline Bitboard attacks_bb(PieceType pt, Square s, Bitboard occupied) {
 
-  assert((pt != PAWN) && (is_ok(s)));
+    assert((pt != PAWN) && (is_ok(s)));
 
-  switch (pt)
-  {
-  case BISHOP: return attacks_bb<BISHOP>(s, occupied);
-  case ROOK  : return attacks_bb<  ROOK>(s, occupied);
-  case QUEEN : return attacks_bb<BISHOP>(s, occupied) | attacks_bb<ROOK>(s, occupied);
-  default    : return PseudoAttacks[pt][s];
-  }
+    switch (pt)
+    {
+    case BISHOP :
+        return attacks_bb<BISHOP>(s, occupied);
+    case ROOK :
+        return attacks_bb<ROOK>(s, occupied);
+    case QUEEN :
+        return attacks_bb<BISHOP>(s, occupied) | attacks_bb<ROOK>(s, occupied);
+    default :
+        return PseudoAttacks[pt][s];
+    }
 }
 
 
-/// popcount() counts the number of non-zero bits in a bitboard
-
+// Counts the number of non-zero bits in a bitboard.
 inline int popcount(Bitboard b) {
 
 #ifndef USE_POPCNT
 
-  union { Bitboard bb; uint16_t u[4]; } v = { b };
-  return PopCnt16[v.u[0]] + PopCnt16[v.u[1]] + PopCnt16[v.u[2]] + PopCnt16[v.u[3]];
+    union {
+        Bitboard bb;
+        uint16_t u[4];
+    } v = {b};
+    return PopCnt16[v.u[0]] + PopCnt16[v.u[1]] + PopCnt16[v.u[2]] + PopCnt16[v.u[3]];
 
-#elif defined(_MSC_VER) || defined(__INTEL_COMPILER)
+#elif defined(_MSC_VER)
 
-  return (int)_mm_popcnt_u64(b);
+    return int(_mm_popcnt_u64(b));
 
-#else // Assumed gcc or compatible compiler
+#else  // Assumed gcc or compatible compiler
 
-  return __builtin_popcountll(b);
+    return __builtin_popcountll(b);
 
 #endif
 }
 
-
-/// lsb() and msb() return the least/most significant bit in a non-zero bitboard
-
-#if defined(__GNUC__)  // GCC, Clang, ICC
-
+// Returns the least significant bit in a non-zero bitboard.
 inline Square lsb(Bitboard b) {
-  assert(b);
-  return Square(__builtin_ctzll(b));
-}
+    assert(b);
 
-inline Square msb(Bitboard b) {
-  assert(b);
-  return Square(63 ^ __builtin_clzll(b));
-}
+#if defined(__GNUC__)  // GCC, Clang, ICX
 
-#elif defined(_MSC_VER)  // MSVC
+    return Square(__builtin_ctzll(b));
 
-#ifdef _WIN64  // MSVC, WIN64
+#elif defined(_MSC_VER)
+    #ifdef _WIN64  // MSVC, WIN64
 
-inline Square lsb(Bitboard b) {
-  assert(b);
-  unsigned long idx;
-  _BitScanForward64(&idx, b);
-  return (Square) idx;
-}
+    unsigned long idx;
+    _BitScanForward64(&idx, b);
+    return Square(idx);
 
-inline Square msb(Bitboard b) {
-  assert(b);
-  unsigned long idx;
-  _BitScanReverse64(&idx, b);
-  return (Square) idx;
-}
-
-#else  // MSVC, WIN32
-
-inline Square lsb(Bitboard b) {
-  assert(b);
-  unsigned long idx;
-
-  if (b & 0xffffffff) {
-      _BitScanForward(&idx, int32_t(b));
-      return Square(idx);
-  } else {
-      _BitScanForward(&idx, int32_t(b >> 32));
-      return Square(idx + 32);
-  }
-}
-
-inline Square msb(Bitboard b) {
-  assert(b);
-  unsigned long idx;
-
-  if (b >> 32) {
-      _BitScanReverse(&idx, int32_t(b >> 32));
-      return Square(idx + 32);
-  } else {
-      _BitScanReverse(&idx, int32_t(b));
-      return Square(idx);
-  }
-}
-
-#endif
+    #else  // MSVC, WIN32
+    unsigned long idx;
 
+    if (b & 0xffffffff)
+    {
+        _BitScanForward(&idx, int32_t(b));
+        return Square(idx);
+    }
+    else
+    {
+        _BitScanForward(&idx, int32_t(b >> 32));
+        return Square(idx + 32);
+    }
+    #endif
 #else  // Compiler is neither GCC nor MSVC compatible
-
-#error "Compiler not supported."
-
+    #error "Compiler not supported."
 #endif
-
-
-/// pop_lsb() finds and clears the least significant bit in a non-zero bitboard
-
-inline Square pop_lsb(Bitboard* b) {
-  assert(*b);
-  const Square s = lsb(*b);
-  *b &= *b - 1;
-  return s;
 }
 
+// Returns the most significant bit in a non-zero bitboard.
+inline Square msb(Bitboard b) {
+    assert(b);
 
-/// frontmost_sq() returns the most advanced square for the given color,
-/// requires a non-zero bitboard.
-inline Square frontmost_sq(Color c, Bitboard b) {
-  assert(b);
-  return c == WHITE ? msb(b) : lsb(b);
+#if defined(__GNUC__)  // GCC, Clang, ICX
+
+    return Square(63 ^ __builtin_clzll(b));
+
+#elif defined(_MSC_VER)
+    #ifdef _WIN64  // MSVC, WIN64
+
+    unsigned long idx;
+    _BitScanReverse64(&idx, b);
+    return Square(idx);
+
+    #else  // MSVC, WIN32
+
+    unsigned long idx;
+
+    if (b >> 32)
+    {
+        _BitScanReverse(&idx, int32_t(b >> 32));
+        return Square(idx + 32);
+    }
+    else
+    {
+        _BitScanReverse(&idx, int32_t(b));
+        return Square(idx);
+    }
+    #endif
+#else  // Compiler is neither GCC nor MSVC compatible
+    #error "Compiler not supported."
+#endif
 }
 
-#endif // #ifndef BITBOARD_H_INCLUDED
+// Returns the bitboard of the least significant
+// square of a non-zero bitboard. It is equivalent to square_bb(lsb(bb)).
+inline Bitboard least_significant_square_bb(Bitboard b) {
+    assert(b);
+    return b & -b;
+}
+
+// Finds and clears the least significant bit in a non-zero bitboard.
+inline Square pop_lsb(Bitboard& b) {
+    assert(b);
+    const Square s = lsb(b);
+    b &= b - 1;
+    return s;
+}
+
+}  // namespace Stockfish
+
+#endif  // #ifndef BITBOARD_H_INCLUDED

src/cluster.cpp

@@ -0,0 +1,480 @@
+/*
+  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+  Copyright (C) 2004-2020 The Stockfish developers (see AUTHORS file)
+
+  Stockfish is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  Stockfish is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifdef USE_MPI
+
+    #include <array>
+    #include <cstddef>
+    #include <cstdlib>
+    #include <iostream>
+    #include <istream>
+    #include <map>
+    #include <mpi.h>
+    #include <string>
+    #include <vector>
+
+    #include "cluster.h"
+    #include "thread.h"
+    #include "timeman.h"
+    #include "tt.h"
+    #include "search.h"
+
+namespace Stockfish {
+namespace Cluster {
+
+// Total number of ranks and rank within the communicator
+static int world_rank = MPI_PROC_NULL;
+static int world_size = 0;
+
+// Signals between ranks exchange basic info using a dedicated communicator
+static MPI_Comm    signalsComm        = MPI_COMM_NULL;
+static MPI_Request reqSignals         = MPI_REQUEST_NULL;
+static uint64_t    signalsCallCounter = 0;
+
+// Signals are the number of nodes searched, stop, table base hits, transposition table saves
+enum Signals : int {
+    SIG_NODES = 0,
+    SIG_STOP  = 1,
+    SIG_TB    = 2,
+    SIG_TTS   = 3,
+    SIG_NB    = 4
+};
+static uint64_t signalsSend[SIG_NB] = {};
+static uint64_t signalsRecv[SIG_NB] = {};
+static uint64_t nodesSearchedOthers = 0;
+static uint64_t tbHitsOthers        = 0;
+static uint64_t TTsavesOthers       = 0;
+static uint64_t stopSignalsPosted   = 0;
+
+// The UCI threads of each rank exchange use a dedicated communicator
+static MPI_Comm InputComm = MPI_COMM_NULL;
+
+// bestMove requires MoveInfo communicators and data types
+static MPI_Comm     MoveComm   = MPI_COMM_NULL;
+static MPI_Datatype MIDatatype = MPI_DATATYPE_NULL;
+
+// TT entries are communicated with a dedicated communicator.
+// The receive buffer is used to gather information from all ranks.
+// THe TTCacheCounter tracks the number of local elements that are ready to be sent.
+static MPI_Comm                                 TTComm = MPI_COMM_NULL;
+static std::array<std::vector<KeyedTTEntry>, 2> TTSendRecvBuffs;
+static std::array<MPI_Request, 2> reqsTTSendRecv = {MPI_REQUEST_NULL, MPI_REQUEST_NULL};
+static uint64_t                   sendRecvPosted = 0;
+static std::atomic<uint64_t>      TTCacheCounter = {};
+
+/// Initialize MPI and associated data types. Note that the MPI library must be configured
+/// to support MPI_THREAD_MULTIPLE, since multiple threads access MPI simultaneously.
+void init() {
+
+    int thread_support;
+    MPI_Init_thread(nullptr, nullptr, MPI_THREAD_MULTIPLE, &thread_support);
+    if (thread_support < MPI_THREAD_MULTIPLE)
+    {
+        std::cerr << "Stockfish requires support for MPI_THREAD_MULTIPLE." << std::endl;
+        std::exit(EXIT_FAILURE);
+    }
+
+    MPI_Comm_rank(MPI_COMM_WORLD, &world_rank);
+    MPI_Comm_size(MPI_COMM_WORLD, &world_size);
+
+    const std::array<MPI_Aint, 5> MIdisps = {offsetof(MoveInfo, move), offsetof(MoveInfo, ponder),
+                                             offsetof(MoveInfo, depth), offsetof(MoveInfo, score),
+                                             offsetof(MoveInfo, rank)};
+    MPI_Type_create_hindexed_block(5, 1, MIdisps.data(), MPI_INT, &MIDatatype);
+    MPI_Type_commit(&MIDatatype);
+
+    MPI_Comm_dup(MPI_COMM_WORLD, &InputComm);
+    MPI_Comm_dup(MPI_COMM_WORLD, &TTComm);
+    MPI_Comm_dup(MPI_COMM_WORLD, &MoveComm);
+    MPI_Comm_dup(MPI_COMM_WORLD, &signalsComm);
+}
+
+/// Finalize MPI and free the associated data types.
+void finalize() {
+
+    MPI_Type_free(&MIDatatype);
+
+    MPI_Comm_free(&InputComm);
+    MPI_Comm_free(&TTComm);
+    MPI_Comm_free(&MoveComm);
+    MPI_Comm_free(&signalsComm);
+
+    MPI_Finalize();
+}
+
+/// Return the total number of ranks
+int size() { return world_size; }
+
+/// Return the rank (index) of the process
+int rank() { return world_rank; }
+
+/// The receive buffer depends on the number of MPI ranks and threads, resize as needed
+void ttSendRecvBuff_resize(size_t nThreads) {
+
+    for (int i : {0, 1})
+    {
+        TTSendRecvBuffs[i].resize(TTCacheSize * world_size * nThreads);
+        std::fill(TTSendRecvBuffs[i].begin(), TTSendRecvBuffs[i].end(), KeyedTTEntry());
+    }
+}
+
+/// As input is only received by the root (rank 0) of the cluster, this input must be relayed
+/// to the UCI threads of all ranks, in order to setup the position, etc. We do this with a
+/// dedicated getline implementation, where the root broadcasts to all other ranks the received
+/// information.
+bool getline(std::istream& input, std::string& str) {
+
+    int               size;
+    std::vector<char> vec;
+    int               state;
+
+    if (is_root())
+    {
+        state = static_cast<bool>(std::getline(input, str));
+        vec.assign(str.begin(), str.end());
+        size = vec.size();
+    }
+
+    // Some MPI implementations use busy-wait polling, while we need yielding as otherwise
+    // the UCI thread on the non-root ranks would be consuming resources.
+    static MPI_Request reqInput = MPI_REQUEST_NULL;
+    MPI_Ibcast(&size, 1, MPI_INT, 0, InputComm, &reqInput);
+    if (is_root())
+        MPI_Wait(&reqInput, MPI_STATUS_IGNORE);
+    else
+    {
+        while (true)
+        {
+            int flag;
+            MPI_Test(&reqInput, &flag, MPI_STATUS_IGNORE);
+            if (flag)
+                break;
+            else
+                std::this_thread::sleep_for(std::chrono::milliseconds(10));
+        }
+    }
+
+    // Broadcast received string
+    if (!is_root())
+        vec.resize(size);
+    MPI_Bcast(vec.data(), size, MPI_CHAR, 0, InputComm);
+    if (!is_root())
+        str.assign(vec.begin(), vec.end());
+    MPI_Bcast(&state, 1, MPI_INT, 0, InputComm);
+
+    return state;
+}
+
+/// Sending part of the signal communication loop
+namespace {
+void signals_send(const ThreadPool& threads) {
+
+    signalsSend[SIG_NODES] = threads.nodes_searched();
+    signalsSend[SIG_TB]    = threads.tb_hits();
+    signalsSend[SIG_TTS]   = threads.TT_saves();
+    signalsSend[SIG_STOP]  = threads.stop;
+    MPI_Iallreduce(signalsSend, signalsRecv, SIG_NB, MPI_UINT64_T, MPI_SUM, signalsComm,
+                   &reqSignals);
+    ++signalsCallCounter;
+}
+
+
+/// Processing part of the signal communication loop.
+/// For some counters (e.g. nodes) we only keep their sum on the other nodes
+/// allowing to add local counters at any time for more fine grained process,
+/// which is useful to indicate progress during early iterations, and to have
+/// node counts that exactly match the non-MPI code in the single rank case.
+/// This call also propagates the stop signal between ranks.
+void signals_process(ThreadPool& threads) {
+
+    nodesSearchedOthers = signalsRecv[SIG_NODES] - signalsSend[SIG_NODES];
+    tbHitsOthers        = signalsRecv[SIG_TB] - signalsSend[SIG_TB];
+    TTsavesOthers       = signalsRecv[SIG_TTS] - signalsSend[SIG_TTS];
+    stopSignalsPosted   = signalsRecv[SIG_STOP];
+    if (signalsRecv[SIG_STOP] > 0)
+        threads.stop = true;
+}
+
+void sendrecv_post() {
+
+    ++sendRecvPosted;
+    MPI_Irecv(TTSendRecvBuffs[sendRecvPosted % 2].data(),
+              TTSendRecvBuffs[sendRecvPosted % 2].size() * sizeof(KeyedTTEntry), MPI_BYTE,
+              (rank() + size() - 1) % size(), 42, TTComm, &reqsTTSendRecv[0]);
+    MPI_Isend(TTSendRecvBuffs[(sendRecvPosted + 1) % 2].data(),
+              TTSendRecvBuffs[(sendRecvPosted + 1) % 2].size() * sizeof(KeyedTTEntry), MPI_BYTE,
+              (rank() + 1) % size(), 42, TTComm, &reqsTTSendRecv[1]);
+}
+}
+
+/// During search, most message passing is asynchronous, but at the end of
+/// search it makes sense to bring them to a common, finalized state.
+void signals_sync(ThreadPool& threads) {
+
+    while (stopSignalsPosted < uint64_t(size()))
+        signals_poll(threads);
+
+    // Finalize outstanding messages of the signal loops.
+    // We might have issued one call less than needed on some ranks.
+    uint64_t globalCounter;
+    MPI_Allreduce(&signalsCallCounter, &globalCounter, 1, MPI_UINT64_T, MPI_MAX, MoveComm);
+    if (signalsCallCounter < globalCounter)
+    {
+        MPI_Wait(&reqSignals, MPI_STATUS_IGNORE);
+        signals_send(threads);
+    }
+    assert(signalsCallCounter == globalCounter);
+    MPI_Wait(&reqSignals, MPI_STATUS_IGNORE);
+    signals_process(threads);
+
+    // Finalize outstanding messages in the sendRecv loop
+    MPI_Allreduce(&sendRecvPosted, &globalCounter, 1, MPI_UINT64_T, MPI_MAX, MoveComm);
+    while (sendRecvPosted < globalCounter)
+    {
+        MPI_Waitall(reqsTTSendRecv.size(), reqsTTSendRecv.data(), MPI_STATUSES_IGNORE);
+        sendrecv_post();
+    }
+    assert(sendRecvPosted == globalCounter);
+    MPI_Waitall(reqsTTSendRecv.size(), reqsTTSendRecv.data(), MPI_STATUSES_IGNORE);
+}
+
+/// Initialize signal counters to zero.
+void signals_init() {
+
+    stopSignalsPosted = tbHitsOthers = TTsavesOthers = nodesSearchedOthers = 0;
+
+    signalsSend[SIG_NODES] = signalsRecv[SIG_NODES] = 0;
+    signalsSend[SIG_TB] = signalsRecv[SIG_TB] = 0;
+    signalsSend[SIG_TTS] = signalsRecv[SIG_TTS] = 0;
+    signalsSend[SIG_STOP] = signalsRecv[SIG_STOP] = 0;
+}
+
+/// Poll the signal loop, and start next round as needed.
+void signals_poll(ThreadPool& threads) {
+
+    int flag;
+    MPI_Test(&reqSignals, &flag, MPI_STATUS_IGNORE);
+    if (flag)
+    {
+        signals_process(threads);
+        signals_send(threads);
+    }
+}
+
+/// Provide basic info related the cluster performance, in particular, the number of signals send,
+/// signals per sounds (sps), the number of gathers, the number of positions gathered (per node and per second, gpps)
+/// The number of TT saves and TT saves per second. If gpps equals approximately TTSavesps the gather loop has enough bandwidth.
+void cluster_info(const ThreadPool& threads, Depth depth, TimePoint elapsed) {
+
+    // TimePoint elapsed = Time.elapsed() + 1;
+    uint64_t TTSaves = TT_saves(threads);
+
+    sync_cout << "info depth " << depth << " cluster "
+              << " signals " << signalsCallCounter << " sps " << signalsCallCounter * 1000 / elapsed
+              << " sendRecvs " << sendRecvPosted << " srpps "
+              << TTSendRecvBuffs[0].size() * sendRecvPosted * 1000 / elapsed << " TTSaves "
+              << TTSaves << " TTSavesps " << TTSaves * 1000 / elapsed << sync_endl;
+}
+
+/// When a TT entry is saved, additional steps are taken if the entry is of sufficient depth.
+/// If sufficient entries has been collected, a communication is initiated.
+/// If a communication has been completed, the received results are saved to the TT.
+void save(TranspositionTable& TT,
+          ThreadPool&         threads,
+          Search::Worker*     thread,
+          TTEntry*            tte,
+          Key                 k,
+          Value               v,
+          bool                PvHit,
+          Bound               b,
+          Depth               d,
+          Move                m,
+          Value               ev,
+          uint8_t             generation8) {
+
+    // Standard save to the TT
+    tte->save(k, v, PvHit, b, d, m, ev, generation8);
+
+    // If the entry is of sufficient depth to be worth communicating, take action.
+    if (d > 3)
+    {
+        // count the TTsaves to information: this should be relatively similar
+        // to the number of entries we can send/recv.
+        thread->TTsaves.fetch_add(1, std::memory_order_relaxed);
+
+        // Add to thread's send buffer, the locking here avoids races when the master thread
+        // prepares the send buffer.
+        {
+            std::lock_guard<std::mutex> lk(thread->ttCache.mutex);
+            thread->ttCache.buffer.replace(KeyedTTEntry(k, *tte));
+            ++TTCacheCounter;
+        }
+
+        size_t recvBuffPerRankSize = threads.size() * TTCacheSize;
+
+        // Communicate on main search thread, as soon the threads combined have collected
+        // sufficient data to fill the send buffers.
+        if (thread == threads.main_thread()->worker.get() && TTCacheCounter > recvBuffPerRankSize)
+        {
+            // Test communication status
+            int flag;
+            MPI_Testall(reqsTTSendRecv.size(), reqsTTSendRecv.data(), &flag, MPI_STATUSES_IGNORE);
+
+            // Current communication is complete
+            if (flag)
+            {
+                // Save all received entries to TT, and store our TTCaches, ready for the next round of communication
+                for (size_t irank = 0; irank < size_t(size()); ++irank)
+                {
+                    if (irank
+                        == size_t(
+                          rank()))  // this is our part, fill the part of the buffer for sending
+                    {
+                        // Copy from the thread caches to the right spot in the buffer
+                        size_t i = irank * recvBuffPerRankSize;
+                        for (auto&& th : threads)
+                        {
+                            std::lock_guard<std::mutex> lk(th->worker->ttCache.mutex);
+
+                            for (auto&& e : th->worker->ttCache.buffer)
+                                TTSendRecvBuffs[sendRecvPosted % 2][i++] = e;
+
+                            // Reset thread's send buffer
+                            th->worker->ttCache.buffer = {};
+                        }
+
+                        TTCacheCounter = 0;
+                    }
+                    else  // process data received from the corresponding rank.
+                        for (size_t i = irank * recvBuffPerRankSize;
+                             i < (irank + 1) * recvBuffPerRankSize; ++i)
+                        {
+                            auto&&   e = TTSendRecvBuffs[sendRecvPosted % 2][i];
+                            bool     found;
+                            TTEntry* replace_tte;
+                            replace_tte = TT.probe(e.first, found);
+                            replace_tte->save(e.first, e.second.value(), e.second.is_pv(),
+                                              e.second.bound(), e.second.depth(), e.second.move(),
+                                              e.second.eval(), TT.generation());
+                        }
+                }
+
+                // Start next communication
+                sendrecv_post();
+
+                // Force check of time on the next occasion, the above actions might have taken some time.
+                thread->main_manager()->callsCnt = 0;
+            }
+        }
+    }
+}
+
+/// Picks the bestMove across ranks, and send the associated info and PV to the root of the cluster.
+/// Note that this bestMove and PV must be output by the root, the guarantee proper ordering of output.
+/// TODO update to the scheme in master.. can this use aggregation of votes?
+void pick_moves(MoveInfo& mi, std::string& PVLine) {
+
+    MoveInfo* pMoveInfo = NULL;
+    if (is_root())
+    {
+        pMoveInfo = (MoveInfo*) malloc(sizeof(MoveInfo) * size());
+    }
+    MPI_Gather(&mi, 1, MIDatatype, pMoveInfo, 1, MIDatatype, 0, MoveComm);
+
+    if (is_root())
+    {
+        std::map<int, int> votes;
+        int                minScore = pMoveInfo[0].score;
+        for (int i = 0; i < size(); ++i)
+        {
+            minScore                 = std::min(minScore, pMoveInfo[i].score);
+            votes[pMoveInfo[i].move] = 0;
+        }
+        for (int i = 0; i < size(); ++i)
+        {
+            votes[pMoveInfo[i].move] += pMoveInfo[i].score - minScore + pMoveInfo[i].depth;
+        }
+        int bestVote = votes[pMoveInfo[0].move];
+        for (int i = 0; i < size(); ++i)
+        {
+            if (votes[pMoveInfo[i].move] > bestVote)
+            {
+                bestVote = votes[pMoveInfo[i].move];
+                mi       = pMoveInfo[i];
+            }
+        }
+        free(pMoveInfo);
+    }
+
+    // Send around the final result
+    MPI_Bcast(&mi, 1, MIDatatype, 0, MoveComm);
+
+    // Send PV line to root as needed
+    if (mi.rank != 0 && mi.rank == rank())
+    {
+        int               size;
+        std::vector<char> vec;
+        vec.assign(PVLine.begin(), PVLine.end());
+        size = vec.size();
+        MPI_Send(&size, 1, MPI_INT, 0, 42, MoveComm);
+        MPI_Send(vec.data(), size, MPI_CHAR, 0, 42, MoveComm);
+    }
+    if (mi.rank != 0 && is_root())
+    {
+        int               size;
+        std::vector<char> vec;
+        MPI_Recv(&size, 1, MPI_INT, mi.rank, 42, MoveComm, MPI_STATUS_IGNORE);
+        vec.resize(size);
+        MPI_Recv(vec.data(), size, MPI_CHAR, mi.rank, 42, MoveComm, MPI_STATUS_IGNORE);
+        PVLine.assign(vec.begin(), vec.end());
+    }
+}
+
+/// Return nodes searched (lazily updated cluster wide in the signal loop)
+uint64_t nodes_searched(const ThreadPool& threads) {
+    return nodesSearchedOthers + threads.nodes_searched();
+}
+
+/// Return table base hits (lazily updated cluster wide in the signal loop)
+uint64_t tb_hits(const ThreadPool& threads) { return tbHitsOthers + threads.tb_hits(); }
+
+/// Return the number of saves to the TT buffers, (lazily updated cluster wide in the signal loop)
+uint64_t TT_saves(const ThreadPool& threads) { return TTsavesOthers + threads.TT_saves(); }
+
+
+}
+}
+
+#else
+
+    #include "cluster.h"
+    #include "thread.h"
+
+namespace Stockfish {
+namespace Cluster {
+
+uint64_t nodes_searched(const ThreadPool& threads) { return threads.nodes_searched(); }
+
+uint64_t tb_hits(const ThreadPool& threads) { return threads.tb_hits(); }
+
+uint64_t TT_saves(const ThreadPool& threads) { return threads.TT_saves(); }
+
+}
+}
+
+#endif  // USE_MPI

src/cluster.h

@@ -0,0 +1,157 @@
+/*
+  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+  Copyright (C) 2004-2020 The Stockfish developers (see AUTHORS file)
+
+  Stockfish is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  Stockfish is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef CLUSTER_H_INCLUDED
+#define CLUSTER_H_INCLUDED
+
+#include <algorithm>
+#include <array>
+#include <istream>
+#include <string>
+
+#include "tt.h"
+
+namespace Stockfish {
+class Thread;
+class ThreadPool;
+
+namespace Search {
+class Worker;
+}
+
+/// The Cluster namespace contains functionality required to run on distributed
+/// memory architectures using MPI as the message passing interface. On a high level,
+/// a 'lazy SMP'-like scheme is implemented where TT saves of sufficient depth are
+/// collected on each rank and distributed to, and used by, all other ranks,
+/// which search essentially independently.  The root (MPI rank 0) of the cluster
+/// is responsible for all I/O and time management, communicating this info to
+/// the other ranks as needed. UCI options such as Threads and Hash specify these
+/// quantities per MPI rank.  It is recommended to have one rank (MPI process) per node.
+/// For the non-MPI case, wrappers that will be compiler-optimized away are provided.
+
+namespace Cluster {
+
+/// Basic info to find the cluster-wide bestMove
+struct MoveInfo {
+    int move;
+    int ponder;
+    int depth;
+    int score;
+    int rank;
+};
+
+#ifdef USE_MPI
+
+// store the TTEntry with its full key, so it can be saved on the receiver side
+using KeyedTTEntry                = std::pair<Key, TTEntry>;
+constexpr std::size_t TTCacheSize = 16;
+
+// Threads locally cache their high-depth TT entries till a batch can be send by MPI
+template<std::size_t N>
+class TTCache: public std::array<KeyedTTEntry, N> {
+
+    struct Compare {
+        inline bool operator()(const KeyedTTEntry& lhs, const KeyedTTEntry& rhs) {
+            return lhs.second.depth() > rhs.second.depth();
+        }
+    };
+    Compare compare;
+
+   public:
+    // Keep a heap of entries replacing low depth with high depth entries
+    bool replace(const KeyedTTEntry& value) {
+
+        if (compare(value, this->front()))
+        {
+            std::pop_heap(this->begin(), this->end(), compare);
+            this->back() = value;
+            std::push_heap(this->begin(), this->end(), compare);
+            return true;
+        }
+        return false;
+    }
+};
+
+void        init();
+void        finalize();
+bool        getline(std::istream& input, std::string& str);
+int         size();
+int         rank();
+inline bool is_root() { return rank() == 0; }
+void        save(TranspositionTable&,
+                 ThreadPool&,
+                 Search::Worker* thread,
+                 TTEntry*        tte,
+                 Key             k,
+                 Value           v,
+                 bool            PvHit,
+                 Bound           b,
+                 Depth           d,
+                 Move            m,
+                 Value           ev,
+                 uint8_t         generation8);
+void        pick_moves(MoveInfo& mi, std::string& PVLine);
+void        ttSendRecvBuff_resize(size_t nThreads);
+uint64_t    nodes_searched(const ThreadPool&);
+uint64_t    tb_hits(const ThreadPool&);
+uint64_t    TT_saves(const ThreadPool&);
+void        cluster_info(const ThreadPool&, Depth depth, TimePoint elapsed);
+void        signals_init();
+void        signals_poll(ThreadPool& threads);
+void        signals_sync(ThreadPool& threads);
+
+#else
+
+inline void init() {}
+inline void finalize() {}
+inline bool getline(std::istream& input, std::string& str) {
+    return static_cast<bool>(std::getline(input, str));
+}
+constexpr int  size() { return 1; }
+constexpr int  rank() { return 0; }
+constexpr bool is_root() { return true; }
+inline void    save(TranspositionTable&,
+                    ThreadPool&,
+                    Search::Worker*,
+                    TTEntry* tte,
+                    Key      k,
+                    Value    v,
+                    bool     PvHit,
+                    Bound    b,
+                    Depth    d,
+                    Move     m,
+                    Value    ev,
+                    uint8_t  generation8) {
+    tte->save(k, v, PvHit, b, d, m, ev, generation8);
+}
+inline void pick_moves(MoveInfo&, std::string&) {}
+inline void ttSendRecvBuff_resize(size_t) {}
+uint64_t    nodes_searched(const ThreadPool&);
+uint64_t    tb_hits(const ThreadPool&);
+uint64_t    TT_saves(const ThreadPool&);
+inline void cluster_info(const ThreadPool&, Depth, TimePoint) {}
+inline void signals_init() {}
+inline void signals_poll(ThreadPool& threads) {}
+inline void signals_sync(ThreadPool& threads) {}
+
+#endif /* USE_MPI */
+
+}
+}
+
+#endif  // #ifndef CLUSTER_H_INCLUDED

src/endgame.cpp

@@ -1,743 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
-
-  Stockfish is free software: you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation, either version 3 of the License, or
-  (at your option) any later version.
-
-  Stockfish is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-#include <cassert>
-
-#include "bitboard.h"
-#include "endgame.h"
-#include "movegen.h"
-
-namespace {
-
-  // Used to drive the king towards the edge of the board
-  // in KX vs K and KQ vs KR endgames.
-  // Values range from 27 (center squares) to 90 (in the corners)
-  inline int push_to_edge(Square s) {
-      int rd = edge_distance(rank_of(s)), fd = edge_distance(file_of(s));
-      return 90 - (7 * fd * fd / 2 + 7 * rd * rd / 2);
-  }
-
-  // Used to drive the king towards A1H8 corners in KBN vs K endgames.
-  // Values range from 0 on A8H1 diagonal to 7 in A1H8 corners
-  inline int push_to_corner(Square s) {
-      return abs(7 - rank_of(s) - file_of(s));
-  }
-
-  // Drive a piece close to or away from another piece
-  inline int push_close(Square s1, Square s2) { return 140 - 20 * distance(s1, s2); }
-  inline int push_away(Square s1, Square s2) { return 120 - push_close(s1, s2); }
-
-#ifndef NDEBUG
-  bool verify_material(const Position& pos, Color c, Value npm, int pawnsCnt) {
-    return pos.non_pawn_material(c) == npm && pos.count<PAWN>(c) == pawnsCnt;
-  }
-#endif
-
-  // Map the square as if strongSide is white and strongSide's only pawn
-  // is on the left half of the board.
-  Square normalize(const Position& pos, Color strongSide, Square sq) {
-
-    assert(pos.count<PAWN>(strongSide) == 1);
-
-    if (file_of(pos.square<PAWN>(strongSide)) >= FILE_E)
-        sq = flip_file(sq);
-
-    return strongSide == WHITE ? sq : flip_rank(sq);
-  }
-
-} // namespace
-
-
-namespace Endgames {
-
-  std::pair<Map<Value>, Map<ScaleFactor>> maps;
-
-  void init() {
-
-    add<KPK>("KPK");
-    add<KNNK>("KNNK");
-    add<KBNK>("KBNK");
-    add<KRKP>("KRKP");
-    add<KRKB>("KRKB");
-    add<KRKN>("KRKN");
-    add<KQKP>("KQKP");
-    add<KQKR>("KQKR");
-    add<KNNKP>("KNNKP");
-
-    add<KRPKR>("KRPKR");
-    add<KRPKB>("KRPKB");
-    add<KBPKB>("KBPKB");
-    add<KBPKN>("KBPKN");
-    add<KBPPKB>("KBPPKB");
-    add<KRPPKRP>("KRPPKRP");
-  }
-}
-
-
-/// Mate with KX vs K. This function is used to evaluate positions with
-/// king and plenty of material vs a lone king. It simply gives the
-/// attacking side a bonus for driving the defending king towards the edge
-/// of the board, and for keeping the distance between the two kings small.
-template<>
-Value Endgame<KXK>::operator()(const Position& pos) const {
-
-  assert(verify_material(pos, weakSide, VALUE_ZERO, 0));
-  assert(!pos.checkers()); // Eval is never called when in check
-
-  // Stalemate detection with lone king
-  if (pos.side_to_move() == weakSide && !MoveList<LEGAL>(pos).size())
-      return VALUE_DRAW;
-
-  Square strongKing = pos.square<KING>(strongSide);
-  Square weakKing   = pos.square<KING>(weakSide);
-
-  Value result =  pos.non_pawn_material(strongSide)
-                + pos.count<PAWN>(strongSide) * PawnValueEg
-                + push_to_edge(weakKing)
-                + push_close(strongKing, weakKing);
-
-  if (   pos.count<QUEEN>(strongSide)
-      || pos.count<ROOK>(strongSide)
-      ||(pos.count<BISHOP>(strongSide) && pos.count<KNIGHT>(strongSide))
-      || (   (pos.pieces(strongSide, BISHOP) & ~DarkSquares)
-          && (pos.pieces(strongSide, BISHOP) &  DarkSquares)))
-      result = std::min(result + VALUE_KNOWN_WIN, VALUE_TB_WIN_IN_MAX_PLY - 1);
-
-  return strongSide == pos.side_to_move() ? result : -result;
-}
-
-
-/// Mate with KBN vs K. This is similar to KX vs K, but we have to drive the
-/// defending king towards a corner square that our bishop attacks.
-template<>
-Value Endgame<KBNK>::operator()(const Position& pos) const {
-
-  assert(verify_material(pos, strongSide, KnightValueMg + BishopValueMg, 0));
-  assert(verify_material(pos, weakSide, VALUE_ZERO, 0));
-
-  Square strongKing   = pos.square<KING>(strongSide);
-  Square strongBishop = pos.square<BISHOP>(strongSide);
-  Square weakKing     = pos.square<KING>(weakSide);
-
-  // If our bishop does not attack A1/H8, we flip the enemy king square
-  // to drive to opposite corners (A8/H1).
-
-  Value result =  (VALUE_KNOWN_WIN + 3520)
-                + push_close(strongKing, weakKing)
-                + 420 * push_to_corner(opposite_colors(strongBishop, SQ_A1) ? flip_file(weakKing) : weakKing);
-
-  assert(abs(result) < VALUE_TB_WIN_IN_MAX_PLY);
-  return strongSide == pos.side_to_move() ? result : -result;
-}
-
-
-/// KP vs K. This endgame is evaluated with the help of a bitbase
-template<>
-Value Endgame<KPK>::operator()(const Position& pos) const {
-
-  assert(verify_material(pos, strongSide, VALUE_ZERO, 1));
-  assert(verify_material(pos, weakSide, VALUE_ZERO, 0));
-
-  // Assume strongSide is white and the pawn is on files A-D
-  Square strongKing = normalize(pos, strongSide, pos.square<KING>(strongSide));
-  Square strongPawn = normalize(pos, strongSide, pos.square<PAWN>(strongSide));
-  Square weakKing   = normalize(pos, strongSide, pos.square<KING>(weakSide));
-
-  Color us = strongSide == pos.side_to_move() ? WHITE : BLACK;
-
-  if (!Bitbases::probe(strongKing, strongPawn, weakKing, us))
-      return VALUE_DRAW;
-
-  Value result = VALUE_KNOWN_WIN + PawnValueEg + Value(rank_of(strongPawn));
-
-  return strongSide == pos.side_to_move() ? result : -result;
-}
-
-
-/// KR vs KP. This is a somewhat tricky endgame to evaluate precisely without
-/// a bitbase. The function below returns drawish scores when the pawn is
-/// far advanced with support of the king, while the attacking king is far
-/// away.
-template<>
-Value Endgame<KRKP>::operator()(const Position& pos) const {
-
-  assert(verify_material(pos, strongSide, RookValueMg, 0));
-  assert(verify_material(pos, weakSide, VALUE_ZERO, 1));
-
-  Square strongKing = pos.square<KING>(strongSide);
-  Square weakKing   = pos.square<KING>(weakSide);
-  Square strongRook = pos.square<ROOK>(strongSide);
-  Square weakPawn   = pos.square<PAWN>(weakSide);
-  Square queeningSquare = make_square(file_of(weakPawn), relative_rank(weakSide, RANK_8));
-  Value result;
-
-  // If the stronger side's king is in front of the pawn, it's a win
-  if (forward_file_bb(strongSide, strongKing) & weakPawn)
-      result = RookValueEg - distance(strongKing, weakPawn);
-
-  // If the weaker side's king is too far from the pawn and the rook,
-  // it's a win.
-  else if (   distance(weakKing, weakPawn) >= 3 + (pos.side_to_move() == weakSide)
-           && distance(weakKing, strongRook) >= 3)
-      result = RookValueEg - distance(strongKing, weakPawn);
-
-  // If the pawn is far advanced and supported by the defending king,
-  // the position is drawish
-  else if (   relative_rank(strongSide, weakKing) <= RANK_3
-           && distance(weakKing, weakPawn) == 1
-           && relative_rank(strongSide, strongKing) >= RANK_4
-           && distance(strongKing, weakPawn) > 2 + (pos.side_to_move() == strongSide))
-      result = Value(80) - 8 * distance(strongKing, weakPawn);
-
-  else
-      result =  Value(200) - 8 * (  distance(strongKing, weakPawn + pawn_push(weakSide))
-                                  - distance(weakKing, weakPawn + pawn_push(weakSide))
-                                  - distance(weakPawn, queeningSquare));
-
-  return strongSide == pos.side_to_move() ? result : -result;
-}
-
-
-/// KR vs KB. This is very simple, and always returns drawish scores. The
-/// score is slightly bigger when the defending king is close to the edge.
-template<>
-Value Endgame<KRKB>::operator()(const Position& pos) const {
-
-  assert(verify_material(pos, strongSide, RookValueMg, 0));
-  assert(verify_material(pos, weakSide, BishopValueMg, 0));
-
-  Value result = Value(push_to_edge(pos.square<KING>(weakSide)));
-  return strongSide == pos.side_to_move() ? result : -result;
-}
-
-
-/// KR vs KN. The attacking side has slightly better winning chances than
-/// in KR vs KB, particularly if the king and the knight are far apart.
-template<>
-Value Endgame<KRKN>::operator()(const Position& pos) const {
-
-  assert(verify_material(pos, strongSide, RookValueMg, 0));
-  assert(verify_material(pos, weakSide, KnightValueMg, 0));
-
-  Square weakKing   = pos.square<KING>(weakSide);
-  Square weakKnight = pos.square<KNIGHT>(weakSide);
-  Value result = Value(push_to_edge(weakKing) + push_away(weakKing, weakKnight));
-  return strongSide == pos.side_to_move() ? result : -result;
-}
-
-
-/// KQ vs KP. In general, this is a win for the stronger side, but there are a
-/// few important exceptions. A pawn on 7th rank and on the A,C,F or H files
-/// with a king positioned next to it can be a draw, so in that case, we only
-/// use the distance between the kings.
-template<>
-Value Endgame<KQKP>::operator()(const Position& pos) const {
-
-  assert(verify_material(pos, strongSide, QueenValueMg, 0));
-  assert(verify_material(pos, weakSide, VALUE_ZERO, 1));
-
-  Square strongKing = pos.square<KING>(strongSide);
-  Square weakKing   = pos.square<KING>(weakSide);
-  Square weakPawn   = pos.square<PAWN>(weakSide);
-
-  Value result = Value(push_close(strongKing, weakKing));
-
-  if (   relative_rank(weakSide, weakPawn) != RANK_7
-      || distance(weakKing, weakPawn) != 1
-      || ((FileBBB | FileDBB | FileEBB | FileGBB) & weakPawn))
-      result += QueenValueEg - PawnValueEg;
-
-  return strongSide == pos.side_to_move() ? result : -result;
-}
-
-
-/// KQ vs KR. This is almost identical to KX vs K: we give the attacking
-/// king a bonus for having the kings close together, and for forcing the
-/// defending king towards the edge. If we also take care to avoid null move for
-/// the defending side in the search, this is usually sufficient to win KQ vs KR.
-template<>
-Value Endgame<KQKR>::operator()(const Position& pos) const {
-
-  assert(verify_material(pos, strongSide, QueenValueMg, 0));
-  assert(verify_material(pos, weakSide, RookValueMg, 0));
-
-  Square strongKing = pos.square<KING>(strongSide);
-  Square weakKing   = pos.square<KING>(weakSide);
-
-  Value result =  QueenValueEg
-                - RookValueEg
-                + push_to_edge(weakKing)
-                + push_close(strongKing, weakKing);
-
-  return strongSide == pos.side_to_move() ? result : -result;
-}
-
-
-/// KNN vs KP. Very drawish, but there are some mate opportunities if we can
-/// press the weakSide King to a corner before the pawn advances too much.
-template<>
-Value Endgame<KNNKP>::operator()(const Position& pos) const {
-
-  assert(verify_material(pos, strongSide, 2 * KnightValueMg, 0));
-  assert(verify_material(pos, weakSide, VALUE_ZERO, 1));
-
-  Square weakKing = pos.square<KING>(weakSide);
-  Square weakPawn = pos.square<PAWN>(weakSide);
-
-  Value result =      PawnValueEg
-               +  2 * push_to_edge(weakKing)
-               - 10 * relative_rank(weakSide, weakPawn);
-
-  return strongSide == pos.side_to_move() ? result : -result;
-}
-
-
-/// Some cases of trivial draws
-template<> Value Endgame<KNNK>::operator()(const Position&) const { return VALUE_DRAW; }
-
-
-/// KB and one or more pawns vs K. It checks for draws with rook pawns and
-/// a bishop of the wrong color. If such a draw is detected, SCALE_FACTOR_DRAW
-/// is returned. If not, the return value is SCALE_FACTOR_NONE, i.e. no scaling
-/// will be used.
-template<>
-ScaleFactor Endgame<KBPsK>::operator()(const Position& pos) const {
-
-  assert(pos.non_pawn_material(strongSide) == BishopValueMg);
-  assert(pos.count<PAWN>(strongSide) >= 1);
-
-  // No assertions about the material of weakSide, because we want draws to
-  // be detected even when the weaker side has some pawns.
-
-  Bitboard strongPawns = pos.pieces(strongSide, PAWN);
-  Bitboard allPawns = pos.pieces(PAWN);
-
-  Square strongBishop = pos.square<BISHOP>(strongSide);
-  Square weakKing = pos.square<KING>(weakSide);
-  Square strongKing = pos.square<KING>(strongSide);
-
-  // All strongSide pawns are on a single rook file?
-  if (!(strongPawns & ~FileABB) || !(strongPawns & ~FileHBB))
-  {
-      Square queeningSquare = relative_square(strongSide, make_square(file_of(lsb(strongPawns)), RANK_8));
-
-      if (   opposite_colors(queeningSquare, strongBishop)
-          && distance(queeningSquare, weakKing) <= 1)
-          return SCALE_FACTOR_DRAW;
-  }
-
-  // If all the pawns are on the same B or G file, then it's potentially a draw
-  if ((!(allPawns & ~FileBBB) || !(allPawns & ~FileGBB))
-      && pos.non_pawn_material(weakSide) == 0
-      && pos.count<PAWN>(weakSide) >= 1)
-  {
-      // Get the least advanced weakSide pawn
-      Square weakPawn = frontmost_sq(strongSide, pos.pieces(weakSide, PAWN));
-
-      // There's potential for a draw if our pawn is blocked on the 7th rank,
-      // the bishop cannot attack it or they only have one pawn left.
-      if (   relative_rank(strongSide, weakPawn) == RANK_7
-          && (strongPawns & (weakPawn + pawn_push(weakSide)))
-          && (opposite_colors(strongBishop, weakPawn) || !more_than_one(strongPawns)))
-      {
-          int strongKingDist = distance(weakPawn, strongKing);
-          int weakKingDist = distance(weakPawn, weakKing);
-
-          // It's a draw if the weak king is on its back two ranks, within 2
-          // squares of the blocking pawn and the strong king is not
-          // closer. (I think this rule only fails in practically
-          // unreachable positions such as 5k1K/6p1/6P1/8/8/3B4/8/8 w
-          // and positions where qsearch will immediately correct the
-          // problem such as 8/4k1p1/6P1/1K6/3B4/8/8/8 w).
-          if (   relative_rank(strongSide, weakKing) >= RANK_7
-              && weakKingDist <= 2
-              && weakKingDist <= strongKingDist)
-              return SCALE_FACTOR_DRAW;
-      }
-  }
-
-  return SCALE_FACTOR_NONE;
-}
-
-
-/// KQ vs KR and one or more pawns. It tests for fortress draws with a rook on
-/// the third rank defended by a pawn.
-template<>
-ScaleFactor Endgame<KQKRPs>::operator()(const Position& pos) const {
-
-  assert(verify_material(pos, strongSide, QueenValueMg, 0));
-  assert(pos.count<ROOK>(weakSide) == 1);
-  assert(pos.count<PAWN>(weakSide) >= 1);
-
-  Square strongKing = pos.square<KING>(strongSide);
-  Square weakKing   = pos.square<KING>(weakSide);
-  Square weakRook   = pos.square<ROOK>(weakSide);
-
-  if (    relative_rank(weakSide,   weakKing) <= RANK_2
-      &&  relative_rank(weakSide, strongKing) >= RANK_4
-      &&  relative_rank(weakSide,   weakRook) == RANK_3
-      && (  pos.pieces(weakSide, PAWN)
-          & attacks_bb<KING>(weakKing)
-          & pawn_attacks_bb(strongSide, weakRook)))
-          return SCALE_FACTOR_DRAW;
-
-  return SCALE_FACTOR_NONE;
-}
-
-
-/// KRP vs KR. This function knows a handful of the most important classes of
-/// drawn positions, but is far from perfect. It would probably be a good idea
-/// to add more knowledge in the future.
-///
-/// It would also be nice to rewrite the actual code for this function,
-/// which is mostly copied from Glaurung 1.x, and isn't very pretty.
-template<>
-ScaleFactor Endgame<KRPKR>::operator()(const Position& pos) const {
-
-  assert(verify_material(pos, strongSide, RookValueMg, 1));
-  assert(verify_material(pos, weakSide,   RookValueMg, 0));
-
-  // Assume strongSide is white and the pawn is on files A-D
-  Square strongKing = normalize(pos, strongSide, pos.square<KING>(strongSide));
-  Square strongRook = normalize(pos, strongSide, pos.square<ROOK>(strongSide));
-  Square strongPawn = normalize(pos, strongSide, pos.square<PAWN>(strongSide));
-  Square weakKing = normalize(pos, strongSide, pos.square<KING>(weakSide));
-  Square weakRook = normalize(pos, strongSide, pos.square<ROOK>(weakSide));
-
-  File pawnFile = file_of(strongPawn);
-  Rank pawnRank = rank_of(strongPawn);
-  Square queeningSquare = make_square(pawnFile, RANK_8);
-  int tempo = (pos.side_to_move() == strongSide);
-
-  // If the pawn is not too far advanced and the defending king defends the
-  // queening square, use the third-rank defence.
-  if (   pawnRank <= RANK_5
-      && distance(weakKing, queeningSquare) <= 1
-      && strongKing <= SQ_H5
-      && (rank_of(weakRook) == RANK_6 || (pawnRank <= RANK_3 && rank_of(strongRook) != RANK_6)))
-      return SCALE_FACTOR_DRAW;
-
-  // The defending side saves a draw by checking from behind in case the pawn
-  // has advanced to the 6th rank with the king behind.
-  if (   pawnRank == RANK_6
-      && distance(weakKing, queeningSquare) <= 1
-      && rank_of(strongKing) + tempo <= RANK_6
-      && (rank_of(weakRook) == RANK_1 || (!tempo && distance<File>(weakRook, strongPawn) >= 3)))
-      return SCALE_FACTOR_DRAW;
-
-  if (   pawnRank >= RANK_6
-      && weakKing == queeningSquare
-      && rank_of(weakRook) == RANK_1
-      && (!tempo || distance(strongKing, strongPawn) >= 2))
-      return SCALE_FACTOR_DRAW;
-
-  // White pawn on a7 and rook on a8 is a draw if black's king is on g7 or h7
-  // and the black rook is behind the pawn.
-  if (   strongPawn == SQ_A7
-      && strongRook == SQ_A8
-      && (weakKing == SQ_H7 || weakKing == SQ_G7)
-      && file_of(weakRook) == FILE_A
-      && (rank_of(weakRook) <= RANK_3 || file_of(strongKing) >= FILE_D || rank_of(strongKing) <= RANK_5))
-      return SCALE_FACTOR_DRAW;
-
-  // If the defending king blocks the pawn and the attacking king is too far
-  // away, it's a draw.
-  if (   pawnRank <= RANK_5
-      && weakKing == strongPawn + NORTH
-      && distance(strongKing, strongPawn) - tempo >= 2
-      && distance(strongKing, weakRook) - tempo >= 2)
-      return SCALE_FACTOR_DRAW;
-
-  // Pawn on the 7th rank supported by the rook from behind usually wins if the
-  // attacking king is closer to the queening square than the defending king,
-  // and the defending king cannot gain tempi by threatening the attacking rook.
-  if (   pawnRank == RANK_7
-      && pawnFile != FILE_A
-      && file_of(strongRook) == pawnFile
-      && strongRook != queeningSquare
-      && (distance(strongKing, queeningSquare) < distance(weakKing, queeningSquare) - 2 + tempo)
-      && (distance(strongKing, queeningSquare) < distance(weakKing, strongRook) + tempo))
-      return ScaleFactor(SCALE_FACTOR_MAX - 2 * distance(strongKing, queeningSquare));
-
-  // Similar to the above, but with the pawn further back
-  if (   pawnFile != FILE_A
-      && file_of(strongRook) == pawnFile
-      && strongRook < strongPawn
-      && (distance(strongKing, queeningSquare) < distance(weakKing, queeningSquare) - 2 + tempo)
-      && (distance(strongKing, strongPawn + NORTH) < distance(weakKing, strongPawn + NORTH) - 2 + tempo)
-      && (  distance(weakKing, strongRook) + tempo >= 3
-          || (    distance(strongKing, queeningSquare) < distance(weakKing, strongRook) + tempo
-              && (distance(strongKing, strongPawn + NORTH) < distance(weakKing, strongPawn) + tempo))))
-      return ScaleFactor(  SCALE_FACTOR_MAX
-                         - 8 * distance(strongPawn, queeningSquare)
-                         - 2 * distance(strongKing, queeningSquare));
-
-  // If the pawn is not far advanced and the defending king is somewhere in
-  // the pawn's path, it's probably a draw.
-  if (pawnRank <= RANK_4 && weakKing > strongPawn)
-  {
-      if (file_of(weakKing) == file_of(strongPawn))
-          return ScaleFactor(10);
-      if (   distance<File>(weakKing, strongPawn) == 1
-          && distance(strongKing, weakKing) > 2)
-          return ScaleFactor(24 - 2 * distance(strongKing, weakKing));
-  }
-  return SCALE_FACTOR_NONE;
-}
-
-template<>
-ScaleFactor Endgame<KRPKB>::operator()(const Position& pos) const {
-
-  assert(verify_material(pos, strongSide, RookValueMg, 1));
-  assert(verify_material(pos, weakSide, BishopValueMg, 0));
-
-  // Test for a rook pawn
-  if (pos.pieces(PAWN) & (FileABB | FileHBB))
-  {
-      Square weakKing = pos.square<KING>(weakSide);
-      Square weakBishop = pos.square<BISHOP>(weakSide);
-      Square strongKing = pos.square<KING>(strongSide);
-      Square strongPawn = pos.square<PAWN>(strongSide);
-      Rank pawnRank = relative_rank(strongSide, strongPawn);
-      Direction push = pawn_push(strongSide);
-
-      // If the pawn is on the 5th rank and the pawn (currently) is on
-      // the same color square as the bishop then there is a chance of
-      // a fortress. Depending on the king position give a moderate
-      // reduction or a stronger one if the defending king is near the
-      // corner but not trapped there.
-      if (pawnRank == RANK_5 && !opposite_colors(weakBishop, strongPawn))
-      {
-          int d = distance(strongPawn + 3 * push, weakKing);
-
-          if (d <= 2 && !(d == 0 && weakKing == strongKing + 2 * push))
-              return ScaleFactor(24);
-          else
-              return ScaleFactor(48);
-      }
-
-      // When the pawn has moved to the 6th rank we can be fairly sure
-      // it's drawn if the bishop attacks the square in front of the
-      // pawn from a reasonable distance and the defending king is near
-      // the corner
-      if (   pawnRank == RANK_6
-          && distance(strongPawn + 2 * push, weakKing) <= 1
-          && (attacks_bb<BISHOP>(weakBishop) & (strongPawn + push))
-          && distance<File>(weakBishop, strongPawn) >= 2)
-          return ScaleFactor(8);
-  }
-
-  return SCALE_FACTOR_NONE;
-}
-
-/// KRPP vs KRP. There is just a single rule: if the stronger side has no passed
-/// pawns and the defending king is actively placed, the position is drawish.
-template<>
-ScaleFactor Endgame<KRPPKRP>::operator()(const Position& pos) const {
-
-  assert(verify_material(pos, strongSide, RookValueMg, 2));
-  assert(verify_material(pos, weakSide,   RookValueMg, 1));
-
-  Square strongPawn1 = lsb(pos.pieces(strongSide, PAWN));
-  Square strongPawn2 = msb(pos.pieces(strongSide, PAWN));
-  Square weakKing = pos.square<KING>(weakSide);
-
-  // Does the stronger side have a passed pawn?
-  if (pos.pawn_passed(strongSide, strongPawn1) || pos.pawn_passed(strongSide, strongPawn2))
-      return SCALE_FACTOR_NONE;
-
-  Rank pawnRank = std::max(relative_rank(strongSide, strongPawn1), relative_rank(strongSide, strongPawn2));
-
-  if (   distance<File>(weakKing, strongPawn1) <= 1
-      && distance<File>(weakKing, strongPawn2) <= 1
-      && relative_rank(strongSide, weakKing) > pawnRank)
-  {
-      assert(pawnRank > RANK_1 && pawnRank < RANK_7);
-      return ScaleFactor(7 * pawnRank);
-  }
-  return SCALE_FACTOR_NONE;
-}
-
-
-/// K and two or more pawns vs K. There is just a single rule here: if all pawns
-/// are on the same rook file and are blocked by the defending king, it's a draw.
-template<>
-ScaleFactor Endgame<KPsK>::operator()(const Position& pos) const {
-
-  assert(pos.non_pawn_material(strongSide) == VALUE_ZERO);
-  assert(pos.count<PAWN>(strongSide) >= 2);
-  assert(verify_material(pos, weakSide, VALUE_ZERO, 0));
-
-  Square weakKing = pos.square<KING>(weakSide);
-  Bitboard strongPawns = pos.pieces(strongSide, PAWN);
-
-  // If all pawns are ahead of the king on a single rook file, it's a draw.
-  if (   !(strongPawns & ~(FileABB | FileHBB))
-      && !(strongPawns & ~passed_pawn_span(weakSide, weakKing)))
-      return SCALE_FACTOR_DRAW;
-
-  return SCALE_FACTOR_NONE;
-}
-
-
-/// KBP vs KB. There are two rules: if the defending king is somewhere along the
-/// path of the pawn, and the square of the king is not of the same color as the
-/// stronger side's bishop, it's a draw. If the two bishops have opposite color,
-/// it's almost always a draw.
-template<>
-ScaleFactor Endgame<KBPKB>::operator()(const Position& pos) const {
-
-  assert(verify_material(pos, strongSide, BishopValueMg, 1));
-  assert(verify_material(pos, weakSide,   BishopValueMg, 0));
-
-  Square strongPawn = pos.square<PAWN>(strongSide);
-  Square strongBishop = pos.square<BISHOP>(strongSide);
-  Square weakBishop = pos.square<BISHOP>(weakSide);
-  Square weakKing = pos.square<KING>(weakSide);
-
-  // Case 1: Defending king blocks the pawn, and cannot be driven away
-  if (   (forward_file_bb(strongSide, strongPawn) & weakKing)
-      && (   opposite_colors(weakKing, strongBishop)
-          || relative_rank(strongSide, weakKing) <= RANK_6))
-      return SCALE_FACTOR_DRAW;
-
-  // Case 2: Opposite colored bishops
-  if (opposite_colors(strongBishop, weakBishop))
-      return SCALE_FACTOR_DRAW;
-
-  return SCALE_FACTOR_NONE;
-}
-
-
-/// KBPP vs KB. It detects a few basic draws with opposite-colored bishops
-template<>
-ScaleFactor Endgame<KBPPKB>::operator()(const Position& pos) const {
-
-  assert(verify_material(pos, strongSide, BishopValueMg, 2));
-  assert(verify_material(pos, weakSide,   BishopValueMg, 0));
-
-  Square strongBishop = pos.square<BISHOP>(strongSide);
-  Square weakBishop   = pos.square<BISHOP>(weakSide);
-
-  if (!opposite_colors(strongBishop, weakBishop))
-      return SCALE_FACTOR_NONE;
-
-  Square weakKing = pos.square<KING>(weakSide);
-  Square strongPawn1 = lsb(pos.pieces(strongSide, PAWN));
-  Square strongPawn2 = msb(pos.pieces(strongSide, PAWN));
-  Square blockSq1, blockSq2;
-
-  if (relative_rank(strongSide, strongPawn1) > relative_rank(strongSide, strongPawn2))
-  {
-      blockSq1 = strongPawn1 + pawn_push(strongSide);
-      blockSq2 = make_square(file_of(strongPawn2), rank_of(strongPawn1));
-  }
-  else
-  {
-      blockSq1 = strongPawn2 + pawn_push(strongSide);
-      blockSq2 = make_square(file_of(strongPawn1), rank_of(strongPawn2));
-  }
-
-  switch (distance<File>(strongPawn1, strongPawn2))
-  {
-  case 0:
-    // Both pawns are on the same file. It's an easy draw if the defender firmly
-    // controls some square in the frontmost pawn's path.
-    if (   file_of(weakKing) == file_of(blockSq1)
-        && relative_rank(strongSide, weakKing) >= relative_rank(strongSide, blockSq1)
-        && opposite_colors(weakKing, strongBishop))
-        return SCALE_FACTOR_DRAW;
-    else
-        return SCALE_FACTOR_NONE;
-
-  case 1:
-    // Pawns on adjacent files. It's a draw if the defender firmly controls the
-    // square in front of the frontmost pawn's path, and the square diagonally
-    // behind this square on the file of the other pawn.
-    if (   weakKing == blockSq1
-        && opposite_colors(weakKing, strongBishop)
-        && (   weakBishop == blockSq2
-            || (attacks_bb<BISHOP>(blockSq2, pos.pieces()) & pos.pieces(weakSide, BISHOP))
-            || distance<Rank>(strongPawn1, strongPawn2) >= 2))
-        return SCALE_FACTOR_DRAW;
-
-    else if (   weakKing == blockSq2
-             && opposite_colors(weakKing, strongBishop)
-             && (   weakBishop == blockSq1
-                 || (attacks_bb<BISHOP>(blockSq1, pos.pieces()) & pos.pieces(weakSide, BISHOP))))
-        return SCALE_FACTOR_DRAW;
-    else
-        return SCALE_FACTOR_NONE;
-
-  default:
-    // The pawns are not on the same file or adjacent files. No scaling.
-    return SCALE_FACTOR_NONE;
-  }
-}
-
-
-/// KBP vs KN. There is a single rule: if the defending king is somewhere along
-/// the path of the pawn, and the square of the king is not of the same color as
-/// the stronger side's bishop, it's a draw.
-template<>
-ScaleFactor Endgame<KBPKN>::operator()(const Position& pos) const {
-
-  assert(verify_material(pos, strongSide, BishopValueMg, 1));
-  assert(verify_material(pos, weakSide, KnightValueMg, 0));
-
-  Square strongPawn = pos.square<PAWN>(strongSide);
-  Square strongBishop = pos.square<BISHOP>(strongSide);
-  Square weakKing = pos.square<KING>(weakSide);
-
-  if (   file_of(weakKing) == file_of(strongPawn)
-      && relative_rank(strongSide, strongPawn) < relative_rank(strongSide, weakKing)
-      && (   opposite_colors(weakKing, strongBishop)
-          || relative_rank(strongSide, weakKing) <= RANK_6))
-      return SCALE_FACTOR_DRAW;
-
-  return SCALE_FACTOR_NONE;
-}
-
-
-/// KP vs KP. This is done by removing the weakest side's pawn and probing the
-/// KP vs K bitbase: if the weakest side has a draw without the pawn, it probably
-/// has at least a draw with the pawn as well. The exception is when the stronger
-/// side's pawn is far advanced and not on a rook file; in this case it is often
-/// possible to win (e.g. 8/4k3/3p4/3P4/6K1/8/8/8 w - - 0 1).
-template<>
-ScaleFactor Endgame<KPKP>::operator()(const Position& pos) const {
-
-  assert(verify_material(pos, strongSide, VALUE_ZERO, 1));
-  assert(verify_material(pos, weakSide,   VALUE_ZERO, 1));
-
-  // Assume strongSide is white and the pawn is on files A-D
-  Square strongKing = normalize(pos, strongSide, pos.square<KING>(strongSide));
-  Square weakKing   = normalize(pos, strongSide, pos.square<KING>(weakSide));
-  Square strongPawn = normalize(pos, strongSide, pos.square<PAWN>(strongSide));
-
-  Color us = strongSide == pos.side_to_move() ? WHITE : BLACK;
-
-  // If the pawn has advanced to the fifth rank or further, and is not a
-  // rook pawn, it's too dangerous to assume that it's at least a draw.
-  if (rank_of(strongPawn) >= RANK_5 && file_of(strongPawn) != FILE_A)
-      return SCALE_FACTOR_NONE;
-
-  // Probe the KPK bitbase with the weakest side's pawn removed. If it's a draw,
-  // it's probably at least a draw even with the pawn.
-  return Bitbases::probe(strongKing, strongPawn, weakKing, us) ? SCALE_FACTOR_NONE : SCALE_FACTOR_DRAW;
-}

src/endgame.h

@@ -1,123 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
-
-  Stockfish is free software: you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation, either version 3 of the License, or
-  (at your option) any later version.
-
-  Stockfish is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-#ifndef ENDGAME_H_INCLUDED
-#define ENDGAME_H_INCLUDED
-
-#include <memory>
-#include <string>
-#include <type_traits>
-#include <unordered_map>
-#include <utility>
-
-#include "position.h"
-#include "types.h"
-
-
-/// EndgameCode lists all supported endgame functions by corresponding codes
-
-enum EndgameCode {
-
-  EVALUATION_FUNCTIONS,
-  KNNK,  // KNN vs K
-  KNNKP, // KNN vs KP
-  KXK,   // Generic "mate lone king" eval
-  KBNK,  // KBN vs K
-  KPK,   // KP vs K
-  KRKP,  // KR vs KP
-  KRKB,  // KR vs KB
-  KRKN,  // KR vs KN
-  KQKP,  // KQ vs KP
-  KQKR,  // KQ vs KR
-
-  SCALING_FUNCTIONS,
-  KBPsK,   // KB and pawns vs K
-  KQKRPs,  // KQ vs KR and pawns
-  KRPKR,   // KRP vs KR
-  KRPKB,   // KRP vs KB
-  KRPPKRP, // KRPP vs KRP
-  KPsK,    // K and pawns vs K
-  KBPKB,   // KBP vs KB
-  KBPPKB,  // KBPP vs KB
-  KBPKN,   // KBP vs KN
-  KPKP     // KP vs KP
-};
-
-
-/// Endgame functions can be of two types depending on whether they return a
-/// Value or a ScaleFactor.
-
-template<EndgameCode E> using
-eg_type = typename std::conditional<(E < SCALING_FUNCTIONS), Value, ScaleFactor>::type;
-
-
-/// Base and derived functors for endgame evaluation and scaling functions
-
-template<typename T>
-struct EndgameBase {
-
-  explicit EndgameBase(Color c) : strongSide(c), weakSide(~c) {}
-  virtual ~EndgameBase() = default;
-  virtual T operator()(const Position&) const = 0;
-
-  const Color strongSide, weakSide;
-};
-
-
-template<EndgameCode E, typename T = eg_type<E>>
-struct Endgame : public EndgameBase<T> {
-
-  explicit Endgame(Color c) : EndgameBase<T>(c) {}
-  T operator()(const Position&) const override;
-};
-
-
-/// The Endgames namespace handles the pointers to endgame evaluation and scaling
-/// base objects in two std::map. We use polymorphism to invoke the actual
-/// endgame function by calling its virtual operator().
-
-namespace Endgames {
-
-  template<typename T> using Ptr = std::unique_ptr<EndgameBase<T>>;
-  template<typename T> using Map = std::unordered_map<Key, Ptr<T>>;
-
-  extern std::pair<Map<Value>, Map<ScaleFactor>> maps;
-
-  void init();
-
-  template<typename T>
-  Map<T>& map() {
-    return std::get<std::is_same<T, ScaleFactor>::value>(maps);
-  }
-
-  template<EndgameCode E, typename T = eg_type<E>>
-  void add(const std::string& code) {
-
-    StateInfo st;
-    map<T>()[Position().set(code, WHITE, &st).material_key()] = Ptr<T>(new Endgame<E>(WHITE));
-    map<T>()[Position().set(code, BLACK, &st).material_key()] = Ptr<T>(new Endgame<E>(BLACK));
-  }
-
-  template<typename T>
-  const EndgameBase<T>* probe(Key key) {
-    auto it = map<T>().find(key);
-    return it != map<T>().end() ? it->second.get() : nullptr;
-  }
-}
-
-#endif // #ifndef ENDGAME_H_INCLUDED

src/evaluate.h

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -23,30 +23,33 @@
 
 #include "types.h"
 
+namespace Stockfish {
+
 class Position;
 
 namespace Eval {
 
-  std::string trace(const Position& pos);
-  Value evaluate(const Position& pos);
+constexpr inline int SmallNetThreshold = 1165, PsqtOnlyThreshold = 2500;
 
-  extern bool useNNUE;
-  extern std::string eval_file_loaded;
+// The default net name MUST follow the format nn-[SHA256 first 12 digits].nnue
+// for the build process (profile-build and fishtest) to work. Do not change the
+// name of the macro or the location where this macro is defined, as it is used
+// in the Makefile/Fishtest.
+#define EvalFileDefaultNameBig "nn-ae6a388e4a1a.nnue"
+#define EvalFileDefaultNameSmall "nn-baff1ede1f90.nnue"
 
-  // The default net name MUST follow the format nn-[SHA256 first 12 digits].nnue
-  // for the build process (profile-build and fishtest) to work. Do not change the
-  // name of the macro, as it is used in the Makefile.
-  #define EvalFileDefaultName   "nn-62ef826d1a6d.nnue"
+namespace NNUE {
+struct Networks;
+}
 
-  namespace NNUE {
+std::string trace(Position& pos, const Eval::NNUE::Networks& networks);
 
-    Value evaluate(const Position& pos);
-    bool load_eval(std::string name, std::istream& stream);
-    void init();
-    void verify();
+int   simple_eval(const Position& pos, Color c);
+Value evaluate(const NNUE::Networks& networks, const Position& pos, int optimism);
 
-  } // namespace NNUE
 
-} // namespace Eval
+}  // namespace Eval
 
-#endif // #ifndef EVALUATE_H_INCLUDED
+}  // namespace Stockfish
+
+#endif  // #ifndef EVALUATE_H_INCLUDED

src/incbin/incbin.h

@@ -3,8 +3,8 @@
  * @author Dale Weiler
  * @brief Utility for including binary files
  *
- * Facilities for including binary files into the current translation unit and
- * making use from them externally in other translation units.
+ * Facilities for including binary files into the current translation unit
+ * and making use of them externally in other translation units.
  */
 #ifndef INCBIN_HDR
 #define INCBIN_HDR
@@ -139,7 +139,7 @@
 #endif
 
 #if defined(__APPLE__)
-/* The directives are different for Apple branded compilers */
+/* The directives are different for Apple-branded compilers */
 #  define INCBIN_SECTION         INCBIN_OUTPUT_SECTION "\n"
 #  define INCBIN_GLOBAL(NAME)    ".globl " INCBIN_MANGLE INCBIN_STRINGIZE(INCBIN_PREFIX) #NAME "\n"
 #  define INCBIN_INT             ".long "
@@ -261,8 +261,8 @@
     INCBIN_STRINGIZE( \
         INCBIN_STYLE_IDENT(TYPE)) \
 
-/* Generate the global labels by indirectly invoking the macro with our style
- * type and concatenating the name against them. */
+/* Generate the global labels by indirectly invoking the macro
+ * with our style type and concatenate the name against them. */
 #define INCBIN_GLOBAL_LABELS(NAME, TYPE) \
     INCBIN_INVOKE( \
         INCBIN_GLOBAL, \

src/main.cpp

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -19,33 +19,30 @@
 #include <iostream>
 
 #include "bitboard.h"
-#include "endgame.h"
+#include "misc.h"
 #include "position.h"
-#include "psqt.h"
-#include "search.h"
-#include "syzygy/tbprobe.h"
-#include "thread.h"
-#include "tt.h"
+#include "tune.h"
+#include "types.h"
 #include "uci.h"
 
+using namespace Stockfish;
+
 int main(int argc, char* argv[]) {
 
-  std::cout << engine_info() << std::endl;
+    Cluster::init();
+    if (Cluster::is_root())
+        std::cout << engine_info() << std::endl;
 
-  CommandLine::init(argc, argv);
-  UCI::init(Options);
-  Tune::init();
-  PSQT::init();
-  Bitboards::init();
-  Position::init();
-  Bitbases::init();
-  Endgames::init();
-  Threads.set(size_t(Options["Threads"]));
-  Search::clear(); // After threads are up
-  Eval::NNUE::init();
+    Bitboards::init();
+    Position::init();
 
-  UCI::loop(argc, argv);
+    UCI uci(argc, argv);
 
-  Threads.set(0);
-  return 0;
+    Tune::init(uci.options);
+
+    uci.loop();
+
+    Cluster::finalize();
+
+    return 0;
 }

src/material.cpp

@@ -1,225 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
-
-  Stockfish is free software: you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation, either version 3 of the License, or
-  (at your option) any later version.
-
-  Stockfish is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-#include <cassert>
-#include <cstring>   // For std::memset
-
-#include "material.h"
-#include "thread.h"
-
-using namespace std;
-
-namespace {
-  #define S(mg, eg) make_score(mg, eg)
-
-  // Polynomial material imbalance parameters
-
-  // One Score parameter for each pair (our piece, another of our pieces)
-  constexpr Score QuadraticOurs[][PIECE_TYPE_NB] = {
-    // OUR PIECE 2
-    // bishop pair    pawn         knight       bishop       rook           queen
-    {S(1419, 1455)                                                                  }, // Bishop pair
-    {S( 101,   28), S( 37,  39)                                                     }, // Pawn
-    {S(  57,   64), S(249, 187), S(-49, -62)                                        }, // Knight      OUR PIECE 1
-    {S(   0,    0), S(118, 137), S( 10,  27), S(  0,   0)                           }, // Bishop
-    {S( -63,  -68), S( -5,   3), S(100,  81), S(132, 118), S(-246, -244)            }, // Rook
-    {S(-210, -211), S( 37,  14), S(147, 141), S(161, 105), S(-158, -174), S(-9,-31) }  // Queen
-  };
-
-  // One Score parameter for each pair (our piece, their piece)
-  constexpr Score QuadraticTheirs[][PIECE_TYPE_NB] = {
-    // THEIR PIECE
-    // bishop pair   pawn         knight       bishop       rook         queen
-    {                                                                               }, // Bishop pair
-    {S(  33,  30)                                                                   }, // Pawn
-    {S(  46,  18), S(106,  84)                                                      }, // Knight      OUR PIECE
-    {S(  75,  35), S( 59,  44), S( 60,  15)                                         }, // Bishop
-    {S(  26,  35), S(  6,  22), S( 38,  39), S(-12,  -2)                            }, // Rook
-    {S(  97,  93), S(100, 163), S(-58, -91), S(112, 192), S(276, 225)               }  // Queen
-  };
-
-  #undef S
-
-  // Endgame evaluation and scaling functions are accessed directly and not through
-  // the function maps because they correspond to more than one material hash key.
-  Endgame<KXK>    EvaluateKXK[] = { Endgame<KXK>(WHITE),    Endgame<KXK>(BLACK) };
-
-  Endgame<KBPsK>  ScaleKBPsK[]  = { Endgame<KBPsK>(WHITE),  Endgame<KBPsK>(BLACK) };
-  Endgame<KQKRPs> ScaleKQKRPs[] = { Endgame<KQKRPs>(WHITE), Endgame<KQKRPs>(BLACK) };
-  Endgame<KPsK>   ScaleKPsK[]   = { Endgame<KPsK>(WHITE),   Endgame<KPsK>(BLACK) };
-  Endgame<KPKP>   ScaleKPKP[]   = { Endgame<KPKP>(WHITE),   Endgame<KPKP>(BLACK) };
-
-  // Helper used to detect a given material distribution
-  bool is_KXK(const Position& pos, Color us) {
-    return  !more_than_one(pos.pieces(~us))
-          && pos.non_pawn_material(us) >= RookValueMg;
-  }
-
-  bool is_KBPsK(const Position& pos, Color us) {
-    return   pos.non_pawn_material(us) == BishopValueMg
-          && pos.count<PAWN  >(us) >= 1;
-  }
-
-  bool is_KQKRPs(const Position& pos, Color us) {
-    return  !pos.count<PAWN>(us)
-          && pos.non_pawn_material(us) == QueenValueMg
-          && pos.count<ROOK>(~us) == 1
-          && pos.count<PAWN>(~us) >= 1;
-  }
-
-
-  /// imbalance() calculates the imbalance by comparing the piece count of each
-  /// piece type for both colors.
-
-  template<Color Us>
-  Score imbalance(const int pieceCount[][PIECE_TYPE_NB]) {
-
-    constexpr Color Them = ~Us;
-
-    Score bonus = SCORE_ZERO;
-
-    // Second-degree polynomial material imbalance, by Tord Romstad
-    for (int pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; ++pt1)
-    {
-        if (!pieceCount[Us][pt1])
-            continue;
-
-        int v = QuadraticOurs[pt1][pt1] * pieceCount[Us][pt1];
-
-        for (int pt2 = NO_PIECE_TYPE; pt2 < pt1; ++pt2)
-            v +=  QuadraticOurs[pt1][pt2] * pieceCount[Us][pt2]
-                + QuadraticTheirs[pt1][pt2] * pieceCount[Them][pt2];
-
-        bonus += pieceCount[Us][pt1] * v;
-    }
-
-    return bonus;
-  }
-
-} // namespace
-
-namespace Material {
-
-
-/// Material::probe() looks up the current position's material configuration in
-/// the material hash table. It returns a pointer to the Entry if the position
-/// is found. Otherwise a new Entry is computed and stored there, so we don't
-/// have to recompute all when the same material configuration occurs again.
-
-Entry* probe(const Position& pos) {
-
-  Key key = pos.material_key();
-  Entry* e = pos.this_thread()->materialTable[key];
-
-  if (e->key == key)
-      return e;
-
-  std::memset(e, 0, sizeof(Entry));
-  e->key = key;
-  e->factor[WHITE] = e->factor[BLACK] = (uint8_t)SCALE_FACTOR_NORMAL;
-
-  Value npm_w = pos.non_pawn_material(WHITE);
-  Value npm_b = pos.non_pawn_material(BLACK);
-  Value npm   = std::clamp(npm_w + npm_b, EndgameLimit, MidgameLimit);
-
-  // Map total non-pawn material into [PHASE_ENDGAME, PHASE_MIDGAME]
-  e->gamePhase = Phase(((npm - EndgameLimit) * PHASE_MIDGAME) / (MidgameLimit - EndgameLimit));
-
-  // Let's look if we have a specialized evaluation function for this particular
-  // material configuration. Firstly we look for a fixed configuration one, then
-  // for a generic one if the previous search failed.
-  if ((e->evaluationFunction = Endgames::probe<Value>(key)) != nullptr)
-      return e;
-
-  for (Color c : { WHITE, BLACK })
-      if (is_KXK(pos, c))
-      {
-          e->evaluationFunction = &EvaluateKXK[c];
-          return e;
-      }
-
-  // OK, we didn't find any special evaluation function for the current material
-  // configuration. Is there a suitable specialized scaling function?
-  const auto* sf = Endgames::probe<ScaleFactor>(key);
-
-  if (sf)
-  {
-      e->scalingFunction[sf->strongSide] = sf; // Only strong color assigned
-      return e;
-  }
-
-  // We didn't find any specialized scaling function, so fall back on generic
-  // ones that refer to more than one material distribution. Note that in this
-  // case we don't return after setting the function.
-  for (Color c : { WHITE, BLACK })
-  {
-    if (is_KBPsK(pos, c))
-        e->scalingFunction[c] = &ScaleKBPsK[c];
-
-    else if (is_KQKRPs(pos, c))
-        e->scalingFunction[c] = &ScaleKQKRPs[c];
-  }
-
-  if (npm_w + npm_b == VALUE_ZERO && pos.pieces(PAWN)) // Only pawns on the board
-  {
-      if (!pos.count<PAWN>(BLACK))
-      {
-          assert(pos.count<PAWN>(WHITE) >= 2);
-
-          e->scalingFunction[WHITE] = &ScaleKPsK[WHITE];
-      }
-      else if (!pos.count<PAWN>(WHITE))
-      {
-          assert(pos.count<PAWN>(BLACK) >= 2);
-
-          e->scalingFunction[BLACK] = &ScaleKPsK[BLACK];
-      }
-      else if (pos.count<PAWN>(WHITE) == 1 && pos.count<PAWN>(BLACK) == 1)
-      {
-          // This is a special case because we set scaling functions
-          // for both colors instead of only one.
-          e->scalingFunction[WHITE] = &ScaleKPKP[WHITE];
-          e->scalingFunction[BLACK] = &ScaleKPKP[BLACK];
-      }
-  }
-
-  // Zero or just one pawn makes it difficult to win, even with a small material
-  // advantage. This catches some trivial draws like KK, KBK and KNK and gives a
-  // drawish scale factor for cases such as KRKBP and KmmKm (except for KBBKN).
-  if (!pos.count<PAWN>(WHITE) && npm_w - npm_b <= BishopValueMg)
-      e->factor[WHITE] = uint8_t(npm_w <  RookValueMg   ? SCALE_FACTOR_DRAW :
-                                 npm_b <= BishopValueMg ? 4 : 14);
-
-  if (!pos.count<PAWN>(BLACK) && npm_b - npm_w <= BishopValueMg)
-      e->factor[BLACK] = uint8_t(npm_b <  RookValueMg   ? SCALE_FACTOR_DRAW :
-                                 npm_w <= BishopValueMg ? 4 : 14);
-
-  // Evaluate the material imbalance. We use PIECE_TYPE_NONE as a place holder
-  // for the bishop pair "extended piece", which allows us to be more flexible
-  // in defining bishop pair bonuses.
-  const int pieceCount[COLOR_NB][PIECE_TYPE_NB] = {
-  { pos.count<BISHOP>(WHITE) > 1, pos.count<PAWN>(WHITE), pos.count<KNIGHT>(WHITE),
-    pos.count<BISHOP>(WHITE)    , pos.count<ROOK>(WHITE), pos.count<QUEEN >(WHITE) },
-  { pos.count<BISHOP>(BLACK) > 1, pos.count<PAWN>(BLACK), pos.count<KNIGHT>(BLACK),
-    pos.count<BISHOP>(BLACK)    , pos.count<ROOK>(BLACK), pos.count<QUEEN >(BLACK) } };
-
-  e->score = (imbalance<WHITE>(pieceCount) - imbalance<BLACK>(pieceCount)) / 16;
-  return e;
-}
-
-} // namespace Material

src/material.h

@@ -1,71 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
-
-  Stockfish is free software: you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation, either version 3 of the License, or
-  (at your option) any later version.
-
-  Stockfish is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-#ifndef MATERIAL_H_INCLUDED
-#define MATERIAL_H_INCLUDED
-
-#include "endgame.h"
-#include "misc.h"
-#include "position.h"
-#include "types.h"
-
-namespace Material {
-
-/// Material::Entry contains various information about a material configuration.
-/// It contains a material imbalance evaluation, a function pointer to a special
-/// endgame evaluation function (which in most cases is NULL, meaning that the
-/// standard evaluation function will be used), and scale factors.
-///
-/// The scale factors are used to scale the evaluation score up or down. For
-/// instance, in KRB vs KR endgames, the score is scaled down by a factor of 4,
-/// which will result in scores of absolute value less than one pawn.
-
-struct Entry {
-
-  Score imbalance() const { return score; }
-  Phase game_phase() const { return (Phase)gamePhase; }
-  bool specialized_eval_exists() const { return evaluationFunction != nullptr; }
-  Value evaluate(const Position& pos) const { return (*evaluationFunction)(pos); }
-
-  // scale_factor() takes a position and a color as input and returns a scale factor
-  // for the given color. We have to provide the position in addition to the color
-  // because the scale factor may also be a function which should be applied to
-  // the position. For instance, in KBP vs K endgames, the scaling function looks
-  // for rook pawns and wrong-colored bishops.
-  ScaleFactor scale_factor(const Position& pos, Color c) const {
-    ScaleFactor sf = scalingFunction[c] ? (*scalingFunction[c])(pos)
-                                        :  SCALE_FACTOR_NONE;
-    return sf != SCALE_FACTOR_NONE ? sf : ScaleFactor(factor[c]);
-  }
-
-  Key key;
-  const EndgameBase<Value>* evaluationFunction;
-  const EndgameBase<ScaleFactor>* scalingFunction[COLOR_NB]; // Could be one for each
-                                                             // side (e.g. KPKP, KBPsK)
-  Score score;
-  int16_t gamePhase;
-  uint8_t factor[COLOR_NB];
-};
-
-typedef HashTable<Entry, 8192> Table;
-
-Entry* probe(const Position& pos);
-
-} // namespace Material
-
-#endif // #ifndef MATERIAL_H_INCLUDED

src/misc.h

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -19,128 +19,215 @@
 #ifndef MISC_H_INCLUDED
 #define MISC_H_INCLUDED
 
+#include <algorithm>
 #include <cassert>
 #include <chrono>
-#include <ostream>
+#include <cstddef>
+#include <cstdint>
+#include <iosfwd>
+#include <memory>
 #include <string>
 #include <vector>
-#include <cstdint>
 
-#include "types.h"
+#define stringify2(x) #x
+#define stringify(x) stringify2(x)
 
-const std::string engine_info(bool to_uci = false);
-const std::string compiler_info();
+namespace Stockfish {
+
+std::string engine_info(bool to_uci = false);
+std::string compiler_info();
+
+// Preloads the given address in L1/L2 cache. This is a non-blocking
+// function that doesn't stall the CPU waiting for data to be loaded from memory,
+// which can be quite slow.
 void prefetch(void* addr);
-void start_logger(const std::string& fname);
+
+void  start_logger(const std::string& fname);
 void* std_aligned_alloc(size_t alignment, size_t size);
-void std_aligned_free(void* ptr);
-void* aligned_large_pages_alloc(size_t size); // memory aligned by page size, min alignment: 4096 bytes
-void aligned_large_pages_free(void* mem); // nop if mem == nullptr
+void  std_aligned_free(void* ptr);
+// memory aligned by page size, min alignment: 4096 bytes
+void* aligned_large_pages_alloc(size_t size);
+// nop if mem == nullptr
+void aligned_large_pages_free(void* mem);
 
-void dbg_hit_on(bool b);
-void dbg_hit_on(bool c, bool b);
-void dbg_mean_of(int v);
-void dbg_print();
-
-typedef std::chrono::milliseconds::rep TimePoint; // A value in milliseconds
-static_assert(sizeof(TimePoint) == sizeof(int64_t), "TimePoint should be 64 bits");
-inline TimePoint now() {
-  return std::chrono::duration_cast<std::chrono::milliseconds>
-        (std::chrono::steady_clock::now().time_since_epoch()).count();
-}
-
-template<class Entry, int Size>
-struct HashTable {
-  Entry* operator[](Key key) { return &table[(uint32_t)key & (Size - 1)]; }
-
-private:
-  std::vector<Entry> table = std::vector<Entry>(Size); // Allocate on the heap
+// Deleter for automating release of memory area
+template<typename T>
+struct AlignedDeleter {
+    void operator()(T* ptr) const {
+        ptr->~T();
+        std_aligned_free(ptr);
+    }
 };
 
+template<typename T>
+struct LargePageDeleter {
+    void operator()(T* ptr) const {
+        ptr->~T();
+        aligned_large_pages_free(ptr);
+    }
+};
 
-enum SyncCout { IO_LOCK, IO_UNLOCK };
+template<typename T>
+using AlignedPtr = std::unique_ptr<T, AlignedDeleter<T>>;
+
+template<typename T>
+using LargePagePtr = std::unique_ptr<T, LargePageDeleter<T>>;
+
+
+void dbg_hit_on(bool cond, int slot = 0);
+void dbg_mean_of(int64_t value, int slot = 0);
+void dbg_stdev_of(int64_t value, int slot = 0);
+void dbg_correl_of(int64_t value1, int64_t value2, int slot = 0);
+void dbg_print();
+
+using TimePoint = std::chrono::milliseconds::rep;  // A value in milliseconds
+static_assert(sizeof(TimePoint) == sizeof(int64_t), "TimePoint should be 64 bits");
+inline TimePoint now() {
+    return std::chrono::duration_cast<std::chrono::milliseconds>(
+             std::chrono::steady_clock::now().time_since_epoch())
+      .count();
+}
+
+
+enum SyncCout {
+    IO_LOCK,
+    IO_UNLOCK
+};
 std::ostream& operator<<(std::ostream&, SyncCout);
 
 #define sync_cout std::cout << IO_LOCK
 #define sync_endl std::endl << IO_UNLOCK
 
-// `ptr` must point to an array of size at least
-// `sizeof(T) * N + alignment` bytes, where `N` is the
-// number of elements in the array.
-template <uintptr_t Alignment, typename T>
-T* align_ptr_up(T* ptr)
-{
-  static_assert(alignof(T) < Alignment);
 
-  const uintptr_t ptrint = reinterpret_cast<uintptr_t>(reinterpret_cast<char*>(ptr));
-  return reinterpret_cast<T*>(reinterpret_cast<char*>((ptrint + (Alignment - 1)) / Alignment * Alignment));
+// Get the first aligned element of an array.
+// ptr must point to an array of size at least `sizeof(T) * N + alignment` bytes,
+// where N is the number of elements in the array.
+template<uintptr_t Alignment, typename T>
+T* align_ptr_up(T* ptr) {
+    static_assert(alignof(T) < Alignment);
+
+    const uintptr_t ptrint = reinterpret_cast<uintptr_t>(reinterpret_cast<char*>(ptr));
+    return reinterpret_cast<T*>(
+      reinterpret_cast<char*>((ptrint + (Alignment - 1)) / Alignment * Alignment));
 }
 
-/// xorshift64star Pseudo-Random Number Generator
-/// This class is based on original code written and dedicated
-/// to the public domain by Sebastiano Vigna (2014).
-/// It has the following characteristics:
-///
-///  -  Outputs 64-bit numbers
-///  -  Passes Dieharder and SmallCrush test batteries
-///  -  Does not require warm-up, no zeroland to escape
-///  -  Internal state is a single 64-bit integer
-///  -  Period is 2^64 - 1
-///  -  Speed: 1.60 ns/call (Core i7 @3.40GHz)
-///
-/// For further analysis see
-///   <http://vigna.di.unimi.it/ftp/papers/xorshift.pdf>
+
+// True if and only if the binary is compiled on a little-endian machine
+static inline const union {
+    uint32_t i;
+    char     c[4];
+} Le                                    = {0x01020304};
+static inline const bool IsLittleEndian = (Le.c[0] == 4);
+
+
+template<typename T, std::size_t MaxSize>
+class ValueList {
+
+   public:
+    std::size_t size() const { return size_; }
+    void        push_back(const T& value) { values_[size_++] = value; }
+    const T*    begin() const { return values_; }
+    const T*    end() const { return values_ + size_; }
+    const T&    operator[](int index) const { return values_[index]; }
+
+   private:
+    T           values_[MaxSize];
+    std::size_t size_ = 0;
+};
+
+
+// xorshift64star Pseudo-Random Number Generator
+// This class is based on original code written and dedicated
+// to the public domain by Sebastiano Vigna (2014).
+// It has the following characteristics:
+//
+//  -  Outputs 64-bit numbers
+//  -  Passes Dieharder and SmallCrush test batteries
+//  -  Does not require warm-up, no zeroland to escape
+//  -  Internal state is a single 64-bit integer
+//  -  Period is 2^64 - 1
+//  -  Speed: 1.60 ns/call (Core i7 @3.40GHz)
+//
+// For further analysis see
+//   <http://vigna.di.unimi.it/ftp/papers/xorshift.pdf>
 
 class PRNG {
 
-  uint64_t s;
+    uint64_t s;
 
-  uint64_t rand64() {
+    uint64_t rand64() {
 
-    s ^= s >> 12, s ^= s << 25, s ^= s >> 27;
-    return s * 2685821657736338717LL;
-  }
+        s ^= s >> 12, s ^= s << 25, s ^= s >> 27;
+        return s * 2685821657736338717LL;
+    }
 
-public:
-  PRNG(uint64_t seed) : s(seed) { assert(seed); }
+   public:
+    PRNG(uint64_t seed) :
+        s(seed) {
+        assert(seed);
+    }
 
-  template<typename T> T rand() { return T(rand64()); }
+    template<typename T>
+    T rand() {
+        return T(rand64());
+    }
 
-  /// Special generator used to fast init magic numbers.
-  /// Output values only have 1/8th of their bits set on average.
-  template<typename T> T sparse_rand()
-  { return T(rand64() & rand64() & rand64()); }
+    // Special generator used to fast init magic numbers.
+    // Output values only have 1/8th of their bits set on average.
+    template<typename T>
+    T sparse_rand() {
+        return T(rand64() & rand64() & rand64());
+    }
 };
 
 inline uint64_t mul_hi64(uint64_t a, uint64_t b) {
 #if defined(__GNUC__) && defined(IS_64BIT)
-    __extension__ typedef unsigned __int128 uint128;
-    return ((uint128)a * (uint128)b) >> 64;
+    __extension__ using uint128 = unsigned __int128;
+    return (uint128(a) * uint128(b)) >> 64;
 #else
-    uint64_t aL = (uint32_t)a, aH = a >> 32;
-    uint64_t bL = (uint32_t)b, bH = b >> 32;
+    uint64_t aL = uint32_t(a), aH = a >> 32;
+    uint64_t bL = uint32_t(b), bH = b >> 32;
     uint64_t c1 = (aL * bL) >> 32;
     uint64_t c2 = aH * bL + c1;
-    uint64_t c3 = aL * bH + (uint32_t)c2;
+    uint64_t c3 = aL * bH + uint32_t(c2);
     return aH * bH + (c2 >> 32) + (c3 >> 32);
 #endif
 }
 
-/// Under Windows it is not possible for a process to run on more than one
-/// logical processor group. This usually means to be limited to use max 64
-/// cores. To overcome this, some special platform specific API should be
-/// called to set group affinity for each thread. Original code from Texel by
-/// Peter Österlund.
-
+// Under Windows it is not possible for a process to run on more than one
+// logical processor group. This usually means being limited to using max 64
+// cores. To overcome this, some special platform-specific API should be
+// called to set group affinity for each thread. Original code from Texel by
+// Peter Österlund.
 namespace WinProcGroup {
-  void bindThisThread(size_t idx);
+void bind_this_thread(size_t idx);
 }
 
-namespace CommandLine {
-  void init(int argc, char* argv[]);
 
-  extern std::string binaryDirectory;  // path of the executable directory
-  extern std::string workingDirectory; // path of the working directory
+struct CommandLine {
+   public:
+    CommandLine(int, char**);
+
+    int    argc;
+    char** argv;
+
+    std::string binaryDirectory;   // path of the executable directory
+    std::string workingDirectory;  // path of the working directory
+};
+
+namespace Utility {
+
+template<typename T, typename Predicate>
+void move_to_front(std::vector<T>& vec, Predicate pred) {
+    auto it = std::find_if(vec.begin(), vec.end(), pred);
+
+    if (it != vec.end())
+    {
+        std::rotate(vec.begin(), it, it + 1);
+    }
+}
 }
 
-#endif // #ifndef MISC_H_INCLUDED
+}  // namespace Stockfish
+
+#endif  // #ifndef MISC_H_INCLUDED

src/movegen.cpp

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -16,147 +16,132 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <cassert>
-
 #include "movegen.h"
+
+#include <cassert>
+#include <initializer_list>
+
+#include "bitboard.h"
 #include "position.h"
 
+namespace Stockfish {
+
 namespace {
 
-  template<GenType Type, Direction D>
-  ExtMove* make_promotions(ExtMove* moveList, Square to, Square ksq) {
+template<GenType Type, Direction D, bool Enemy>
+ExtMove* make_promotions(ExtMove* moveList, [[maybe_unused]] Square to) {
 
-    if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS)
-    {
-        *moveList++ = make<PROMOTION>(to - D, to, QUEEN);
-        if (attacks_bb<KNIGHT>(to) & ksq)
-            *moveList++ = make<PROMOTION>(to - D, to, KNIGHT);
-    }
+    constexpr bool all = Type == EVASIONS || Type == NON_EVASIONS;
 
-    if (Type == QUIETS || Type == EVASIONS || Type == NON_EVASIONS)
+    if constexpr (Type == CAPTURES || all)
+        *moveList++ = Move::make<PROMOTION>(to - D, to, QUEEN);
+
+    if constexpr ((Type == CAPTURES && Enemy) || (Type == QUIETS && !Enemy) || all)
     {
-        *moveList++ = make<PROMOTION>(to - D, to, ROOK);
-        *moveList++ = make<PROMOTION>(to - D, to, BISHOP);
-        if (!(attacks_bb<KNIGHT>(to) & ksq))
-            *moveList++ = make<PROMOTION>(to - D, to, KNIGHT);
+        *moveList++ = Move::make<PROMOTION>(to - D, to, ROOK);
+        *moveList++ = Move::make<PROMOTION>(to - D, to, BISHOP);
+        *moveList++ = Move::make<PROMOTION>(to - D, to, KNIGHT);
     }
 
     return moveList;
-  }
+}
 
 
-  template<Color Us, GenType Type>
-  ExtMove* generate_pawn_moves(const Position& pos, ExtMove* moveList, Bitboard target) {
+template<Color Us, GenType Type>
+ExtMove* generate_pawn_moves(const Position& pos, ExtMove* moveList, Bitboard target) {
 
     constexpr Color     Them     = ~Us;
-    constexpr Bitboard  TRank7BB = (Us == WHITE ? Rank7BB    : Rank2BB);
-    constexpr Bitboard  TRank3BB = (Us == WHITE ? Rank3BB    : Rank6BB);
+    constexpr Bitboard  TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB);
+    constexpr Bitboard  TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
     constexpr Direction Up       = pawn_push(Us);
     constexpr Direction UpRight  = (Us == WHITE ? NORTH_EAST : SOUTH_WEST);
     constexpr Direction UpLeft   = (Us == WHITE ? NORTH_WEST : SOUTH_EAST);
 
-    const Square ksq = pos.square<KING>(Them);
-    Bitboard emptySquares;
+    const Bitboard emptySquares = ~pos.pieces();
+    const Bitboard enemies      = Type == EVASIONS ? pos.checkers() : pos.pieces(Them);
 
-    Bitboard pawnsOn7    = pos.pieces(Us, PAWN) &  TRank7BB;
+    Bitboard pawnsOn7    = pos.pieces(Us, PAWN) & TRank7BB;
     Bitboard pawnsNotOn7 = pos.pieces(Us, PAWN) & ~TRank7BB;
 
-    Bitboard enemies = (Type == EVASIONS ? pos.pieces(Them) & target:
-                        Type == CAPTURES ? target : pos.pieces(Them));
-
     // Single and double pawn pushes, no promotions
-    if (Type != CAPTURES)
+    if constexpr (Type != CAPTURES)
     {
-        emptySquares = (Type == QUIETS || Type == QUIET_CHECKS ? target : ~pos.pieces());
-
-        Bitboard b1 = shift<Up>(pawnsNotOn7)   & emptySquares;
+        Bitboard b1 = shift<Up>(pawnsNotOn7) & emptySquares;
         Bitboard b2 = shift<Up>(b1 & TRank3BB) & emptySquares;
 
-        if (Type == EVASIONS) // Consider only blocking squares
+        if constexpr (Type == EVASIONS)  // Consider only blocking squares
         {
             b1 &= target;
             b2 &= target;
         }
 
-        if (Type == QUIET_CHECKS)
+        if constexpr (Type == QUIET_CHECKS)
         {
-            b1 &= pawn_attacks_bb(Them, ksq);
-            b2 &= pawn_attacks_bb(Them, ksq);
-
-            // Add pawn pushes which give discovered check. This is possible only
-            // if the pawn is not on the same file as the enemy king, because we
-            // don't generate captures. Note that a possible discovered check
-            // promotion has been already generated amongst the captures.
-            Bitboard dcCandidateQuiets = pos.blockers_for_king(Them) & pawnsNotOn7;
-            if (dcCandidateQuiets)
-            {
-                Bitboard dc1 = shift<Up>(dcCandidateQuiets) & emptySquares & ~file_bb(ksq);
-                Bitboard dc2 = shift<Up>(dc1 & TRank3BB) & emptySquares;
-
-                b1 |= dc1;
-                b2 |= dc2;
-            }
+            // To make a quiet check, you either make a direct check by pushing a pawn
+            // or push a blocker pawn that is not on the same file as the enemy king.
+            // Discovered check promotion has been already generated amongst the captures.
+            Square   ksq              = pos.square<KING>(Them);
+            Bitboard dcCandidatePawns = pos.blockers_for_king(Them) & ~file_bb(ksq);
+            b1 &= pawn_attacks_bb(Them, ksq) | shift<Up>(dcCandidatePawns);
+            b2 &= pawn_attacks_bb(Them, ksq) | shift<Up + Up>(dcCandidatePawns);
         }
 
         while (b1)
         {
-            Square to = pop_lsb(&b1);
-            *moveList++ = make_move(to - Up, to);
+            Square to   = pop_lsb(b1);
+            *moveList++ = Move(to - Up, to);
         }
 
         while (b2)
         {
-            Square to = pop_lsb(&b2);
-            *moveList++ = make_move(to - Up - Up, to);
+            Square to   = pop_lsb(b2);
+            *moveList++ = Move(to - Up - Up, to);
         }
     }
 
     // Promotions and underpromotions
     if (pawnsOn7)
     {
-        if (Type == CAPTURES)
-            emptySquares = ~pos.pieces();
-
-        if (Type == EVASIONS)
-            emptySquares &= target;
-
         Bitboard b1 = shift<UpRight>(pawnsOn7) & enemies;
-        Bitboard b2 = shift<UpLeft >(pawnsOn7) & enemies;
-        Bitboard b3 = shift<Up     >(pawnsOn7) & emptySquares;
+        Bitboard b2 = shift<UpLeft>(pawnsOn7) & enemies;
+        Bitboard b3 = shift<Up>(pawnsOn7) & emptySquares;
+
+        if constexpr (Type == EVASIONS)
+            b3 &= target;
 
         while (b1)
-            moveList = make_promotions<Type, UpRight>(moveList, pop_lsb(&b1), ksq);
+            moveList = make_promotions<Type, UpRight, true>(moveList, pop_lsb(b1));
 
         while (b2)
-            moveList = make_promotions<Type, UpLeft >(moveList, pop_lsb(&b2), ksq);
+            moveList = make_promotions<Type, UpLeft, true>(moveList, pop_lsb(b2));
 
         while (b3)
-            moveList = make_promotions<Type, Up     >(moveList, pop_lsb(&b3), ksq);
+            moveList = make_promotions<Type, Up, false>(moveList, pop_lsb(b3));
     }
 
     // Standard and en passant captures
-    if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS)
+    if constexpr (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS)
     {
         Bitboard b1 = shift<UpRight>(pawnsNotOn7) & enemies;
-        Bitboard b2 = shift<UpLeft >(pawnsNotOn7) & enemies;
+        Bitboard b2 = shift<UpLeft>(pawnsNotOn7) & enemies;
 
         while (b1)
         {
-            Square to = pop_lsb(&b1);
-            *moveList++ = make_move(to - UpRight, to);
+            Square to   = pop_lsb(b1);
+            *moveList++ = Move(to - UpRight, to);
         }
 
         while (b2)
         {
-            Square to = pop_lsb(&b2);
-            *moveList++ = make_move(to - UpLeft, to);
+            Square to   = pop_lsb(b2);
+            *moveList++ = Move(to - UpLeft, to);
         }
 
         if (pos.ep_square() != SQ_NONE)
         {
             assert(rank_of(pos.ep_square()) == relative_rank(Us, RANK_6));
 
-            // An en passant capture cannot resolve a discovered check.
+            // An en passant capture cannot resolve a discovered check
             if (Type == EVASIONS && (target & (pos.ep_square() + Up)))
                 return moveList;
 
@@ -165,200 +150,131 @@ namespace {
             assert(b1);
 
             while (b1)
-                *moveList++ = make<EN_PASSANT>(pop_lsb(&b1), pos.ep_square());
+                *moveList++ = Move::make<EN_PASSANT>(pop_lsb(b1), pos.ep_square());
         }
     }
 
     return moveList;
-  }
+}
 
 
-  template<PieceType Pt, bool Checks>
-  ExtMove* generate_moves(const Position& pos, ExtMove* moveList, Bitboard piecesToMove, Bitboard target) {
+template<Color Us, PieceType Pt, bool Checks>
+ExtMove* generate_moves(const Position& pos, ExtMove* moveList, Bitboard target) {
 
     static_assert(Pt != KING && Pt != PAWN, "Unsupported piece type in generate_moves()");
 
-    Bitboard bb = piecesToMove & pos.pieces(Pt);
+    Bitboard bb = pos.pieces(Us, Pt);
 
-    if (!bb)
-        return moveList;
+    while (bb)
+    {
+        Square   from = pop_lsb(bb);
+        Bitboard b    = attacks_bb<Pt>(from, pos.pieces()) & target;
 
-    [[maybe_unused]] const Bitboard checkSquares = pos.check_squares(Pt);
-
-    while (bb) {
-        Square from = pop_lsb(&bb);
-
-        Bitboard b = attacks_bb<Pt>(from, pos.pieces()) & target;
-        if constexpr (Checks)
-            b &= checkSquares;
+        // To check, you either move freely a blocker or make a direct check.
+        if (Checks && (Pt == QUEEN || !(pos.blockers_for_king(~Us) & from)))
+            b &= pos.check_squares(Pt);
 
         while (b)
-            *moveList++ = make_move(from, pop_lsb(&b));
+            *moveList++ = Move(from, pop_lsb(b));
     }
 
     return moveList;
-  }
+}
 
 
-  template<Color Us, GenType Type>
-  ExtMove* generate_all(const Position& pos, ExtMove* moveList) {
+template<Color Us, GenType Type>
+ExtMove* generate_all(const Position& pos, ExtMove* moveList) {
 
     static_assert(Type != LEGAL, "Unsupported type in generate_all()");
 
-    constexpr bool Checks = Type == QUIET_CHECKS; // Reduce template instantiations
-    Bitboard target, piecesToMove = pos.pieces(Us);
+    constexpr bool Checks = Type == QUIET_CHECKS;  // Reduce template instantiations
+    const Square   ksq    = pos.square<KING>(Us);
+    Bitboard       target;
 
-    if(Type == QUIET_CHECKS)
-        piecesToMove &= ~pos.blockers_for_king(~Us);
-
-    switch (Type)
+    // Skip generating non-king moves when in double check
+    if (Type != EVASIONS || !more_than_one(pos.checkers()))
     {
-        case CAPTURES:
-            target =  pos.pieces(~Us);
-            break;
-        case QUIETS:
-        case QUIET_CHECKS:
-            target = ~pos.pieces();
-            break;
-        case EVASIONS:
-        {
-            Square checksq = lsb(pos.checkers());
-            target = between_bb(pos.square<KING>(Us), checksq) | checksq;
-            break;
-        }
-        case NON_EVASIONS:
-            target = ~pos.pieces(Us);
-            break;
+        target = Type == EVASIONS     ? between_bb(ksq, lsb(pos.checkers()))
+               : Type == NON_EVASIONS ? ~pos.pieces(Us)
+               : Type == CAPTURES     ? pos.pieces(~Us)
+                                      : ~pos.pieces();  // QUIETS || QUIET_CHECKS
+
+        moveList = generate_pawn_moves<Us, Type>(pos, moveList, target);
+        moveList = generate_moves<Us, KNIGHT, Checks>(pos, moveList, target);
+        moveList = generate_moves<Us, BISHOP, Checks>(pos, moveList, target);
+        moveList = generate_moves<Us, ROOK, Checks>(pos, moveList, target);
+        moveList = generate_moves<Us, QUEEN, Checks>(pos, moveList, target);
     }
 
-    moveList = generate_pawn_moves<Us, Type>(pos, moveList, target);
-    moveList = generate_moves<KNIGHT, Checks>(pos, moveList, piecesToMove, target);
-    moveList = generate_moves<BISHOP, Checks>(pos, moveList, piecesToMove, target);
-    moveList = generate_moves<  ROOK, Checks>(pos, moveList, piecesToMove, target);
-    moveList = generate_moves< QUEEN, Checks>(pos, moveList, piecesToMove, target);
-
-    if (Type != QUIET_CHECKS && Type != EVASIONS)
+    if (!Checks || pos.blockers_for_king(~Us) & ksq)
     {
-        Square ksq = pos.square<KING>(Us);
-        Bitboard b = attacks_bb<KING>(ksq) & target;
-        while (b)
-            *moveList++ = make_move(ksq, pop_lsb(&b));
+        Bitboard b = attacks_bb<KING>(ksq) & (Type == EVASIONS ? ~pos.pieces(Us) : target);
+        if (Checks)
+            b &= ~attacks_bb<QUEEN>(pos.square<KING>(~Us));
 
-        if ((Type != CAPTURES) && pos.can_castle(Us & ANY_CASTLING))
-            for (CastlingRights cr : { Us & KING_SIDE, Us & QUEEN_SIDE } )
+        while (b)
+            *moveList++ = Move(ksq, pop_lsb(b));
+
+        if ((Type == QUIETS || Type == NON_EVASIONS) && pos.can_castle(Us & ANY_CASTLING))
+            for (CastlingRights cr : {Us & KING_SIDE, Us & QUEEN_SIDE})
                 if (!pos.castling_impeded(cr) && pos.can_castle(cr))
-                    *moveList++ = make<CASTLING>(ksq, pos.castling_rook_square(cr));
+                    *moveList++ = Move::make<CASTLING>(ksq, pos.castling_rook_square(cr));
     }
 
     return moveList;
-  }
+}
 
-} // namespace
+}  // namespace
 
 
-/// <CAPTURES>     Generates all pseudo-legal captures plus queen and checking knight promotions
-/// <QUIETS>       Generates all pseudo-legal non-captures and underpromotions (except checking knight)
-/// <NON_EVASIONS> Generates all pseudo-legal captures and non-captures
-///
-/// Returns a pointer to the end of the move list.
-
+// <CAPTURES>     Generates all pseudo-legal captures plus queen promotions
+// <QUIETS>       Generates all pseudo-legal non-captures and underpromotions
+// <EVASIONS>     Generates all pseudo-legal check evasions
+// <NON_EVASIONS> Generates all pseudo-legal captures and non-captures
+// <QUIET_CHECKS> Generates all pseudo-legal non-captures giving check,
+//                except castling and promotions
+//
+// Returns a pointer to the end of the move list.
 template<GenType Type>
 ExtMove* generate(const Position& pos, ExtMove* moveList) {
 
-  static_assert(Type == CAPTURES || Type == QUIETS || Type == NON_EVASIONS, "Unsupported type in generate()");
-  assert(!pos.checkers());
+    static_assert(Type != LEGAL, "Unsupported type in generate()");
+    assert((Type == EVASIONS) == bool(pos.checkers()));
 
-  Color us = pos.side_to_move();
+    Color us = pos.side_to_move();
 
-  return us == WHITE ? generate_all<WHITE, Type>(pos, moveList)
-                     : generate_all<BLACK, Type>(pos, moveList);
+    return us == WHITE ? generate_all<WHITE, Type>(pos, moveList)
+                       : generate_all<BLACK, Type>(pos, moveList);
 }
 
 // Explicit template instantiations
 template ExtMove* generate<CAPTURES>(const Position&, ExtMove*);
 template ExtMove* generate<QUIETS>(const Position&, ExtMove*);
+template ExtMove* generate<EVASIONS>(const Position&, ExtMove*);
+template ExtMove* generate<QUIET_CHECKS>(const Position&, ExtMove*);
 template ExtMove* generate<NON_EVASIONS>(const Position&, ExtMove*);
 
 
-/// generate<QUIET_CHECKS> generates all pseudo-legal non-captures giving check,
-/// except castling. Returns a pointer to the end of the move list.
-template<>
-ExtMove* generate<QUIET_CHECKS>(const Position& pos, ExtMove* moveList) {
-
-  assert(!pos.checkers());
-
-  Color us = pos.side_to_move();
-  Bitboard dc = pos.blockers_for_king(~us) & pos.pieces(us) & ~pos.pieces(PAWN);
-
-  while (dc)
-  {
-     Square from = pop_lsb(&dc);
-     PieceType pt = type_of(pos.piece_on(from));
-
-     Bitboard b = attacks_bb(pt, from, pos.pieces()) & ~pos.pieces();
-
-     if (pt == KING)
-         b &= ~attacks_bb<QUEEN>(pos.square<KING>(~us));
-
-     while (b)
-         *moveList++ = make_move(from, pop_lsb(&b));
-  }
-
-  return us == WHITE ? generate_all<WHITE, QUIET_CHECKS>(pos, moveList)
-                     : generate_all<BLACK, QUIET_CHECKS>(pos, moveList);
-}
-
-
-/// generate<EVASIONS> generates all pseudo-legal check evasions when the side
-/// to move is in check. Returns a pointer to the end of the move list.
-template<>
-ExtMove* generate<EVASIONS>(const Position& pos, ExtMove* moveList) {
-
-  assert(pos.checkers());
-
-  Color us = pos.side_to_move();
-  Square ksq = pos.square<KING>(us);
-  Bitboard sliderAttacks = 0;
-  Bitboard sliders = pos.checkers() & ~pos.pieces(KNIGHT, PAWN);
-
-  // Find all the squares attacked by slider checkers. We will remove them from
-  // the king evasions in order to skip known illegal moves, which avoids any
-  // useless legality checks later on.
-  while (sliders)
-      sliderAttacks |= line_bb(ksq, pop_lsb(&sliders)) & ~pos.checkers();
-
-  // Generate evasions for king, capture and non capture moves
-  Bitboard b = attacks_bb<KING>(ksq) & ~pos.pieces(us) & ~sliderAttacks;
-  while (b)
-      *moveList++ = make_move(ksq, pop_lsb(&b));
-
-  if (more_than_one(pos.checkers()))
-      return moveList; // Double check, only a king move can save the day
-
-  // Generate blocking evasions or captures of the checking piece
-  return us == WHITE ? generate_all<WHITE, EVASIONS>(pos, moveList)
-                     : generate_all<BLACK, EVASIONS>(pos, moveList);
-}
-
-
-/// generate<LEGAL> generates all the legal moves in the given position
+// generate<LEGAL> generates all the legal moves in the given position
 
 template<>
 ExtMove* generate<LEGAL>(const Position& pos, ExtMove* moveList) {
 
-  Color us = pos.side_to_move();
-  Bitboard pinned = pos.blockers_for_king(us) & pos.pieces(us);
-  Square ksq = pos.square<KING>(us);
-  ExtMove* cur = moveList;
+    Color    us     = pos.side_to_move();
+    Bitboard pinned = pos.blockers_for_king(us) & pos.pieces(us);
+    Square   ksq    = pos.square<KING>(us);
+    ExtMove* cur    = moveList;
 
-  moveList = pos.checkers() ? generate<EVASIONS    >(pos, moveList)
-                            : generate<NON_EVASIONS>(pos, moveList);
-  while (cur != moveList)
-      if (  ((pinned && pinned & from_sq(*cur)) || from_sq(*cur) == ksq || type_of(*cur) == EN_PASSANT)
-          && !pos.legal(*cur))
-          *cur = (--moveList)->move;
-      else
-          ++cur;
+    moveList =
+      pos.checkers() ? generate<EVASIONS>(pos, moveList) : generate<NON_EVASIONS>(pos, moveList);
+    while (cur != moveList)
+        if (((pinned & cur->from_sq()) || cur->from_sq() == ksq || cur->type_of() == EN_PASSANT)
+            && !pos.legal(*cur))
+            *cur = *(--moveList);
+        else
+            ++cur;
 
-  return moveList;
+    return moveList;
 }
+
+}  // namespace Stockfish

src/movegen.h

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -19,55 +19,56 @@
 #ifndef MOVEGEN_H_INCLUDED
 #define MOVEGEN_H_INCLUDED
 
-#include <algorithm>
+#include <algorithm>  // IWYU pragma: keep
+#include <cstddef>
 
 #include "types.h"
 
+namespace Stockfish {
+
 class Position;
 
 enum GenType {
-  CAPTURES,
-  QUIETS,
-  QUIET_CHECKS,
-  EVASIONS,
-  NON_EVASIONS,
-  LEGAL
+    CAPTURES,
+    QUIETS,
+    QUIET_CHECKS,
+    EVASIONS,
+    NON_EVASIONS,
+    LEGAL
 };
 
-struct ExtMove {
-  Move move;
-  int value;
+struct ExtMove: public Move {
+    int value;
 
-  operator Move() const { return move; }
-  void operator=(Move m) { move = m; }
+    void operator=(Move m) { data = m.raw(); }
 
-  // Inhibit unwanted implicit conversions to Move
-  // with an ambiguity that yields to a compile error.
-  operator float() const = delete;
+    // Inhibit unwanted implicit conversions to Move
+    // with an ambiguity that yields to a compile error.
+    operator float() const = delete;
 };
 
-inline bool operator<(const ExtMove& f, const ExtMove& s) {
-  return f.value < s.value;
-}
+inline bool operator<(const ExtMove& f, const ExtMove& s) { return f.value < s.value; }
 
 template<GenType>
 ExtMove* generate(const Position& pos, ExtMove* moveList);
 
-/// The MoveList struct is a simple wrapper around generate(). It sometimes comes
-/// in handy to use this class instead of the low level generate() function.
+// The MoveList struct wraps the generate() function and returns a convenient
+// list of moves. Using MoveList is sometimes preferable to directly calling
+// the lower level generate() function.
 template<GenType T>
 struct MoveList {
 
-  explicit MoveList(const Position& pos) : last(generate<T>(pos, moveList)) {}
-  const ExtMove* begin() const { return moveList; }
-  const ExtMove* end() const { return last; }
-  size_t size() const { return last - moveList; }
-  bool contains(Move move) const {
-    return std::find(begin(), end(), move) != end();
-  }
+    explicit MoveList(const Position& pos) :
+        last(generate<T>(pos, moveList)) {}
+    const ExtMove* begin() const { return moveList; }
+    const ExtMove* end() const { return last; }
+    size_t         size() const { return last - moveList; }
+    bool           contains(Move move) const { return std::find(begin(), end(), move) != end(); }
 
-private:
-  ExtMove moveList[MAX_MOVES], *last;
+   private:
+    ExtMove moveList[MAX_MOVES], *last;
 };
 
-#endif // #ifndef MOVEGEN_H_INCLUDED
+}  // namespace Stockfish
+
+#endif  // #ifndef MOVEGEN_H_INCLUDED

src/movepick.cpp

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -16,250 +16,371 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <cassert>
-
 #include "movepick.h"
 
+#include <algorithm>
+#include <cassert>
+#include <iterator>
+#include <utility>
+
+#include "bitboard.h"
+#include "position.h"
+
+namespace Stockfish {
+
 namespace {
 
-  enum Stages {
-    MAIN_TT, CAPTURE_INIT, GOOD_CAPTURE, REFUTATION, QUIET_INIT, QUIET, BAD_CAPTURE,
-    EVASION_TT, EVASION_INIT, EVASION,
-    PROBCUT_TT, PROBCUT_INIT, PROBCUT,
-    QSEARCH_TT, QCAPTURE_INIT, QCAPTURE, QCHECK_INIT, QCHECK
-  };
+enum Stages {
+    // generate main search moves
+    MAIN_TT,
+    CAPTURE_INIT,
+    GOOD_CAPTURE,
+    REFUTATION,
+    QUIET_INIT,
+    GOOD_QUIET,
+    BAD_CAPTURE,
+    BAD_QUIET,
 
-  // partial_insertion_sort() sorts moves in descending order up to and including
-  // a given limit. The order of moves smaller than the limit is left unspecified.
-  void partial_insertion_sort(ExtMove* begin, ExtMove* end, int limit) {
+    // generate evasion moves
+    EVASION_TT,
+    EVASION_INIT,
+    EVASION,
+
+    // generate probcut moves
+    PROBCUT_TT,
+    PROBCUT_INIT,
+    PROBCUT,
+
+    // generate qsearch moves
+    QSEARCH_TT,
+    QCAPTURE_INIT,
+    QCAPTURE,
+    QCHECK_INIT,
+    QCHECK
+};
+
+// Sort moves in descending order up to and including
+// a given limit. The order of moves smaller than the limit is left unspecified.
+void partial_insertion_sort(ExtMove* begin, ExtMove* end, int limit) {
 
     for (ExtMove *sortedEnd = begin, *p = begin + 1; p < end; ++p)
         if (p->value >= limit)
         {
             ExtMove tmp = *p, *q;
-            *p = *++sortedEnd;
+            *p          = *++sortedEnd;
             for (q = sortedEnd; q != begin && *(q - 1) < tmp; --q)
                 *q = *(q - 1);
             *q = tmp;
         }
-  }
-
-} // namespace
-
-
-/// Constructors of the MovePicker class. As arguments we pass information
-/// to help it to return the (presumably) good moves first, to decide which
-/// moves to return (in the quiescence search, for instance, we only want to
-/// search captures, promotions, and some checks) and how important good move
-/// ordering is at the current node.
-
-/// MovePicker constructor for the main search
-MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh, const LowPlyHistory* lp,
-                       const CapturePieceToHistory* cph, const PieceToHistory** ch, Move cm, const Move* killers, int pl)
-           : pos(p), mainHistory(mh), lowPlyHistory(lp), captureHistory(cph), continuationHistory(ch),
-             ttMove(ttm), refutations{{killers[0], 0}, {killers[1], 0}, {cm, 0}}, depth(d), ply(pl) {
-
-  assert(d > 0);
-
-  stage = (pos.checkers() ? EVASION_TT : MAIN_TT) +
-          !(ttm && pos.pseudo_legal(ttm));
 }
 
-/// MovePicker constructor for quiescence search
-MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh,
-                       const CapturePieceToHistory* cph, const PieceToHistory** ch, Square rs)
-           : pos(p), mainHistory(mh), captureHistory(cph), continuationHistory(ch), ttMove(ttm), recaptureSquare(rs), depth(d) {
+}  // namespace
 
-  assert(d <= 0);
 
-  stage = (pos.checkers() ? EVASION_TT : QSEARCH_TT) +
-          !(   ttm
-            && (pos.checkers() || depth > DEPTH_QS_RECAPTURES || to_sq(ttm) == recaptureSquare)
-            && pos.pseudo_legal(ttm));
+// Constructors of the MovePicker class. As arguments, we pass information
+// to help it return the (presumably) good moves first, to decide which
+// moves to return (in the quiescence search, for instance, we only want to
+// search captures, promotions, and some checks) and how important a good
+// move ordering is at the current node.
+
+// MovePicker constructor for the main search
+MovePicker::MovePicker(const Position&              p,
+                       Move                         ttm,
+                       Depth                        d,
+                       const ButterflyHistory*      mh,
+                       const CapturePieceToHistory* cph,
+                       const PieceToHistory**       ch,
+                       const PawnHistory*           ph,
+                       Move                         cm,
+                       const Move*                  killers) :
+    pos(p),
+    mainHistory(mh),
+    captureHistory(cph),
+    continuationHistory(ch),
+    pawnHistory(ph),
+    ttMove(ttm),
+    refutations{{killers[0], 0}, {killers[1], 0}, {cm, 0}},
+    depth(d) {
+    assert(d > 0);
+
+    stage = (pos.checkers() ? EVASION_TT : MAIN_TT) + !(ttm && pos.pseudo_legal(ttm));
 }
 
-/// MovePicker constructor for ProbCut: we generate captures with SEE greater
-/// than or equal to the given threshold.
-MovePicker::MovePicker(const Position& p, Move ttm, Value th, const CapturePieceToHistory* cph)
-           : pos(p), captureHistory(cph), ttMove(ttm), threshold(th) {
+// Constructor for quiescence search
+MovePicker::MovePicker(const Position&              p,
+                       Move                         ttm,
+                       Depth                        d,
+                       const ButterflyHistory*      mh,
+                       const CapturePieceToHistory* cph,
+                       const PieceToHistory**       ch,
+                       const PawnHistory*           ph) :
+    pos(p),
+    mainHistory(mh),
+    captureHistory(cph),
+    continuationHistory(ch),
+    pawnHistory(ph),
+    ttMove(ttm),
+    depth(d) {
+    assert(d <= 0);
 
-  assert(!pos.checkers());
-
-  stage = PROBCUT_TT + !(ttm && pos.capture(ttm)
-                             && pos.pseudo_legal(ttm)
-                             && pos.see_ge(ttm, threshold));
+    stage = (pos.checkers() ? EVASION_TT : QSEARCH_TT) + !(ttm && pos.pseudo_legal(ttm));
 }
 
-/// MovePicker::score() assigns a numerical value to each move in a list, used
-/// for sorting. Captures are ordered by Most Valuable Victim (MVV), preferring
-/// captures with a good history. Quiets moves are ordered using the histories.
+// Constructor for ProbCut: we generate captures with SEE greater
+// than or equal to the given threshold.
+MovePicker::MovePicker(const Position& p, Move ttm, int th, const CapturePieceToHistory* cph) :
+    pos(p),
+    captureHistory(cph),
+    ttMove(ttm),
+    threshold(th) {
+    assert(!pos.checkers());
+
+    stage = PROBCUT_TT
+          + !(ttm && pos.capture_stage(ttm) && pos.pseudo_legal(ttm) && pos.see_ge(ttm, threshold));
+}
+
+// Assigns a numerical value to each move in a list, used
+// for sorting. Captures are ordered by Most Valuable Victim (MVV), preferring
+// captures with a good history. Quiets moves are ordered using the history tables.
 template<GenType Type>
 void MovePicker::score() {
 
-  static_assert(Type == CAPTURES || Type == QUIETS || Type == EVASIONS, "Wrong type");
+    static_assert(Type == CAPTURES || Type == QUIETS || Type == EVASIONS, "Wrong type");
 
-  for (auto& m : *this)
-      if constexpr (Type == CAPTURES)
-          m.value =  int(PieceValue[MG][pos.piece_on(to_sq(m))]) * 6
-                   + (*captureHistory)[pos.moved_piece(m)][to_sq(m)][type_of(pos.piece_on(to_sq(m)))];
+    [[maybe_unused]] Bitboard threatenedByPawn, threatenedByMinor, threatenedByRook,
+      threatenedPieces;
+    if constexpr (Type == QUIETS)
+    {
+        Color us = pos.side_to_move();
 
-      else if constexpr (Type == QUIETS)
-          m.value =      (*mainHistory)[pos.side_to_move()][from_to(m)]
-                   + 2 * (*continuationHistory[0])[pos.moved_piece(m)][to_sq(m)]
-                   +     (*continuationHistory[1])[pos.moved_piece(m)][to_sq(m)]
-                   +     (*continuationHistory[3])[pos.moved_piece(m)][to_sq(m)]
-                   +     (*continuationHistory[5])[pos.moved_piece(m)][to_sq(m)]
-                   + (ply < MAX_LPH ? std::min(4, depth / 3) * (*lowPlyHistory)[ply][from_to(m)] : 0);
+        threatenedByPawn = pos.attacks_by<PAWN>(~us);
+        threatenedByMinor =
+          pos.attacks_by<KNIGHT>(~us) | pos.attacks_by<BISHOP>(~us) | threatenedByPawn;
+        threatenedByRook = pos.attacks_by<ROOK>(~us) | threatenedByMinor;
 
-      else // Type == EVASIONS
-      {
-          if (pos.capture(m))
-              m.value =  PieceValue[MG][pos.piece_on(to_sq(m))]
-                       - Value(type_of(pos.moved_piece(m)));
-          else
-              m.value =      (*mainHistory)[pos.side_to_move()][from_to(m)]
-                       + 2 * (*continuationHistory[0])[pos.moved_piece(m)][to_sq(m)]
-                       - (1 << 28);
-      }
+        // Pieces threatened by pieces of lesser material value
+        threatenedPieces = (pos.pieces(us, QUEEN) & threatenedByRook)
+                         | (pos.pieces(us, ROOK) & threatenedByMinor)
+                         | (pos.pieces(us, KNIGHT, BISHOP) & threatenedByPawn);
+    }
+
+    for (auto& m : *this)
+        if constexpr (Type == CAPTURES)
+            m.value =
+              7 * int(PieceValue[pos.piece_on(m.to_sq())])
+              + (*captureHistory)[pos.moved_piece(m)][m.to_sq()][type_of(pos.piece_on(m.to_sq()))];
+
+        else if constexpr (Type == QUIETS)
+        {
+            Piece     pc   = pos.moved_piece(m);
+            PieceType pt   = type_of(pc);
+            Square    from = m.from_sq();
+            Square    to   = m.to_sq();
+
+            // histories
+            m.value = 2 * (*mainHistory)[pos.side_to_move()][m.from_to()];
+            m.value += 2 * (*pawnHistory)[pawn_structure_index(pos)][pc][to];
+            m.value += 2 * (*continuationHistory[0])[pc][to];
+            m.value += (*continuationHistory[1])[pc][to];
+            m.value += (*continuationHistory[2])[pc][to] / 4;
+            m.value += (*continuationHistory[3])[pc][to];
+            m.value += (*continuationHistory[5])[pc][to];
+
+            // bonus for checks
+            m.value += bool(pos.check_squares(pt) & to) * 16384;
+
+            // bonus for escaping from capture
+            m.value += threatenedPieces & from ? (pt == QUEEN && !(to & threatenedByRook)   ? 51000
+                                                  : pt == ROOK && !(to & threatenedByMinor) ? 24950
+                                                  : !(to & threatenedByPawn)                ? 14450
+                                                                                            : 0)
+                                               : 0;
+
+            // malus for putting piece en prise
+            m.value -= !(threatenedPieces & from)
+                       ? (pt == QUEEN ? bool(to & threatenedByRook) * 48150
+                                          + bool(to & threatenedByMinor) * 10650
+                          : pt == ROOK ? bool(to & threatenedByMinor) * 24500
+                          : pt != PAWN ? bool(to & threatenedByPawn) * 14950
+                                       : 0)
+                       : 0;
+        }
+
+        else  // Type == EVASIONS
+        {
+            if (pos.capture_stage(m))
+                m.value =
+                  PieceValue[pos.piece_on(m.to_sq())] - type_of(pos.moved_piece(m)) + (1 << 28);
+            else
+                m.value = (*mainHistory)[pos.side_to_move()][m.from_to()]
+                        + (*continuationHistory[0])[pos.moved_piece(m)][m.to_sq()]
+                        + (*pawnHistory)[pawn_structure_index(pos)][pos.moved_piece(m)][m.to_sq()];
+        }
 }
 
-/// MovePicker::select() returns the next move satisfying a predicate function.
-/// It never returns the TT move.
+// Returns the next move satisfying a predicate function.
+// It never returns the TT move.
 template<MovePicker::PickType T, typename Pred>
 Move MovePicker::select(Pred filter) {
 
-  while (cur < endMoves)
-  {
-      if (T == Best)
-          std::swap(*cur, *std::max_element(cur, endMoves));
+    while (cur < endMoves)
+    {
+        if constexpr (T == Best)
+            std::swap(*cur, *std::max_element(cur, endMoves));
 
-      if (*cur != ttMove && filter())
-          return *cur++;
+        if (*cur != ttMove && filter())
+            return *cur++;
 
-      cur++;
-  }
-  return MOVE_NONE;
+        cur++;
+    }
+    return Move::none();
 }
 
-/// MovePicker::next_move() is the most important method of the MovePicker class. It
-/// returns a new pseudo-legal move every time it is called until there are no more
-/// moves left, picking the move with the highest score from a list of generated moves.
+// Most important method of the MovePicker class. It
+// returns a new pseudo-legal move every time it is called until there are no more
+// moves left, picking the move with the highest score from a list of generated moves.
 Move MovePicker::next_move(bool skipQuiets) {
 
+    auto quiet_threshold = [](Depth d) { return -3550 * d; };
+
 top:
-  switch (stage) {
+    switch (stage)
+    {
 
-  case MAIN_TT:
-  case EVASION_TT:
-  case QSEARCH_TT:
-  case PROBCUT_TT:
-      ++stage;
-      return ttMove;
+    case MAIN_TT :
+    case EVASION_TT :
+    case QSEARCH_TT :
+    case PROBCUT_TT :
+        ++stage;
+        return ttMove;
 
-  case CAPTURE_INIT:
-  case PROBCUT_INIT:
-  case QCAPTURE_INIT:
-      cur = endBadCaptures = moves;
-      endMoves = generate<CAPTURES>(pos, cur);
+    case CAPTURE_INIT :
+    case PROBCUT_INIT :
+    case QCAPTURE_INIT :
+        cur = endBadCaptures = moves;
+        endMoves             = generate<CAPTURES>(pos, cur);
 
-      score<CAPTURES>();
-      ++stage;
-      goto top;
+        score<CAPTURES>();
+        partial_insertion_sort(cur, endMoves, std::numeric_limits<int>::min());
+        ++stage;
+        goto top;
 
-  case GOOD_CAPTURE:
-      if (select<Best>([&](){
-                       return pos.see_ge(*cur, Value(-69 * cur->value / 1024)) ?
-                              // Move losing capture to endBadCaptures to be tried later
-                              true : (*endBadCaptures++ = *cur, false); }))
-          return *(cur - 1);
+    case GOOD_CAPTURE :
+        if (select<Next>([&]() {
+                // Move losing capture to endBadCaptures to be tried later
+                return pos.see_ge(*cur, -cur->value / 18) ? true
+                                                          : (*endBadCaptures++ = *cur, false);
+            }))
+            return *(cur - 1);
 
-      // Prepare the pointers to loop over the refutations array
-      cur = std::begin(refutations);
-      endMoves = std::end(refutations);
+        // Prepare the pointers to loop over the refutations array
+        cur      = std::begin(refutations);
+        endMoves = std::end(refutations);
 
-      // If the countermove is the same as a killer, skip it
-      if (   refutations[0].move == refutations[2].move
-          || refutations[1].move == refutations[2].move)
-          --endMoves;
+        // If the countermove is the same as a killer, skip it
+        if (refutations[0] == refutations[2] || refutations[1] == refutations[2])
+            --endMoves;
 
-      ++stage;
-      [[fallthrough]];
+        ++stage;
+        [[fallthrough]];
 
-  case REFUTATION:
-      if (select<Next>([&](){ return    *cur != MOVE_NONE
-                                    && !pos.capture(*cur)
-                                    &&  pos.pseudo_legal(*cur); }))
-          return *(cur - 1);
-      ++stage;
-      [[fallthrough]];
+    case REFUTATION :
+        if (select<Next>([&]() {
+                return *cur != Move::none() && !pos.capture_stage(*cur) && pos.pseudo_legal(*cur);
+            }))
+            return *(cur - 1);
+        ++stage;
+        [[fallthrough]];
 
-  case QUIET_INIT:
-      if (!skipQuiets)
-      {
-          cur = endBadCaptures;
-          endMoves = generate<QUIETS>(pos, cur);
+    case QUIET_INIT :
+        if (!skipQuiets)
+        {
+            cur      = endBadCaptures;
+            endMoves = beginBadQuiets = endBadQuiets = generate<QUIETS>(pos, cur);
 
-          score<QUIETS>();
-          partial_insertion_sort(cur, endMoves, -3000 * depth);
-      }
+            score<QUIETS>();
+            partial_insertion_sort(cur, endMoves, quiet_threshold(depth));
+        }
 
-      ++stage;
-      [[fallthrough]];
+        ++stage;
+        [[fallthrough]];
 
-  case QUIET:
-      if (   !skipQuiets
-          && select<Next>([&](){return   *cur != refutations[0].move
-                                      && *cur != refutations[1].move
-                                      && *cur != refutations[2].move;}))
-          return *(cur - 1);
+    case GOOD_QUIET :
+        if (!skipQuiets && select<Next>([&]() {
+                return *cur != refutations[0] && *cur != refutations[1] && *cur != refutations[2];
+            }))
+        {
+            if ((cur - 1)->value > -8000 || (cur - 1)->value <= quiet_threshold(depth))
+                return *(cur - 1);
 
-      // Prepare the pointers to loop over the bad captures
-      cur = moves;
-      endMoves = endBadCaptures;
+            // Remaining quiets are bad
+            beginBadQuiets = cur - 1;
+        }
 
-      ++stage;
-      [[fallthrough]];
+        // Prepare the pointers to loop over the bad captures
+        cur      = moves;
+        endMoves = endBadCaptures;
 
-  case BAD_CAPTURE:
-      return select<Next>([](){ return true; });
+        ++stage;
+        [[fallthrough]];
 
-  case EVASION_INIT:
-      cur = moves;
-      endMoves = generate<EVASIONS>(pos, cur);
+    case BAD_CAPTURE :
+        if (select<Next>([]() { return true; }))
+            return *(cur - 1);
 
-      score<EVASIONS>();
-      ++stage;
-      [[fallthrough]];
+        // Prepare the pointers to loop over the bad quiets
+        cur      = beginBadQuiets;
+        endMoves = endBadQuiets;
 
-  case EVASION:
-      return select<Best>([](){ return true; });
+        ++stage;
+        [[fallthrough]];
 
-  case PROBCUT:
-      return select<Best>([&](){ return pos.see_ge(*cur, threshold); });
+    case BAD_QUIET :
+        if (!skipQuiets)
+            return select<Next>([&]() {
+                return *cur != refutations[0] && *cur != refutations[1] && *cur != refutations[2];
+            });
 
-  case QCAPTURE:
-      if (select<Best>([&](){ return   depth > DEPTH_QS_RECAPTURES
-                                    || to_sq(*cur) == recaptureSquare; }))
-          return *(cur - 1);
+        return Move::none();
 
-      // If we did not find any move and we do not try checks, we have finished
-      if (depth != DEPTH_QS_CHECKS)
-          return MOVE_NONE;
+    case EVASION_INIT :
+        cur      = moves;
+        endMoves = generate<EVASIONS>(pos, cur);
 
-      ++stage;
-      [[fallthrough]];
+        score<EVASIONS>();
+        ++stage;
+        [[fallthrough]];
 
-  case QCHECK_INIT:
-      cur = moves;
-      endMoves = generate<QUIET_CHECKS>(pos, cur);
+    case EVASION :
+        return select<Best>([]() { return true; });
 
-      ++stage;
-      [[fallthrough]];
+    case PROBCUT :
+        return select<Next>([&]() { return pos.see_ge(*cur, threshold); });
 
-  case QCHECK:
-      return select<Next>([](){ return true; });
-  }
+    case QCAPTURE :
+        if (select<Next>([]() { return true; }))
+            return *(cur - 1);
 
-  assert(false);
-  return MOVE_NONE; // Silence warning
+        // If we did not find any move and we do not try checks, we have finished
+        if (depth != DEPTH_QS_CHECKS)
+            return Move::none();
+
+        ++stage;
+        [[fallthrough]];
+
+    case QCHECK_INIT :
+        cur      = moves;
+        endMoves = generate<QUIET_CHECKS>(pos, cur);
+
+        ++stage;
+        [[fallthrough]];
+
+    case QCHECK :
+        return select<Next>([]() { return true; });
+    }
+
+    assert(false);
+    return Move::none();  // Silence warning
 }
+
+}  // namespace Stockfish

src/movepick.h

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -19,141 +19,184 @@
 #ifndef MOVEPICK_H_INCLUDED
 #define MOVEPICK_H_INCLUDED
 
+#include <algorithm>
 #include <array>
+#include <cassert>
+#include <cmath>
+#include <cstdint>
+#include <cstdlib>
 #include <limits>
-#include <type_traits>
+#include <type_traits>  // IWYU pragma: keep
 
 #include "movegen.h"
 #include "position.h"
 #include "types.h"
 
-/// StatsEntry stores the stat table value. It is usually a number but could
-/// be a move or even a nested history. We use a class instead of naked value
-/// to directly call history update operator<<() on the entry so to use stats
-/// tables at caller sites as simple multi-dim arrays.
+namespace Stockfish {
+
+constexpr int PAWN_HISTORY_SIZE        = 512;    // has to be a power of 2
+constexpr int CORRECTION_HISTORY_SIZE  = 16384;  // has to be a power of 2
+constexpr int CORRECTION_HISTORY_LIMIT = 1024;
+
+static_assert((PAWN_HISTORY_SIZE & (PAWN_HISTORY_SIZE - 1)) == 0,
+              "PAWN_HISTORY_SIZE has to be a power of 2");
+
+static_assert((CORRECTION_HISTORY_SIZE & (CORRECTION_HISTORY_SIZE - 1)) == 0,
+              "CORRECTION_HISTORY_SIZE has to be a power of 2");
+
+enum PawnHistoryType {
+    Normal,
+    Correction
+};
+
+template<PawnHistoryType T = Normal>
+inline int pawn_structure_index(const Position& pos) {
+    return pos.pawn_key() & ((T == Normal ? PAWN_HISTORY_SIZE : CORRECTION_HISTORY_SIZE) - 1);
+}
+
+// StatsEntry stores the stat table value. It is usually a number but could
+// be a move or even a nested history. We use a class instead of a naked value
+// to directly call history update operator<<() on the entry so to use stats
+// tables at caller sites as simple multi-dim arrays.
 template<typename T, int D>
 class StatsEntry {
 
-  T entry;
+    T entry;
 
-public:
-  void operator=(const T& v) { entry = v; }
-  T* operator&() { return &entry; }
-  T* operator->() { return &entry; }
-  operator const T&() const { return entry; }
+   public:
+    void operator=(const T& v) { entry = v; }
+    T*   operator&() { return &entry; }
+    T*   operator->() { return &entry; }
+    operator const T&() const { return entry; }
 
-  void operator<<(int bonus) {
-    assert(abs(bonus) <= D); // Ensure range is [-D, D]
-    static_assert(D <= std::numeric_limits<T>::max(), "D overflows T");
+    void operator<<(int bonus) {
+        static_assert(D <= std::numeric_limits<T>::max(), "D overflows T");
 
-    entry += bonus - entry * abs(bonus) / D;
+        // Make sure that bonus is in range [-D, D]
+        int clampedBonus = std::clamp(bonus, -D, D);
+        entry += clampedBonus - entry * std::abs(clampedBonus) / D;
 
-    assert(abs(entry) <= D);
-  }
+        assert(std::abs(entry) <= D);
+    }
 };
 
-/// Stats is a generic N-dimensional array used to store various statistics.
-/// The first template parameter T is the base type of the array, the second
-/// template parameter D limits the range of updates in [-D, D] when we update
-/// values with the << operator, while the last parameters (Size and Sizes)
-/// encode the dimensions of the array.
-template <typename T, int D, int Size, int... Sizes>
-struct Stats : public std::array<Stats<T, D, Sizes...>, Size>
-{
-  typedef Stats<T, D, Size, Sizes...> stats;
+// Stats is a generic N-dimensional array used to store various statistics.
+// The first template parameter T is the base type of the array, and the second
+// template parameter D limits the range of updates in [-D, D] when we update
+// values with the << operator, while the last parameters (Size and Sizes)
+// encode the dimensions of the array.
+template<typename T, int D, int Size, int... Sizes>
+struct Stats: public std::array<Stats<T, D, Sizes...>, Size> {
+    using stats = Stats<T, D, Size, Sizes...>;
 
-  void fill(const T& v) {
+    void fill(const T& v) {
 
-    // For standard-layout 'this' points to first struct member
-    assert(std::is_standard_layout<stats>::value);
+        // For standard-layout 'this' points to the first struct member
+        assert(std::is_standard_layout_v<stats>);
 
-    typedef StatsEntry<T, D> entry;
-    entry* p = reinterpret_cast<entry*>(this);
-    std::fill(p, p + sizeof(*this) / sizeof(entry), v);
-  }
+        using entry = StatsEntry<T, D>;
+        entry* p    = reinterpret_cast<entry*>(this);
+        std::fill(p, p + sizeof(*this) / sizeof(entry), v);
+    }
 };
 
-template <typename T, int D, int Size>
-struct Stats<T, D, Size> : public std::array<StatsEntry<T, D>, Size> {};
+template<typename T, int D, int Size>
+struct Stats<T, D, Size>: public std::array<StatsEntry<T, D>, Size> {};
 
-/// In stats table, D=0 means that the template parameter is not used
-enum StatsParams { NOT_USED = 0 };
-enum StatsType { NoCaptures, Captures };
+// In stats table, D=0 means that the template parameter is not used
+enum StatsParams {
+    NOT_USED = 0
+};
+enum StatsType {
+    NoCaptures,
+    Captures
+};
 
-/// ButterflyHistory records how often quiet moves have been successful or
-/// unsuccessful during the current search, and is used for reduction and move
-/// ordering decisions. It uses 2 tables (one for each color) indexed by
-/// the move's from and to squares, see www.chessprogramming.org/Butterfly_Boards
-typedef Stats<int16_t, 13365, COLOR_NB, int(SQUARE_NB) * int(SQUARE_NB)> ButterflyHistory;
+// ButterflyHistory records how often quiet moves have been successful or unsuccessful
+// during the current search, and is used for reduction and move ordering decisions.
+// It uses 2 tables (one for each color) indexed by the move's from and to squares,
+// see www.chessprogramming.org/Butterfly_Boards (~11 elo)
+using ButterflyHistory = Stats<int16_t, 7183, COLOR_NB, int(SQUARE_NB) * int(SQUARE_NB)>;
 
-/// At higher depths LowPlyHistory records successful quiet moves near the root
-/// and quiet moves which are/were in the PV (ttPv). It is cleared with each new
-/// search and filled during iterative deepening.
-constexpr int MAX_LPH = 4;
-typedef Stats<int16_t, 10692, MAX_LPH, int(SQUARE_NB) * int(SQUARE_NB)> LowPlyHistory;
+// CounterMoveHistory stores counter moves indexed by [piece][to] of the previous
+// move, see www.chessprogramming.org/Countermove_Heuristic
+using CounterMoveHistory = Stats<Move, NOT_USED, PIECE_NB, SQUARE_NB>;
 
-/// CounterMoveHistory stores counter moves indexed by [piece][to] of the previous
-/// move, see www.chessprogramming.org/Countermove_Heuristic
-typedef Stats<Move, NOT_USED, PIECE_NB, SQUARE_NB> CounterMoveHistory;
+// CapturePieceToHistory is addressed by a move's [piece][to][captured piece type]
+using CapturePieceToHistory = Stats<int16_t, 10692, PIECE_NB, SQUARE_NB, PIECE_TYPE_NB>;
 
-/// CapturePieceToHistory is addressed by a move's [piece][to][captured piece type]
-typedef Stats<int16_t, 10692, PIECE_NB, SQUARE_NB, PIECE_TYPE_NB> CapturePieceToHistory;
+// PieceToHistory is like ButterflyHistory but is addressed by a move's [piece][to]
+using PieceToHistory = Stats<int16_t, 29952, PIECE_NB, SQUARE_NB>;
 
-/// PieceToHistory is like ButterflyHistory but is addressed by a move's [piece][to]
-typedef Stats<int16_t, 29952, PIECE_NB, SQUARE_NB> PieceToHistory;
+// ContinuationHistory is the combined history of a given pair of moves, usually
+// the current one given a previous one. The nested history table is based on
+// PieceToHistory instead of ButterflyBoards.
+// (~63 elo)
+using ContinuationHistory = Stats<PieceToHistory, NOT_USED, PIECE_NB, SQUARE_NB>;
 
-/// ContinuationHistory is the combined history of a given pair of moves, usually
-/// the current one given a previous one. The nested history table is based on
-/// PieceToHistory instead of ButterflyBoards.
-typedef Stats<PieceToHistory, NOT_USED, PIECE_NB, SQUARE_NB> ContinuationHistory;
+// PawnHistory is addressed by the pawn structure and a move's [piece][to]
+using PawnHistory = Stats<int16_t, 8192, PAWN_HISTORY_SIZE, PIECE_NB, SQUARE_NB>;
 
+// CorrectionHistory is addressed by color and pawn structure
+using CorrectionHistory =
+  Stats<int16_t, CORRECTION_HISTORY_LIMIT, COLOR_NB, CORRECTION_HISTORY_SIZE>;
 
-/// MovePicker class is used to pick one pseudo-legal move at a time from the
-/// current position. The most important method is next_move(), which returns a
-/// new pseudo-legal move each time it is called, until there are no moves left,
-/// when MOVE_NONE is returned. In order to improve the efficiency of the
-/// alpha-beta algorithm, MovePicker attempts to return the moves which are most
-/// likely to get a cut-off first.
+// MovePicker class is used to pick one pseudo-legal move at a time from the
+// current position. The most important method is next_move(), which returns a
+// new pseudo-legal move each time it is called, until there are no moves left,
+// when Move::none() is returned. In order to improve the efficiency of the
+// alpha-beta algorithm, MovePicker attempts to return the moves which are most
+// likely to get a cut-off first.
 class MovePicker {
 
-  enum PickType { Next, Best };
+    enum PickType {
+        Next,
+        Best
+    };
 
-public:
-  MovePicker(const MovePicker&) = delete;
-  MovePicker& operator=(const MovePicker&) = delete;
-  MovePicker(const Position&, Move, Value, const CapturePieceToHistory*);
-  MovePicker(const Position&, Move, Depth, const ButterflyHistory*,
-                                           const CapturePieceToHistory*,
-                                           const PieceToHistory**,
-                                           Square);
-  MovePicker(const Position&, Move, Depth, const ButterflyHistory*,
-                                           const LowPlyHistory*,
-                                           const CapturePieceToHistory*,
-                                           const PieceToHistory**,
-                                           Move,
-                                           const Move*,
-                                           int);
-  Move next_move(bool skipQuiets = false);
+   public:
+    MovePicker(const MovePicker&)            = delete;
+    MovePicker& operator=(const MovePicker&) = delete;
+    MovePicker(const Position&,
+               Move,
+               Depth,
+               const ButterflyHistory*,
+               const CapturePieceToHistory*,
+               const PieceToHistory**,
+               const PawnHistory*,
+               Move,
+               const Move*);
+    MovePicker(const Position&,
+               Move,
+               Depth,
+               const ButterflyHistory*,
+               const CapturePieceToHistory*,
+               const PieceToHistory**,
+               const PawnHistory*);
+    MovePicker(const Position&, Move, int, const CapturePieceToHistory*);
+    Move next_move(bool skipQuiets = false);
 
-private:
-  template<PickType T, typename Pred> Move select(Pred);
-  template<GenType> void score();
-  ExtMove* begin() { return cur; }
-  ExtMove* end() { return endMoves; }
+   private:
+    template<PickType T, typename Pred>
+    Move select(Pred);
+    template<GenType>
+    void     score();
+    ExtMove* begin() { return cur; }
+    ExtMove* end() { return endMoves; }
 
-  const Position& pos;
-  const ButterflyHistory* mainHistory;
-  const LowPlyHistory* lowPlyHistory;
-  const CapturePieceToHistory* captureHistory;
-  const PieceToHistory** continuationHistory;
-  Move ttMove;
-  ExtMove refutations[3], *cur, *endMoves, *endBadCaptures;
-  int stage;
-  Square recaptureSquare;
-  Value threshold;
-  Depth depth;
-  int ply;
-  ExtMove moves[MAX_MOVES];
+    const Position&              pos;
+    const ButterflyHistory*      mainHistory;
+    const CapturePieceToHistory* captureHistory;
+    const PieceToHistory**       continuationHistory;
+    const PawnHistory*           pawnHistory;
+    Move                         ttMove;
+    ExtMove refutations[3], *cur, *endMoves, *endBadCaptures, *beginBadQuiets, *endBadQuiets;
+    int     stage;
+    int     threshold;
+    Depth   depth;
+    ExtMove moves[MAX_MOVES];
 };
 
-#endif // #ifndef MOVEPICK_H_INCLUDED
+}  // namespace Stockfish
+
+#endif  // #ifndef MOVEPICK_H_INCLUDED

src/nnue/architectures/halfkp_256x2-32-32.h

@@ -1,54 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
-
-  Stockfish is free software: you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation, either version 3 of the License, or
-  (at your option) any later version.
-
-  Stockfish is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-// Definition of input features and network structure used in NNUE evaluation function
-
-#ifndef NNUE_HALFKP_256X2_32_32_H_INCLUDED
-#define NNUE_HALFKP_256X2_32_32_H_INCLUDED
-
-#include "../features/feature_set.h"
-#include "../features/half_kp.h"
-
-#include "../layers/input_slice.h"
-#include "../layers/affine_transform.h"
-#include "../layers/clipped_relu.h"
-
-namespace Eval::NNUE {
-
-// Input features used in evaluation function
-using RawFeatures = Features::FeatureSet<
-    Features::HalfKP<Features::Side::kFriend>>;
-
-// Number of input feature dimensions after conversion
-constexpr IndexType kTransformedFeatureDimensions = 256;
-
-namespace Layers {
-
-// Define network structure
-using InputLayer = InputSlice<kTransformedFeatureDimensions * 2>;
-using HiddenLayer1 = ClippedReLU<AffineTransform<InputLayer, 32>>;
-using HiddenLayer2 = ClippedReLU<AffineTransform<HiddenLayer1, 32>>;
-using OutputLayer = AffineTransform<HiddenLayer2, 1>;
-
-}  // namespace Layers
-
-using Network = Layers::OutputLayer;
-
-}  // namespace Eval::NNUE
-
-#endif // #ifndef NNUE_HALFKP_256X2_32_32_H_INCLUDED

src/nnue/evaluate_nnue.cpp

@@ -1,144 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
-
-  Stockfish is free software: you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation, either version 3 of the License, or
-  (at your option) any later version.
-
-  Stockfish is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-// Code for calculating NNUE evaluation function
-
-#include <iostream>
-#include <set>
-
-#include "../evaluate.h"
-#include "../position.h"
-#include "../misc.h"
-#include "../uci.h"
-#include "../types.h"
-
-#include "evaluate_nnue.h"
-
-namespace Eval::NNUE {
-
-  // Input feature converter
-  LargePagePtr<FeatureTransformer> feature_transformer;
-
-  // Evaluation function
-  AlignedPtr<Network> network;
-
-  // Evaluation function file name
-  std::string fileName;
-
-  namespace Detail {
-
-  // Initialize the evaluation function parameters
-  template <typename T>
-  void Initialize(AlignedPtr<T>& pointer) {
-
-    pointer.reset(reinterpret_cast<T*>(std_aligned_alloc(alignof(T), sizeof(T))));
-    std::memset(pointer.get(), 0, sizeof(T));
-  }
-
-  template <typename T>
-  void Initialize(LargePagePtr<T>& pointer) {
-
-    static_assert(alignof(T) <= 4096, "aligned_large_pages_alloc() may fail for such a big alignment requirement of T");
-    pointer.reset(reinterpret_cast<T*>(aligned_large_pages_alloc(sizeof(T))));
-    std::memset(pointer.get(), 0, sizeof(T));
-  }
-
-  // Read evaluation function parameters
-  template <typename T>
-  bool ReadParameters(std::istream& stream, T& reference) {
-
-    std::uint32_t header;
-    header = read_little_endian<std::uint32_t>(stream);
-    if (!stream || header != T::GetHashValue()) return false;
-    return reference.ReadParameters(stream);
-  }
-
-  }  // namespace Detail
-
-  // Initialize the evaluation function parameters
-  void Initialize() {
-
-    Detail::Initialize(feature_transformer);
-    Detail::Initialize(network);
-  }
-
-  // Read network header
-  bool ReadHeader(std::istream& stream, std::uint32_t* hash_value, std::string* architecture)
-  {
-    std::uint32_t version, size;
-
-    version     = read_little_endian<std::uint32_t>(stream);
-    *hash_value = read_little_endian<std::uint32_t>(stream);
-    size        = read_little_endian<std::uint32_t>(stream);
-    if (!stream || version != kVersion) return false;
-    architecture->resize(size);
-    stream.read(&(*architecture)[0], size);
-    return !stream.fail();
-  }
-
-  // Read network parameters
-  bool ReadParameters(std::istream& stream) {
-
-    std::uint32_t hash_value;
-    std::string architecture;
-    if (!ReadHeader(stream, &hash_value, &architecture)) return false;
-    if (hash_value != kHashValue) return false;
-    if (!Detail::ReadParameters(stream, *feature_transformer)) return false;
-    if (!Detail::ReadParameters(stream, *network)) return false;
-    return stream && stream.peek() == std::ios::traits_type::eof();
-  }
-
-  // Evaluation function. Perform differential calculation.
-  Value evaluate(const Position& pos) {
-
-    // We manually align the arrays on the stack because with gcc < 9.3
-    // overaligning stack variables with alignas() doesn't work correctly.
-
-    constexpr uint64_t alignment = kCacheLineSize;
-
-#if defined(ALIGNAS_ON_STACK_VARIABLES_BROKEN)
-    TransformedFeatureType transformed_features_unaligned[
-      FeatureTransformer::kBufferSize + alignment / sizeof(TransformedFeatureType)];
-    char buffer_unaligned[Network::kBufferSize + alignment];
-
-    auto* transformed_features = align_ptr_up<alignment>(&transformed_features_unaligned[0]);
-    auto* buffer = align_ptr_up<alignment>(&buffer_unaligned[0]);
-#else
-    alignas(alignment)
-      TransformedFeatureType transformed_features[FeatureTransformer::kBufferSize];
-    alignas(alignment) char buffer[Network::kBufferSize];
-#endif
-
-    ASSERT_ALIGNED(transformed_features, alignment);
-    ASSERT_ALIGNED(buffer, alignment);
-
-    feature_transformer->Transform(pos, transformed_features);
-    const auto output = network->Propagate(transformed_features, buffer);
-
-    return static_cast<Value>(output[0] / FV_SCALE);
-  }
-
-  // Load eval, from a file stream or a memory stream
-  bool load_eval(std::string name, std::istream& stream) {
-
-    Initialize();
-    fileName = name;
-    return ReadParameters(stream);
-  }
-
-} // namespace Eval::NNUE

src/nnue/evaluate_nnue.h

@@ -1,59 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
-
-  Stockfish is free software: you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation, either version 3 of the License, or
-  (at your option) any later version.
-
-  Stockfish is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-// header used in NNUE evaluation function
-
-#ifndef NNUE_EVALUATE_NNUE_H_INCLUDED
-#define NNUE_EVALUATE_NNUE_H_INCLUDED
-
-#include "nnue_feature_transformer.h"
-
-#include <memory>
-
-namespace Eval::NNUE {
-
-  // Hash value of evaluation function structure
-  constexpr std::uint32_t kHashValue =
-      FeatureTransformer::GetHashValue() ^ Network::GetHashValue();
-
-  // Deleter for automating release of memory area
-  template <typename T>
-  struct AlignedDeleter {
-    void operator()(T* ptr) const {
-      ptr->~T();
-      std_aligned_free(ptr);
-    }
-  };
-
-  template <typename T>
-  struct LargePageDeleter {
-    void operator()(T* ptr) const {
-      ptr->~T();
-      aligned_large_pages_free(ptr);
-    }
-  };
-
-  template <typename T>
-  using AlignedPtr = std::unique_ptr<T, AlignedDeleter<T>>;
-
-  template <typename T>
-  using LargePagePtr = std::unique_ptr<T, LargePageDeleter<T>>;
-
-}  // namespace Eval::NNUE
-
-#endif // #ifndef NNUE_EVALUATE_NNUE_H_INCLUDED

src/nnue/features/feature_set.h

@@ -1,69 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
-
-  Stockfish is free software: you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation, either version 3 of the License, or
-  (at your option) any later version.
-
-  Stockfish is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-// A class template that represents the input feature set of the NNUE evaluation function
-
-#ifndef NNUE_FEATURE_SET_H_INCLUDED
-#define NNUE_FEATURE_SET_H_INCLUDED
-
-#include "features_common.h"
-#include <array>
-
-namespace Eval::NNUE::Features {
-
-  // Class template that represents a list of values
-  template <typename T, T... Values>
-  struct CompileTimeList;
-
-  template <typename T, T First, T... Remaining>
-  struct CompileTimeList<T, First, Remaining...> {
-    static constexpr bool Contains(T value) {
-      return value == First || CompileTimeList<T, Remaining...>::Contains(value);
-    }
-    static constexpr std::array<T, sizeof...(Remaining) + 1>
-        kValues = {{First, Remaining...}};
-  };
-
-  // Base class of feature set
-  template <typename Derived>
-  class FeatureSetBase {
-
-  };
-
-  // Class template that represents the feature set
-  template <typename FeatureType>
-  class FeatureSet<FeatureType> : public FeatureSetBase<FeatureSet<FeatureType>> {
-
-   public:
-    // Hash value embedded in the evaluation file
-    static constexpr std::uint32_t kHashValue = FeatureType::kHashValue;
-    // Number of feature dimensions
-    static constexpr IndexType kDimensions = FeatureType::kDimensions;
-    // Maximum number of simultaneously active features
-    static constexpr IndexType kMaxActiveDimensions =
-        FeatureType::kMaxActiveDimensions;
-    // Trigger for full calculation instead of difference calculation
-    using SortedTriggerSet =
-        CompileTimeList<TriggerEvent, FeatureType::kRefreshTrigger>;
-    static constexpr auto kRefreshTriggers = SortedTriggerSet::kValues;
-
-  };
-
-}  // namespace Eval::NNUE::Features
-
-#endif // #ifndef NNUE_FEATURE_SET_H_INCLUDED

src/nnue/features/features_common.h

@@ -1,45 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
-
-  Stockfish is free software: you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation, either version 3 of the License, or
-  (at your option) any later version.
-
-  Stockfish is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-//Common header of input features of NNUE evaluation function
-
-#ifndef NNUE_FEATURES_COMMON_H_INCLUDED
-#define NNUE_FEATURES_COMMON_H_INCLUDED
-
-#include "../../evaluate.h"
-#include "../nnue_common.h"
-
-namespace Eval::NNUE::Features {
-
-  class IndexList;
-
-  template <typename... FeatureTypes>
-  class FeatureSet;
-
-  // Trigger to perform full calculations instead of difference only
-  enum class TriggerEvent {
-    kFriendKingMoved // calculate full evaluation when own king moves
-  };
-
-  enum class Side {
-    kFriend // side to move
-  };
-
-}  // namespace Eval::NNUE::Features
-
-#endif // #ifndef NNUE_FEATURES_COMMON_H_INCLUDED

src/nnue/features/half_ka_v2_hm.cpp

@@ -0,0 +1,86 @@
+/*
+  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
+
+  Stockfish is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  Stockfish is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+//Definition of input features HalfKAv2_hm of NNUE evaluation function
+
+#include "half_ka_v2_hm.h"
+
+#include "../../bitboard.h"
+#include "../../position.h"
+#include "../../types.h"
+#include "../nnue_common.h"
+
+namespace Stockfish::Eval::NNUE::Features {
+
+// Index of a feature for a given king position and another piece on some square
+template<Color Perspective>
+inline IndexType HalfKAv2_hm::make_index(Square s, Piece pc, Square ksq) {
+    return IndexType((int(s) ^ OrientTBL[Perspective][ksq]) + PieceSquareIndex[Perspective][pc]
+                     + KingBuckets[Perspective][ksq]);
+}
+
+// Get a list of indices for active features
+template<Color Perspective>
+void HalfKAv2_hm::append_active_indices(const Position& pos, IndexList& active) {
+    Square   ksq = pos.square<KING>(Perspective);
+    Bitboard bb  = pos.pieces();
+    while (bb)
+    {
+        Square s = pop_lsb(bb);
+        active.push_back(make_index<Perspective>(s, pos.piece_on(s), ksq));
+    }
+}
+
+// Explicit template instantiations
+template void HalfKAv2_hm::append_active_indices<WHITE>(const Position& pos, IndexList& active);
+template void HalfKAv2_hm::append_active_indices<BLACK>(const Position& pos, IndexList& active);
+
+// Get a list of indices for recently changed features
+template<Color Perspective>
+void HalfKAv2_hm::append_changed_indices(Square            ksq,
+                                         const DirtyPiece& dp,
+                                         IndexList&        removed,
+                                         IndexList&        added) {
+    for (int i = 0; i < dp.dirty_num; ++i)
+    {
+        if (dp.from[i] != SQ_NONE)
+            removed.push_back(make_index<Perspective>(dp.from[i], dp.piece[i], ksq));
+        if (dp.to[i] != SQ_NONE)
+            added.push_back(make_index<Perspective>(dp.to[i], dp.piece[i], ksq));
+    }
+}
+
+// Explicit template instantiations
+template void HalfKAv2_hm::append_changed_indices<WHITE>(Square            ksq,
+                                                         const DirtyPiece& dp,
+                                                         IndexList&        removed,
+                                                         IndexList&        added);
+template void HalfKAv2_hm::append_changed_indices<BLACK>(Square            ksq,
+                                                         const DirtyPiece& dp,
+                                                         IndexList&        removed,
+                                                         IndexList&        added);
+
+int HalfKAv2_hm::update_cost(const StateInfo* st) { return st->dirtyPiece.dirty_num; }
+
+int HalfKAv2_hm::refresh_cost(const Position& pos) { return pos.count<ALL_PIECES>(); }
+
+bool HalfKAv2_hm::requires_refresh(const StateInfo* st, Color perspective) {
+    return st->dirtyPiece.piece[0] == make_piece(perspective, KING);
+}
+
+}  // namespace Stockfish::Eval::NNUE::Features

src/nnue/features/half_ka_v2_hm.h

@@ -0,0 +1,150 @@
+/*
+  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
+
+  Stockfish is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  Stockfish is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+//Definition of input features HalfKP of NNUE evaluation function
+
+#ifndef NNUE_FEATURES_HALF_KA_V2_HM_H_INCLUDED
+#define NNUE_FEATURES_HALF_KA_V2_HM_H_INCLUDED
+
+#include <cstdint>
+
+#include "../../misc.h"
+#include "../../types.h"
+#include "../nnue_common.h"
+
+namespace Stockfish {
+struct StateInfo;
+class Position;
+}
+
+namespace Stockfish::Eval::NNUE::Features {
+
+// Feature HalfKAv2_hm: Combination of the position of own king and the
+// position of pieces. Position mirrored such that king is always on e..h files.
+class HalfKAv2_hm {
+
+    // Unique number for each piece type on each square
+    enum {
+        PS_NONE     = 0,
+        PS_W_PAWN   = 0,
+        PS_B_PAWN   = 1 * SQUARE_NB,
+        PS_W_KNIGHT = 2 * SQUARE_NB,
+        PS_B_KNIGHT = 3 * SQUARE_NB,
+        PS_W_BISHOP = 4 * SQUARE_NB,
+        PS_B_BISHOP = 5 * SQUARE_NB,
+        PS_W_ROOK   = 6 * SQUARE_NB,
+        PS_B_ROOK   = 7 * SQUARE_NB,
+        PS_W_QUEEN  = 8 * SQUARE_NB,
+        PS_B_QUEEN  = 9 * SQUARE_NB,
+        PS_KING     = 10 * SQUARE_NB,
+        PS_NB       = 11 * SQUARE_NB
+    };
+
+    static constexpr IndexType PieceSquareIndex[COLOR_NB][PIECE_NB] = {
+      // Convention: W - us, B - them
+      // Viewed from other side, W and B are reversed
+      {PS_NONE, PS_W_PAWN, PS_W_KNIGHT, PS_W_BISHOP, PS_W_ROOK, PS_W_QUEEN, PS_KING, PS_NONE,
+       PS_NONE, PS_B_PAWN, PS_B_KNIGHT, PS_B_BISHOP, PS_B_ROOK, PS_B_QUEEN, PS_KING, PS_NONE},
+      {PS_NONE, PS_B_PAWN, PS_B_KNIGHT, PS_B_BISHOP, PS_B_ROOK, PS_B_QUEEN, PS_KING, PS_NONE,
+       PS_NONE, PS_W_PAWN, PS_W_KNIGHT, PS_W_BISHOP, PS_W_ROOK, PS_W_QUEEN, PS_KING, PS_NONE}};
+
+    // Index of a feature for a given king position and another piece on some square
+    template<Color Perspective>
+    static IndexType make_index(Square s, Piece pc, Square ksq);
+
+   public:
+    // Feature name
+    static constexpr const char* Name = "HalfKAv2_hm(Friend)";
+
+    // Hash value embedded in the evaluation file
+    static constexpr std::uint32_t HashValue = 0x7f234cb8u;
+
+    // Number of feature dimensions
+    static constexpr IndexType Dimensions =
+      static_cast<IndexType>(SQUARE_NB) * static_cast<IndexType>(PS_NB) / 2;
+
+#define B(v) (v * PS_NB)
+    // clang-format off
+    static constexpr int KingBuckets[COLOR_NB][SQUARE_NB] = {
+      { B(28), B(29), B(30), B(31), B(31), B(30), B(29), B(28),
+        B(24), B(25), B(26), B(27), B(27), B(26), B(25), B(24),
+        B(20), B(21), B(22), B(23), B(23), B(22), B(21), B(20),
+        B(16), B(17), B(18), B(19), B(19), B(18), B(17), B(16),
+        B(12), B(13), B(14), B(15), B(15), B(14), B(13), B(12),
+        B( 8), B( 9), B(10), B(11), B(11), B(10), B( 9), B( 8),
+        B( 4), B( 5), B( 6), B( 7), B( 7), B( 6), B( 5), B( 4),
+        B( 0), B( 1), B( 2), B( 3), B( 3), B( 2), B( 1), B( 0) },
+      { B( 0), B( 1), B( 2), B( 3), B( 3), B( 2), B( 1), B( 0),
+        B( 4), B( 5), B( 6), B( 7), B( 7), B( 6), B( 5), B( 4),
+        B( 8), B( 9), B(10), B(11), B(11), B(10), B( 9), B( 8),
+        B(12), B(13), B(14), B(15), B(15), B(14), B(13), B(12),
+        B(16), B(17), B(18), B(19), B(19), B(18), B(17), B(16),
+        B(20), B(21), B(22), B(23), B(23), B(22), B(21), B(20),
+        B(24), B(25), B(26), B(27), B(27), B(26), B(25), B(24),
+        B(28), B(29), B(30), B(31), B(31), B(30), B(29), B(28) }
+    };
+    // clang-format on
+#undef B
+    // clang-format off
+    // Orient a square according to perspective (rotates by 180 for black)
+    static constexpr int OrientTBL[COLOR_NB][SQUARE_NB] = {
+      { SQ_H1, SQ_H1, SQ_H1, SQ_H1, SQ_A1, SQ_A1, SQ_A1, SQ_A1,
+        SQ_H1, SQ_H1, SQ_H1, SQ_H1, SQ_A1, SQ_A1, SQ_A1, SQ_A1,
+        SQ_H1, SQ_H1, SQ_H1, SQ_H1, SQ_A1, SQ_A1, SQ_A1, SQ_A1,
+        SQ_H1, SQ_H1, SQ_H1, SQ_H1, SQ_A1, SQ_A1, SQ_A1, SQ_A1,
+        SQ_H1, SQ_H1, SQ_H1, SQ_H1, SQ_A1, SQ_A1, SQ_A1, SQ_A1,
+        SQ_H1, SQ_H1, SQ_H1, SQ_H1, SQ_A1, SQ_A1, SQ_A1, SQ_A1,
+        SQ_H1, SQ_H1, SQ_H1, SQ_H1, SQ_A1, SQ_A1, SQ_A1, SQ_A1,
+        SQ_H1, SQ_H1, SQ_H1, SQ_H1, SQ_A1, SQ_A1, SQ_A1, SQ_A1 },
+      { SQ_H8, SQ_H8, SQ_H8, SQ_H8, SQ_A8, SQ_A8, SQ_A8, SQ_A8,
+        SQ_H8, SQ_H8, SQ_H8, SQ_H8, SQ_A8, SQ_A8, SQ_A8, SQ_A8,
+        SQ_H8, SQ_H8, SQ_H8, SQ_H8, SQ_A8, SQ_A8, SQ_A8, SQ_A8,
+        SQ_H8, SQ_H8, SQ_H8, SQ_H8, SQ_A8, SQ_A8, SQ_A8, SQ_A8,
+        SQ_H8, SQ_H8, SQ_H8, SQ_H8, SQ_A8, SQ_A8, SQ_A8, SQ_A8,
+        SQ_H8, SQ_H8, SQ_H8, SQ_H8, SQ_A8, SQ_A8, SQ_A8, SQ_A8,
+        SQ_H8, SQ_H8, SQ_H8, SQ_H8, SQ_A8, SQ_A8, SQ_A8, SQ_A8,
+        SQ_H8, SQ_H8, SQ_H8, SQ_H8, SQ_A8, SQ_A8, SQ_A8, SQ_A8 }
+    };
+    // clang-format on
+
+    // Maximum number of simultaneously active features.
+    static constexpr IndexType MaxActiveDimensions = 32;
+    using IndexList                                = ValueList<IndexType, MaxActiveDimensions>;
+
+    // Get a list of indices for active features
+    template<Color Perspective>
+    static void append_active_indices(const Position& pos, IndexList& active);
+
+    // Get a list of indices for recently changed features
+    template<Color Perspective>
+    static void
+    append_changed_indices(Square ksq, const DirtyPiece& dp, IndexList& removed, IndexList& added);
+
+    // Returns the cost of updating one perspective, the most costly one.
+    // Assumes no refresh needed.
+    static int update_cost(const StateInfo* st);
+    static int refresh_cost(const Position& pos);
+
+    // Returns whether the change stored in this StateInfo means
+    // that a full accumulator refresh is required.
+    static bool requires_refresh(const StateInfo* st, Color perspective);
+};
+
+}  // namespace Stockfish::Eval::NNUE::Features
+
+#endif  // #ifndef NNUE_FEATURES_HALF_KA_V2_HM_H_INCLUDED

src/nnue/features/half_kp.cpp

@@ -1,68 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
-
-  Stockfish is free software: you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation, either version 3 of the License, or
-  (at your option) any later version.
-
-  Stockfish is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-//Definition of input features HalfKP of NNUE evaluation function
-
-#include "half_kp.h"
-#include "index_list.h"
-
-namespace Eval::NNUE::Features {
-
-  // Orient a square according to perspective (rotates by 180 for black)
-  inline Square orient(Color perspective, Square s) {
-    return Square(int(s) ^ (bool(perspective) * 63));
-  }
-
-  // Index of a feature for a given king position and another piece on some square
-  inline IndexType make_index(Color perspective, Square s, Piece pc, Square ksq) {
-    return IndexType(orient(perspective, s) + kpp_board_index[perspective][pc] + PS_END * ksq);
-  }
-
-  // Get a list of indices for active features
-  template <Side AssociatedKing>
-  void HalfKP<AssociatedKing>::AppendActiveIndices(
-      const Position& pos, Color perspective, IndexList* active) {
-
-    Square ksq = orient(perspective, pos.square<KING>(perspective));
-    Bitboard bb = pos.pieces() & ~pos.pieces(KING);
-    while (bb) {
-      Square s = pop_lsb(&bb);
-      active->push_back(make_index(perspective, s, pos.piece_on(s), ksq));
-    }
-  }
-
-  // Get a list of indices for recently changed features
-  template <Side AssociatedKing>
-  void HalfKP<AssociatedKing>::AppendChangedIndices(
-      const Position& pos, const DirtyPiece& dp, Color perspective,
-      IndexList* removed, IndexList* added) {
-
-    Square ksq = orient(perspective, pos.square<KING>(perspective));
-    for (int i = 0; i < dp.dirty_num; ++i) {
-      Piece pc = dp.piece[i];
-      if (type_of(pc) == KING) continue;
-      if (dp.from[i] != SQ_NONE)
-        removed->push_back(make_index(perspective, dp.from[i], pc, ksq));
-      if (dp.to[i] != SQ_NONE)
-        added->push_back(make_index(perspective, dp.to[i], pc, ksq));
-    }
-  }
-
-  template class HalfKP<Side::kFriend>;
-
-}  // namespace Eval::NNUE::Features

src/nnue/features/half_kp.h

@@ -1,59 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
-
-  Stockfish is free software: you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation, either version 3 of the License, or
-  (at your option) any later version.
-
-  Stockfish is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-//Definition of input features HalfKP of NNUE evaluation function
-
-#ifndef NNUE_FEATURES_HALF_KP_H_INCLUDED
-#define NNUE_FEATURES_HALF_KP_H_INCLUDED
-
-#include "../../evaluate.h"
-#include "features_common.h"
-
-namespace Eval::NNUE::Features {
-
-  // Feature HalfKP: Combination of the position of own king
-  // and the position of pieces other than kings
-  template <Side AssociatedKing>
-  class HalfKP {
-
-   public:
-    // Feature name
-    static constexpr const char* kName = "HalfKP(Friend)";
-    // Hash value embedded in the evaluation file
-    static constexpr std::uint32_t kHashValue =
-        0x5D69D5B9u ^ (AssociatedKing == Side::kFriend);
-    // Number of feature dimensions
-    static constexpr IndexType kDimensions =
-        static_cast<IndexType>(SQUARE_NB) * static_cast<IndexType>(PS_END);
-    // Maximum number of simultaneously active features
-    static constexpr IndexType kMaxActiveDimensions = 30; // Kings don't count
-    // Trigger for full calculation instead of difference calculation
-    static constexpr TriggerEvent kRefreshTrigger = TriggerEvent::kFriendKingMoved;
-
-    // Get a list of indices for active features
-    static void AppendActiveIndices(const Position& pos, Color perspective,
-                                    IndexList* active);
-
-    // Get a list of indices for recently changed features
-    static void AppendChangedIndices(const Position& pos, const DirtyPiece& dp, Color perspective,
-                                     IndexList* removed, IndexList* added);
-  };
-
-}  // namespace Eval::NNUE::Features
-
-#endif // #ifndef NNUE_FEATURES_HALF_KP_H_INCLUDED

src/nnue/features/index_list.h

@@ -1,64 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
-
-  Stockfish is free software: you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation, either version 3 of the License, or
-  (at your option) any later version.
-
-  Stockfish is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-// Definition of index list of input features
-
-#ifndef NNUE_FEATURES_INDEX_LIST_H_INCLUDED
-#define NNUE_FEATURES_INDEX_LIST_H_INCLUDED
-
-#include "../../position.h"
-#include "../nnue_architecture.h"
-
-namespace Eval::NNUE::Features {
-
-  // Class template used for feature index list
-  template <typename T, std::size_t MaxSize>
-  class ValueList {
-
-   public:
-    std::size_t size() const { return size_; }
-    void resize(std::size_t size) { size_ = size; }
-    void push_back(const T& value) { values_[size_++] = value; }
-    T& operator[](std::size_t index) { return values_[index]; }
-    T* begin() { return values_; }
-    T* end() { return values_ + size_; }
-    const T& operator[](std::size_t index) const { return values_[index]; }
-    const T* begin() const { return values_; }
-    const T* end() const { return values_ + size_; }
-
-    void swap(ValueList& other) {
-      const std::size_t max_size = std::max(size_, other.size_);
-      for (std::size_t i = 0; i < max_size; ++i) {
-        std::swap(values_[i], other.values_[i]);
-      }
-      std::swap(size_, other.size_);
-    }
-
-   private:
-    T values_[MaxSize];
-    std::size_t size_ = 0;
-  };
-
-  //Type of feature index list
-  class IndexList
-      : public ValueList<IndexType, RawFeatures::kMaxActiveDimensions> {
-  };
-
-}  // namespace Eval::NNUE::Features
-
-#endif // NNUE_FEATURES_INDEX_LIST_H_INCLUDED

src/nnue/layers/affine_transform.h

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -21,444 +21,288 @@
 #ifndef NNUE_LAYERS_AFFINE_TRANSFORM_H_INCLUDED
 #define NNUE_LAYERS_AFFINE_TRANSFORM_H_INCLUDED
 
+#include <cstdint>
 #include <iostream>
+
 #include "../nnue_common.h"
+#include "simd.h"
 
-namespace Eval::NNUE::Layers {
+/*
+  This file contains the definition for a fully connected layer (aka affine transform).
 
-  // Affine transformation layer
-  template <typename PreviousLayer, IndexType OutputDimensions>
-  class AffineTransform {
-   public:
-    // Input/output type
-    using InputType = typename PreviousLayer::OutputType;
-    using OutputType = std::int32_t;
-    static_assert(std::is_same<InputType, std::uint8_t>::value, "");
+    - expected use-case is for when PaddedInputDimensions == 32 and InputDimensions <= 32.
+      - that's why AVX512 is hard to implement
+    - expected use-case is small layers
+    - inputs are processed in chunks of 4, weights are respectively transposed
+    - accumulation happens directly to int32s
+*/
 
-    // Number of input/output dimensions
-    static constexpr IndexType kInputDimensions =
-        PreviousLayer::kOutputDimensions;
-    static constexpr IndexType kOutputDimensions = OutputDimensions;
-    static constexpr IndexType kPaddedInputDimensions =
-        CeilToMultiple<IndexType>(kInputDimensions, kMaxSimdWidth);
-#if defined (USE_AVX512)
-    static constexpr const IndexType kOutputSimdWidth = kSimdWidth / 2;
-#elif defined (USE_SSSE3)
-    static constexpr const IndexType kOutputSimdWidth = kSimdWidth / 4;
-#endif
+namespace Stockfish::Eval::NNUE::Layers {
 
-    // Size of forward propagation buffer used in this layer
-    static constexpr std::size_t kSelfBufferSize =
-        CeilToMultiple(kOutputDimensions * sizeof(OutputType), kCacheLineSize);
+// Fallback implementation for older/other architectures.
+// Requires the input to be padded to at least 16 values.
+#if !defined(USE_SSSE3)
+template<IndexType InputDimensions, IndexType PaddedInputDimensions, IndexType OutputDimensions>
+static void affine_transform_non_ssse3(std::int32_t*       output,
+                                       const std::int8_t*  weights,
+                                       const std::int32_t* biases,
+                                       const std::uint8_t* input) {
+    #if defined(USE_SSE2) || defined(USE_NEON_DOTPROD) || defined(USE_NEON)
+        #if defined(USE_SSE2)
+    // At least a multiple of 16, with SSE2.
+    constexpr IndexType NumChunks   = ceil_to_multiple<IndexType>(InputDimensions, 16) / 16;
+    const __m128i       Zeros       = _mm_setzero_si128();
+    const auto          inputVector = reinterpret_cast<const __m128i*>(input);
 
-    // Size of the forward propagation buffer used from the input layer to this layer
-    static constexpr std::size_t kBufferSize =
-        PreviousLayer::kBufferSize + kSelfBufferSize;
+        #elif defined(USE_NEON_DOTPROD)
+    constexpr IndexType NumChunks   = ceil_to_multiple<IndexType>(InputDimensions, 16) / 16;
+    const auto          inputVector = reinterpret_cast<const int8x16_t*>(input);
 
-    // Hash value embedded in the evaluation file
-    static constexpr std::uint32_t GetHashValue() {
-      std::uint32_t hash_value = 0xCC03DAE4u;
-      hash_value += kOutputDimensions;
-      hash_value ^= PreviousLayer::GetHashValue() >> 1;
-      hash_value ^= PreviousLayer::GetHashValue() << 31;
-      return hash_value;
-    }
+        #elif defined(USE_NEON)
+    constexpr IndexType NumChunks   = ceil_to_multiple<IndexType>(InputDimensions, 16) / 16;
+    const auto          inputVector = reinterpret_cast<const int8x8_t*>(input);
+        #endif
 
-   // Read network parameters
-    bool ReadParameters(std::istream& stream) {
-      if (!previous_layer_.ReadParameters(stream)) return false;
-      for (std::size_t i = 0; i < kOutputDimensions; ++i)
-        biases_[i] = read_little_endian<BiasType>(stream);
-      for (std::size_t i = 0; i < kOutputDimensions * kPaddedInputDimensions; ++i)
-#if !defined (USE_SSSE3)
-        weights_[i] = read_little_endian<WeightType>(stream);
-#else
-        weights_[
-          (i / 4) % (kPaddedInputDimensions / 4) * kOutputDimensions * 4 +
-          i / kPaddedInputDimensions * 4 +
-          i % 4
-        ] = read_little_endian<WeightType>(stream);
+    for (IndexType i = 0; i < OutputDimensions; ++i)
+    {
+        const IndexType offset = i * PaddedInputDimensions;
 
-      // Determine if eights of weight and input products can be summed using 16bits
-      // without saturation. We assume worst case combinations of 0 and 127 for all inputs.
-      if (kOutputDimensions > 1 && !stream.fail())
-      {
-          canSaturate16.count = 0;
-#if !defined(USE_VNNI)
-          for (IndexType i = 0; i < kPaddedInputDimensions; i += 16)
-              for (IndexType j = 0; j < kOutputDimensions; ++j)
-                  for (int x = 0; x < 2; ++x)
-                  {
-                      WeightType* w = &weights_[i * kOutputDimensions + j * 4 + x * 2];
-                      int sum[2] = {0, 0};
-                      for (int k = 0; k < 8; ++k)
-                      {
-                          IndexType idx = k / 2 * kOutputDimensions * 4 + k % 2;
-                          sum[w[idx] < 0] += w[idx];
-                      }
-                      for (int sign : {-1, 1})
-                          while (sign * sum[sign == -1] > 258)
-                          {
-                              int maxK = 0, maxW = 0;
-                              for (int k = 0; k < 8; ++k)
-                              {
-                                  IndexType idx = k / 2 * kOutputDimensions * 4 + k % 2;
-                                  if (maxW < sign * w[idx])
-                                      maxK = k, maxW = sign * w[idx];
-                              }
-
-                              IndexType idx = maxK / 2 * kOutputDimensions * 4 + maxK % 2;
-                              sum[sign == -1] -= w[idx];
-                              canSaturate16.add(j, i + maxK / 2 * 4 + maxK % 2 + x * 2, w[idx]);
-                              w[idx] = 0;
-                          }
-                  }
-
-          // Non functional optimization for faster more linear access
-          std::sort(canSaturate16.ids, canSaturate16.ids + canSaturate16.count,
-                    [](const typename CanSaturate::Entry& e1, const typename CanSaturate::Entry& e2)
-                    { return e1.in == e2.in ? e1.out < e2.out : e1.in < e2.in; });
-#endif
-      }
-#endif
-
-      return !stream.fail();
-    }
-
-    // Forward propagation
-    const OutputType* Propagate(
-        const TransformedFeatureType* transformed_features, char* buffer) const {
-      const auto input = previous_layer_.Propagate(
-          transformed_features, buffer + kSelfBufferSize);
-
-#if defined (USE_AVX512)
-
-      [[maybe_unused]] const __m512i kOnes512 = _mm512_set1_epi16(1);
-
-      [[maybe_unused]] auto m512_hadd = [](__m512i sum, int bias) -> int {
-        return _mm512_reduce_add_epi32(sum) + bias;
-      };
-
-      [[maybe_unused]] auto m512_add_dpbusd_epi32 = [=](__m512i& acc, __m512i a, __m512i b) {
-#if defined (USE_VNNI)
-        acc = _mm512_dpbusd_epi32(acc, a, b);
-#else
-        __m512i product0 = _mm512_maddubs_epi16(a, b);
-        product0 = _mm512_madd_epi16(product0, kOnes512);
-        acc = _mm512_add_epi32(acc, product0);
-#endif
-      };
-
-      [[maybe_unused]] auto m512_add_dpbusd_epi32x4 = [=](__m512i& acc, __m512i a0, __m512i b0, __m512i a1, __m512i b1,
-                                                                        __m512i a2, __m512i b2, __m512i a3, __m512i b3) {
-#if defined (USE_VNNI)
-        acc = _mm512_dpbusd_epi32(acc, a0, b0);
-        acc = _mm512_dpbusd_epi32(acc, a1, b1);
-        acc = _mm512_dpbusd_epi32(acc, a2, b2);
-        acc = _mm512_dpbusd_epi32(acc, a3, b3);
-#else
-        __m512i product0 = _mm512_maddubs_epi16(a0, b0);
-        __m512i product1 = _mm512_maddubs_epi16(a1, b1);
-        __m512i product2 = _mm512_maddubs_epi16(a2, b2);
-        __m512i product3 = _mm512_maddubs_epi16(a3, b3);
-        product0 = _mm512_add_epi16(product0, product1);
-        product2 = _mm512_add_epi16(product2, product3);
-        product0 = _mm512_add_epi16(product0, product2);
-        product0 = _mm512_madd_epi16(product0, kOnes512);
-        acc = _mm512_add_epi32(acc, product0);
-#endif
-      };
-
-#endif
-#if defined (USE_AVX2)
-
-      [[maybe_unused]] const __m256i kOnes256 = _mm256_set1_epi16(1);
-
-      [[maybe_unused]] auto m256_hadd = [](__m256i sum, int bias) -> int {
-        __m128i sum128 = _mm_add_epi32(_mm256_castsi256_si128(sum), _mm256_extracti128_si256(sum, 1));
-        sum128 = _mm_add_epi32(sum128, _mm_shuffle_epi32(sum128, _MM_PERM_BADC));
-        sum128 = _mm_add_epi32(sum128, _mm_shuffle_epi32(sum128, _MM_PERM_CDAB));
-        return _mm_cvtsi128_si32(sum128) + bias;
-      };
-
-      [[maybe_unused]] auto m256_add_dpbusd_epi32 = [=](__m256i& acc, __m256i a, __m256i b) {
-#if defined (USE_VNNI)
-        acc = _mm256_dpbusd_epi32(acc, a, b);
-#else
-        __m256i product0 = _mm256_maddubs_epi16(a, b);
-        product0 = _mm256_madd_epi16(product0, kOnes256);
-        acc = _mm256_add_epi32(acc, product0);
-#endif
-      };
-
-      [[maybe_unused]] auto m256_add_dpbusd_epi32x4 = [=](__m256i& acc, __m256i a0, __m256i b0, __m256i a1, __m256i b1,
-                                                                        __m256i a2, __m256i b2, __m256i a3, __m256i b3) {
-#if defined (USE_VNNI)
-        acc = _mm256_dpbusd_epi32(acc, a0, b0);
-        acc = _mm256_dpbusd_epi32(acc, a1, b1);
-        acc = _mm256_dpbusd_epi32(acc, a2, b2);
-        acc = _mm256_dpbusd_epi32(acc, a3, b3);
-#else
-        __m256i product0 = _mm256_maddubs_epi16(a0, b0);
-        __m256i product1 = _mm256_maddubs_epi16(a1, b1);
-        __m256i product2 = _mm256_maddubs_epi16(a2, b2);
-        __m256i product3 = _mm256_maddubs_epi16(a3, b3);
-        product0 = _mm256_add_epi16(product0, product1);
-        product2 = _mm256_add_epi16(product2, product3);
-        product0 = _mm256_add_epi16(product0, product2);
-        product0 = _mm256_madd_epi16(product0, kOnes256);
-        acc = _mm256_add_epi32(acc, product0);
-#endif
-      };
-
-#endif
-#if defined (USE_SSSE3)
-
-      [[maybe_unused]] const __m128i kOnes128 = _mm_set1_epi16(1);
-
-      [[maybe_unused]] auto m128_hadd = [](__m128i sum, int bias) -> int {
-        sum = _mm_add_epi32(sum, _mm_shuffle_epi32(sum, 0x4E)); //_MM_PERM_BADC
-        sum = _mm_add_epi32(sum, _mm_shuffle_epi32(sum, 0xB1)); //_MM_PERM_CDAB
-        return _mm_cvtsi128_si32(sum) + bias;
-      };
-
-      [[maybe_unused]] auto m128_add_dpbusd_epi32 = [=](__m128i& acc, __m128i a, __m128i b) {
-        __m128i product0 = _mm_maddubs_epi16(a, b);
-        product0 = _mm_madd_epi16(product0, kOnes128);
-        acc = _mm_add_epi32(acc, product0);
-      };
-
-      [[maybe_unused]] auto m128_add_dpbusd_epi32x4 = [=](__m128i& acc, __m128i a0, __m128i b0, __m128i a1, __m128i b1,
-                                                                        __m128i a2, __m128i b2, __m128i a3, __m128i b3) {
-        __m128i product0 = _mm_maddubs_epi16(a0, b0);
-        __m128i product1 = _mm_maddubs_epi16(a1, b1);
-        __m128i product2 = _mm_maddubs_epi16(a2, b2);
-        __m128i product3 = _mm_maddubs_epi16(a3, b3);
-        product0 = _mm_adds_epi16(product0, product1);
-        product2 = _mm_adds_epi16(product2, product3);
-        product0 = _mm_adds_epi16(product0, product2);
-        product0 = _mm_madd_epi16(product0, kOnes128);
-        acc = _mm_add_epi32(acc, product0);
-      };
-
-#endif
-
-#if defined (USE_AVX512)
-      using vec_t = __m512i;
-      #define vec_setzero _mm512_setzero_si512
-      #define vec_set_32 _mm512_set1_epi32
-      auto& vec_add_dpbusd_32 = m512_add_dpbusd_epi32;
-      auto& vec_add_dpbusd_32x4 = m512_add_dpbusd_epi32x4;
-      auto& vec_hadd = m512_hadd;
-#elif defined (USE_AVX2)
-      using vec_t = __m256i;
-      #define vec_setzero _mm256_setzero_si256
-      #define vec_set_32 _mm256_set1_epi32
-      auto& vec_add_dpbusd_32 = m256_add_dpbusd_epi32;
-      auto& vec_add_dpbusd_32x4 = m256_add_dpbusd_epi32x4;
-      auto& vec_hadd = m256_hadd;
-#elif defined (USE_SSSE3)
-      using vec_t = __m128i;
-      #define vec_setzero _mm_setzero_si128
-      #define vec_set_32 _mm_set1_epi32
-      auto& vec_add_dpbusd_32 = m128_add_dpbusd_epi32;
-      auto& vec_add_dpbusd_32x4 = m128_add_dpbusd_epi32x4;
-      auto& vec_hadd = m128_hadd;
-#endif
-
-#if defined (USE_SSSE3)
-
-      const auto output = reinterpret_cast<OutputType*>(buffer);
-      const auto input_vector = reinterpret_cast<const vec_t*>(input);
-
-      static_assert(kOutputDimensions % kOutputSimdWidth == 0 || kOutputDimensions == 1);
-
-      // kOutputDimensions is either 1 or a multiple of kSimdWidth
-      // because then it is also an input dimension.
-      if constexpr (kOutputDimensions % kOutputSimdWidth == 0)
-      {
-          constexpr IndexType kNumChunks = kPaddedInputDimensions / 4;
-
-          const auto input32 = reinterpret_cast<const std::int32_t*>(input);
-          vec_t* outptr = reinterpret_cast<vec_t*>(output);
-          std::memcpy(output, biases_, kOutputDimensions * sizeof(OutputType));
-
-          for (int i = 0; i < (int)kNumChunks - 3; i += 4)
-          {
-              const vec_t in0 = vec_set_32(input32[i + 0]);
-              const vec_t in1 = vec_set_32(input32[i + 1]);
-              const vec_t in2 = vec_set_32(input32[i + 2]);
-              const vec_t in3 = vec_set_32(input32[i + 3]);
-              const auto col0 = reinterpret_cast<const vec_t*>(&weights_[(i + 0) * kOutputDimensions * 4]);
-              const auto col1 = reinterpret_cast<const vec_t*>(&weights_[(i + 1) * kOutputDimensions * 4]);
-              const auto col2 = reinterpret_cast<const vec_t*>(&weights_[(i + 2) * kOutputDimensions * 4]);
-              const auto col3 = reinterpret_cast<const vec_t*>(&weights_[(i + 3) * kOutputDimensions * 4]);
-              for (int j = 0; j * kOutputSimdWidth < kOutputDimensions; ++j)
-                  vec_add_dpbusd_32x4(outptr[j], in0, col0[j], in1, col1[j], in2, col2[j], in3, col3[j]);
-          }
-          for (int i = 0; i < canSaturate16.count; ++i)
-              output[canSaturate16.ids[i].out] += input[canSaturate16.ids[i].in] * canSaturate16.ids[i].w;
-      }
-      else if constexpr (kOutputDimensions == 1)
-      {
-#if defined (USE_AVX512)
-          if constexpr (kPaddedInputDimensions % (kSimdWidth * 2) != 0)
-          {
-              constexpr IndexType kNumChunks = kPaddedInputDimensions / kSimdWidth;
-              const auto input_vector256 = reinterpret_cast<const __m256i*>(input);
-
-              __m256i sum0 = _mm256_setzero_si256();
-              const auto row0 = reinterpret_cast<const __m256i*>(&weights_[0]);
-
-              for (int j = 0; j < (int)kNumChunks; ++j)
-              {
-                  const __m256i in = input_vector256[j];
-                  m256_add_dpbusd_epi32(sum0, in, row0[j]);
-              }
-              output[0] = m256_hadd(sum0, biases_[0]);
-          }
-          else
-#endif
-          {
-#if defined (USE_AVX512)
-              constexpr IndexType kNumChunks = kPaddedInputDimensions / (kSimdWidth * 2);
-#else
-              constexpr IndexType kNumChunks = kPaddedInputDimensions / kSimdWidth;
-#endif
-              vec_t sum0 = vec_setzero();
-              const auto row0 = reinterpret_cast<const vec_t*>(&weights_[0]);
-
-              for (int j = 0; j < (int)kNumChunks; ++j)
-              {
-                  const vec_t in = input_vector[j];
-                  vec_add_dpbusd_32(sum0, in, row0[j]);
-              }
-              output[0] = vec_hadd(sum0, biases_[0]);
-          }
-      }
-
-#else
-
-// Use old implementation for the other architectures.
-
-      auto output = reinterpret_cast<OutputType*>(buffer);
-
-#if defined(USE_SSE2)
-      constexpr IndexType kNumChunks = kPaddedInputDimensions / kSimdWidth;
-      const __m128i kZeros = _mm_setzero_si128();
-      const auto input_vector = reinterpret_cast<const __m128i*>(input);
-
-#elif defined(USE_MMX)
-      constexpr IndexType kNumChunks = kPaddedInputDimensions / kSimdWidth;
-      const __m64 kZeros = _mm_setzero_si64();
-      const auto input_vector = reinterpret_cast<const __m64*>(input);
-
-#elif defined(USE_NEON)
-      constexpr IndexType kNumChunks = kPaddedInputDimensions / kSimdWidth;
-      const auto input_vector = reinterpret_cast<const int8x8_t*>(input);
-#endif
-
-      for (IndexType i = 0; i < kOutputDimensions; ++i) {
-        const IndexType offset = i * kPaddedInputDimensions;
-
-#if defined(USE_SSE2)
-        __m128i sum_lo = _mm_cvtsi32_si128(biases_[i]);
-        __m128i sum_hi = kZeros;
-        const auto row = reinterpret_cast<const __m128i*>(&weights_[offset]);
-        for (IndexType j = 0; j < kNumChunks; ++j) {
-          __m128i row_j = _mm_load_si128(&row[j]);
-          __m128i input_j = _mm_load_si128(&input_vector[j]);
-          __m128i extended_row_lo = _mm_srai_epi16(_mm_unpacklo_epi8(row_j, row_j), 8);
-          __m128i extended_row_hi = _mm_srai_epi16(_mm_unpackhi_epi8(row_j, row_j), 8);
-          __m128i extended_input_lo = _mm_unpacklo_epi8(input_j, kZeros);
-          __m128i extended_input_hi = _mm_unpackhi_epi8(input_j, kZeros);
-          __m128i product_lo = _mm_madd_epi16(extended_row_lo, extended_input_lo);
-          __m128i product_hi = _mm_madd_epi16(extended_row_hi, extended_input_hi);
-          sum_lo = _mm_add_epi32(sum_lo, product_lo);
-          sum_hi = _mm_add_epi32(sum_hi, product_hi);
+        #if defined(USE_SSE2)
+        __m128i    sumLo = _mm_cvtsi32_si128(biases[i]);
+        __m128i    sumHi = Zeros;
+        const auto row   = reinterpret_cast<const __m128i*>(&weights[offset]);
+        for (IndexType j = 0; j < NumChunks; ++j)
+        {
+            __m128i row_j           = _mm_load_si128(&row[j]);
+            __m128i input_j         = _mm_load_si128(&inputVector[j]);
+            __m128i extendedRowLo   = _mm_srai_epi16(_mm_unpacklo_epi8(row_j, row_j), 8);
+            __m128i extendedRowHi   = _mm_srai_epi16(_mm_unpackhi_epi8(row_j, row_j), 8);
+            __m128i extendedInputLo = _mm_unpacklo_epi8(input_j, Zeros);
+            __m128i extendedInputHi = _mm_unpackhi_epi8(input_j, Zeros);
+            __m128i productLo       = _mm_madd_epi16(extendedRowLo, extendedInputLo);
+            __m128i productHi       = _mm_madd_epi16(extendedRowHi, extendedInputHi);
+            sumLo                   = _mm_add_epi32(sumLo, productLo);
+            sumHi                   = _mm_add_epi32(sumHi, productHi);
         }
-        __m128i sum = _mm_add_epi32(sum_lo, sum_hi);
-        __m128i sum_high_64 = _mm_shuffle_epi32(sum, _MM_SHUFFLE(1, 0, 3, 2));
-        sum = _mm_add_epi32(sum, sum_high_64);
+        __m128i sum           = _mm_add_epi32(sumLo, sumHi);
+        __m128i sumHigh_64    = _mm_shuffle_epi32(sum, _MM_SHUFFLE(1, 0, 3, 2));
+        sum                   = _mm_add_epi32(sum, sumHigh_64);
         __m128i sum_second_32 = _mm_shufflelo_epi16(sum, _MM_SHUFFLE(1, 0, 3, 2));
-        sum = _mm_add_epi32(sum, sum_second_32);
-        output[i] = _mm_cvtsi128_si32(sum);
+        sum                   = _mm_add_epi32(sum, sum_second_32);
+        output[i]             = _mm_cvtsi128_si32(sum);
 
-#elif defined(USE_MMX)
-        __m64 sum_lo = _mm_cvtsi32_si64(biases_[i]);
-        __m64 sum_hi = kZeros;
-        const auto row = reinterpret_cast<const __m64*>(&weights_[offset]);
-        for (IndexType j = 0; j < kNumChunks; ++j) {
-          __m64 row_j = row[j];
-          __m64 input_j = input_vector[j];
-          __m64 extended_row_lo = _mm_srai_pi16(_mm_unpacklo_pi8(row_j, row_j), 8);
-          __m64 extended_row_hi = _mm_srai_pi16(_mm_unpackhi_pi8(row_j, row_j), 8);
-          __m64 extended_input_lo = _mm_unpacklo_pi8(input_j, kZeros);
-          __m64 extended_input_hi = _mm_unpackhi_pi8(input_j, kZeros);
-          __m64 product_lo = _mm_madd_pi16(extended_row_lo, extended_input_lo);
-          __m64 product_hi = _mm_madd_pi16(extended_row_hi, extended_input_hi);
-          sum_lo = _mm_add_pi32(sum_lo, product_lo);
-          sum_hi = _mm_add_pi32(sum_hi, product_hi);
+        #elif defined(USE_NEON_DOTPROD)
+        int32x4_t  sum = {biases[i]};
+        const auto row = reinterpret_cast<const int8x16_t*>(&weights[offset]);
+        for (IndexType j = 0; j < NumChunks; ++j)
+        {
+            sum = vdotq_s32(sum, inputVector[j], row[j]);
         }
-        __m64 sum = _mm_add_pi32(sum_lo, sum_hi);
-        sum = _mm_add_pi32(sum, _mm_unpackhi_pi32(sum, sum));
-        output[i] = _mm_cvtsi64_si32(sum);
+        output[i] = vaddvq_s32(sum);
 
-#elif defined(USE_NEON)
-        int32x4_t sum = {biases_[i]};
-        const auto row = reinterpret_cast<const int8x8_t*>(&weights_[offset]);
-        for (IndexType j = 0; j < kNumChunks; ++j) {
-          int16x8_t product = vmull_s8(input_vector[j * 2], row[j * 2]);
-          product = vmlal_s8(product, input_vector[j * 2 + 1], row[j * 2 + 1]);
-          sum = vpadalq_s16(sum, product);
+        #elif defined(USE_NEON)
+        int32x4_t  sum = {biases[i]};
+        const auto row = reinterpret_cast<const int8x8_t*>(&weights[offset]);
+        for (IndexType j = 0; j < NumChunks; ++j)
+        {
+            int16x8_t product = vmull_s8(inputVector[j * 2], row[j * 2]);
+            product           = vmlal_s8(product, inputVector[j * 2 + 1], row[j * 2 + 1]);
+            sum               = vpadalq_s16(sum, product);
         }
         output[i] = sum[0] + sum[1] + sum[2] + sum[3];
 
-#else
-        OutputType sum = biases_[i];
-        for (IndexType j = 0; j < kInputDimensions; ++j) {
-          sum += weights_[offset + j] * input[j];
+        #endif
+    }
+    #else
+    std::memcpy(output, biases, sizeof(std::int32_t) * OutputDimensions);
+
+    // Traverse weights in transpose order to take advantage of input sparsity
+    for (IndexType i = 0; i < InputDimensions; ++i)
+        if (input[i])
+        {
+            const std::int8_t* w  = &weights[i];
+            const int          in = input[i];
+            for (IndexType j = 0; j < OutputDimensions; ++j)
+                output[j] += w[j * PaddedInputDimensions] * in;
         }
-        output[i] = sum;
+    #endif
+}
 #endif
 
-      }
-#if defined(USE_MMX)
-      _mm_empty();
-#endif
+template<IndexType InDims, IndexType OutDims>
+class AffineTransform {
+   public:
+    // Input/output type
+    using InputType  = std::uint8_t;
+    using OutputType = std::int32_t;
 
-#endif
+    // Number of input/output dimensions
+    static constexpr IndexType InputDimensions  = InDims;
+    static constexpr IndexType OutputDimensions = OutDims;
 
-      return output;
+    static constexpr IndexType PaddedInputDimensions =
+      ceil_to_multiple<IndexType>(InputDimensions, MaxSimdWidth);
+    static constexpr IndexType PaddedOutputDimensions =
+      ceil_to_multiple<IndexType>(OutputDimensions, MaxSimdWidth);
+
+    using OutputBuffer = OutputType[PaddedOutputDimensions];
+
+    // Hash value embedded in the evaluation file
+    static constexpr std::uint32_t get_hash_value(std::uint32_t prevHash) {
+        std::uint32_t hashValue = 0xCC03DAE4u;
+        hashValue += OutputDimensions;
+        hashValue ^= prevHash >> 1;
+        hashValue ^= prevHash << 31;
+        return hashValue;
+    }
+
+    static constexpr IndexType get_weight_index_scrambled(IndexType i) {
+        return (i / 4) % (PaddedInputDimensions / 4) * OutputDimensions * 4
+             + i / PaddedInputDimensions * 4 + i % 4;
+    }
+
+    static constexpr IndexType get_weight_index(IndexType i) {
+#if defined(USE_SSSE3)
+        return get_weight_index_scrambled(i);
+#else
+        return i;
+#endif
+    }
+
+    // Read network parameters
+    bool read_parameters(std::istream& stream) {
+        read_little_endian<BiasType>(stream, biases, OutputDimensions);
+        for (IndexType i = 0; i < OutputDimensions * PaddedInputDimensions; ++i)
+            weights[get_weight_index(i)] = read_little_endian<WeightType>(stream);
+
+        return !stream.fail();
+    }
+
+    // Write network parameters
+    bool write_parameters(std::ostream& stream) const {
+        write_little_endian<BiasType>(stream, biases, OutputDimensions);
+
+        for (IndexType i = 0; i < OutputDimensions * PaddedInputDimensions; ++i)
+            write_little_endian<WeightType>(stream, weights[get_weight_index(i)]);
+
+        return !stream.fail();
+    }
+    // Forward propagation
+    void propagate(const InputType* input, OutputType* output) const {
+
+#if defined(USE_SSSE3)
+
+        if constexpr (OutputDimensions > 1)
+        {
+
+    #if defined(USE_AVX512)
+            using vec_t = __m512i;
+        #define vec_setzero _mm512_setzero_si512
+        #define vec_set_32 _mm512_set1_epi32
+        #define vec_add_dpbusd_32 Simd::m512_add_dpbusd_epi32
+        #define vec_hadd Simd::m512_hadd
+    #elif defined(USE_AVX2)
+            using vec_t = __m256i;
+        #define vec_setzero _mm256_setzero_si256
+        #define vec_set_32 _mm256_set1_epi32
+        #define vec_add_dpbusd_32 Simd::m256_add_dpbusd_epi32
+        #define vec_hadd Simd::m256_hadd
+    #elif defined(USE_SSSE3)
+            using vec_t = __m128i;
+        #define vec_setzero _mm_setzero_si128
+        #define vec_set_32 _mm_set1_epi32
+        #define vec_add_dpbusd_32 Simd::m128_add_dpbusd_epi32
+        #define vec_hadd Simd::m128_hadd
+    #endif
+
+            static constexpr IndexType OutputSimdWidth = sizeof(vec_t) / sizeof(OutputType);
+
+            static_assert(OutputDimensions % OutputSimdWidth == 0);
+
+            constexpr IndexType NumChunks = ceil_to_multiple<IndexType>(InputDimensions, 8) / 4;
+            constexpr IndexType NumRegs   = OutputDimensions / OutputSimdWidth;
+
+            const auto   input32 = reinterpret_cast<const std::int32_t*>(input);
+            const vec_t* biasvec = reinterpret_cast<const vec_t*>(biases);
+            vec_t        acc[NumRegs];
+            for (IndexType k = 0; k < NumRegs; ++k)
+                acc[k] = biasvec[k];
+
+            for (IndexType i = 0; i < NumChunks; ++i)
+            {
+                const vec_t in0 = vec_set_32(input32[i]);
+                const auto  col0 =
+                  reinterpret_cast<const vec_t*>(&weights[i * OutputDimensions * 4]);
+
+                for (IndexType k = 0; k < NumRegs; ++k)
+                    vec_add_dpbusd_32(acc[k], in0, col0[k]);
+            }
+
+            vec_t* outptr = reinterpret_cast<vec_t*>(output);
+            for (IndexType k = 0; k < NumRegs; ++k)
+                outptr[k] = acc[k];
+
+    #undef vec_setzero
+    #undef vec_set_32
+    #undef vec_add_dpbusd_32
+    #undef vec_hadd
+        }
+        else if constexpr (OutputDimensions == 1)
+        {
+
+    // We cannot use AVX512 for the last layer because there are only 32 inputs
+    // and the buffer is not padded to 64 elements.
+    #if defined(USE_AVX2)
+            using vec_t = __m256i;
+        #define vec_setzero _mm256_setzero_si256
+        #define vec_set_32 _mm256_set1_epi32
+        #define vec_add_dpbusd_32 Simd::m256_add_dpbusd_epi32
+        #define vec_hadd Simd::m256_hadd
+    #elif defined(USE_SSSE3)
+            using vec_t = __m128i;
+        #define vec_setzero _mm_setzero_si128
+        #define vec_set_32 _mm_set1_epi32
+        #define vec_add_dpbusd_32 Simd::m128_add_dpbusd_epi32
+        #define vec_hadd Simd::m128_hadd
+    #endif
+
+            const auto inputVector = reinterpret_cast<const vec_t*>(input);
+
+            static constexpr IndexType InputSimdWidth = sizeof(vec_t) / sizeof(InputType);
+
+            static_assert(PaddedInputDimensions % InputSimdWidth == 0);
+
+            constexpr IndexType NumChunks = PaddedInputDimensions / InputSimdWidth;
+            vec_t               sum0      = vec_setzero();
+            const auto          row0      = reinterpret_cast<const vec_t*>(&weights[0]);
+
+            for (int j = 0; j < int(NumChunks); ++j)
+            {
+                const vec_t in = inputVector[j];
+                vec_add_dpbusd_32(sum0, in, row0[j]);
+            }
+            output[0] = vec_hadd(sum0, biases[0]);
+
+    #undef vec_setzero
+    #undef vec_set_32
+    #undef vec_add_dpbusd_32
+    #undef vec_hadd
+        }
+#else
+        // Use old implementation for the other architectures.
+        affine_transform_non_ssse3<InputDimensions, PaddedInputDimensions, OutputDimensions>(
+          output, weights, biases, input);
+#endif
     }
 
    private:
-    using BiasType = OutputType;
+    using BiasType   = OutputType;
     using WeightType = std::int8_t;
 
-    PreviousLayer previous_layer_;
+    alignas(CacheLineSize) BiasType biases[OutputDimensions];
+    alignas(CacheLineSize) WeightType weights[OutputDimensions * PaddedInputDimensions];
+};
 
-    alignas(kCacheLineSize) BiasType biases_[kOutputDimensions];
-    alignas(kCacheLineSize) WeightType weights_[kOutputDimensions * kPaddedInputDimensions];
-#if defined (USE_SSSE3)
-    struct CanSaturate {
-        int count;
-        struct Entry {
-            uint16_t out;
-            uint16_t in;
-            int8_t w;
-        } ids[kPaddedInputDimensions * kOutputDimensions * 3 / 4];
+}  // namespace Stockfish::Eval::NNUE::Layers
 
-        void add(int i, int j, int8_t w) {
-            ids[count].out = i;
-            ids[count].in = j;
-            ids[count].w = w;
-            ++count;
-        }
-    } canSaturate16;
-#endif
-  };
-
-}  // namespace Eval::NNUE::Layers
-
-#endif // #ifndef NNUE_LAYERS_AFFINE_TRANSFORM_H_INCLUDED
+#endif  // #ifndef NNUE_LAYERS_AFFINE_TRANSFORM_H_INCLUDED

src/nnue/layers/affine_transform_sparse_input.h

@@ -0,0 +1,278 @@
+/*
+  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
+
+  Stockfish is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  Stockfish is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+// Definition of layer AffineTransformSparseInput of NNUE evaluation function
+
+#ifndef NNUE_LAYERS_AFFINE_TRANSFORM_SPARSE_INPUT_H_INCLUDED
+#define NNUE_LAYERS_AFFINE_TRANSFORM_SPARSE_INPUT_H_INCLUDED
+
+#include <algorithm>
+#include <array>
+#include <cstdint>
+#include <iostream>
+
+#include "../../bitboard.h"
+#include "../nnue_common.h"
+#include "affine_transform.h"
+#include "simd.h"
+
+/*
+  This file contains the definition for a fully connected layer (aka affine transform) with block sparse input.
+*/
+
+namespace Stockfish::Eval::NNUE::Layers {
+
+#if (USE_SSSE3 | (USE_NEON >= 8))
+alignas(CacheLineSize) static inline const
+  std::array<std::array<std::uint16_t, 8>, 256> lookup_indices = []() {
+      std::array<std::array<std::uint16_t, 8>, 256> v{};
+      for (unsigned i = 0; i < 256; ++i)
+      {
+          std::uint64_t j = i, k = 0;
+          while (j)
+              v[i][k++] = pop_lsb(j);
+      }
+      return v;
+  }();
+
+// Find indices of nonzero numbers in an int32_t array
+template<const IndexType InputDimensions>
+void find_nnz(const std::int32_t* input, std::uint16_t* out, IndexType& count_out) {
+    #if defined(USE_SSSE3)
+        #if defined(USE_AVX512)
+    using vec_t = __m512i;
+            #define vec_nnz(a) _mm512_cmpgt_epi32_mask(a, _mm512_setzero_si512())
+        #elif defined(USE_AVX2)
+    using vec_t = __m256i;
+            #if defined(USE_VNNI) && !defined(USE_AVXVNNI)
+                #define vec_nnz(a) _mm256_cmpgt_epi32_mask(a, _mm256_setzero_si256())
+            #else
+                #define vec_nnz(a) \
+                    _mm256_movemask_ps( \
+                      _mm256_castsi256_ps(_mm256_cmpgt_epi32(a, _mm256_setzero_si256())))
+            #endif
+        #elif defined(USE_SSSE3)
+    using vec_t = __m128i;
+            #define vec_nnz(a) \
+                _mm_movemask_ps(_mm_castsi128_ps(_mm_cmpgt_epi32(a, _mm_setzero_si128())))
+        #endif
+    using vec128_t = __m128i;
+        #define vec128_zero _mm_setzero_si128()
+        #define vec128_set_16(a) _mm_set1_epi16(a)
+        #define vec128_load(a) _mm_load_si128(a)
+        #define vec128_storeu(a, b) _mm_storeu_si128(a, b)
+        #define vec128_add(a, b) _mm_add_epi16(a, b)
+    #elif defined(USE_NEON)
+    using vec_t                        = uint32x4_t;
+    static const std::uint32_t Mask[4] = {1, 2, 4, 8};
+        #define vec_nnz(a) vaddvq_u32(vandq_u32(vtstq_u32(a, a), vld1q_u32(Mask)))
+    using vec128_t                     = uint16x8_t;
+        #define vec128_zero vdupq_n_u16(0)
+        #define vec128_set_16(a) vdupq_n_u16(a)
+        #define vec128_load(a) vld1q_u16(reinterpret_cast<const std::uint16_t*>(a))
+        #define vec128_storeu(a, b) vst1q_u16(reinterpret_cast<std::uint16_t*>(a), b)
+        #define vec128_add(a, b) vaddq_u16(a, b)
+    #endif
+    constexpr IndexType InputSimdWidth = sizeof(vec_t) / sizeof(std::int32_t);
+    // Inputs are processed InputSimdWidth at a time and outputs are processed 8 at a time so we process in chunks of max(InputSimdWidth, 8)
+    constexpr IndexType ChunkSize       = std::max<IndexType>(InputSimdWidth, 8);
+    constexpr IndexType NumChunks       = InputDimensions / ChunkSize;
+    constexpr IndexType InputsPerChunk  = ChunkSize / InputSimdWidth;
+    constexpr IndexType OutputsPerChunk = ChunkSize / 8;
+
+    const auto     inputVector = reinterpret_cast<const vec_t*>(input);
+    IndexType      count       = 0;
+    vec128_t       base        = vec128_zero;
+    const vec128_t increment   = vec128_set_16(8);
+    for (IndexType i = 0; i < NumChunks; ++i)
+    {
+        // bitmask of nonzero values in this chunk
+        unsigned nnz = 0;
+        for (IndexType j = 0; j < InputsPerChunk; ++j)
+        {
+            const vec_t inputChunk = inputVector[i * InputsPerChunk + j];
+            nnz |= unsigned(vec_nnz(inputChunk)) << (j * InputSimdWidth);
+        }
+        for (IndexType j = 0; j < OutputsPerChunk; ++j)
+        {
+            const auto lookup = (nnz >> (j * 8)) & 0xFF;
+            const auto offsets =
+              vec128_load(reinterpret_cast<const vec128_t*>(&lookup_indices[lookup]));
+            vec128_storeu(reinterpret_cast<vec128_t*>(out + count), vec128_add(base, offsets));
+            count += popcount(lookup);
+            base = vec128_add(base, increment);
+        }
+    }
+    count_out = count;
+}
+    #undef vec_nnz
+    #undef vec128_zero
+    #undef vec128_set_16
+    #undef vec128_load
+    #undef vec128_storeu
+    #undef vec128_add
+#endif
+
+// Sparse input implementation
+template<IndexType InDims, IndexType OutDims>
+class AffineTransformSparseInput {
+   public:
+    // Input/output type
+    using InputType  = std::uint8_t;
+    using OutputType = std::int32_t;
+
+    // Number of input/output dimensions
+    static constexpr IndexType InputDimensions  = InDims;
+    static constexpr IndexType OutputDimensions = OutDims;
+
+    static_assert(OutputDimensions % 16 == 0,
+                  "Only implemented for OutputDimensions divisible by 16.");
+
+    static constexpr IndexType PaddedInputDimensions =
+      ceil_to_multiple<IndexType>(InputDimensions, MaxSimdWidth);
+    static constexpr IndexType PaddedOutputDimensions =
+      ceil_to_multiple<IndexType>(OutputDimensions, MaxSimdWidth);
+
+#if (USE_SSSE3 | (USE_NEON >= 8))
+    static constexpr IndexType ChunkSize = 4;
+#else
+    static constexpr IndexType ChunkSize = 1;
+#endif
+
+    using OutputBuffer = OutputType[PaddedOutputDimensions];
+
+    // Hash value embedded in the evaluation file
+    static constexpr std::uint32_t get_hash_value(std::uint32_t prevHash) {
+        std::uint32_t hashValue = 0xCC03DAE4u;
+        hashValue += OutputDimensions;
+        hashValue ^= prevHash >> 1;
+        hashValue ^= prevHash << 31;
+        return hashValue;
+    }
+
+    static constexpr IndexType get_weight_index_scrambled(IndexType i) {
+        return (i / ChunkSize) % (PaddedInputDimensions / ChunkSize) * OutputDimensions * ChunkSize
+             + i / PaddedInputDimensions * ChunkSize + i % ChunkSize;
+    }
+
+    static constexpr IndexType get_weight_index(IndexType i) {
+#if (USE_SSSE3 | (USE_NEON >= 8))
+        return get_weight_index_scrambled(i);
+#else
+        return i;
+#endif
+    }
+
+    // Read network parameters
+    bool read_parameters(std::istream& stream) {
+        read_little_endian<BiasType>(stream, biases, OutputDimensions);
+        for (IndexType i = 0; i < OutputDimensions * PaddedInputDimensions; ++i)
+            weights[get_weight_index(i)] = read_little_endian<WeightType>(stream);
+
+        return !stream.fail();
+    }
+
+    // Write network parameters
+    bool write_parameters(std::ostream& stream) const {
+        write_little_endian<BiasType>(stream, biases, OutputDimensions);
+
+        for (IndexType i = 0; i < OutputDimensions * PaddedInputDimensions; ++i)
+            write_little_endian<WeightType>(stream, weights[get_weight_index(i)]);
+
+        return !stream.fail();
+    }
+    // Forward propagation
+    void propagate(const InputType* input, OutputType* output) const {
+
+#if (USE_SSSE3 | (USE_NEON >= 8))
+    #if defined(USE_AVX512)
+        using invec_t  = __m512i;
+        using outvec_t = __m512i;
+        #define vec_set_32 _mm512_set1_epi32
+        #define vec_add_dpbusd_32 Simd::m512_add_dpbusd_epi32
+    #elif defined(USE_AVX2)
+        using invec_t  = __m256i;
+        using outvec_t = __m256i;
+        #define vec_set_32 _mm256_set1_epi32
+        #define vec_add_dpbusd_32 Simd::m256_add_dpbusd_epi32
+    #elif defined(USE_SSSE3)
+        using invec_t  = __m128i;
+        using outvec_t = __m128i;
+        #define vec_set_32 _mm_set1_epi32
+        #define vec_add_dpbusd_32 Simd::m128_add_dpbusd_epi32
+    #elif defined(USE_NEON_DOTPROD)
+        using invec_t  = int8x16_t;
+        using outvec_t = int32x4_t;
+        #define vec_set_32(a) vreinterpretq_s8_u32(vdupq_n_u32(a))
+        #define vec_add_dpbusd_32 Simd::dotprod_m128_add_dpbusd_epi32
+    #elif defined(USE_NEON)
+        using invec_t  = int8x16_t;
+        using outvec_t = int32x4_t;
+        #define vec_set_32(a) vreinterpretq_s8_u32(vdupq_n_u32(a))
+        #define vec_add_dpbusd_32 Simd::neon_m128_add_dpbusd_epi32
+    #endif
+        static constexpr IndexType OutputSimdWidth = sizeof(outvec_t) / sizeof(OutputType);
+
+        constexpr IndexType NumChunks = ceil_to_multiple<IndexType>(InputDimensions, 8) / ChunkSize;
+        constexpr IndexType NumRegs   = OutputDimensions / OutputSimdWidth;
+        std::uint16_t       nnz[NumChunks];
+        IndexType           count;
+
+        const auto input32 = reinterpret_cast<const std::int32_t*>(input);
+
+        // Find indices of nonzero 32-bit blocks
+        find_nnz<NumChunks>(input32, nnz, count);
+
+        const outvec_t* biasvec = reinterpret_cast<const outvec_t*>(biases);
+        outvec_t        acc[NumRegs];
+        for (IndexType k = 0; k < NumRegs; ++k)
+            acc[k] = biasvec[k];
+
+        for (IndexType j = 0; j < count; ++j)
+        {
+            const auto    i  = nnz[j];
+            const invec_t in = vec_set_32(input32[i]);
+            const auto    col =
+              reinterpret_cast<const invec_t*>(&weights[i * OutputDimensions * ChunkSize]);
+            for (IndexType k = 0; k < NumRegs; ++k)
+                vec_add_dpbusd_32(acc[k], in, col[k]);
+        }
+
+        outvec_t* outptr = reinterpret_cast<outvec_t*>(output);
+        for (IndexType k = 0; k < NumRegs; ++k)
+            outptr[k] = acc[k];
+    #undef vec_set_32
+    #undef vec_add_dpbusd_32
+#else
+        // Use dense implementation for the other architectures.
+        affine_transform_non_ssse3<InputDimensions, PaddedInputDimensions, OutputDimensions>(
+          output, weights, biases, input);
+#endif
+    }
+
+   private:
+    using BiasType   = OutputType;
+    using WeightType = std::int8_t;
+
+    alignas(CacheLineSize) BiasType biases[OutputDimensions];
+    alignas(CacheLineSize) WeightType weights[OutputDimensions * PaddedInputDimensions];
+};
+
+}  // namespace Stockfish::Eval::NNUE::Layers
+
+#endif  // #ifndef NNUE_LAYERS_AFFINE_TRANSFORM_SPARSE_INPUT_H_INCLUDED

src/nnue/layers/clipped_relu.h

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -21,146 +21,148 @@
 #ifndef NNUE_LAYERS_CLIPPED_RELU_H_INCLUDED
 #define NNUE_LAYERS_CLIPPED_RELU_H_INCLUDED
 
+#include <algorithm>
+#include <cstdint>
+#include <iosfwd>
+
 #include "../nnue_common.h"
 
-namespace Eval::NNUE::Layers {
+namespace Stockfish::Eval::NNUE::Layers {
 
-  // Clipped ReLU
-  template <typename PreviousLayer>
-  class ClippedReLU {
+// Clipped ReLU
+template<IndexType InDims>
+class ClippedReLU {
    public:
     // Input/output type
-    using InputType = typename PreviousLayer::OutputType;
+    using InputType  = std::int32_t;
     using OutputType = std::uint8_t;
-    static_assert(std::is_same<InputType, std::int32_t>::value, "");
 
     // Number of input/output dimensions
-    static constexpr IndexType kInputDimensions =
-        PreviousLayer::kOutputDimensions;
-    static constexpr IndexType kOutputDimensions = kInputDimensions;
+    static constexpr IndexType InputDimensions  = InDims;
+    static constexpr IndexType OutputDimensions = InputDimensions;
+    static constexpr IndexType PaddedOutputDimensions =
+      ceil_to_multiple<IndexType>(OutputDimensions, 32);
 
-    // Size of forward propagation buffer used in this layer
-    static constexpr std::size_t kSelfBufferSize =
-        CeilToMultiple(kOutputDimensions * sizeof(OutputType), kCacheLineSize);
-
-    // Size of the forward propagation buffer used from the input layer to this layer
-    static constexpr std::size_t kBufferSize =
-        PreviousLayer::kBufferSize + kSelfBufferSize;
+    using OutputBuffer = OutputType[PaddedOutputDimensions];
 
     // Hash value embedded in the evaluation file
-    static constexpr std::uint32_t GetHashValue() {
-      std::uint32_t hash_value = 0x538D24C7u;
-      hash_value += PreviousLayer::GetHashValue();
-      return hash_value;
+    static constexpr std::uint32_t get_hash_value(std::uint32_t prevHash) {
+        std::uint32_t hashValue = 0x538D24C7u;
+        hashValue += prevHash;
+        return hashValue;
     }
 
     // Read network parameters
-    bool ReadParameters(std::istream& stream) {
-      return previous_layer_.ReadParameters(stream);
-    }
+    bool read_parameters(std::istream&) { return true; }
+
+    // Write network parameters
+    bool write_parameters(std::ostream&) const { return true; }
 
     // Forward propagation
-    const OutputType* Propagate(
-        const TransformedFeatureType* transformed_features, char* buffer) const {
-      const auto input = previous_layer_.Propagate(
-          transformed_features, buffer + kSelfBufferSize);
-      const auto output = reinterpret_cast<OutputType*>(buffer);
+    void propagate(const InputType* input, OutputType* output) const {
 
-  #if defined(USE_AVX2)
-      constexpr IndexType kNumChunks = kInputDimensions / kSimdWidth;
-      const __m256i kZero = _mm256_setzero_si256();
-      const __m256i kOffsets = _mm256_set_epi32(7, 3, 6, 2, 5, 1, 4, 0);
-      const auto in = reinterpret_cast<const __m256i*>(input);
-      const auto out = reinterpret_cast<__m256i*>(output);
-      for (IndexType i = 0; i < kNumChunks; ++i) {
-        const __m256i words0 = _mm256_srai_epi16(_mm256_packs_epi32(
-            _mm256_load_si256(&in[i * 4 + 0]),
-            _mm256_load_si256(&in[i * 4 + 1])), kWeightScaleBits);
-        const __m256i words1 = _mm256_srai_epi16(_mm256_packs_epi32(
-            _mm256_load_si256(&in[i * 4 + 2]),
-            _mm256_load_si256(&in[i * 4 + 3])), kWeightScaleBits);
-        _mm256_store_si256(&out[i], _mm256_permutevar8x32_epi32(_mm256_max_epi8(
-            _mm256_packs_epi16(words0, words1), kZero), kOffsets));
-      }
-      constexpr IndexType kStart = kNumChunks * kSimdWidth;
+#if defined(USE_AVX2)
+        if constexpr (InputDimensions % SimdWidth == 0)
+        {
+            constexpr IndexType NumChunks = InputDimensions / SimdWidth;
+            const __m256i       Zero      = _mm256_setzero_si256();
+            const __m256i       Offsets   = _mm256_set_epi32(7, 3, 6, 2, 5, 1, 4, 0);
+            const auto          in        = reinterpret_cast<const __m256i*>(input);
+            const auto          out       = reinterpret_cast<__m256i*>(output);
+            for (IndexType i = 0; i < NumChunks; ++i)
+            {
+                const __m256i words0 =
+                  _mm256_srai_epi16(_mm256_packs_epi32(_mm256_load_si256(&in[i * 4 + 0]),
+                                                       _mm256_load_si256(&in[i * 4 + 1])),
+                                    WeightScaleBits);
+                const __m256i words1 =
+                  _mm256_srai_epi16(_mm256_packs_epi32(_mm256_load_si256(&in[i * 4 + 2]),
+                                                       _mm256_load_si256(&in[i * 4 + 3])),
+                                    WeightScaleBits);
+                _mm256_store_si256(
+                  &out[i], _mm256_permutevar8x32_epi32(
+                             _mm256_max_epi8(_mm256_packs_epi16(words0, words1), Zero), Offsets));
+            }
+        }
+        else
+        {
+            constexpr IndexType NumChunks = InputDimensions / (SimdWidth / 2);
+            const __m128i       Zero      = _mm_setzero_si128();
+            const auto          in        = reinterpret_cast<const __m128i*>(input);
+            const auto          out       = reinterpret_cast<__m128i*>(output);
+            for (IndexType i = 0; i < NumChunks; ++i)
+            {
+                const __m128i words0 = _mm_srai_epi16(
+                  _mm_packs_epi32(_mm_load_si128(&in[i * 4 + 0]), _mm_load_si128(&in[i * 4 + 1])),
+                  WeightScaleBits);
+                const __m128i words1 = _mm_srai_epi16(
+                  _mm_packs_epi32(_mm_load_si128(&in[i * 4 + 2]), _mm_load_si128(&in[i * 4 + 3])),
+                  WeightScaleBits);
+                const __m128i packedbytes = _mm_packs_epi16(words0, words1);
+                _mm_store_si128(&out[i], _mm_max_epi8(packedbytes, Zero));
+            }
+        }
+        constexpr IndexType Start = InputDimensions % SimdWidth == 0
+                                    ? InputDimensions / SimdWidth * SimdWidth
+                                    : InputDimensions / (SimdWidth / 2) * (SimdWidth / 2);
 
-  #elif defined(USE_SSE2)
-      constexpr IndexType kNumChunks = kInputDimensions / kSimdWidth;
+#elif defined(USE_SSE2)
+        constexpr IndexType NumChunks = InputDimensions / SimdWidth;
 
-  #ifdef USE_SSE41
-      const __m128i kZero = _mm_setzero_si128();
-  #else
-      const __m128i k0x80s = _mm_set1_epi8(-128);
-  #endif
+    #ifdef USE_SSE41
+        const __m128i Zero = _mm_setzero_si128();
+    #else
+        const __m128i k0x80s = _mm_set1_epi8(-128);
+    #endif
 
-      const auto in = reinterpret_cast<const __m128i*>(input);
-      const auto out = reinterpret_cast<__m128i*>(output);
-      for (IndexType i = 0; i < kNumChunks; ++i) {
-        const __m128i words0 = _mm_srai_epi16(_mm_packs_epi32(
-            _mm_load_si128(&in[i * 4 + 0]),
-            _mm_load_si128(&in[i * 4 + 1])), kWeightScaleBits);
-        const __m128i words1 = _mm_srai_epi16(_mm_packs_epi32(
-            _mm_load_si128(&in[i * 4 + 2]),
-            _mm_load_si128(&in[i * 4 + 3])), kWeightScaleBits);
-        const __m128i packedbytes = _mm_packs_epi16(words0, words1);
-        _mm_store_si128(&out[i],
+        const auto in  = reinterpret_cast<const __m128i*>(input);
+        const auto out = reinterpret_cast<__m128i*>(output);
+        for (IndexType i = 0; i < NumChunks; ++i)
+        {
+            const __m128i words0 = _mm_srai_epi16(
+              _mm_packs_epi32(_mm_load_si128(&in[i * 4 + 0]), _mm_load_si128(&in[i * 4 + 1])),
+              WeightScaleBits);
+            const __m128i words1 = _mm_srai_epi16(
+              _mm_packs_epi32(_mm_load_si128(&in[i * 4 + 2]), _mm_load_si128(&in[i * 4 + 3])),
+              WeightScaleBits);
+            const __m128i packedbytes = _mm_packs_epi16(words0, words1);
+            _mm_store_si128(&out[i],
 
-  #ifdef USE_SSE41
-          _mm_max_epi8(packedbytes, kZero)
-  #else
-          _mm_subs_epi8(_mm_adds_epi8(packedbytes, k0x80s), k0x80s)
-  #endif
+    #ifdef USE_SSE41
+                            _mm_max_epi8(packedbytes, Zero)
+    #else
+                            _mm_subs_epi8(_mm_adds_epi8(packedbytes, k0x80s), k0x80s)
+    #endif
 
-        );
-      }
-      constexpr IndexType kStart = kNumChunks * kSimdWidth;
+            );
+        }
+        constexpr IndexType Start = NumChunks * SimdWidth;
 
-  #elif defined(USE_MMX)
-      constexpr IndexType kNumChunks = kInputDimensions / kSimdWidth;
-      const __m64 k0x80s = _mm_set1_pi8(-128);
-      const auto in = reinterpret_cast<const __m64*>(input);
-      const auto out = reinterpret_cast<__m64*>(output);
-      for (IndexType i = 0; i < kNumChunks; ++i) {
-        const __m64 words0 = _mm_srai_pi16(
-            _mm_packs_pi32(in[i * 4 + 0], in[i * 4 + 1]),
-            kWeightScaleBits);
-        const __m64 words1 = _mm_srai_pi16(
-            _mm_packs_pi32(in[i * 4 + 2], in[i * 4 + 3]),
-            kWeightScaleBits);
-        const __m64 packedbytes = _mm_packs_pi16(words0, words1);
-        out[i] = _mm_subs_pi8(_mm_adds_pi8(packedbytes, k0x80s), k0x80s);
-      }
-      _mm_empty();
-      constexpr IndexType kStart = kNumChunks * kSimdWidth;
+#elif defined(USE_NEON)
+        constexpr IndexType NumChunks = InputDimensions / (SimdWidth / 2);
+        const int8x8_t      Zero      = {0};
+        const auto          in        = reinterpret_cast<const int32x4_t*>(input);
+        const auto          out       = reinterpret_cast<int8x8_t*>(output);
+        for (IndexType i = 0; i < NumChunks; ++i)
+        {
+            int16x8_t  shifted;
+            const auto pack = reinterpret_cast<int16x4_t*>(&shifted);
+            pack[0]         = vqshrn_n_s32(in[i * 2 + 0], WeightScaleBits);
+            pack[1]         = vqshrn_n_s32(in[i * 2 + 1], WeightScaleBits);
+            out[i]          = vmax_s8(vqmovn_s16(shifted), Zero);
+        }
+        constexpr IndexType Start = NumChunks * (SimdWidth / 2);
+#else
+        constexpr IndexType Start = 0;
+#endif
 
-  #elif defined(USE_NEON)
-      constexpr IndexType kNumChunks = kInputDimensions / (kSimdWidth / 2);
-      const int8x8_t kZero = {0};
-      const auto in = reinterpret_cast<const int32x4_t*>(input);
-      const auto out = reinterpret_cast<int8x8_t*>(output);
-      for (IndexType i = 0; i < kNumChunks; ++i) {
-        int16x8_t shifted;
-        const auto pack = reinterpret_cast<int16x4_t*>(&shifted);
-        pack[0] = vqshrn_n_s32(in[i * 2 + 0], kWeightScaleBits);
-        pack[1] = vqshrn_n_s32(in[i * 2 + 1], kWeightScaleBits);
-        out[i] = vmax_s8(vqmovn_s16(shifted), kZero);
-      }
-      constexpr IndexType kStart = kNumChunks * (kSimdWidth / 2);
-  #else
-      constexpr IndexType kStart = 0;
-  #endif
-
-      for (IndexType i = kStart; i < kInputDimensions; ++i) {
-        output[i] = static_cast<OutputType>(
-            std::max(0, std::min(127, input[i] >> kWeightScaleBits)));
-      }
-      return output;
+        for (IndexType i = Start; i < InputDimensions; ++i)
+        {
+            output[i] = static_cast<OutputType>(std::clamp(input[i] >> WeightScaleBits, 0, 127));
+        }
     }
+};
 
-   private:
-    PreviousLayer previous_layer_;
-  };
+}  // namespace Stockfish::Eval::NNUE::Layers
 
-}  // namespace Eval::NNUE::Layers
-
-#endif // NNUE_LAYERS_CLIPPED_RELU_H_INCLUDED
+#endif  // NNUE_LAYERS_CLIPPED_RELU_H_INCLUDED

src/nnue/layers/input_slice.h

@@ -1,68 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
-
-  Stockfish is free software: you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation, either version 3 of the License, or
-  (at your option) any later version.
-
-  Stockfish is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-// NNUE evaluation function layer InputSlice definition
-
-#ifndef NNUE_LAYERS_INPUT_SLICE_H_INCLUDED
-#define NNUE_LAYERS_INPUT_SLICE_H_INCLUDED
-
-#include "../nnue_common.h"
-
-namespace Eval::NNUE::Layers {
-
-// Input layer
-template <IndexType OutputDimensions, IndexType Offset = 0>
-class InputSlice {
- public:
-  // Need to maintain alignment
-  static_assert(Offset % kMaxSimdWidth == 0, "");
-
-  // Output type
-  using OutputType = TransformedFeatureType;
-
-  // Output dimensionality
-  static constexpr IndexType kOutputDimensions = OutputDimensions;
-
-  // Size of forward propagation buffer used from the input layer to this layer
-  static constexpr std::size_t kBufferSize = 0;
-
-  // Hash value embedded in the evaluation file
-  static constexpr std::uint32_t GetHashValue() {
-    std::uint32_t hash_value = 0xEC42E90Du;
-    hash_value ^= kOutputDimensions ^ (Offset << 10);
-    return hash_value;
-  }
-
-  // Read network parameters
-  bool ReadParameters(std::istream& /*stream*/) {
-    return true;
-  }
-
-  // Forward propagation
-  const OutputType* Propagate(
-      const TransformedFeatureType* transformed_features,
-      char* /*buffer*/) const {
-    return transformed_features + Offset;
-  }
-
- private:
-};
-
-}  // namespace Layers
-
-#endif // #ifndef NNUE_LAYERS_INPUT_SLICE_H_INCLUDED

src/nnue/layers/simd.h

@@ -0,0 +1,167 @@
+/*
+  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
+
+  Stockfish is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  Stockfish is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef STOCKFISH_SIMD_H_INCLUDED
+#define STOCKFISH_SIMD_H_INCLUDED
+
+#if defined(USE_AVX2)
+    #include <immintrin.h>
+
+#elif defined(USE_SSE41)
+    #include <smmintrin.h>
+
+#elif defined(USE_SSSE3)
+    #include <tmmintrin.h>
+
+#elif defined(USE_SSE2)
+    #include <emmintrin.h>
+
+#elif defined(USE_NEON)
+    #include <arm_neon.h>
+#endif
+
+namespace Stockfish::Simd {
+
+#if defined(USE_AVX512)
+
+[[maybe_unused]] static int m512_hadd(__m512i sum, int bias) {
+    return _mm512_reduce_add_epi32(sum) + bias;
+}
+
+/*
+      Parameters:
+        sum0 = [zmm0.i128[0], zmm0.i128[1], zmm0.i128[2], zmm0.i128[3]]
+        sum1 = [zmm1.i128[0], zmm1.i128[1], zmm1.i128[2], zmm1.i128[3]]
+        sum2 = [zmm2.i128[0], zmm2.i128[1], zmm2.i128[2], zmm2.i128[3]]
+        sum3 = [zmm3.i128[0], zmm3.i128[1], zmm3.i128[2], zmm3.i128[3]]
+
+      Returns:
+        ret = [
+          reduce_add_epi32(zmm0.i128[0]), reduce_add_epi32(zmm1.i128[0]), reduce_add_epi32(zmm2.i128[0]), reduce_add_epi32(zmm3.i128[0]),
+          reduce_add_epi32(zmm0.i128[1]), reduce_add_epi32(zmm1.i128[1]), reduce_add_epi32(zmm2.i128[1]), reduce_add_epi32(zmm3.i128[1]),
+          reduce_add_epi32(zmm0.i128[2]), reduce_add_epi32(zmm1.i128[2]), reduce_add_epi32(zmm2.i128[2]), reduce_add_epi32(zmm3.i128[2]),
+          reduce_add_epi32(zmm0.i128[3]), reduce_add_epi32(zmm1.i128[3]), reduce_add_epi32(zmm2.i128[3]), reduce_add_epi32(zmm3.i128[3])
+        ]
+    */
+[[maybe_unused]] static __m512i
+m512_hadd128x16_interleave(__m512i sum0, __m512i sum1, __m512i sum2, __m512i sum3) {
+
+    __m512i sum01a = _mm512_unpacklo_epi32(sum0, sum1);
+    __m512i sum01b = _mm512_unpackhi_epi32(sum0, sum1);
+
+    __m512i sum23a = _mm512_unpacklo_epi32(sum2, sum3);
+    __m512i sum23b = _mm512_unpackhi_epi32(sum2, sum3);
+
+    __m512i sum01 = _mm512_add_epi32(sum01a, sum01b);
+    __m512i sum23 = _mm512_add_epi32(sum23a, sum23b);
+
+    __m512i sum0123a = _mm512_unpacklo_epi64(sum01, sum23);
+    __m512i sum0123b = _mm512_unpackhi_epi64(sum01, sum23);
+
+    return _mm512_add_epi32(sum0123a, sum0123b);
+}
+
+[[maybe_unused]] static void m512_add_dpbusd_epi32(__m512i& acc, __m512i a, __m512i b) {
+
+    #if defined(USE_VNNI)
+    acc = _mm512_dpbusd_epi32(acc, a, b);
+    #else
+    __m512i product0 = _mm512_maddubs_epi16(a, b);
+    product0         = _mm512_madd_epi16(product0, _mm512_set1_epi16(1));
+    acc              = _mm512_add_epi32(acc, product0);
+    #endif
+}
+
+#endif
+
+#if defined(USE_AVX2)
+
+[[maybe_unused]] static int m256_hadd(__m256i sum, int bias) {
+    __m128i sum128 = _mm_add_epi32(_mm256_castsi256_si128(sum), _mm256_extracti128_si256(sum, 1));
+    sum128         = _mm_add_epi32(sum128, _mm_shuffle_epi32(sum128, _MM_PERM_BADC));
+    sum128         = _mm_add_epi32(sum128, _mm_shuffle_epi32(sum128, _MM_PERM_CDAB));
+    return _mm_cvtsi128_si32(sum128) + bias;
+}
+
+[[maybe_unused]] static void m256_add_dpbusd_epi32(__m256i& acc, __m256i a, __m256i b) {
+
+    #if defined(USE_VNNI)
+    acc = _mm256_dpbusd_epi32(acc, a, b);
+    #else
+    __m256i product0 = _mm256_maddubs_epi16(a, b);
+    product0         = _mm256_madd_epi16(product0, _mm256_set1_epi16(1));
+    acc              = _mm256_add_epi32(acc, product0);
+    #endif
+}
+
+#endif
+
+#if defined(USE_SSSE3)
+
+[[maybe_unused]] static int m128_hadd(__m128i sum, int bias) {
+    sum = _mm_add_epi32(sum, _mm_shuffle_epi32(sum, 0x4E));  //_MM_PERM_BADC
+    sum = _mm_add_epi32(sum, _mm_shuffle_epi32(sum, 0xB1));  //_MM_PERM_CDAB
+    return _mm_cvtsi128_si32(sum) + bias;
+}
+
+[[maybe_unused]] static void m128_add_dpbusd_epi32(__m128i& acc, __m128i a, __m128i b) {
+
+    __m128i product0 = _mm_maddubs_epi16(a, b);
+    product0         = _mm_madd_epi16(product0, _mm_set1_epi16(1));
+    acc              = _mm_add_epi32(acc, product0);
+}
+
+#endif
+
+#if defined(USE_NEON_DOTPROD)
+
+[[maybe_unused]] static void
+dotprod_m128_add_dpbusd_epi32(int32x4_t& acc, int8x16_t a, int8x16_t b) {
+
+    acc = vdotq_s32(acc, a, b);
+}
+#endif
+
+#if defined(USE_NEON)
+
+[[maybe_unused]] static int neon_m128_reduce_add_epi32(int32x4_t s) {
+    #if USE_NEON >= 8
+    return vaddvq_s32(s);
+    #else
+    return s[0] + s[1] + s[2] + s[3];
+    #endif
+}
+
+[[maybe_unused]] static int neon_m128_hadd(int32x4_t sum, int bias) {
+    return neon_m128_reduce_add_epi32(sum) + bias;
+}
+
+#endif
+
+#if USE_NEON >= 8
+[[maybe_unused]] static void neon_m128_add_dpbusd_epi32(int32x4_t& acc, int8x16_t a, int8x16_t b) {
+
+    int16x8_t product0 = vmull_s8(vget_low_s8(a), vget_low_s8(b));
+    int16x8_t product1 = vmull_high_s8(a, b);
+    int16x8_t sum      = vpaddq_s16(product0, product1);
+    acc                = vpadalq_s16(acc, sum);
+}
+#endif
+}
+
+#endif  // STOCKFISH_SIMD_H_INCLUDED

src/nnue/layers/sqr_clipped_relu.h

@@ -0,0 +1,103 @@
+/*
+  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
+
+  Stockfish is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  Stockfish is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+// Definition of layer ClippedReLU of NNUE evaluation function
+
+#ifndef NNUE_LAYERS_SQR_CLIPPED_RELU_H_INCLUDED
+#define NNUE_LAYERS_SQR_CLIPPED_RELU_H_INCLUDED
+
+#include <algorithm>
+#include <cstdint>
+#include <iosfwd>
+
+#include "../nnue_common.h"
+
+namespace Stockfish::Eval::NNUE::Layers {
+
+// Clipped ReLU
+template<IndexType InDims>
+class SqrClippedReLU {
+   public:
+    // Input/output type
+    using InputType  = std::int32_t;
+    using OutputType = std::uint8_t;
+
+    // Number of input/output dimensions
+    static constexpr IndexType InputDimensions  = InDims;
+    static constexpr IndexType OutputDimensions = InputDimensions;
+    static constexpr IndexType PaddedOutputDimensions =
+      ceil_to_multiple<IndexType>(OutputDimensions, 32);
+
+    using OutputBuffer = OutputType[PaddedOutputDimensions];
+
+    // Hash value embedded in the evaluation file
+    static constexpr std::uint32_t get_hash_value(std::uint32_t prevHash) {
+        std::uint32_t hashValue = 0x538D24C7u;
+        hashValue += prevHash;
+        return hashValue;
+    }
+
+    // Read network parameters
+    bool read_parameters(std::istream&) { return true; }
+
+    // Write network parameters
+    bool write_parameters(std::ostream&) const { return true; }
+
+    // Forward propagation
+    void propagate(const InputType* input, OutputType* output) const {
+
+#if defined(USE_SSE2)
+        constexpr IndexType NumChunks = InputDimensions / 16;
+
+        static_assert(WeightScaleBits == 6);
+        const auto in  = reinterpret_cast<const __m128i*>(input);
+        const auto out = reinterpret_cast<__m128i*>(output);
+        for (IndexType i = 0; i < NumChunks; ++i)
+        {
+            __m128i words0 =
+              _mm_packs_epi32(_mm_load_si128(&in[i * 4 + 0]), _mm_load_si128(&in[i * 4 + 1]));
+            __m128i words1 =
+              _mm_packs_epi32(_mm_load_si128(&in[i * 4 + 2]), _mm_load_si128(&in[i * 4 + 3]));
+
+            // We shift by WeightScaleBits * 2 = 12 and divide by 128
+            // which is an additional shift-right of 7, meaning 19 in total.
+            // MulHi strips the lower 16 bits so we need to shift out 3 more to match.
+            words0 = _mm_srli_epi16(_mm_mulhi_epi16(words0, words0), 3);
+            words1 = _mm_srli_epi16(_mm_mulhi_epi16(words1, words1), 3);
+
+            _mm_store_si128(&out[i], _mm_packs_epi16(words0, words1));
+        }
+        constexpr IndexType Start = NumChunks * 16;
+
+#else
+        constexpr IndexType Start = 0;
+#endif
+
+        for (IndexType i = Start; i < InputDimensions; ++i)
+        {
+            output[i] = static_cast<OutputType>(
+              // Really should be /127 but we need to make it fast so we right-shift
+              // by an extra 7 bits instead. Needs to be accounted for in the trainer.
+              std::min(127ll, ((long long) (input[i]) * input[i]) >> (2 * WeightScaleBits + 7)));
+        }
+    }
+};
+
+}  // namespace Stockfish::Eval::NNUE::Layers
+
+#endif  // NNUE_LAYERS_SQR_CLIPPED_RELU_H_INCLUDED

src/nnue/network.cpp

@@ -0,0 +1,444 @@
+/*
+  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
+
+  Stockfish is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  Stockfish is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "network.h"
+
+#include <cmath>
+#include <cstdlib>
+#include <cstring>
+#include <fstream>
+#include <iostream>
+#include <optional>
+#include <type_traits>
+#include <vector>
+
+#include "../cluster.h"
+#include "../evaluate.h"
+#include "../incbin/incbin.h"
+#include "../misc.h"
+#include "../position.h"
+#include "../types.h"
+#include "nnue_architecture.h"
+#include "nnue_common.h"
+#include "nnue_misc.h"
+
+namespace {
+// Macro to embed the default efficiently updatable neural network (NNUE) file
+// data in the engine binary (using incbin.h, by Dale Weiler).
+// This macro invocation will declare the following three variables
+//     const unsigned char        gEmbeddedNNUEData[];  // a pointer to the embedded data
+//     const unsigned char *const gEmbeddedNNUEEnd;     // a marker to the end
+//     const unsigned int         gEmbeddedNNUESize;    // the size of the embedded file
+// Note that this does not work in Microsoft Visual Studio.
+#if !defined(_MSC_VER) && !defined(NNUE_EMBEDDING_OFF)
+INCBIN(EmbeddedNNUEBig, EvalFileDefaultNameBig);
+INCBIN(EmbeddedNNUESmall, EvalFileDefaultNameSmall);
+#else
+const unsigned char        gEmbeddedNNUEBigData[1]   = {0x0};
+const unsigned char* const gEmbeddedNNUEBigEnd       = &gEmbeddedNNUEBigData[1];
+const unsigned int         gEmbeddedNNUEBigSize      = 1;
+const unsigned char        gEmbeddedNNUESmallData[1] = {0x0};
+const unsigned char* const gEmbeddedNNUESmallEnd     = &gEmbeddedNNUESmallData[1];
+const unsigned int         gEmbeddedNNUESmallSize    = 1;
+#endif
+
+struct EmbeddedNNUE {
+    EmbeddedNNUE(const unsigned char* embeddedData,
+                 const unsigned char* embeddedEnd,
+                 const unsigned int   embeddedSize) :
+        data(embeddedData),
+        end(embeddedEnd),
+        size(embeddedSize) {}
+    const unsigned char* data;
+    const unsigned char* end;
+    const unsigned int   size;
+};
+
+using namespace Stockfish::Eval::NNUE;
+
+EmbeddedNNUE get_embedded(EmbeddedNNUEType type) {
+    if (type == EmbeddedNNUEType::BIG)
+        return EmbeddedNNUE(gEmbeddedNNUEBigData, gEmbeddedNNUEBigEnd, gEmbeddedNNUEBigSize);
+    else
+        return EmbeddedNNUE(gEmbeddedNNUESmallData, gEmbeddedNNUESmallEnd, gEmbeddedNNUESmallSize);
+}
+
+}
+
+
+namespace Stockfish::Eval::NNUE {
+
+
+namespace Detail {
+
+// Initialize the evaluation function parameters
+template<typename T>
+void initialize(AlignedPtr<T>& pointer) {
+
+    pointer.reset(reinterpret_cast<T*>(std_aligned_alloc(alignof(T), sizeof(T))));
+    std::memset(pointer.get(), 0, sizeof(T));
+}
+
+template<typename T>
+void initialize(LargePagePtr<T>& pointer) {
+
+    static_assert(alignof(T) <= 4096,
+                  "aligned_large_pages_alloc() may fail for such a big alignment requirement of T");
+    pointer.reset(reinterpret_cast<T*>(aligned_large_pages_alloc(sizeof(T))));
+    std::memset(pointer.get(), 0, sizeof(T));
+}
+
+// Read evaluation function parameters
+template<typename T>
+bool read_parameters(std::istream& stream, T& reference) {
+
+    std::uint32_t header;
+    header = read_little_endian<std::uint32_t>(stream);
+    if (!stream || header != T::get_hash_value())
+        return false;
+    return reference.read_parameters(stream);
+}
+
+// Write evaluation function parameters
+template<typename T>
+bool write_parameters(std::ostream& stream, const T& reference) {
+
+    write_little_endian<std::uint32_t>(stream, T::get_hash_value());
+    return reference.write_parameters(stream);
+}
+
+}  // namespace Detail
+
+
+template<typename Arch, typename Transformer>
+void Network<Arch, Transformer>::load(const std::string& rootDirectory, std::string evalfilePath) {
+#if defined(DEFAULT_NNUE_DIRECTORY)
+    std::vector<std::string> dirs = {"<internal>", "", rootDirectory,
+                                     stringify(DEFAULT_NNUE_DIRECTORY)};
+#else
+    std::vector<std::string> dirs = {"<internal>", "", rootDirectory};
+#endif
+
+    if (evalfilePath.empty())
+        evalfilePath = evalFile.defaultName;
+
+    for (const auto& directory : dirs)
+    {
+        if (evalFile.current != evalfilePath)
+        {
+            if (directory != "<internal>")
+            {
+                load_user_net(directory, evalfilePath);
+            }
+
+            if (directory == "<internal>" && evalfilePath == evalFile.defaultName)
+            {
+                load_internal();
+            }
+        }
+    }
+}
+
+
+template<typename Arch, typename Transformer>
+bool Network<Arch, Transformer>::save(const std::optional<std::string>& filename) const {
+    std::string actualFilename;
+    std::string msg;
+
+    if (filename.has_value())
+        actualFilename = filename.value();
+    else
+    {
+        if (evalFile.current != evalFile.defaultName)
+        {
+            msg = "Failed to export a net. "
+                  "A non-embedded net can only be saved if the filename is specified";
+
+            sync_cout << msg << sync_endl;
+            return false;
+        }
+
+        actualFilename = evalFile.defaultName;
+    }
+
+    std::ofstream stream(actualFilename, std::ios_base::binary);
+    bool          saved = save(stream, evalFile.current, evalFile.netDescription);
+
+    msg = saved ? "Network saved successfully to " + actualFilename : "Failed to export a net";
+
+    sync_cout << msg << sync_endl;
+    return saved;
+}
+
+
+template<typename Arch, typename Transformer>
+Value Network<Arch, Transformer>::evaluate(const Position& pos,
+                                           bool            adjusted,
+                                           int*            complexity,
+                                           bool            psqtOnly) const {
+    // We manually align the arrays on the stack because with gcc < 9.3
+    // overaligning stack variables with alignas() doesn't work correctly.
+
+    constexpr uint64_t alignment = CacheLineSize;
+    constexpr int      delta     = 24;
+
+#if defined(ALIGNAS_ON_STACK_VARIABLES_BROKEN)
+    TransformedFeatureType transformedFeaturesUnaligned
+      [FeatureTransformer<Arch::TransformedFeatureDimensions, nullptr>::BufferSize
+       + alignment / sizeof(TransformedFeatureType)];
+
+    auto* transformedFeatures = align_ptr_up<alignment>(&transformedFeaturesUnaligned[0]);
+#else
+    alignas(alignment) TransformedFeatureType transformedFeatures
+      [FeatureTransformer<Arch::TransformedFeatureDimensions, nullptr>::BufferSize];
+#endif
+
+    ASSERT_ALIGNED(transformedFeatures, alignment);
+
+    const int  bucket = (pos.count<ALL_PIECES>() - 1) / 4;
+    const auto psqt   = featureTransformer->transform(pos, transformedFeatures, bucket, psqtOnly);
+    const auto positional = !psqtOnly ? (network[bucket]->propagate(transformedFeatures)) : 0;
+
+    if (complexity)
+        *complexity = !psqtOnly ? std::abs(psqt - positional) / OutputScale : 0;
+
+    // Give more value to positional evaluation when adjusted flag is set
+    if (adjusted)
+        return static_cast<Value>(((1024 - delta) * psqt + (1024 + delta) * positional)
+                                  / (1024 * OutputScale));
+    else
+        return static_cast<Value>((psqt + positional) / OutputScale);
+}
+
+
+template<typename Arch, typename Transformer>
+void Network<Arch, Transformer>::verify(std::string evalfilePath) const {
+    if (evalfilePath.empty())
+        evalfilePath = evalFile.defaultName;
+
+    if (evalFile.current != evalfilePath)
+    {
+        std::string msg1 =
+          "Network evaluation parameters compatible with the engine must be available.";
+        std::string msg2 = "The network file " + evalfilePath + " was not loaded successfully.";
+        std::string msg3 = "The UCI option EvalFile might need to specify the full path, "
+                           "including the directory name, to the network file.";
+        std::string msg4 = "The default net can be downloaded from: "
+                           "https://tests.stockfishchess.org/api/nn/"
+                         + evalFile.defaultName;
+        std::string msg5 = "The engine will be terminated now.";
+
+        sync_cout << "info string ERROR: " << msg1 << sync_endl;
+        sync_cout << "info string ERROR: " << msg2 << sync_endl;
+        sync_cout << "info string ERROR: " << msg3 << sync_endl;
+        sync_cout << "info string ERROR: " << msg4 << sync_endl;
+        sync_cout << "info string ERROR: " << msg5 << sync_endl;
+        exit(EXIT_FAILURE);
+    }
+
+    if (Cluster::is_root())
+        sync_cout << "info string NNUE evaluation using " << evalfilePath << sync_endl;
+}
+
+
+template<typename Arch, typename Transformer>
+void Network<Arch, Transformer>::hint_common_access(const Position& pos, bool psqtOnl) const {
+    featureTransformer->hint_common_access(pos, psqtOnl);
+}
+
+
+template<typename Arch, typename Transformer>
+NnueEvalTrace Network<Arch, Transformer>::trace_evaluate(const Position& pos) const {
+    // We manually align the arrays on the stack because with gcc < 9.3
+    // overaligning stack variables with alignas() doesn't work correctly.
+    constexpr uint64_t alignment = CacheLineSize;
+
+#if defined(ALIGNAS_ON_STACK_VARIABLES_BROKEN)
+    TransformedFeatureType transformedFeaturesUnaligned
+      [FeatureTransformer<Arch::TransformedFeatureDimensions, nullptr>::BufferSize
+       + alignment / sizeof(TransformedFeatureType)];
+
+    auto* transformedFeatures = align_ptr_up<alignment>(&transformedFeaturesUnaligned[0]);
+#else
+    alignas(alignment) TransformedFeatureType transformedFeatures
+      [FeatureTransformer<Arch::TransformedFeatureDimensions, nullptr>::BufferSize];
+#endif
+
+    ASSERT_ALIGNED(transformedFeatures, alignment);
+
+    NnueEvalTrace t{};
+    t.correctBucket = (pos.count<ALL_PIECES>() - 1) / 4;
+    for (IndexType bucket = 0; bucket < LayerStacks; ++bucket)
+    {
+        const auto materialist =
+          featureTransformer->transform(pos, transformedFeatures, bucket, false);
+        const auto positional = network[bucket]->propagate(transformedFeatures);
+
+        t.psqt[bucket]       = static_cast<Value>(materialist / OutputScale);
+        t.positional[bucket] = static_cast<Value>(positional / OutputScale);
+    }
+
+    return t;
+}
+
+
+template<typename Arch, typename Transformer>
+void Network<Arch, Transformer>::load_user_net(const std::string& dir,
+                                               const std::string& evalfilePath) {
+    std::ifstream stream(dir + evalfilePath, std::ios::binary);
+    auto          description = load(stream);
+
+    if (description.has_value())
+    {
+        evalFile.current        = evalfilePath;
+        evalFile.netDescription = description.value();
+    }
+}
+
+
+template<typename Arch, typename Transformer>
+void Network<Arch, Transformer>::load_internal() {
+    // C++ way to prepare a buffer for a memory stream
+    class MemoryBuffer: public std::basic_streambuf<char> {
+       public:
+        MemoryBuffer(char* p, size_t n) {
+            setg(p, p, p + n);
+            setp(p, p + n);
+        }
+    };
+
+    const auto embedded = get_embedded(embeddedType);
+
+    MemoryBuffer buffer(const_cast<char*>(reinterpret_cast<const char*>(embedded.data)),
+                        size_t(embedded.size));
+
+    std::istream stream(&buffer);
+    auto         description = load(stream);
+
+    if (description.has_value())
+    {
+        evalFile.current        = evalFile.defaultName;
+        evalFile.netDescription = description.value();
+    }
+}
+
+
+template<typename Arch, typename Transformer>
+void Network<Arch, Transformer>::initialize() {
+    Detail::initialize(featureTransformer);
+    for (std::size_t i = 0; i < LayerStacks; ++i)
+        Detail::initialize(network[i]);
+}
+
+
+template<typename Arch, typename Transformer>
+bool Network<Arch, Transformer>::save(std::ostream&      stream,
+                                      const std::string& name,
+                                      const std::string& netDescription) const {
+    if (name.empty() || name == "None")
+        return false;
+
+    return write_parameters(stream, netDescription);
+}
+
+
+template<typename Arch, typename Transformer>
+std::optional<std::string> Network<Arch, Transformer>::load(std::istream& stream) {
+    initialize();
+    std::string description;
+
+    return read_parameters(stream, description) ? std::make_optional(description) : std::nullopt;
+}
+
+
+// Read network header
+template<typename Arch, typename Transformer>
+bool Network<Arch, Transformer>::read_header(std::istream&  stream,
+                                             std::uint32_t* hashValue,
+                                             std::string*   desc) const {
+    std::uint32_t version, size;
+
+    version    = read_little_endian<std::uint32_t>(stream);
+    *hashValue = read_little_endian<std::uint32_t>(stream);
+    size       = read_little_endian<std::uint32_t>(stream);
+    if (!stream || version != Version)
+        return false;
+    desc->resize(size);
+    stream.read(&(*desc)[0], size);
+    return !stream.fail();
+}
+
+
+// Write network header
+template<typename Arch, typename Transformer>
+bool Network<Arch, Transformer>::write_header(std::ostream&      stream,
+                                              std::uint32_t      hashValue,
+                                              const std::string& desc) const {
+    write_little_endian<std::uint32_t>(stream, Version);
+    write_little_endian<std::uint32_t>(stream, hashValue);
+    write_little_endian<std::uint32_t>(stream, std::uint32_t(desc.size()));
+    stream.write(&desc[0], desc.size());
+    return !stream.fail();
+}
+
+
+template<typename Arch, typename Transformer>
+bool Network<Arch, Transformer>::read_parameters(std::istream& stream,
+                                                 std::string&  netDescription) const {
+    std::uint32_t hashValue;
+    if (!read_header(stream, &hashValue, &netDescription))
+        return false;
+    if (hashValue != Network::hash)
+        return false;
+    if (!Detail::read_parameters(stream, *featureTransformer))
+        return false;
+    for (std::size_t i = 0; i < LayerStacks; ++i)
+    {
+        if (!Detail::read_parameters(stream, *(network[i])))
+            return false;
+    }
+    return stream && stream.peek() == std::ios::traits_type::eof();
+}
+
+
+template<typename Arch, typename Transformer>
+bool Network<Arch, Transformer>::write_parameters(std::ostream&      stream,
+                                                  const std::string& netDescription) const {
+    if (!write_header(stream, Network::hash, netDescription))
+        return false;
+    if (!Detail::write_parameters(stream, *featureTransformer))
+        return false;
+    for (std::size_t i = 0; i < LayerStacks; ++i)
+    {
+        if (!Detail::write_parameters(stream, *(network[i])))
+            return false;
+    }
+    return bool(stream);
+}
+
+// Explicit template instantiation
+
+template class Network<
+  NetworkArchitecture<TransformedFeatureDimensionsBig, L2Big, L3Big>,
+  FeatureTransformer<TransformedFeatureDimensionsBig, &StateInfo::accumulatorBig>>;
+
+template class Network<
+  NetworkArchitecture<TransformedFeatureDimensionsSmall, L2Small, L3Small>,
+  FeatureTransformer<TransformedFeatureDimensionsSmall, &StateInfo::accumulatorSmall>>;
+
+}  // namespace Stockfish::Eval::NNUE

src/nnue/network.h

@@ -0,0 +1,120 @@
+/*
+  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
+
+  Stockfish is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  Stockfish is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef NETWORK_H_INCLUDED
+#define NETWORK_H_INCLUDED
+
+#include <cstdint>
+#include <iostream>
+#include <optional>
+#include <string>
+#include <utility>
+
+#include "../misc.h"
+#include "../position.h"
+#include "../types.h"
+#include "nnue_architecture.h"
+#include "nnue_feature_transformer.h"
+#include "nnue_misc.h"
+
+namespace Stockfish::Eval::NNUE {
+
+
+enum class EmbeddedNNUEType {
+    BIG,
+    SMALL,
+};
+
+
+template<typename Arch, typename Transformer>
+class Network {
+   public:
+    Network(EvalFile file, EmbeddedNNUEType type) :
+        evalFile(file),
+        embeddedType(type) {}
+
+    void load(const std::string& rootDirectory, std::string evalfilePath);
+    bool save(const std::optional<std::string>& filename) const;
+
+
+    Value evaluate(const Position& pos,
+                   bool            adjusted   = false,
+                   int*            complexity = nullptr,
+                   bool            psqtOnly   = false) const;
+
+
+    void hint_common_access(const Position& pos, bool psqtOnl) const;
+
+    void          verify(std::string evalfilePath) const;
+    NnueEvalTrace trace_evaluate(const Position& pos) const;
+
+   private:
+    void load_user_net(const std::string&, const std::string&);
+    void load_internal();
+
+    void initialize();
+
+    bool                       save(std::ostream&, const std::string&, const std::string&) const;
+    std::optional<std::string> load(std::istream&);
+
+    bool read_header(std::istream&, std::uint32_t*, std::string*) const;
+    bool write_header(std::ostream&, std::uint32_t, const std::string&) const;
+
+    bool read_parameters(std::istream&, std::string&) const;
+    bool write_parameters(std::ostream&, const std::string&) const;
+
+    // Input feature converter
+    LargePagePtr<Transformer> featureTransformer;
+
+    // Evaluation function
+    AlignedPtr<Arch> network[LayerStacks];
+
+    EvalFile         evalFile;
+    EmbeddedNNUEType embeddedType;
+
+    // Hash value of evaluation function structure
+    static constexpr std::uint32_t hash = Transformer::get_hash_value() ^ Arch::get_hash_value();
+};
+
+// Definitions of the network types
+using SmallFeatureTransformer =
+  FeatureTransformer<TransformedFeatureDimensionsSmall, &StateInfo::accumulatorSmall>;
+using SmallNetworkArchitecture =
+  NetworkArchitecture<TransformedFeatureDimensionsSmall, L2Small, L3Small>;
+
+using BigFeatureTransformer =
+  FeatureTransformer<TransformedFeatureDimensionsBig, &StateInfo::accumulatorBig>;
+using BigNetworkArchitecture = NetworkArchitecture<TransformedFeatureDimensionsBig, L2Big, L3Big>;
+
+using NetworkBig   = Network<BigNetworkArchitecture, BigFeatureTransformer>;
+using NetworkSmall = Network<SmallNetworkArchitecture, SmallFeatureTransformer>;
+
+
+struct Networks {
+    Networks(NetworkBig&& nB, NetworkSmall&& nS) :
+        big(std::move(nB)),
+        small(std::move(nS)) {}
+
+    NetworkBig   big;
+    NetworkSmall small;
+};
+
+
+}  // namespace Stockfish
+
+#endif

src/nnue/nnue_accumulator.h

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -21,20 +21,22 @@
 #ifndef NNUE_ACCUMULATOR_H_INCLUDED
 #define NNUE_ACCUMULATOR_H_INCLUDED
 
+#include <cstdint>
+
 #include "nnue_architecture.h"
+#include "nnue_common.h"
 
-namespace Eval::NNUE {
+namespace Stockfish::Eval::NNUE {
 
-  // The accumulator of a StateInfo without parent is set to the INIT state
-  enum AccumulatorState { EMPTY, COMPUTED, INIT };
+// Class that holds the result of affine transformation of input features
+template<IndexType Size>
+struct alignas(CacheLineSize) Accumulator {
+    std::int16_t accumulation[2][Size];
+    std::int32_t psqtAccumulation[2][PSQTBuckets];
+    bool         computed[2];
+    bool         computedPSQT[2];
+};
 
-  // Class that holds the result of affine transformation of input features
-  struct alignas(kCacheLineSize) Accumulator {
-    std::int16_t
-        accumulation[2][kRefreshTriggers.size()][kTransformedFeatureDimensions];
-    AccumulatorState state[2];
-  };
+}  // namespace Stockfish::Eval::NNUE
 
-}  // namespace Eval::NNUE
-
-#endif // NNUE_ACCUMULATOR_H_INCLUDED
+#endif  // NNUE_ACCUMULATOR_H_INCLUDED

src/nnue/nnue_architecture.h

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -21,18 +21,117 @@
 #ifndef NNUE_ARCHITECTURE_H_INCLUDED
 #define NNUE_ARCHITECTURE_H_INCLUDED
 
-// Defines the network structure
-#include "architectures/halfkp_256x2-32-32.h"
+#include <cstdint>
+#include <cstring>
+#include <iosfwd>
 
-namespace Eval::NNUE {
+#include "features/half_ka_v2_hm.h"
+#include "layers/affine_transform.h"
+#include "layers/affine_transform_sparse_input.h"
+#include "layers/clipped_relu.h"
+#include "layers/sqr_clipped_relu.h"
+#include "nnue_common.h"
 
-  static_assert(kTransformedFeatureDimensions % kMaxSimdWidth == 0, "");
-  static_assert(Network::kOutputDimensions == 1, "");
-  static_assert(std::is_same<Network::OutputType, std::int32_t>::value, "");
+namespace Stockfish::Eval::NNUE {
 
-  // Trigger for full calculation instead of difference calculation
-  constexpr auto kRefreshTriggers = RawFeatures::kRefreshTriggers;
+// Input features used in evaluation function
+using FeatureSet = Features::HalfKAv2_hm;
 
-}  // namespace Eval::NNUE
+// Number of input feature dimensions after conversion
+constexpr IndexType TransformedFeatureDimensionsBig = 3072;
+constexpr int       L2Big                           = 15;
+constexpr int       L3Big                           = 32;
 
-#endif // #ifndef NNUE_ARCHITECTURE_H_INCLUDED
+constexpr IndexType TransformedFeatureDimensionsSmall = 128;
+constexpr int       L2Small                           = 15;
+constexpr int       L3Small                           = 32;
+
+constexpr IndexType PSQTBuckets = 8;
+constexpr IndexType LayerStacks = 8;
+
+template<IndexType L1, int L2, int L3>
+struct NetworkArchitecture {
+    static constexpr IndexType TransformedFeatureDimensions = L1;
+    static constexpr int       FC_0_OUTPUTS                 = L2;
+    static constexpr int       FC_1_OUTPUTS                 = L3;
+
+    Layers::AffineTransformSparseInput<TransformedFeatureDimensions, FC_0_OUTPUTS + 1> fc_0;
+    Layers::SqrClippedReLU<FC_0_OUTPUTS + 1>                                           ac_sqr_0;
+    Layers::ClippedReLU<FC_0_OUTPUTS + 1>                                              ac_0;
+    Layers::AffineTransform<FC_0_OUTPUTS * 2, FC_1_OUTPUTS>                            fc_1;
+    Layers::ClippedReLU<FC_1_OUTPUTS>                                                  ac_1;
+    Layers::AffineTransform<FC_1_OUTPUTS, 1>                                           fc_2;
+
+    // Hash value embedded in the evaluation file
+    static constexpr std::uint32_t get_hash_value() {
+        // input slice hash
+        std::uint32_t hashValue = 0xEC42E90Du;
+        hashValue ^= TransformedFeatureDimensions * 2;
+
+        hashValue = decltype(fc_0)::get_hash_value(hashValue);
+        hashValue = decltype(ac_0)::get_hash_value(hashValue);
+        hashValue = decltype(fc_1)::get_hash_value(hashValue);
+        hashValue = decltype(ac_1)::get_hash_value(hashValue);
+        hashValue = decltype(fc_2)::get_hash_value(hashValue);
+
+        return hashValue;
+    }
+
+    // Read network parameters
+    bool read_parameters(std::istream& stream) {
+        return fc_0.read_parameters(stream) && ac_0.read_parameters(stream)
+            && fc_1.read_parameters(stream) && ac_1.read_parameters(stream)
+            && fc_2.read_parameters(stream);
+    }
+
+    // Write network parameters
+    bool write_parameters(std::ostream& stream) const {
+        return fc_0.write_parameters(stream) && ac_0.write_parameters(stream)
+            && fc_1.write_parameters(stream) && ac_1.write_parameters(stream)
+            && fc_2.write_parameters(stream);
+    }
+
+    std::int32_t propagate(const TransformedFeatureType* transformedFeatures) {
+        struct alignas(CacheLineSize) Buffer {
+            alignas(CacheLineSize) typename decltype(fc_0)::OutputBuffer fc_0_out;
+            alignas(CacheLineSize) typename decltype(ac_sqr_0)::OutputType
+              ac_sqr_0_out[ceil_to_multiple<IndexType>(FC_0_OUTPUTS * 2, 32)];
+            alignas(CacheLineSize) typename decltype(ac_0)::OutputBuffer ac_0_out;
+            alignas(CacheLineSize) typename decltype(fc_1)::OutputBuffer fc_1_out;
+            alignas(CacheLineSize) typename decltype(ac_1)::OutputBuffer ac_1_out;
+            alignas(CacheLineSize) typename decltype(fc_2)::OutputBuffer fc_2_out;
+
+            Buffer() { std::memset(this, 0, sizeof(*this)); }
+        };
+
+#if defined(__clang__) && (__APPLE__)
+        // workaround for a bug reported with xcode 12
+        static thread_local auto tlsBuffer = std::make_unique<Buffer>();
+        // Access TLS only once, cache result.
+        Buffer& buffer = *tlsBuffer;
+#else
+        alignas(CacheLineSize) static thread_local Buffer buffer;
+#endif
+
+        fc_0.propagate(transformedFeatures, buffer.fc_0_out);
+        ac_sqr_0.propagate(buffer.fc_0_out, buffer.ac_sqr_0_out);
+        ac_0.propagate(buffer.fc_0_out, buffer.ac_0_out);
+        std::memcpy(buffer.ac_sqr_0_out + FC_0_OUTPUTS, buffer.ac_0_out,
+                    FC_0_OUTPUTS * sizeof(typename decltype(ac_0)::OutputType));
+        fc_1.propagate(buffer.ac_sqr_0_out, buffer.fc_1_out);
+        ac_1.propagate(buffer.fc_1_out, buffer.ac_1_out);
+        fc_2.propagate(buffer.ac_1_out, buffer.fc_2_out);
+
+        // buffer.fc_0_out[FC_0_OUTPUTS] is such that 1.0 is equal to 127*(1<<WeightScaleBits) in
+        // quantized form, but we want 1.0 to be equal to 600*OutputScale
+        std::int32_t fwdOut =
+          (buffer.fc_0_out[FC_0_OUTPUTS]) * (600 * OutputScale) / (127 * (1 << WeightScaleBits));
+        std::int32_t outputValue = buffer.fc_2_out[0] + fwdOut;
+
+        return outputValue;
+    }
+};
+
+}  // namespace Stockfish::Eval::NNUE
+
+#endif  // #ifndef NNUE_ARCHITECTURE_H_INCLUDED

src/nnue/nnue_common.h

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -21,112 +21,264 @@
 #ifndef NNUE_COMMON_H_INCLUDED
 #define NNUE_COMMON_H_INCLUDED
 
+#include <algorithm>
+#include <cassert>
+#include <cstdint>
 #include <cstring>
 #include <iostream>
+#include <type_traits>
+
+#include "../misc.h"
 
 #if defined(USE_AVX2)
-#include <immintrin.h>
+    #include <immintrin.h>
 
 #elif defined(USE_SSE41)
-#include <smmintrin.h>
+    #include <smmintrin.h>
 
 #elif defined(USE_SSSE3)
-#include <tmmintrin.h>
+    #include <tmmintrin.h>
 
 #elif defined(USE_SSE2)
-#include <emmintrin.h>
-
-#elif defined(USE_MMX)
-#include <mmintrin.h>
+    #include <emmintrin.h>
 
 #elif defined(USE_NEON)
-#include <arm_neon.h>
+    #include <arm_neon.h>
 #endif
 
-namespace Eval::NNUE {
+namespace Stockfish::Eval::NNUE {
 
-  // Version of the evaluation file
-  constexpr std::uint32_t kVersion = 0x7AF32F16u;
+// Version of the evaluation file
+constexpr std::uint32_t Version = 0x7AF32F20u;
 
-  // Constant used in evaluation value calculation
-  constexpr int FV_SCALE = 16;
-  constexpr int kWeightScaleBits = 6;
+// Constant used in evaluation value calculation
+constexpr int OutputScale     = 16;
+constexpr int WeightScaleBits = 6;
 
-  // Size of cache line (in bytes)
-  constexpr std::size_t kCacheLineSize = 64;
+// Size of cache line (in bytes)
+constexpr std::size_t CacheLineSize = 64;
 
-  // SIMD width (in bytes)
-  #if defined(USE_AVX2)
-  constexpr std::size_t kSimdWidth = 32;
+constexpr const char        Leb128MagicString[]   = "COMPRESSED_LEB128";
+constexpr const std::size_t Leb128MagicStringSize = sizeof(Leb128MagicString) - 1;
 
-  #elif defined(USE_SSE2)
-  constexpr std::size_t kSimdWidth = 16;
+// SIMD width (in bytes)
+#if defined(USE_AVX2)
+constexpr std::size_t SimdWidth = 32;
 
-  #elif defined(USE_MMX)
-  constexpr std::size_t kSimdWidth = 8;
+#elif defined(USE_SSE2)
+constexpr std::size_t SimdWidth = 16;
 
-  #elif defined(USE_NEON)
-  constexpr std::size_t kSimdWidth = 16;
-  #endif
+#elif defined(USE_NEON)
+constexpr std::size_t SimdWidth = 16;
+#endif
 
-  constexpr std::size_t kMaxSimdWidth = 32;
+constexpr std::size_t MaxSimdWidth = 32;
 
-  // unique number for each piece type on each square
-  enum {
-    PS_NONE     =  0,
-    PS_W_PAWN   =  1,
-    PS_B_PAWN   =  1 * SQUARE_NB + 1,
-    PS_W_KNIGHT =  2 * SQUARE_NB + 1,
-    PS_B_KNIGHT =  3 * SQUARE_NB + 1,
-    PS_W_BISHOP =  4 * SQUARE_NB + 1,
-    PS_B_BISHOP =  5 * SQUARE_NB + 1,
-    PS_W_ROOK   =  6 * SQUARE_NB + 1,
-    PS_B_ROOK   =  7 * SQUARE_NB + 1,
-    PS_W_QUEEN  =  8 * SQUARE_NB + 1,
-    PS_B_QUEEN  =  9 * SQUARE_NB + 1,
-    PS_W_KING   = 10 * SQUARE_NB + 1,
-    PS_END      = PS_W_KING, // pieces without kings (pawns included)
-    PS_B_KING   = 11 * SQUARE_NB + 1,
-    PS_END2     = 12 * SQUARE_NB + 1
-  };
+// Type of input feature after conversion
+using TransformedFeatureType = std::uint8_t;
+using IndexType              = std::uint32_t;
 
-  constexpr uint32_t kpp_board_index[COLOR_NB][PIECE_NB] = {
-    // convention: W - us, B - them
-    // viewed from other side, W and B are reversed
-    { PS_NONE, PS_W_PAWN, PS_W_KNIGHT, PS_W_BISHOP, PS_W_ROOK, PS_W_QUEEN, PS_W_KING, PS_NONE,
-      PS_NONE, PS_B_PAWN, PS_B_KNIGHT, PS_B_BISHOP, PS_B_ROOK, PS_B_QUEEN, PS_B_KING, PS_NONE },
-    { PS_NONE, PS_B_PAWN, PS_B_KNIGHT, PS_B_BISHOP, PS_B_ROOK, PS_B_QUEEN, PS_B_KING, PS_NONE,
-      PS_NONE, PS_W_PAWN, PS_W_KNIGHT, PS_W_BISHOP, PS_W_ROOK, PS_W_QUEEN, PS_W_KING, PS_NONE }
-  };
+// Round n up to be a multiple of base
+template<typename IntType>
+constexpr IntType ceil_to_multiple(IntType n, IntType base) {
+    return (n + base - 1) / base * base;
+}
 
-  // Type of input feature after conversion
-  using TransformedFeatureType = std::uint8_t;
-  using IndexType = std::uint32_t;
 
-  // Round n up to be a multiple of base
-  template <typename IntType>
-  constexpr IntType CeilToMultiple(IntType n, IntType base) {
-      return (n + base - 1) / base * base;
-  }
+// Utility to read an integer (signed or unsigned, any size)
+// from a stream in little-endian order. We swap the byte order after the read if
+// necessary to return a result with the byte ordering of the compiling machine.
+template<typename IntType>
+inline IntType read_little_endian(std::istream& stream) {
+    IntType result;
 
-  // read_little_endian() is our utility to read an integer (signed or unsigned, any size)
-  // from a stream in little-endian order. We swap the byte order after the read if
-  // necessary to return a result with the byte ordering of the compiling machine.
-  template <typename IntType>
-  inline IntType read_little_endian(std::istream& stream) {
+    if (IsLittleEndian)
+        stream.read(reinterpret_cast<char*>(&result), sizeof(IntType));
+    else
+    {
+        std::uint8_t                  u[sizeof(IntType)];
+        std::make_unsigned_t<IntType> v = 0;
 
-      IntType result;
-      std::uint8_t u[sizeof(IntType)];
-      typename std::make_unsigned<IntType>::type v = 0;
+        stream.read(reinterpret_cast<char*>(u), sizeof(IntType));
+        for (std::size_t i = 0; i < sizeof(IntType); ++i)
+            v = (v << 8) | u[sizeof(IntType) - i - 1];
 
-      stream.read(reinterpret_cast<char*>(u), sizeof(IntType));
-      for (std::size_t i = 0; i < sizeof(IntType); ++i)
-          v = (v << 8) | u[sizeof(IntType) - i - 1];
+        std::memcpy(&result, &v, sizeof(IntType));
+    }
 
-      std::memcpy(&result, &v, sizeof(IntType));
-      return result;
-  }
+    return result;
+}
 
-}  // namespace Eval::NNUE
 
-#endif // #ifndef NNUE_COMMON_H_INCLUDED
+// Utility to write an integer (signed or unsigned, any size)
+// to a stream in little-endian order. We swap the byte order before the write if
+// necessary to always write in little-endian order, independently of the byte
+// ordering of the compiling machine.
+template<typename IntType>
+inline void write_little_endian(std::ostream& stream, IntType value) {
+
+    if (IsLittleEndian)
+        stream.write(reinterpret_cast<const char*>(&value), sizeof(IntType));
+    else
+    {
+        std::uint8_t                  u[sizeof(IntType)];
+        std::make_unsigned_t<IntType> v = value;
+
+        std::size_t i = 0;
+        // if constexpr to silence the warning about shift by 8
+        if constexpr (sizeof(IntType) > 1)
+        {
+            for (; i + 1 < sizeof(IntType); ++i)
+            {
+                u[i] = std::uint8_t(v);
+                v >>= 8;
+            }
+        }
+        u[i] = std::uint8_t(v);
+
+        stream.write(reinterpret_cast<char*>(u), sizeof(IntType));
+    }
+}
+
+
+// Read integers in bulk from a little-endian stream.
+// This reads N integers from stream s and puts them in array out.
+template<typename IntType>
+inline void read_little_endian(std::istream& stream, IntType* out, std::size_t count) {
+    if (IsLittleEndian)
+        stream.read(reinterpret_cast<char*>(out), sizeof(IntType) * count);
+    else
+        for (std::size_t i = 0; i < count; ++i)
+            out[i] = read_little_endian<IntType>(stream);
+}
+
+
+// Write integers in bulk to a little-endian stream.
+// This takes N integers from array values and writes them on stream s.
+template<typename IntType>
+inline void write_little_endian(std::ostream& stream, const IntType* values, std::size_t count) {
+    if (IsLittleEndian)
+        stream.write(reinterpret_cast<const char*>(values), sizeof(IntType) * count);
+    else
+        for (std::size_t i = 0; i < count; ++i)
+            write_little_endian<IntType>(stream, values[i]);
+}
+
+
+// Read N signed integers from the stream s, putting them in the array out.
+// The stream is assumed to be compressed using the signed LEB128 format.
+// See https://en.wikipedia.org/wiki/LEB128 for a description of the compression scheme.
+template<typename IntType>
+inline void read_leb_128(std::istream& stream, IntType* out, std::size_t count) {
+
+    // Check the presence of our LEB128 magic string
+    char leb128MagicString[Leb128MagicStringSize];
+    stream.read(leb128MagicString, Leb128MagicStringSize);
+    assert(strncmp(Leb128MagicString, leb128MagicString, Leb128MagicStringSize) == 0);
+
+    static_assert(std::is_signed_v<IntType>, "Not implemented for unsigned types");
+
+    const std::uint32_t BUF_SIZE = 4096;
+    std::uint8_t        buf[BUF_SIZE];
+
+    auto bytes_left = read_little_endian<std::uint32_t>(stream);
+
+    std::uint32_t buf_pos = BUF_SIZE;
+    for (std::size_t i = 0; i < count; ++i)
+    {
+        IntType result = 0;
+        size_t  shift  = 0;
+        do
+        {
+            if (buf_pos == BUF_SIZE)
+            {
+                stream.read(reinterpret_cast<char*>(buf), std::min(bytes_left, BUF_SIZE));
+                buf_pos = 0;
+            }
+
+            std::uint8_t byte = buf[buf_pos++];
+            --bytes_left;
+            result |= (byte & 0x7f) << shift;
+            shift += 7;
+
+            if ((byte & 0x80) == 0)
+            {
+                out[i] = (sizeof(IntType) * 8 <= shift || (byte & 0x40) == 0)
+                         ? result
+                         : result | ~((1 << shift) - 1);
+                break;
+            }
+        } while (shift < sizeof(IntType) * 8);
+    }
+
+    assert(bytes_left == 0);
+}
+
+
+// Write signed integers to a stream with LEB128 compression.
+// This takes N integers from array values, compresses them with
+// the LEB128 algorithm and writes the result on the stream s.
+// See https://en.wikipedia.org/wiki/LEB128 for a description of the compression scheme.
+template<typename IntType>
+inline void write_leb_128(std::ostream& stream, const IntType* values, std::size_t count) {
+
+    // Write our LEB128 magic string
+    stream.write(Leb128MagicString, Leb128MagicStringSize);
+
+    static_assert(std::is_signed_v<IntType>, "Not implemented for unsigned types");
+
+    std::uint32_t byte_count = 0;
+    for (std::size_t i = 0; i < count; ++i)
+    {
+        IntType      value = values[i];
+        std::uint8_t byte;
+        do
+        {
+            byte = value & 0x7f;
+            value >>= 7;
+            ++byte_count;
+        } while ((byte & 0x40) == 0 ? value != 0 : value != -1);
+    }
+
+    write_little_endian(stream, byte_count);
+
+    const std::uint32_t BUF_SIZE = 4096;
+    std::uint8_t        buf[BUF_SIZE];
+    std::uint32_t       buf_pos = 0;
+
+    auto flush = [&]() {
+        if (buf_pos > 0)
+        {
+            stream.write(reinterpret_cast<char*>(buf), buf_pos);
+            buf_pos = 0;
+        }
+    };
+
+    auto write = [&](std::uint8_t byte) {
+        buf[buf_pos++] = byte;
+        if (buf_pos == BUF_SIZE)
+            flush();
+    };
+
+    for (std::size_t i = 0; i < count; ++i)
+    {
+        IntType value = values[i];
+        while (true)
+        {
+            std::uint8_t byte = value & 0x7f;
+            value >>= 7;
+            if ((byte & 0x40) == 0 ? value == 0 : value == -1)
+            {
+                write(byte);
+                break;
+            }
+            write(byte | 0x80);
+        }
+    }
+
+    flush();
+}
+
+}  // namespace Stockfish::Eval::NNUE
+
+#endif  // #ifndef NNUE_COMMON_H_INCLUDED

src/nnue/nnue_misc.cpp

@@ -0,0 +1,203 @@
+/*
+  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
+
+  Stockfish is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  Stockfish is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+// Code for calculating NNUE evaluation function
+
+#include "nnue_misc.h"
+
+#include <cmath>
+#include <cstdlib>
+#include <cstring>
+#include <iomanip>
+#include <iosfwd>
+#include <iostream>
+#include <sstream>
+#include <string_view>
+
+#include "../evaluate.h"
+#include "../position.h"
+#include "../types.h"
+#include "../uci.h"
+#include "network.h"
+#include "nnue_accumulator.h"
+
+namespace Stockfish::Eval::NNUE {
+
+
+constexpr std::string_view PieceToChar(" PNBRQK  pnbrqk");
+
+
+void hint_common_parent_position(const Position& pos, const Networks& networks) {
+
+    int simpleEvalAbs = std::abs(simple_eval(pos, pos.side_to_move()));
+    if (simpleEvalAbs > Eval::SmallNetThreshold)
+        networks.small.hint_common_access(pos, simpleEvalAbs > Eval::PsqtOnlyThreshold);
+    else
+        networks.big.hint_common_access(pos, false);
+}
+
+namespace {
+// Converts a Value into (centi)pawns and writes it in a buffer.
+// The buffer must have capacity for at least 5 chars.
+void format_cp_compact(Value v, char* buffer, const Position& pos) {
+
+    buffer[0] = (v < 0 ? '-' : v > 0 ? '+' : ' ');
+
+    int cp = std::abs(UCI::to_cp(v, pos));
+    if (cp >= 10000)
+    {
+        buffer[1] = '0' + cp / 10000;
+        cp %= 10000;
+        buffer[2] = '0' + cp / 1000;
+        cp %= 1000;
+        buffer[3] = '0' + cp / 100;
+        buffer[4] = ' ';
+    }
+    else if (cp >= 1000)
+    {
+        buffer[1] = '0' + cp / 1000;
+        cp %= 1000;
+        buffer[2] = '0' + cp / 100;
+        cp %= 100;
+        buffer[3] = '.';
+        buffer[4] = '0' + cp / 10;
+    }
+    else
+    {
+        buffer[1] = '0' + cp / 100;
+        cp %= 100;
+        buffer[2] = '.';
+        buffer[3] = '0' + cp / 10;
+        cp %= 10;
+        buffer[4] = '0' + cp / 1;
+    }
+}
+
+
+// Converts a Value into pawns, always keeping two decimals
+void format_cp_aligned_dot(Value v, std::stringstream& stream, const Position& pos) {
+
+    const double pawns = std::abs(0.01 * UCI::to_cp(v, pos));
+
+    stream << (v < 0   ? '-'
+               : v > 0 ? '+'
+                       : ' ')
+           << std::setiosflags(std::ios::fixed) << std::setw(6) << std::setprecision(2) << pawns;
+}
+}
+
+
+// Returns a string with the value of each piece on a board,
+// and a table for (PSQT, Layers) values bucket by bucket.
+std::string trace(Position& pos, const Eval::NNUE::Networks& networks) {
+
+    std::stringstream ss;
+
+    char board[3 * 8 + 1][8 * 8 + 2];
+    std::memset(board, ' ', sizeof(board));
+    for (int row = 0; row < 3 * 8 + 1; ++row)
+        board[row][8 * 8 + 1] = '\0';
+
+    // A lambda to output one box of the board
+    auto writeSquare = [&board, &pos](File file, Rank rank, Piece pc, Value value) {
+        const int x = int(file) * 8;
+        const int y = (7 - int(rank)) * 3;
+        for (int i = 1; i < 8; ++i)
+            board[y][x + i] = board[y + 3][x + i] = '-';
+        for (int i = 1; i < 3; ++i)
+            board[y + i][x] = board[y + i][x + 8] = '|';
+        board[y][x] = board[y][x + 8] = board[y + 3][x + 8] = board[y + 3][x] = '+';
+        if (pc != NO_PIECE)
+            board[y + 1][x + 4] = PieceToChar[pc];
+        if (value != VALUE_NONE)
+            format_cp_compact(value, &board[y + 2][x + 2], pos);
+    };
+
+    // We estimate the value of each piece by doing a differential evaluation from
+    // the current base eval, simulating the removal of the piece from its square.
+    Value base = networks.big.evaluate(pos);
+    base       = pos.side_to_move() == WHITE ? base : -base;
+
+    for (File f = FILE_A; f <= FILE_H; ++f)
+        for (Rank r = RANK_1; r <= RANK_8; ++r)
+        {
+            Square sq = make_square(f, r);
+            Piece  pc = pos.piece_on(sq);
+            Value  v  = VALUE_NONE;
+
+            if (pc != NO_PIECE && type_of(pc) != KING)
+            {
+                auto st = pos.state();
+
+                pos.remove_piece(sq);
+                st->accumulatorBig.computed[WHITE]       = st->accumulatorBig.computed[BLACK] =
+                  st->accumulatorBig.computedPSQT[WHITE] = st->accumulatorBig.computedPSQT[BLACK] =
+                    false;
+
+                Value eval = networks.big.evaluate(pos);
+                eval       = pos.side_to_move() == WHITE ? eval : -eval;
+                v          = base - eval;
+
+                pos.put_piece(pc, sq);
+                st->accumulatorBig.computed[WHITE]       = st->accumulatorBig.computed[BLACK] =
+                  st->accumulatorBig.computedPSQT[WHITE] = st->accumulatorBig.computedPSQT[BLACK] =
+                    false;
+            }
+
+            writeSquare(f, r, pc, v);
+        }
+
+    ss << " NNUE derived piece values:\n";
+    for (int row = 0; row < 3 * 8 + 1; ++row)
+        ss << board[row] << '\n';
+    ss << '\n';
+
+    auto t = networks.big.trace_evaluate(pos);
+
+    ss << " NNUE network contributions "
+       << (pos.side_to_move() == WHITE ? "(White to move)" : "(Black to move)") << std::endl
+       << "+------------+------------+------------+------------+\n"
+       << "|   Bucket   |  Material  | Positional |   Total    |\n"
+       << "|            |   (PSQT)   |  (Layers)  |            |\n"
+       << "+------------+------------+------------+------------+\n";
+
+    for (std::size_t bucket = 0; bucket < LayerStacks; ++bucket)
+    {
+        ss << "|  " << bucket << "        ";
+        ss << " |  ";
+        format_cp_aligned_dot(t.psqt[bucket], ss, pos);
+        ss << "  "
+           << " |  ";
+        format_cp_aligned_dot(t.positional[bucket], ss, pos);
+        ss << "  "
+           << " |  ";
+        format_cp_aligned_dot(t.psqt[bucket] + t.positional[bucket], ss, pos);
+        ss << "  "
+           << " |";
+        if (bucket == t.correctBucket)
+            ss << " <-- this bucket is used";
+        ss << '\n';
+    }
+
+    ss << "+------------+------------+------------+------------+\n";
+
+    return ss.str();
+}
+
+
+}  // namespace Stockfish::Eval::NNUE

src/nnue/nnue_misc.h

@@ -0,0 +1,63 @@
+/*
+  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
+
+  Stockfish is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  Stockfish is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef NNUE_MISC_H_INCLUDED
+#define NNUE_MISC_H_INCLUDED
+
+#include <cstddef>
+#include <string>
+
+#include "../types.h"
+#include "nnue_architecture.h"
+
+namespace Stockfish {
+
+class Position;
+
+namespace Eval::NNUE {
+
+struct EvalFile {
+    // Default net name, will use one of the EvalFileDefaultName* macros defined
+    // in evaluate.h
+    std::string defaultName;
+    // Selected net name, either via uci option or default
+    std::string current;
+    // Net description extracted from the net file
+    std::string netDescription;
+};
+
+
+struct NnueEvalTrace {
+    static_assert(LayerStacks == PSQTBuckets);
+
+    Value       psqt[LayerStacks];
+    Value       positional[LayerStacks];
+    std::size_t correctBucket;
+};
+
+
+struct Networks;
+
+
+std::string trace(Position& pos, const Networks& networks);
+void        hint_common_parent_position(const Position& pos, const Networks& networks);
+
+}  // namespace Stockfish::Eval::NNUE
+}  // namespace Stockfish
+
+#endif  // #ifndef NNUE_MISC_H_INCLUDED

src/pawns.cpp

@@ -1,300 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
-
-  Stockfish is free software: you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation, either version 3 of the License, or
-  (at your option) any later version.
-
-  Stockfish is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-#include <algorithm>
-#include <cassert>
-
-#include "bitboard.h"
-#include "pawns.h"
-#include "position.h"
-#include "thread.h"
-
-namespace {
-
-  #define V Value
-  #define S(mg, eg) make_score(mg, eg)
-
-  // Pawn penalties
-  constexpr Score Backward      = S( 9, 22);
-  constexpr Score Doubled       = S(13, 51);
-  constexpr Score DoubledEarly  = S(20,  7);
-  constexpr Score Isolated      = S( 3, 15);
-  constexpr Score WeakLever     = S( 4, 58);
-  constexpr Score WeakUnopposed = S(13, 24);
-
-  // Bonus for blocked pawns at 5th or 6th rank
-  constexpr Score BlockedPawn[2] = { S(-17, -6), S(-9, 2) };
-
-  constexpr Score BlockedStorm[RANK_NB] = {
-    S(0, 0), S(0, 0), S(75, 78), S(-8, 16), S(-6, 10), S(-6, 6), S(0, 2)
-  };
-
-  // Connected pawn bonus
-  constexpr int Connected[RANK_NB] = { 0, 5, 7, 11, 23, 48, 87 };
-
-  // Strength of pawn shelter for our king by [distance from edge][rank].
-  // RANK_1 = 0 is used for files where we have no pawn, or pawn is behind our king.
-  constexpr Value ShelterStrength[int(FILE_NB) / 2][RANK_NB] = {
-    { V( -5), V( 82), V( 92), V( 54), V( 36), V( 22), V(  28) },
-    { V(-44), V( 63), V( 33), V(-50), V(-30), V(-12), V( -62) },
-    { V(-11), V( 77), V( 22), V( -6), V( 31), V(  8), V( -45) },
-    { V(-39), V(-12), V(-29), V(-50), V(-43), V(-68), V(-164) }
-  };
-
-  // Danger of enemy pawns moving toward our king by [distance from edge][rank].
-  // RANK_1 = 0 is used for files where the enemy has no pawn, or their pawn
-  // is behind our king. Note that UnblockedStorm[0][1-2] accommodate opponent pawn
-  // on edge, likely blocked by our king.
-  constexpr Value UnblockedStorm[int(FILE_NB) / 2][RANK_NB] = {
-    { V( 87), V(-288), V(-168), V( 96), V( 47), V( 44), V( 46) },
-    { V( 42), V( -25), V( 120), V( 45), V( 34), V( -9), V( 24) },
-    { V( -8), V(  51), V( 167), V( 35), V( -4), V(-16), V(-12) },
-    { V(-17), V( -13), V( 100), V(  4), V(  9), V(-16), V(-31) }
-  };
-
-
-  // KingOnFile[semi-open Us][semi-open Them] contains bonuses/penalties
-  // for king when the king is on a semi-open or open file.
-  constexpr Score KingOnFile[2][2] = {{ S(-21,10), S(-7, 1)  },
-                                     {  S(  0,-3), S( 9,-4) }};
-
-  #undef S
-  #undef V
-
-
-  /// evaluate() calculates a score for the static pawn structure of the given position.
-  /// We cannot use the location of pieces or king in this function, as the evaluation
-  /// of the pawn structure will be stored in a small cache for speed reasons, and will
-  /// be re-used even when the pieces have moved.
-
-  template<Color Us>
-  Score evaluate(const Position& pos, Pawns::Entry* e) {
-
-    constexpr Color     Them = ~Us;
-    constexpr Direction Up   = pawn_push(Us);
-    constexpr Direction Down = -Up;
-
-    Bitboard neighbours, stoppers, support, phalanx, opposed;
-    Bitboard lever, leverPush, blocked;
-    Square s;
-    bool backward, passed, doubled;
-    Score score = SCORE_ZERO;
-    Bitboard b = pos.pieces(Us, PAWN);
-
-    Bitboard ourPawns   = pos.pieces(  Us, PAWN);
-    Bitboard theirPawns = pos.pieces(Them, PAWN);
-
-    Bitboard doubleAttackThem = pawn_double_attacks_bb<Them>(theirPawns);
-
-    e->passedPawns[Us] = 0;
-    e->kingSquares[Us] = SQ_NONE;
-    e->pawnAttacks[Us] = e->pawnAttacksSpan[Us] = pawn_attacks_bb<Us>(ourPawns);
-    e->blockedCount += popcount(shift<Up>(ourPawns) & (theirPawns | doubleAttackThem));
-
-    // Loop through all pawns of the current color and score each pawn
-    while (b) {
-        s = pop_lsb(&b);
-
-        assert(pos.piece_on(s) == make_piece(Us, PAWN));
-
-        Rank r = relative_rank(Us, s);
-
-        // Flag the pawn
-        opposed    = theirPawns & forward_file_bb(Us, s);
-        blocked    = theirPawns & (s + Up);
-        stoppers   = theirPawns & passed_pawn_span(Us, s);
-        lever      = theirPawns & pawn_attacks_bb(Us, s);
-        leverPush  = theirPawns & pawn_attacks_bb(Us, s + Up);
-        doubled    = ourPawns   & (s - Up);
-        neighbours = ourPawns   & adjacent_files_bb(s);
-        phalanx    = neighbours & rank_bb(s);
-        support    = neighbours & rank_bb(s - Up);
-
-        if (doubled)
-        {
-            // Additional doubled penalty if none of their pawns is fixed
-            if (!(ourPawns & shift<Down>(theirPawns | pawn_attacks_bb<Them>(theirPawns))))
-                score -= DoubledEarly;
-        }
-
-        // A pawn is backward when it is behind all pawns of the same color on
-        // the adjacent files and cannot safely advance.
-        backward =  !(neighbours & forward_ranks_bb(Them, s + Up))
-                  && (leverPush | blocked);
-
-        // Compute additional span if pawn is not backward nor blocked
-        if (!backward && !blocked)
-            e->pawnAttacksSpan[Us] |= pawn_attack_span(Us, s);
-
-        // A pawn is passed if one of the three following conditions is true:
-        // (a) there is no stoppers except some levers
-        // (b) the only stoppers are the leverPush, but we outnumber them
-        // (c) there is only one front stopper which can be levered.
-        //     (Refined in Evaluation::passed)
-        passed =   !(stoppers ^ lever)
-                || (   !(stoppers ^ leverPush)
-                    && popcount(phalanx) >= popcount(leverPush))
-                || (   stoppers == blocked && r >= RANK_5
-                    && (shift<Up>(support) & ~(theirPawns | doubleAttackThem)));
-
-        passed &= !(forward_file_bb(Us, s) & ourPawns);
-
-        // Passed pawns will be properly scored later in evaluation when we have
-        // full attack info.
-        if (passed)
-            e->passedPawns[Us] |= s;
-
-        // Score this pawn
-        if (support | phalanx)
-        {
-            int v =  Connected[r] * (2 + bool(phalanx) - bool(opposed))
-                   + 22 * popcount(support);
-
-            score += make_score(v, v * (r - 2) / 4);
-        }
-
-        else if (!neighbours)
-        {
-            if (     opposed
-                &&  (ourPawns & forward_file_bb(Them, s))
-                && !(theirPawns & adjacent_files_bb(s)))
-                score -= Doubled;
-            else
-                score -=  Isolated
-                        + WeakUnopposed * !opposed;
-        }
-
-        else if (backward)
-            score -=  Backward
-                    + WeakUnopposed * !opposed * bool(~(FileABB | FileHBB) & s);
-
-        if (!support)
-            score -=  Doubled * doubled
-                    + WeakLever * more_than_one(lever);
-
-        if (blocked && r >= RANK_5)
-            score += BlockedPawn[r - RANK_5];
-    }
-
-    return score;
-  }
-
-} // namespace
-
-namespace Pawns {
-
-
-/// Pawns::probe() looks up the current position's pawns configuration in
-/// the pawns hash table. It returns a pointer to the Entry if the position
-/// is found. Otherwise a new Entry is computed and stored there, so we don't
-/// have to recompute all when the same pawns configuration occurs again.
-
-Entry* probe(const Position& pos) {
-
-  Key key = pos.pawn_key();
-  Entry* e = pos.this_thread()->pawnsTable[key];
-
-  if (e->key == key)
-      return e;
-
-  e->key = key;
-  e->blockedCount = 0;
-  e->scores[WHITE] = evaluate<WHITE>(pos, e);
-  e->scores[BLACK] = evaluate<BLACK>(pos, e);
-
-  return e;
-}
-
-
-/// Entry::evaluate_shelter() calculates the shelter bonus and the storm
-/// penalty for a king, looking at the king file and the two closest files.
-
-template<Color Us>
-Score Entry::evaluate_shelter(const Position& pos, Square ksq) const {
-
-  constexpr Color Them = ~Us;
-
-  Bitboard b = pos.pieces(PAWN) & ~forward_ranks_bb(Them, ksq);
-  Bitboard ourPawns = b & pos.pieces(Us) & ~pawnAttacks[Them];
-  Bitboard theirPawns = b & pos.pieces(Them);
-
-  Score bonus = make_score(5, 5);
-
-  File center = std::clamp(file_of(ksq), FILE_B, FILE_G);
-  for (File f = File(center - 1); f <= File(center + 1); ++f)
-  {
-      b = ourPawns & file_bb(f);
-      int ourRank = b ? relative_rank(Us, frontmost_sq(Them, b)) : 0;
-
-      b = theirPawns & file_bb(f);
-      int theirRank = b ? relative_rank(Us, frontmost_sq(Them, b)) : 0;
-
-      int d = edge_distance(f);
-      bonus += make_score(ShelterStrength[d][ourRank], 0);
-
-      if (ourRank && (ourRank == theirRank - 1))
-          bonus -= BlockedStorm[theirRank];
-      else
-          bonus -= make_score(UnblockedStorm[d][theirRank], 0);
-  }
-
-  // King On File
-  bonus -= KingOnFile[pos.is_on_semiopen_file(Us, ksq)][pos.is_on_semiopen_file(Them, ksq)];
-
-  return bonus;
-}
-
-
-/// Entry::do_king_safety() calculates a bonus for king safety. It is called only
-/// when king square changes, which is about 20% of total king_safety() calls.
-
-template<Color Us>
-Score Entry::do_king_safety(const Position& pos) {
-
-  Square ksq = pos.square<KING>(Us);
-  kingSquares[Us] = ksq;
-  castlingRights[Us] = pos.castling_rights(Us);
-  auto compare = [](Score a, Score b) { return mg_value(a) < mg_value(b); };
-
-  Score shelter = evaluate_shelter<Us>(pos, ksq);
-
-  // If we can castle use the bonus after castling if it is bigger
-
-  if (pos.can_castle(Us & KING_SIDE))
-      shelter = std::max(shelter, evaluate_shelter<Us>(pos, relative_square(Us, SQ_G1)), compare);
-
-  if (pos.can_castle(Us & QUEEN_SIDE))
-      shelter = std::max(shelter, evaluate_shelter<Us>(pos, relative_square(Us, SQ_C1)), compare);
-
-  // In endgame we like to bring our king near our closest pawn
-  Bitboard pawns = pos.pieces(Us, PAWN);
-  int minPawnDist = 6;
-
-  if (pawns & attacks_bb<KING>(ksq))
-      minPawnDist = 1;
-  else while (pawns)
-      minPawnDist = std::min(minPawnDist, distance(ksq, pop_lsb(&pawns)));
-
-  return shelter - make_score(0, 16 * minPawnDist);
-}
-
-// Explicit template instantiation
-template Score Entry::do_king_safety<WHITE>(const Position& pos);
-template Score Entry::do_king_safety<BLACK>(const Position& pos);
-
-} // namespace Pawns

src/pawns.h

@@ -1,70 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
-
-  Stockfish is free software: you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation, either version 3 of the License, or
-  (at your option) any later version.
-
-  Stockfish is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-#ifndef PAWNS_H_INCLUDED
-#define PAWNS_H_INCLUDED
-
-#include "misc.h"
-#include "position.h"
-#include "types.h"
-
-namespace Pawns {
-
-/// Pawns::Entry contains various information about a pawn structure. A lookup
-/// to the pawn hash table (performed by calling the probe function) returns a
-/// pointer to an Entry object.
-
-struct Entry {
-
-  Score pawn_score(Color c) const { return scores[c]; }
-  Bitboard pawn_attacks(Color c) const { return pawnAttacks[c]; }
-  Bitboard passed_pawns(Color c) const { return passedPawns[c]; }
-  Bitboard pawn_attacks_span(Color c) const { return pawnAttacksSpan[c]; }
-  int passed_count() const { return popcount(passedPawns[WHITE] | passedPawns[BLACK]); }
-  int blocked_count() const { return blockedCount; }
-
-  template<Color Us>
-  Score king_safety(const Position& pos) {
-    return  kingSquares[Us] == pos.square<KING>(Us) && castlingRights[Us] == pos.castling_rights(Us)
-          ? kingSafety[Us] : (kingSafety[Us] = do_king_safety<Us>(pos));
-  }
-
-  template<Color Us>
-  Score do_king_safety(const Position& pos);
-
-  template<Color Us>
-  Score evaluate_shelter(const Position& pos, Square ksq) const;
-
-  Key key;
-  Score scores[COLOR_NB];
-  Bitboard passedPawns[COLOR_NB];
-  Bitboard pawnAttacks[COLOR_NB];
-  Bitboard pawnAttacksSpan[COLOR_NB];
-  Square kingSquares[COLOR_NB];
-  Score kingSafety[COLOR_NB];
-  int castlingRights[COLOR_NB];
-  int blockedCount;
-};
-
-typedef HashTable<Entry, 131072> Table;
-
-Entry* probe(const Position& pos);
-
-} // namespace Pawns
-
-#endif // #ifndef PAWNS_H_INCLUDED

src/perft.h

@@ -0,0 +1,71 @@
+/*
+  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
+
+  Stockfish is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  Stockfish is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef PERFT_H_INCLUDED
+#define PERFT_H_INCLUDED
+
+#include <cstdint>
+
+#include "cluster.h"
+#include "movegen.h"
+#include "position.h"
+#include "types.h"
+#include "uci.h"
+
+namespace Stockfish {
+
+// Utility to verify move generation. All the leaf nodes up
+// to the given depth are generated and counted, and the sum is returned.
+template<bool Root>
+uint64_t perft(Position& pos, Depth depth) {
+
+    StateInfo st;
+    ASSERT_ALIGNED(&st, Eval::NNUE::CacheLineSize);
+
+    uint64_t   cnt, nodes = 0;
+    const bool leaf = (depth == 2);
+
+    for (const auto& m : MoveList<LEGAL>(pos))
+    {
+        if (Root && depth <= 1)
+            cnt = 1, nodes++;
+        else
+        {
+            pos.do_move(m, st);
+            cnt = leaf ? MoveList<LEGAL>(pos).size() : perft<false>(pos, depth - 1);
+            nodes += cnt;
+            pos.undo_move(m);
+        }
+        if (Root && Cluster::is_root())
+            sync_cout << UCI::move(m, pos.is_chess960()) << ": " << cnt << sync_endl;
+    }
+    return nodes;
+}
+
+inline void perft(const std::string& fen, Depth depth, bool isChess960) {
+    StateListPtr states(new std::deque<StateInfo>(1));
+    Position     p;
+    p.set(fen, isChess960, &states->back());
+
+    uint64_t nodes = perft<true>(p, depth);
+    if (Cluster::is_root())
+        sync_cout << "\nNodes searched: " << nodes << "\n" << sync_endl;
+}
+}
+
+#endif  // PERFT_H_INCLUDED

src/position.h

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -21,406 +21,344 @@
 
 #include <cassert>
 #include <deque>
-#include <memory> // For std::unique_ptr
+#include <iosfwd>
+#include <memory>
 #include <string>
 
 #include "bitboard.h"
-#include "evaluate.h"
-#include "psqt.h"
+#include "nnue/nnue_accumulator.h"
+#include "nnue/nnue_architecture.h"
 #include "types.h"
 
-#include "nnue/nnue_accumulator.h"
+namespace Stockfish {
 
+class TranspositionTable;
 
-/// StateInfo struct stores information needed to restore a Position object to
-/// its previous state when we retract a move. Whenever a move is made on the
-/// board (by calling Position::do_move), a StateInfo object must be passed.
+// StateInfo struct stores information needed to restore a Position object to
+// its previous state when we retract a move. Whenever a move is made on the
+// board (by calling Position::do_move), a StateInfo object must be passed.
 
 struct StateInfo {
 
-  // Copied when making a move
-  Key    pawnKey;
-  Key    materialKey;
-  Value  nonPawnMaterial[COLOR_NB];
-  int    castlingRights;
-  int    rule50;
-  int    pliesFromNull;
-  Square epSquare;
+    // Copied when making a move
+    Key    materialKey;
+    Key    pawnKey;
+    Value  nonPawnMaterial[COLOR_NB];
+    int    castlingRights;
+    int    rule50;
+    int    pliesFromNull;
+    Square epSquare;
 
-  // Not copied when making a move (will be recomputed anyhow)
-  Key        key;
-  Bitboard   checkersBB;
-  Piece      capturedPiece;
-  StateInfo* previous;
-  Bitboard   blockersForKing[COLOR_NB];
-  Bitboard   pinners[COLOR_NB];
-  Bitboard   checkSquares[PIECE_TYPE_NB];
-  int        repetition;
+    // Not copied when making a move (will be recomputed anyhow)
+    Key        key;
+    Bitboard   checkersBB;
+    StateInfo* previous;
+    Bitboard   blockersForKing[COLOR_NB];
+    Bitboard   pinners[COLOR_NB];
+    Bitboard   checkSquares[PIECE_TYPE_NB];
+    Piece      capturedPiece;
+    int        repetition;
 
-  // Used by NNUE
-  Eval::NNUE::Accumulator accumulator;
-  DirtyPiece dirtyPiece;
+    // Used by NNUE
+    Eval::NNUE::Accumulator<Eval::NNUE::TransformedFeatureDimensionsBig>   accumulatorBig;
+    Eval::NNUE::Accumulator<Eval::NNUE::TransformedFeatureDimensionsSmall> accumulatorSmall;
+    DirtyPiece                                                             dirtyPiece;
 };
 
 
-/// A list to keep track of the position states along the setup moves (from the
-/// start position to the position just before the search starts). Needed by
-/// 'draw by repetition' detection. Use a std::deque because pointers to
-/// elements are not invalidated upon list resizing.
-typedef std::unique_ptr<std::deque<StateInfo>> StateListPtr;
+// A list to keep track of the position states along the setup moves (from the
+// start position to the position just before the search starts). Needed by
+// 'draw by repetition' detection. Use a std::deque because pointers to
+// elements are not invalidated upon list resizing.
+using StateListPtr = std::unique_ptr<std::deque<StateInfo>>;
 
 
-/// Position class stores information regarding the board representation as
-/// pieces, side to move, hash keys, castling info, etc. Important methods are
-/// do_move() and undo_move(), used by the search to update node info when
-/// traversing the search tree.
-class Thread;
-
+// Position class stores information regarding the board representation as
+// pieces, side to move, hash keys, castling info, etc. Important methods are
+// do_move() and undo_move(), used by the search to update node info when
+// traversing the search tree.
 class Position {
-public:
-  static void init();
+   public:
+    static void init();
 
-  Position() = default;
-  Position(const Position&) = delete;
-  Position& operator=(const Position&) = delete;
+    Position()                           = default;
+    Position(const Position&)            = delete;
+    Position& operator=(const Position&) = delete;
 
-  // FEN string input/output
-  Position& set(const std::string& fenStr, bool isChess960, StateInfo* si, Thread* th);
-  Position& set(const std::string& code, Color c, StateInfo* si);
-  const std::string fen() const;
+    // FEN string input/output
+    Position&   set(const std::string& fenStr, bool isChess960, StateInfo* si);
+    Position&   set(const std::string& code, Color c, StateInfo* si);
+    std::string fen() const;
 
-  // Position representation
-  Bitboard pieces(PieceType pt) const;
-  Bitboard pieces(PieceType pt1, PieceType pt2) const;
-  Bitboard pieces(Color c) const;
-  Bitboard pieces(Color c, PieceType pt) const;
-  Bitboard pieces(Color c, PieceType pt1, PieceType pt2) const;
-  Piece piece_on(Square s) const;
-  Square ep_square() const;
-  bool empty(Square s) const;
-  template<PieceType Pt> int count(Color c) const;
-  template<PieceType Pt> int count() const;
-  template<PieceType Pt> Square square(Color c) const;
-  bool is_on_semiopen_file(Color c, Square s) const;
+    // Position representation
+    Bitboard pieces(PieceType pt = ALL_PIECES) const;
+    template<typename... PieceTypes>
+    Bitboard pieces(PieceType pt, PieceTypes... pts) const;
+    Bitboard pieces(Color c) const;
+    template<typename... PieceTypes>
+    Bitboard pieces(Color c, PieceTypes... pts) const;
+    Piece    piece_on(Square s) const;
+    Square   ep_square() const;
+    bool     empty(Square s) const;
+    template<PieceType Pt>
+    int count(Color c) const;
+    template<PieceType Pt>
+    int count() const;
+    template<PieceType Pt>
+    Square square(Color c) const;
 
-  // Castling
-  CastlingRights castling_rights(Color c) const;
-  bool can_castle(CastlingRights cr) const;
-  bool castling_impeded(CastlingRights cr) const;
-  Square castling_rook_square(CastlingRights cr) const;
+    // Castling
+    CastlingRights castling_rights(Color c) const;
+    bool           can_castle(CastlingRights cr) const;
+    bool           castling_impeded(CastlingRights cr) const;
+    Square         castling_rook_square(CastlingRights cr) const;
 
-  // Checking
-  Bitboard checkers() const;
-  Bitboard blockers_for_king(Color c) const;
-  Bitboard check_squares(PieceType pt) const;
-  Bitboard pinners(Color c) const;
-  bool is_discovered_check_on_king(Color c, Move m) const;
+    // Checking
+    Bitboard checkers() const;
+    Bitboard blockers_for_king(Color c) const;
+    Bitboard check_squares(PieceType pt) const;
+    Bitboard pinners(Color c) const;
 
-  // Attacks to/from a given square
-  Bitboard attackers_to(Square s) const;
-  Bitboard attackers_to(Square s, Bitboard occupied) const;
-  Bitboard slider_blockers(Bitboard sliders, Square s, Bitboard& pinners) const;
+    // Attacks to/from a given square
+    Bitboard attackers_to(Square s) const;
+    Bitboard attackers_to(Square s, Bitboard occupied) const;
+    void     update_slider_blockers(Color c) const;
+    template<PieceType Pt>
+    Bitboard attacks_by(Color c) const;
 
-  // Properties of moves
-  bool legal(Move m) const;
-  bool pseudo_legal(const Move m) const;
-  bool capture(Move m) const;
-  bool capture_or_promotion(Move m) const;
-  bool gives_check(Move m) const;
-  bool advanced_pawn_push(Move m) const;
-  Piece moved_piece(Move m) const;
-  Piece captured_piece() const;
+    // Properties of moves
+    bool  legal(Move m) const;
+    bool  pseudo_legal(const Move m) const;
+    bool  capture(Move m) const;
+    bool  capture_stage(Move m) const;
+    bool  gives_check(Move m) const;
+    Piece moved_piece(Move m) const;
+    Piece captured_piece() const;
 
-  // Piece specific
-  bool pawn_passed(Color c, Square s) const;
-  bool opposite_bishops() const;
-  int  pawns_on_same_color_squares(Color c, Square s) const;
+    // Doing and undoing moves
+    void do_move(Move m, StateInfo& newSt);
+    void do_move(Move m, StateInfo& newSt, bool givesCheck);
+    void undo_move(Move m);
+    void do_null_move(StateInfo& newSt, TranspositionTable& tt);
+    void undo_null_move();
 
-  // Doing and undoing moves
-  void do_move(Move m, StateInfo& newSt);
-  void do_move(Move m, StateInfo& newSt, bool givesCheck);
-  void undo_move(Move m);
-  void do_null_move(StateInfo& newSt);
-  void undo_null_move();
+    // Static Exchange Evaluation
+    bool see_ge(Move m, int threshold = 0) const;
 
-  // Static Exchange Evaluation
-  bool see_ge(Move m, Value threshold = VALUE_ZERO) const;
+    // Accessing hash keys
+    Key key() const;
+    Key key_after(Move m) const;
+    Key material_key() const;
+    Key pawn_key() const;
 
-  // Accessing hash keys
-  Key key() const;
-  Key key_after(Move m) const;
-  Key material_key() const;
-  Key pawn_key() const;
+    // Other properties of the position
+    Color side_to_move() const;
+    int   game_ply() const;
+    bool  is_chess960() const;
+    bool  is_draw(int ply) const;
+    bool  has_game_cycle(int ply) const;
+    bool  has_repeated() const;
+    int   rule50_count() const;
+    Value non_pawn_material(Color c) const;
+    Value non_pawn_material() const;
 
-  // Other properties of the position
-  Color side_to_move() const;
-  int game_ply() const;
-  bool is_chess960() const;
-  Thread* this_thread() const;
-  bool is_draw(int ply) const;
-  bool has_game_cycle(int ply) const;
-  bool has_repeated() const;
-  int rule50_count() const;
-  Score psq_score() const;
-  Value non_pawn_material(Color c) const;
-  Value non_pawn_material() const;
+    // Position consistency check, for debugging
+    bool pos_is_ok() const;
+    void flip();
 
-  // Position consistency check, for debugging
-  bool pos_is_ok() const;
-  void flip();
+    // Used by NNUE
+    StateInfo* state() const;
 
-  // Used by NNUE
-  StateInfo* state() const;
+    void put_piece(Piece pc, Square s);
+    void remove_piece(Square s);
 
-private:
-  // Initialization helpers (used while setting up a position)
-  void set_castling_right(Color c, Square rfrom);
-  void set_state(StateInfo* si) const;
-  void set_check_info(StateInfo* si) const;
+   private:
+    // Initialization helpers (used while setting up a position)
+    void set_castling_right(Color c, Square rfrom);
+    void set_state() const;
+    void set_check_info() const;
 
-  // Other helpers
-  void put_piece(Piece pc, Square s);
-  void remove_piece(Square s);
-  void move_piece(Square from, Square to);
-  template<bool Do>
-  void do_castling(Color us, Square from, Square& to, Square& rfrom, Square& rto);
+    // Other helpers
+    void move_piece(Square from, Square to);
+    template<bool Do>
+    void do_castling(Color us, Square from, Square& to, Square& rfrom, Square& rto);
+    template<bool AfterMove>
+    Key adjust_key50(Key k) const;
 
-  // Data members
-  Piece board[SQUARE_NB];
-  Bitboard byTypeBB[PIECE_TYPE_NB];
-  Bitboard byColorBB[COLOR_NB];
-  int pieceCount[PIECE_NB];
-  int castlingRightsMask[SQUARE_NB];
-  Square castlingRookSquare[CASTLING_RIGHT_NB];
-  Bitboard castlingPath[CASTLING_RIGHT_NB];
-  int gamePly;
-  Color sideToMove;
-  Score psq;
-  Thread* thisThread;
-  StateInfo* st;
-  bool chess960;
+    // Data members
+    Piece      board[SQUARE_NB];
+    Bitboard   byTypeBB[PIECE_TYPE_NB];
+    Bitboard   byColorBB[COLOR_NB];
+    int        pieceCount[PIECE_NB];
+    int        castlingRightsMask[SQUARE_NB];
+    Square     castlingRookSquare[CASTLING_RIGHT_NB];
+    Bitboard   castlingPath[CASTLING_RIGHT_NB];
+    StateInfo* st;
+    int        gamePly;
+    Color      sideToMove;
+    bool       chess960;
 };
 
-extern std::ostream& operator<<(std::ostream& os, const Position& pos);
+std::ostream& operator<<(std::ostream& os, const Position& pos);
 
-inline Color Position::side_to_move() const {
-  return sideToMove;
-}
+inline Color Position::side_to_move() const { return sideToMove; }
 
 inline Piece Position::piece_on(Square s) const {
-  assert(is_ok(s));
-  return board[s];
+    assert(is_ok(s));
+    return board[s];
 }
 
-inline bool Position::empty(Square s) const {
-  return piece_on(s) == NO_PIECE;
+inline bool Position::empty(Square s) const { return piece_on(s) == NO_PIECE; }
+
+inline Piece Position::moved_piece(Move m) const { return piece_on(m.from_sq()); }
+
+inline Bitboard Position::pieces(PieceType pt) const { return byTypeBB[pt]; }
+
+template<typename... PieceTypes>
+inline Bitboard Position::pieces(PieceType pt, PieceTypes... pts) const {
+    return pieces(pt) | pieces(pts...);
 }
 
-inline Piece Position::moved_piece(Move m) const {
-  return piece_on(from_sq(m));
+inline Bitboard Position::pieces(Color c) const { return byColorBB[c]; }
+
+template<typename... PieceTypes>
+inline Bitboard Position::pieces(Color c, PieceTypes... pts) const {
+    return pieces(c) & pieces(pts...);
 }
 
-inline Bitboard Position::pieces(PieceType pt = ALL_PIECES) const {
-  return byTypeBB[pt];
+template<PieceType Pt>
+inline int Position::count(Color c) const {
+    return pieceCount[make_piece(c, Pt)];
 }
 
-inline Bitboard Position::pieces(PieceType pt1, PieceType pt2) const {
-  return pieces(pt1) | pieces(pt2);
+template<PieceType Pt>
+inline int Position::count() const {
+    return count<Pt>(WHITE) + count<Pt>(BLACK);
 }
 
-inline Bitboard Position::pieces(Color c) const {
-  return byColorBB[c];
+template<PieceType Pt>
+inline Square Position::square(Color c) const {
+    assert(count<Pt>(c) == 1);
+    return lsb(pieces(c, Pt));
 }
 
-inline Bitboard Position::pieces(Color c, PieceType pt) const {
-  return pieces(c) & pieces(pt);
-}
+inline Square Position::ep_square() const { return st->epSquare; }
 
-inline Bitboard Position::pieces(Color c, PieceType pt1, PieceType pt2) const {
-  return pieces(c) & (pieces(pt1) | pieces(pt2));
-}
-
-template<PieceType Pt> inline int Position::count(Color c) const {
-  return pieceCount[make_piece(c, Pt)];
-}
-
-template<PieceType Pt> inline int Position::count() const {
-  return count<Pt>(WHITE) + count<Pt>(BLACK);
-}
-
-template<PieceType Pt> inline Square Position::square(Color c) const {
-  assert(count<Pt>(c) == 1);
-  return lsb(pieces(c, Pt));
-}
-
-inline Square Position::ep_square() const {
-  return st->epSquare;
-}
-
-inline bool Position::is_on_semiopen_file(Color c, Square s) const {
-  return !(pieces(c, PAWN) & file_bb(s));
-}
-
-inline bool Position::can_castle(CastlingRights cr) const {
-  return st->castlingRights & cr;
-}
+inline bool Position::can_castle(CastlingRights cr) const { return st->castlingRights & cr; }
 
 inline CastlingRights Position::castling_rights(Color c) const {
-  return c & CastlingRights(st->castlingRights);
+    return c & CastlingRights(st->castlingRights);
 }
 
 inline bool Position::castling_impeded(CastlingRights cr) const {
-  assert(cr == WHITE_OO || cr == WHITE_OOO || cr == BLACK_OO || cr == BLACK_OOO);
-
-  return pieces() & castlingPath[cr];
+    assert(cr == WHITE_OO || cr == WHITE_OOO || cr == BLACK_OO || cr == BLACK_OOO);
+    return pieces() & castlingPath[cr];
 }
 
 inline Square Position::castling_rook_square(CastlingRights cr) const {
-  assert(cr == WHITE_OO || cr == WHITE_OOO || cr == BLACK_OO || cr == BLACK_OOO);
-
-  return castlingRookSquare[cr];
+    assert(cr == WHITE_OO || cr == WHITE_OOO || cr == BLACK_OO || cr == BLACK_OOO);
+    return castlingRookSquare[cr];
 }
 
-inline Bitboard Position::attackers_to(Square s) const {
-  return attackers_to(s, pieces());
+inline Bitboard Position::attackers_to(Square s) const { return attackers_to(s, pieces()); }
+
+template<PieceType Pt>
+inline Bitboard Position::attacks_by(Color c) const {
+
+    if constexpr (Pt == PAWN)
+        return c == WHITE ? pawn_attacks_bb<WHITE>(pieces(WHITE, PAWN))
+                          : pawn_attacks_bb<BLACK>(pieces(BLACK, PAWN));
+    else
+    {
+        Bitboard threats   = 0;
+        Bitboard attackers = pieces(c, Pt);
+        while (attackers)
+            threats |= attacks_bb<Pt>(pop_lsb(attackers), pieces());
+        return threats;
+    }
 }
 
-inline Bitboard Position::checkers() const {
-  return st->checkersBB;
+inline Bitboard Position::checkers() const { return st->checkersBB; }
+
+inline Bitboard Position::blockers_for_king(Color c) const { return st->blockersForKing[c]; }
+
+inline Bitboard Position::pinners(Color c) const { return st->pinners[c]; }
+
+inline Bitboard Position::check_squares(PieceType pt) const { return st->checkSquares[pt]; }
+
+inline Key Position::key() const { return adjust_key50<false>(st->key); }
+
+template<bool AfterMove>
+inline Key Position::adjust_key50(Key k) const {
+    return st->rule50 < 14 - AfterMove ? k : k ^ make_key((st->rule50 - (14 - AfterMove)) / 8);
 }
 
-inline Bitboard Position::blockers_for_king(Color c) const {
-  return st->blockersForKing[c];
-}
+inline Key Position::pawn_key() const { return st->pawnKey; }
 
-inline Bitboard Position::pinners(Color c) const {
-  return st->pinners[c];
-}
+inline Key Position::material_key() const { return st->materialKey; }
 
-inline Bitboard Position::check_squares(PieceType pt) const {
-  return st->checkSquares[pt];
-}
-
-inline bool Position::is_discovered_check_on_king(Color c, Move m) const {
-  return st->blockersForKing[c] & from_sq(m);
-}
-
-inline bool Position::pawn_passed(Color c, Square s) const {
-  return !(pieces(~c, PAWN) & passed_pawn_span(c, s));
-}
-
-inline bool Position::advanced_pawn_push(Move m) const {
-  return   type_of(moved_piece(m)) == PAWN
-        && relative_rank(sideToMove, to_sq(m)) > RANK_5;
-}
-
-inline int Position::pawns_on_same_color_squares(Color c, Square s) const {
-  return popcount(pieces(c, PAWN) & ((DarkSquares & s) ? DarkSquares : ~DarkSquares));
-}
-
-inline Key Position::key() const {
-  return st->rule50 < 14 ? st->key
-                         : st->key ^ make_key((st->rule50 - 14) / 8);
-}
-
-inline Key Position::pawn_key() const {
-  return st->pawnKey;
-}
-
-inline Key Position::material_key() const {
-  return st->materialKey;
-}
-
-inline Score Position::psq_score() const {
-  return psq;
-}
-
-inline Value Position::non_pawn_material(Color c) const {
-  return st->nonPawnMaterial[c];
-}
+inline Value Position::non_pawn_material(Color c) const { return st->nonPawnMaterial[c]; }
 
 inline Value Position::non_pawn_material() const {
-  return non_pawn_material(WHITE) + non_pawn_material(BLACK);
+    return non_pawn_material(WHITE) + non_pawn_material(BLACK);
 }
 
-inline int Position::game_ply() const {
-  return gamePly;
-}
+inline int Position::game_ply() const { return gamePly; }
 
-inline int Position::rule50_count() const {
-  return st->rule50;
-}
+inline int Position::rule50_count() const { return st->rule50; }
 
-inline bool Position::opposite_bishops() const {
-  return   count<BISHOP>(WHITE) == 1
-        && count<BISHOP>(BLACK) == 1
-        && opposite_colors(square<BISHOP>(WHITE), square<BISHOP>(BLACK));
-}
-
-inline bool Position::is_chess960() const {
-  return chess960;
-}
-
-inline bool Position::capture_or_promotion(Move m) const {
-  assert(is_ok(m));
-  return type_of(m) != NORMAL ? type_of(m) != CASTLING : !empty(to_sq(m));
-}
+inline bool Position::is_chess960() const { return chess960; }
 
 inline bool Position::capture(Move m) const {
-  assert(is_ok(m));
-  // Castling is encoded as "king captures rook"
-  return (!empty(to_sq(m)) && type_of(m) != CASTLING) || type_of(m) == EN_PASSANT;
+    assert(m.is_ok());
+    return (!empty(m.to_sq()) && m.type_of() != CASTLING) || m.type_of() == EN_PASSANT;
 }
 
-inline Piece Position::captured_piece() const {
-  return st->capturedPiece;
+// Returns true if a move is generated from the capture stage, having also
+// queen promotions covered, i.e. consistency with the capture stage move generation
+// is needed to avoid the generation of duplicate moves.
+inline bool Position::capture_stage(Move m) const {
+    assert(m.is_ok());
+    return capture(m) || m.promotion_type() == QUEEN;
 }
 
-inline Thread* Position::this_thread() const {
-  return thisThread;
-}
+inline Piece Position::captured_piece() const { return st->capturedPiece; }
 
 inline void Position::put_piece(Piece pc, Square s) {
 
-  board[s] = pc;
-  byTypeBB[ALL_PIECES] |= byTypeBB[type_of(pc)] |= s;
-  byColorBB[color_of(pc)] |= s;
-  pieceCount[pc]++;
-  pieceCount[make_piece(color_of(pc), ALL_PIECES)]++;
-  psq += PSQT::psq[pc][s];
+    board[s] = pc;
+    byTypeBB[ALL_PIECES] |= byTypeBB[type_of(pc)] |= s;
+    byColorBB[color_of(pc)] |= s;
+    pieceCount[pc]++;
+    pieceCount[make_piece(color_of(pc), ALL_PIECES)]++;
 }
 
 inline void Position::remove_piece(Square s) {
 
-  Piece pc = board[s];
-  byTypeBB[ALL_PIECES] ^= s;
-  byTypeBB[type_of(pc)] ^= s;
-  byColorBB[color_of(pc)] ^= s;
-  /* board[s] = NO_PIECE;  Not needed, overwritten by the capturing one */
-  pieceCount[pc]--;
-  pieceCount[make_piece(color_of(pc), ALL_PIECES)]--;
-  psq -= PSQT::psq[pc][s];
+    Piece pc = board[s];
+    byTypeBB[ALL_PIECES] ^= s;
+    byTypeBB[type_of(pc)] ^= s;
+    byColorBB[color_of(pc)] ^= s;
+    board[s] = NO_PIECE;
+    pieceCount[pc]--;
+    pieceCount[make_piece(color_of(pc), ALL_PIECES)]--;
 }
 
 inline void Position::move_piece(Square from, Square to) {
 
-  Piece pc = board[from];
-  Bitboard fromTo = from | to;
-  byTypeBB[ALL_PIECES] ^= fromTo;
-  byTypeBB[type_of(pc)] ^= fromTo;
-  byColorBB[color_of(pc)] ^= fromTo;
-  board[from] = NO_PIECE;
-  board[to] = pc;
-  psq += PSQT::psq[pc][to] - PSQT::psq[pc][from];
+    Piece    pc     = board[from];
+    Bitboard fromTo = from | to;
+    byTypeBB[ALL_PIECES] ^= fromTo;
+    byTypeBB[type_of(pc)] ^= fromTo;
+    byColorBB[color_of(pc)] ^= fromTo;
+    board[from] = NO_PIECE;
+    board[to]   = pc;
 }
 
-inline void Position::do_move(Move m, StateInfo& newSt) {
-  do_move(m, newSt, gives_check(m));
-}
+inline void Position::do_move(Move m, StateInfo& newSt) { do_move(m, newSt, gives_check(m)); }
 
-inline StateInfo* Position::state() const {
+inline StateInfo* Position::state() const { return st; }
 
-  return st;
-}
+}  // namespace Stockfish
 
-#endif // #ifndef POSITION_H_INCLUDED
+#endif  // #ifndef POSITION_H_INCLUDED

src/psqt.cpp

@@ -1,128 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
-
-  Stockfish is free software: you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation, either version 3 of the License, or
-  (at your option) any later version.
-
-  Stockfish is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-
-#include "psqt.h"
-
-#include <algorithm>
-
-#include "bitboard.h"
-#include "types.h"
-
-
-namespace
-{
-
-auto constexpr S = make_score;
-
-// 'Bonus' contains Piece-Square parameters.
-// Scores are explicit for files A to D, implicitly mirrored for E to H.
-constexpr Score Bonus[][RANK_NB][int(FILE_NB) / 2] = {
-  { },
-  { },
-  { // Knight
-   { S(-175, -96), S(-92,-65), S(-74,-49), S(-73,-21) },
-   { S( -77, -67), S(-41,-54), S(-27,-18), S(-15,  8) },
-   { S( -61, -40), S(-17,-27), S(  6, -8), S( 12, 29) },
-   { S( -35, -35), S(  8, -2), S( 40, 13), S( 49, 28) },
-   { S( -34, -45), S( 13,-16), S( 44,  9), S( 51, 39) },
-   { S(  -9, -51), S( 22,-44), S( 58,-16), S( 53, 17) },
-   { S( -67, -69), S(-27,-50), S(  4,-51), S( 37, 12) },
-   { S(-201,-100), S(-83,-88), S(-56,-56), S(-26,-17) }
-  },
-  { // Bishop
-   { S(-37,-40), S(-4 ,-21), S( -6,-26), S(-16, -8) },
-   { S(-11,-26), S(  6, -9), S( 13,-12), S(  3,  1) },
-   { S(-5 ,-11), S( 15, -1), S( -4, -1), S( 12,  7) },
-   { S(-4 ,-14), S(  8, -4), S( 18,  0), S( 27, 12) },
-   { S(-8 ,-12), S( 20, -1), S( 15,-10), S( 22, 11) },
-   { S(-11,-21), S(  4,  4), S(  1,  3), S(  8,  4) },
-   { S(-12,-22), S(-10,-14), S(  4, -1), S(  0,  1) },
-   { S(-34,-32), S(  1,-29), S(-10,-26), S(-16,-17) }
-  },
-  { // Rook
-   { S(-31, -9), S(-20,-13), S(-14,-10), S(-5, -9) },
-   { S(-21,-12), S(-13, -9), S( -8, -1), S( 6, -2) },
-   { S(-25,  6), S(-11, -8), S( -1, -2), S( 3, -6) },
-   { S(-13, -6), S( -5,  1), S( -4, -9), S(-6,  7) },
-   { S(-27, -5), S(-15,  8), S( -4,  7), S( 3, -6) },
-   { S(-22,  6), S( -2,  1), S(  6, -7), S(12, 10) },
-   { S( -2,  4), S( 12,  5), S( 16, 20), S(18, -5) },
-   { S(-17, 18), S(-19,  0), S( -1, 19), S( 9, 13) }
-  },
-  { // Queen
-   { S( 3,-69), S(-5,-57), S(-5,-47), S( 4,-26) },
-   { S(-3,-54), S( 5,-31), S( 8,-22), S(12, -4) },
-   { S(-3,-39), S( 6,-18), S(13, -9), S( 7,  3) },
-   { S( 4,-23), S( 5, -3), S( 9, 13), S( 8, 24) },
-   { S( 0,-29), S(14, -6), S(12,  9), S( 5, 21) },
-   { S(-4,-38), S(10,-18), S( 6,-11), S( 8,  1) },
-   { S(-5,-50), S( 6,-27), S(10,-24), S( 8, -8) },
-   { S(-2,-74), S(-2,-52), S( 1,-43), S(-2,-34) }
-  },
-  { // King
-   { S(271,  1), S(327, 45), S(271, 85), S(198, 76) },
-   { S(278, 53), S(303,100), S(234,133), S(179,135) },
-   { S(195, 88), S(258,130), S(169,169), S(120,175) },
-   { S(164,103), S(190,156), S(138,172), S( 98,172) },
-   { S(154, 96), S(179,166), S(105,199), S( 70,199) },
-   { S(123, 92), S(145,172), S( 81,184), S( 31,191) },
-   { S( 88, 47), S(120,121), S( 65,116), S( 33,131) },
-   { S( 59, 11), S( 89, 59), S( 45, 73), S( -1, 78) }
-  }
-};
-
-constexpr Score PBonus[RANK_NB][FILE_NB] =
-  { // Pawn (asymmetric distribution)
-   { },
-   { S(  2, -8), S(  4, -6), S( 11,  9), S( 18,  5), S( 16, 16), S( 21,  6), S(  9, -6), S( -3,-18) },
-   { S( -9, -9), S(-15, -7), S( 11,-10), S( 15,  5), S( 31,  2), S( 23,  3), S(  6, -8), S(-20, -5) },
-   { S( -3,  7), S(-20,  1), S(  8, -8), S( 19, -2), S( 39,-14), S( 17,-13), S(  2,-11), S( -5, -6) },
-   { S( 11, 12), S( -4,  6), S(-11,  2), S(  2, -6), S( 11, -5), S(  0, -4), S(-12, 14), S(  5,  9) },
-   { S(  3, 27), S(-11, 18), S( -6, 19), S( 22, 29), S( -8, 30), S( -5,  9), S(-14,  8), S(-11, 14) },
-   { S( -7, -1), S(  6,-14), S( -2, 13), S(-11, 22), S(  4, 24), S(-14, 17), S( 10,  7), S( -9,  7) }
-  };
-
-} // namespace
-
-
-namespace PSQT
-{
-
-Score psq[PIECE_NB][SQUARE_NB];
-
-// PSQT::init() initializes piece-square tables: the white halves of the tables are
-// copied from Bonus[] and PBonus[], adding the piece value, then the black halves of
-// the tables are initialized by flipping and changing the sign of the white scores.
-void init() {
-
-  for (Piece pc : {W_PAWN, W_KNIGHT, W_BISHOP, W_ROOK, W_QUEEN, W_KING})
-  {
-    Score score = make_score(PieceValue[MG][pc], PieceValue[EG][pc]);
-
-    for (Square s = SQ_A1; s <= SQ_H8; ++s)
-    {
-      File f = File(edge_distance(file_of(s)));
-      psq[ pc][s] = score + (type_of(pc) == PAWN ? PBonus[rank_of(s)][file_of(s)]
-                                                 : Bonus[pc][rank_of(s)][f]);
-      psq[~pc][flip_rank(s)] = -psq[pc][s];
-    }
-  }
-}
-
-} // namespace PSQT

src/search.h

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -19,91 +19,278 @@
 #ifndef SEARCH_H_INCLUDED
 #define SEARCH_H_INCLUDED
 
+#include <array>
+#include <atomic>
+#include <cassert>
+#include <cstddef>
+#include <cstdint>
+#include <memory>
+#include <string>
 #include <vector>
+#include <mutex>
 
+#include "cluster.h"
 #include "misc.h"
 #include "movepick.h"
+#include "position.h"
+#include "syzygy/tbprobe.h"
+#include "timeman.h"
 #include "types.h"
 
-class Position;
+namespace Stockfish {
+
+namespace Eval::NNUE {
+struct Networks;
+}
+
+// Different node types, used as a template parameter
+enum NodeType {
+    NonPV,
+    PV,
+    Root
+};
+
+class TranspositionTable;
+class ThreadPool;
+class OptionsMap;
 
 namespace Search {
 
-/// Threshold used for countermoves based pruning
-constexpr int CounterMovePruneThreshold = 0;
-
-
-/// Stack struct keeps track of the information we need to remember from nodes
-/// shallower and deeper in the tree during the search. Each search thread has
-/// its own array of Stack objects, indexed by the current ply.
-
+// Stack struct keeps track of the information we need to remember from nodes
+// shallower and deeper in the tree during the search. Each search thread has
+// its own array of Stack objects, indexed by the current ply.
 struct Stack {
-  Move* pv;
-  PieceToHistory* continuationHistory;
-  int ply;
-  Move currentMove;
-  Move excludedMove;
-  Move killers[2];
-  Value staticEval;
-  int statScore;
-  int moveCount;
-  bool inCheck;
-  bool ttPv;
-  bool ttHit;
+    Move*           pv;
+    PieceToHistory* continuationHistory;
+    int             ply;
+    Move            currentMove;
+    Move            excludedMove;
+    Move            killers[2];
+    Value           staticEval;
+    int             statScore;
+    int             moveCount;
+    bool            inCheck;
+    bool            ttPv;
+    bool            ttHit;
+    int             multipleExtensions;
+    int             cutoffCnt;
 };
 
 
-/// RootMove struct is used for moves at the root of the tree. For each root move
-/// we store a score and a PV (really a refutation in the case of moves which
-/// fail low). Score is normally set at -VALUE_INFINITE for all non-pv moves.
-
+// RootMove struct is used for moves at the root of the tree. For each root move
+// we store a score and a PV (really a refutation in the case of moves which
+// fail low). Score is normally set at -VALUE_INFINITE for all non-pv moves.
 struct RootMove {
 
-  explicit RootMove(Move m) : pv(1, m) {}
-  bool extract_ponder_from_tt(Position& pos);
-  bool operator==(const Move& m) const { return pv[0] == m; }
-  bool operator<(const RootMove& m) const { // Sort in descending order
-    return m.score != score ? m.score < score
-                            : m.previousScore < previousScore;
-  }
+    explicit RootMove(Move m) :
+        pv(1, m) {}
+    bool extract_ponder_from_tt(const TranspositionTable& tt, Position& pos);
+    bool operator==(const Move& m) const { return pv[0] == m; }
+    // Sort in descending order
+    bool operator<(const RootMove& m) const {
+        return m.score != score ? m.score < score : m.previousScore < previousScore;
+    }
 
-  Value score = -VALUE_INFINITE;
-  Value previousScore = -VALUE_INFINITE;
-  int selDepth = 0;
-  int tbRank = 0;
-  Value tbScore;
-  std::vector<Move> pv;
+    uint64_t          effort          = 0;
+    Value             score           = -VALUE_INFINITE;
+    Value             previousScore   = -VALUE_INFINITE;
+    Value             averageScore    = -VALUE_INFINITE;
+    Value             uciScore        = -VALUE_INFINITE;
+    bool              scoreLowerbound = false;
+    bool              scoreUpperbound = false;
+    int               selDepth        = 0;
+    int               tbRank          = 0;
+    Value             tbScore;
+    std::vector<Move> pv;
 };
 
-typedef std::vector<RootMove> RootMoves;
+using RootMoves = std::vector<RootMove>;
 
 
-/// LimitsType struct stores information sent by GUI about available time to
-/// search the current move, maximum depth/time, or if we are in analysis mode.
-
+// LimitsType struct stores information sent by GUI about available time to
+// search the current move, maximum depth/time, or if we are in analysis mode.
 struct LimitsType {
 
-  LimitsType() { // Init explicitly due to broken value-initialization of non POD in MSVC
-    time[WHITE] = time[BLACK] = inc[WHITE] = inc[BLACK] = npmsec = movetime = TimePoint(0);
-    movestogo = depth = mate = perft = infinite = 0;
-    nodes = 0;
-  }
+    // Init explicitly due to broken value-initialization of non POD in MSVC
+    LimitsType() {
+        time[WHITE] = time[BLACK] = inc[WHITE] = inc[BLACK] = npmsec = movetime = TimePoint(0);
+        movestogo = depth = mate = perft = infinite = 0;
+        nodes                                       = 0;
+        ponderMode                                  = false;
+    }
 
-  bool use_time_management() const {
-    return time[WHITE] || time[BLACK];
-  }
+    bool use_time_management() const { return Cluster::is_root() && (time[WHITE] || time[BLACK]); }
 
-  std::vector<Move> searchmoves;
-  TimePoint time[COLOR_NB], inc[COLOR_NB], npmsec, movetime, startTime;
-  int movestogo, depth, mate, perft, infinite;
-  int64_t nodes;
+    std::vector<Move> searchmoves;
+    TimePoint         time[COLOR_NB], inc[COLOR_NB], npmsec, movetime, startTime;
+    int               movestogo, depth, mate, perft, infinite;
+    uint64_t          nodes;
+    bool              ponderMode;
 };
 
-extern LimitsType Limits;
 
-void init();
-void clear();
+// The UCI stores the uci options, thread pool, and transposition table.
+// This struct is used to easily forward data to the Search::Worker class.
+struct SharedState {
+    SharedState(const OptionsMap&           optionsMap,
+                ThreadPool&                 threadPool,
+                TranspositionTable&         transpositionTable,
+                const Eval::NNUE::Networks& nets) :
+        options(optionsMap),
+        threads(threadPool),
+        tt(transpositionTable),
+        networks(nets) {}
 
-} // namespace Search
 
-#endif // #ifndef SEARCH_H_INCLUDED
+    const OptionsMap&           options;
+    ThreadPool&                 threads;
+    TranspositionTable&         tt;
+    const Eval::NNUE::Networks& networks;
+};
+
+class Worker;
+
+// Null Object Pattern, implement a common interface for the SearchManagers.
+// A Null Object will be given to non-mainthread workers.
+class ISearchManager {
+   public:
+    virtual ~ISearchManager() {}
+    virtual void check_time(Search::Worker&) = 0;
+};
+
+// SearchManager manages the search from the main thread. It is responsible for
+// keeping track of the time, and storing data strictly related to the main thread.
+class SearchManager: public ISearchManager {
+   public:
+    void check_time(Search::Worker& worker) override;
+
+    std::string pv(const Search::Worker&     worker,
+                   const ThreadPool&         threads,
+                   const TranspositionTable& tt,
+                   Depth                     depth) const;
+
+    Stockfish::TimeManagement tm;
+    int                       callsCnt;
+    std::atomic_bool          ponder;
+
+    std::array<Value, 4> iterValue;
+    double               previousTimeReduction;
+    Value                bestPreviousScore;
+    Value                bestPreviousAverageScore;
+    bool                 stopOnPonderhit;
+
+    size_t id;
+};
+
+class NullSearchManager: public ISearchManager {
+   public:
+    void check_time(Search::Worker&) override {}
+};
+
+
+// Search::Worker is the class that does the actual search.
+// It is instantiated once per thread, and it is responsible for keeping track
+// of the search history, and storing data required for the search.
+class Worker {
+   public:
+    Worker(SharedState&, std::unique_ptr<ISearchManager>, size_t);
+
+    // Called at instantiation to initialize Reductions tables
+    // Reset histories, usually before a new game
+    void clear();
+
+    // Called when the program receives the UCI 'go' command.
+    // It searches from the root position and outputs the "bestmove".
+    void start_searching();
+
+    bool is_mainthread() const { return thread_idx == 0; }
+
+    // Public because they need to be updatable by the stats
+    CounterMoveHistory    counterMoves;
+    ButterflyHistory      mainHistory;
+    CapturePieceToHistory captureHistory;
+    ContinuationHistory   continuationHistory[2][2];
+    PawnHistory           pawnHistory;
+    CorrectionHistory     correctionHistory;
+
+#ifdef USE_MPI
+    struct {
+        std::mutex                             mutex;
+        Cluster::TTCache<Cluster::TTCacheSize> buffer = {};
+    } ttCache;
+#endif
+
+    std::atomic<uint64_t> TTsaves;
+
+    friend void Cluster::save(TranspositionTable&,
+                              ThreadPool&,
+                              Search::Worker*,
+                              TTEntry* tte,
+                              Key      k,
+                              Value    v,
+                              bool     PvHit,
+                              Bound    b,
+                              Depth    d,
+                              Move     m,
+                              Value    ev,
+                              uint8_t  generation8);
+
+   private:
+    void iterative_deepening();
+
+    // Main search function for both PV and non-PV nodes
+    template<NodeType nodeType>
+    Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth, bool cutNode);
+
+    // Quiescence search function, which is called by the main search
+    template<NodeType nodeType>
+    Value qsearch(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth = 0);
+
+    Depth reduction(bool i, Depth d, int mn, int delta);
+
+    // Get a pointer to the search manager, only allowed to be called by the
+    // main thread.
+    SearchManager* main_manager() const {
+        assert(thread_idx == 0);
+        return static_cast<SearchManager*>(manager.get());
+    }
+
+    LimitsType limits;
+
+    size_t                pvIdx, pvLast;
+    std::atomic<uint64_t> nodes, tbHits, bestMoveChanges;
+    int                   selDepth, nmpMinPly;
+
+    Value optimism[COLOR_NB];
+
+    Position  rootPos;
+    StateInfo rootState;
+    RootMoves rootMoves;
+    Depth     rootDepth, completedDepth;
+    Value     rootDelta;
+
+    size_t thread_idx;
+
+    // Reductions lookup table initialized at startup
+    std::array<int, MAX_MOVES> reductions;  // [depth or moveNumber]
+
+    // The main thread has a SearchManager, the others have a NullSearchManager
+    std::unique_ptr<ISearchManager> manager;
+
+    Tablebases::Config tbConfig;
+
+    const OptionsMap&           options;
+    ThreadPool&                 threads;
+    TranspositionTable&         tt;
+    const Eval::NNUE::Networks& networks;
+
+    friend class Stockfish::ThreadPool;
+    friend class SearchManager;
+};
+
+
+}  // namespace Search
+
+}  // namespace Stockfish
+
+#endif  // #ifndef SEARCH_H_INCLUDED

src/syzygy/tbprobe.h

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -19,60 +19,57 @@
 #ifndef TBPROBE_H
 #define TBPROBE_H
 
-#include <ostream>
+#include <string>
+#include <vector>
 
-#include "../search.h"
 
-namespace Tablebases {
+namespace Stockfish {
+class Position;
+class OptionsMap;
+
+using Depth = int;
+
+namespace Search {
+struct RootMove;
+using RootMoves = std::vector<RootMove>;
+}
+}
+
+namespace Stockfish::Tablebases {
+
+struct Config {
+    int   cardinality = 0;
+    bool  rootInTB    = false;
+    bool  useRule50   = false;
+    Depth probeDepth  = 0;
+};
 
 enum WDLScore {
-    WDLLoss        = -2, // Loss
-    WDLBlessedLoss = -1, // Loss, but draw under 50-move rule
-    WDLDraw        =  0, // Draw
-    WDLCursedWin   =  1, // Win, but draw under 50-move rule
-    WDLWin         =  2, // Win
-
-    WDLScoreNone  = -1000
+    WDLLoss        = -2,  // Loss
+    WDLBlessedLoss = -1,  // Loss, but draw under 50-move rule
+    WDLDraw        = 0,   // Draw
+    WDLCursedWin   = 1,   // Win, but draw under 50-move rule
+    WDLWin         = 2,   // Win
 };
 
 // Possible states after a probing operation
 enum ProbeState {
-    FAIL              =  0, // Probe failed (missing file table)
-    OK                =  1, // Probe succesful
-    CHANGE_STM        = -1, // DTZ should check the other side
-    ZEROING_BEST_MOVE =  2  // Best move zeroes DTZ (capture or pawn move)
+    FAIL              = 0,   // Probe failed (missing file table)
+    OK                = 1,   // Probe successful
+    CHANGE_STM        = -1,  // DTZ should check the other side
+    ZEROING_BEST_MOVE = 2    // Best move zeroes DTZ (capture or pawn move)
 };
 
 extern int MaxCardinality;
 
-void init(const std::string& paths);
+
+void     init(const std::string& paths);
 WDLScore probe_wdl(Position& pos, ProbeState* result);
-int probe_dtz(Position& pos, ProbeState* result);
-bool root_probe(Position& pos, Search::RootMoves& rootMoves);
-bool root_probe_wdl(Position& pos, Search::RootMoves& rootMoves);
-void rank_root_moves(Position& pos, Search::RootMoves& rootMoves);
+int      probe_dtz(Position& pos, ProbeState* result);
+bool     root_probe(Position& pos, Search::RootMoves& rootMoves, bool rule50);
+bool     root_probe_wdl(Position& pos, Search::RootMoves& rootMoves, bool rule50);
+Config   rank_root_moves(const OptionsMap& options, Position& pos, Search::RootMoves& rootMoves);
 
-inline std::ostream& operator<<(std::ostream& os, const WDLScore v) {
-
-    os << (v == WDLLoss        ? "Loss" :
-           v == WDLBlessedLoss ? "Blessed loss" :
-           v == WDLDraw        ? "Draw" :
-           v == WDLCursedWin   ? "Cursed win" :
-           v == WDLWin         ? "Win" : "None");
-
-    return os;
-}
-
-inline std::ostream& operator<<(std::ostream& os, const ProbeState v) {
-
-    os << (v == FAIL              ? "Failed" :
-           v == OK                ? "Success" :
-           v == CHANGE_STM        ? "Probed opponent side" :
-           v == ZEROING_BEST_MOVE ? "Best move zeroes DTZ" : "None");
-
-    return os;
-}
-
-}
+}  // namespace Stockfish::Tablebases
 
 #endif

src/thread.cpp

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -16,223 +16,273 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <cassert>
+#include "thread.h"
 
-#include <algorithm> // For std::count
+#include <algorithm>
+#include <cassert>
+#include <deque>
+#include <memory>
+#include <unordered_map>
+#include <utility>
+
+#include "cluster.h"
+#include "misc.h"
 #include "movegen.h"
 #include "search.h"
-#include "thread.h"
-#include "uci.h"
 #include "syzygy/tbprobe.h"
+#include "timeman.h"
 #include "tt.h"
+#include "types.h"
+#include "ucioption.h"
 
-ThreadPool Threads; // Global object
+namespace Stockfish {
 
+// Constructor launches the thread and waits until it goes to sleep
+// in idle_loop(). Note that 'searching' and 'exit' should be already set.
+Thread::Thread(Search::SharedState&                    sharedState,
+               std::unique_ptr<Search::ISearchManager> sm,
+               size_t                                  n) :
+    worker(std::make_unique<Search::Worker>(sharedState, std::move(sm), n)),
+    idx(n),
+    nthreads(sharedState.options["Threads"]),
+    stdThread(&Thread::idle_loop, this) {
 
-/// Thread constructor launches the thread and waits until it goes to sleep
-/// in idle_loop(). Note that 'searching' and 'exit' should be already set.
-
-Thread::Thread(size_t n) : idx(n), stdThread(&Thread::idle_loop, this) {
-
-  wait_for_search_finished();
+    wait_for_search_finished();
 }
 
 
-/// Thread destructor wakes up the thread in idle_loop() and waits
-/// for its termination. Thread should be already waiting.
-
+// Destructor wakes up the thread in idle_loop() and waits
+// for its termination. Thread should be already waiting.
 Thread::~Thread() {
 
-  assert(!searching);
+    assert(!searching);
 
-  exit = true;
-  start_searching();
-  stdThread.join();
+    exit = true;
+    start_searching();
+    stdThread.join();
 }
 
 
-/// Thread::clear() reset histories, usually before a new game
-
-void Thread::clear() {
-
-  counterMoves.fill(MOVE_NONE);
-  mainHistory.fill(0);
-  lowPlyHistory.fill(0);
-  captureHistory.fill(0);
-
-  for (bool inCheck : { false, true })
-      for (StatsType c : { NoCaptures, Captures })
-      {
-          for (auto& to : continuationHistory[inCheck][c])
-                for (auto& h : to)
-                      h->fill(0);
-          continuationHistory[inCheck][c][NO_PIECE][0]->fill(Search::CounterMovePruneThreshold - 1);
-      }
-}
-
-
-/// Thread::start_searching() wakes up the thread that will start the search
-
+// Wakes up the thread that will start the search
 void Thread::start_searching() {
-
-  std::lock_guard<std::mutex> lk(mutex);
-  searching = true;
-  cv.notify_one(); // Wake up the thread in idle_loop()
+    mutex.lock();
+    searching = true;
+    mutex.unlock();   // Unlock before notifying saves a few CPU-cycles
+    cv.notify_one();  // Wake up the thread in idle_loop()
 }
 
 
-/// Thread::wait_for_search_finished() blocks on the condition variable
-/// until the thread has finished searching.
-
+// Blocks on the condition variable
+// until the thread has finished searching.
 void Thread::wait_for_search_finished() {
 
-  std::unique_lock<std::mutex> lk(mutex);
-  cv.wait(lk, [&]{ return !searching; });
+    std::unique_lock<std::mutex> lk(mutex);
+    cv.wait(lk, [&] { return !searching; });
 }
 
 
-/// Thread::idle_loop() is where the thread is parked, blocked on the
-/// condition variable, when it has no work to do.
+// Thread gets parked here, blocked on the
+// condition variable, when it has no work to do.
 
 void Thread::idle_loop() {
 
-  // If OS already scheduled us on a different group than 0 then don't overwrite
-  // the choice, eventually we are one of many one-threaded processes running on
-  // some Windows NUMA hardware, for instance in fishtest. To make it simple,
-  // just check if running threads are below a threshold, in this case all this
-  // NUMA machinery is not needed.
-  if (Options["Threads"] > 8)
-      WinProcGroup::bindThisThread(idx);
+    // If OS already scheduled us on a different group than 0 then don't overwrite
+    // the choice, eventually we are one of many one-threaded processes running on
+    // some Windows NUMA hardware, for instance in fishtest. To make it simple,
+    // just check if running threads are below a threshold, in this case, all this
+    // NUMA machinery is not needed.
+    if (nthreads > 8)
+        WinProcGroup::bind_this_thread(idx);
 
-  while (true)
-  {
-      std::unique_lock<std::mutex> lk(mutex);
-      searching = false;
-      cv.notify_one(); // Wake up anyone waiting for search finished
-      cv.wait(lk, [&]{ return searching; });
+    while (true)
+    {
+        std::unique_lock<std::mutex> lk(mutex);
+        searching = false;
+        cv.notify_one();  // Wake up anyone waiting for search finished
+        cv.wait(lk, [&] { return searching; });
 
-      if (exit)
-          return;
+        if (exit)
+            return;
 
-      lk.unlock();
+        lk.unlock();
 
-      search();
-  }
+        worker->start_searching();
+    }
 }
 
-/// ThreadPool::set() creates/destroys threads to match the requested number.
-/// Created and launched threads will immediately go to sleep in idle_loop.
-/// Upon resizing, threads are recreated to allow for binding if necessary.
+Search::SearchManager* ThreadPool::main_manager() {
+    return static_cast<Search::SearchManager*>(main_thread()->worker.get()->manager.get());
+}
 
-void ThreadPool::set(size_t requested) {
+uint64_t ThreadPool::nodes_searched() const { return accumulate(&Search::Worker::nodes); }
+uint64_t ThreadPool::tb_hits() const { return accumulate(&Search::Worker::tbHits); }
+uint64_t ThreadPool::TT_saves() const { return accumulate(&Search::Worker::TTsaves); }
 
-  if (size() > 0) { // destroy any existing thread(s)
-      main()->wait_for_search_finished();
+// Creates/destroys threads to match the requested number.
+// Created and launched threads will immediately go to sleep in idle_loop.
+// Upon resizing, threads are recreated to allow for binding if necessary.
+void ThreadPool::set(Search::SharedState sharedState) {
 
-      while (size() > 0)
-          delete back(), pop_back();
-  }
+    if (threads.size() > 0)  // destroy any existing thread(s)
+    {
+        main_thread()->wait_for_search_finished();
 
-  if (requested > 0) { // create new thread(s)
-      push_back(new MainThread(0));
+        while (threads.size() > 0)
+            delete threads.back(), threads.pop_back();
+    }
 
-      while (size() < requested)
-          push_back(new Thread(size()));
-      clear();
+    const size_t requested = sharedState.options["Threads"];
 
-      // Reallocate the hash with the new threadpool size
-      TT.resize(size_t(Options["Hash"]));
+    if (requested > 0)  // create new thread(s)
+    {
+        threads.push_back(new Thread(
+          sharedState, std::unique_ptr<Search::ISearchManager>(new Search::SearchManager()), 0));
 
-      // Init thread number dependent search params.
-      Search::init();
-  }
+
+        while (threads.size() < requested)
+            threads.push_back(new Thread(
+              sharedState, std::unique_ptr<Search::ISearchManager>(new Search::NullSearchManager()),
+              threads.size()));
+        clear();
+
+        main_thread()->wait_for_search_finished();
+
+        // Reallocate the hash with the new threadpool size
+        sharedState.tt.resize(sharedState.options["Hash"], requested);
+
+        // Adjust cluster buffers
+        Cluster::ttSendRecvBuff_resize(requested);
+    }
 }
 
 
-/// ThreadPool::clear() sets threadPool data to initial values
-
+// Sets threadPool data to initial values
 void ThreadPool::clear() {
 
-  for (Thread* th : *this)
-      th->clear();
+    for (Thread* th : threads)
+        th->worker->clear();
 
-  main()->callsCnt = 0;
-  main()->bestPreviousScore = VALUE_INFINITE;
-  main()->previousTimeReduction = 1.0;
+    main_manager()->callsCnt                 = 0;
+    main_manager()->bestPreviousScore        = VALUE_INFINITE;
+    main_manager()->bestPreviousAverageScore = VALUE_INFINITE;
+    main_manager()->previousTimeReduction    = 1.0;
+    main_manager()->tm.clear();
 }
 
 
-/// ThreadPool::start_thinking() wakes up main thread waiting in idle_loop() and
-/// returns immediately. Main thread will wake up other threads and start the search.
+// Wakes up main thread waiting in idle_loop() and
+// returns immediately. Main thread will wake up other threads and start the search.
+void ThreadPool::start_thinking(const OptionsMap&  options,
+                                Position&          pos,
+                                StateListPtr&      states,
+                                Search::LimitsType limits) {
 
-void ThreadPool::start_thinking(Position& pos, StateListPtr& states,
-                                const Search::LimitsType& limits, bool ponderMode) {
+    main_thread()->wait_for_search_finished();
 
-  main()->wait_for_search_finished();
+    main_manager()->stopOnPonderhit = stop = abortedSearch = false;
+    main_manager()->ponder                                 = limits.ponderMode;
 
-  main()->stopOnPonderhit = stop = false;
-  increaseDepth = true;
-  main()->ponder = ponderMode;
-  Search::Limits = limits;
-  Search::RootMoves rootMoves;
+    increaseDepth = true;
 
-  for (const auto& m : MoveList<LEGAL>(pos))
-      if (   limits.searchmoves.empty()
-          || std::count(limits.searchmoves.begin(), limits.searchmoves.end(), m))
-          rootMoves.emplace_back(m);
+    Search::RootMoves rootMoves;
 
-  if (!rootMoves.empty())
-      Tablebases::rank_root_moves(pos, rootMoves);
+    for (const auto& m : MoveList<LEGAL>(pos))
+        if (limits.searchmoves.empty()
+            || std::count(limits.searchmoves.begin(), limits.searchmoves.end(), m))
+            rootMoves.emplace_back(m);
 
-  // After ownership transfer 'states' becomes empty, so if we stop the search
-  // and call 'go' again without setting a new position states.get() == NULL.
-  assert(states.get() || setupStates.get());
+    Tablebases::Config tbConfig = Tablebases::rank_root_moves(options, pos, rootMoves);
 
-  if (states.get())
-      setupStates = std::move(states); // Ownership transfer, states is now empty
+    // After ownership transfer 'states' becomes empty, so if we stop the search
+    // and call 'go' again without setting a new position states.get() == nullptr.
+    assert(states.get() || setupStates.get());
 
-  // We use Position::set() to set root position across threads. But there are
-  // some StateInfo fields (previous, pliesFromNull, capturedPiece) that cannot
-  // be deduced from a fen string, so set() clears them and they are set from
-  // setupStates->back() later. The rootState is per thread, earlier states are shared
-  // since they are read-only.
-  for (Thread* th : *this)
-  {
-      th->nodes = th->tbHits = th->nmpMinPly = th->bestMoveChanges = 0;
-      th->rootDepth = th->completedDepth = 0;
-      th->rootMoves = rootMoves;
-      th->rootPos.set(pos.fen(), pos.is_chess960(), &th->rootState, th);
-      th->rootState = setupStates->back();
-  }
+    if (states.get())
+        setupStates = std::move(states);  // Ownership transfer, states is now empty
 
-  main()->start_searching();
+    // We use Position::set() to set root position across threads. But there are
+    // some StateInfo fields (previous, pliesFromNull, capturedPiece) that cannot
+    // be deduced from a fen string, so set() clears them and they are set from
+    // setupStates->back() later. The rootState is per thread, earlier states are shared
+    // since they are read-only.
+    for (Thread* th : threads)
+    {
+        th->worker->limits = limits;
+        th->worker->nodes = th->worker->tbHits = th->worker->nmpMinPly =
+          th->worker->bestMoveChanges          = 0;
+        th->worker->TTsaves                    = 0;
+        th->worker->rootDepth = th->worker->completedDepth = 0;
+        th->worker->rootMoves                              = rootMoves;
+        th->worker->rootPos.set(pos.fen(), pos.is_chess960(), &th->worker->rootState);
+        th->worker->rootState = setupStates->back();
+        th->worker->tbConfig  = tbConfig;
+    }
+
+    Cluster::signals_init();
+
+    main_thread()->start_searching();
 }
 
 Thread* ThreadPool::get_best_thread() const {
 
-    Thread* bestThread = front();
-    std::map<Move, int64_t> votes;
-    Value minScore = VALUE_NONE;
+    Thread* bestThread = threads.front();
+    Value   minScore   = VALUE_NONE;
 
-    // Find minimum score of all threads
-    for (Thread* th: *this)
-        minScore = std::min(minScore, th->rootMoves[0].score);
+    std::unordered_map<Move, int64_t, Move::MoveHash> votes(
+      2 * std::min(size(), bestThread->worker->rootMoves.size()));
+
+    // Find the minimum score of all threads
+    for (Thread* th : threads)
+        minScore = std::min(minScore, th->worker->rootMoves[0].score);
 
     // Vote according to score and depth, and select the best thread
-    for (Thread* th : *this)
-    {
-        votes[th->rootMoves[0].pv[0]] +=
-            (th->rootMoves[0].score - minScore + 14) * int(th->completedDepth);
+    auto thread_voting_value = [minScore](Thread* th) {
+        return (th->worker->rootMoves[0].score - minScore + 14) * int(th->worker->completedDepth);
+    };
 
-        if (abs(bestThread->rootMoves[0].score) >= VALUE_TB_WIN_IN_MAX_PLY)
+    for (Thread* th : threads)
+        votes[th->worker->rootMoves[0].pv[0]] += thread_voting_value(th);
+
+    for (Thread* th : threads)
+    {
+        const auto bestThreadScore = bestThread->worker->rootMoves[0].score;
+        const auto newThreadScore  = th->worker->rootMoves[0].score;
+
+        const auto& bestThreadPV = bestThread->worker->rootMoves[0].pv;
+        const auto& newThreadPV  = th->worker->rootMoves[0].pv;
+
+        const auto bestThreadMoveVote = votes[bestThreadPV[0]];
+        const auto newThreadMoveVote  = votes[newThreadPV[0]];
+
+        const bool bestThreadInProvenWin = bestThreadScore >= VALUE_TB_WIN_IN_MAX_PLY;
+        const bool newThreadInProvenWin  = newThreadScore >= VALUE_TB_WIN_IN_MAX_PLY;
+
+        const bool bestThreadInProvenLoss =
+          bestThreadScore != -VALUE_INFINITE && bestThreadScore <= VALUE_TB_LOSS_IN_MAX_PLY;
+        const bool newThreadInProvenLoss =
+          newThreadScore != -VALUE_INFINITE && newThreadScore <= VALUE_TB_LOSS_IN_MAX_PLY;
+
+        // Note that we make sure not to pick a thread with truncated-PV for better viewer experience.
+        const bool betterVotingValue =
+          thread_voting_value(th) * int(newThreadPV.size() > 2)
+          > thread_voting_value(bestThread) * int(bestThreadPV.size() > 2);
+
+        if (bestThreadInProvenWin)
         {
-            // Make sure we pick the shortest mate / TB conversion or stave off mate the longest
-            if (th->rootMoves[0].score > bestThread->rootMoves[0].score)
+            // Make sure we pick the shortest mate / TB conversion
+            if (newThreadScore > bestThreadScore)
                 bestThread = th;
         }
-        else if (   th->rootMoves[0].score >= VALUE_TB_WIN_IN_MAX_PLY
-                 || (   th->rootMoves[0].score > VALUE_TB_LOSS_IN_MAX_PLY
-                     && votes[th->rootMoves[0].pv[0]] > votes[bestThread->rootMoves[0].pv[0]]))
+        else if (bestThreadInProvenLoss)
+        {
+            // Make sure we pick the shortest mated / TB conversion
+            if (newThreadInProvenLoss && newThreadScore < bestThreadScore)
+                bestThread = th;
+        }
+        else if (newThreadInProvenWin || newThreadInProvenLoss
+                 || (newThreadScore > VALUE_TB_LOSS_IN_MAX_PLY
+                     && (newThreadMoveVote > bestThreadMoveVote
+                         || (newThreadMoveVote == bestThreadMoveVote && betterVotingValue))))
             bestThread = th;
     }
 
@@ -240,21 +290,23 @@ Thread* ThreadPool::get_best_thread() const {
 }
 
 
-/// Start non-main threads
-
+// Start non-main threads
+// Will be invoked by main thread after it has started searching
 void ThreadPool::start_searching() {
 
-    for (Thread* th : *this)
-        if (th != front())
+    for (Thread* th : threads)
+        if (th != threads.front())
             th->start_searching();
 }
 
 
-/// Wait for non-main threads
+// Wait for non-main threads
 
 void ThreadPool::wait_for_search_finished() const {
 
-    for (Thread* th : *this)
-        if (th != front())
+    for (Thread* th : threads)
+        if (th != threads.front())
             th->wait_for_search_finished();
 }
+
+}  // namespace Stockfish

src/thread.h

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -21,111 +21,101 @@
 
 #include <atomic>
 #include <condition_variable>
+#include <cstddef>
+#include <cstdint>
+#include <memory>
 #include <mutex>
-#include <thread>
 #include <vector>
 
-#include "material.h"
 #include "movepick.h"
-#include "pawns.h"
 #include "position.h"
 #include "search.h"
 #include "thread_win32_osx.h"
 
+namespace Stockfish {
 
-/// Thread class keeps together all the thread-related stuff. We use
-/// per-thread pawn and material hash tables so that once we get a
-/// pointer to an entry its life time is unlimited and we don't have
-/// to care about someone changing the entry under our feet.
 
+class OptionsMap;
+using Value = int;
+
+// Abstraction of a thread. It contains a pointer to the worker and a native thread.
+// After construction, the native thread is started with idle_loop()
+// waiting for a signal to start searching.
+// When the signal is received, the thread starts searching and when
+// the search is finished, it goes back to idle_loop() waiting for a new signal.
 class Thread {
+   public:
+    Thread(Search::SharedState&, std::unique_ptr<Search::ISearchManager>, size_t);
+    virtual ~Thread();
 
-  std::mutex mutex;
-  std::condition_variable cv;
-  size_t idx;
-  bool exit = false, searching = true; // Set before starting std::thread
-  NativeThread stdThread;
+    void   idle_loop();
+    void   start_searching();
+    void   wait_for_search_finished();
+    size_t id() const { return idx; }
 
-public:
-  explicit Thread(size_t);
-  virtual ~Thread();
-  virtual void search();
-  void clear();
-  void idle_loop();
-  void start_searching();
-  void wait_for_search_finished();
+    std::unique_ptr<Search::Worker> worker;
 
-  Pawns::Table pawnsTable;
-  Material::Table materialTable;
-  size_t pvIdx, pvLast;
-  uint64_t ttHitAverage;
-  int selDepth, nmpMinPly;
-  Color nmpColor;
-  std::atomic<uint64_t> nodes, tbHits, bestMoveChanges;
-
-  Position rootPos;
-  StateInfo rootState;
-  Search::RootMoves rootMoves;
-  Depth rootDepth, completedDepth;
-  CounterMoveHistory counterMoves;
-  ButterflyHistory mainHistory;
-  LowPlyHistory lowPlyHistory;
-  CapturePieceToHistory captureHistory;
-  ContinuationHistory continuationHistory[2][2];
-  Score contempt;
-  int failedHighCnt;
+   private:
+    std::mutex              mutex;
+    std::condition_variable cv;
+    size_t                  idx, nthreads;
+    bool                    exit = false, searching = true;  // Set before starting std::thread
+    NativeThread            stdThread;
 };
 
 
-/// MainThread is a derived class specific for main thread
+// ThreadPool struct handles all the threads-related stuff like init, starting,
+// parking and, most importantly, launching a thread. All the access to threads
+// is done through this class.
+class ThreadPool {
 
-struct MainThread : public Thread {
+   public:
+    ~ThreadPool() {
+        // destroy any existing thread(s)
+        if (threads.size() > 0)
+        {
+            main_thread()->wait_for_search_finished();
 
-  using Thread::Thread;
+            while (threads.size() > 0)
+                delete threads.back(), threads.pop_back();
+        }
+    }
 
-  void search() override;
-  void check_time();
+    void start_thinking(const OptionsMap&, Position&, StateListPtr&, Search::LimitsType);
+    void clear();
+    void set(Search::SharedState);
 
-  double previousTimeReduction;
-  Value bestPreviousScore;
-  Value iterValue[4];
-  int callsCnt;
-  bool stopOnPonderhit;
-  std::atomic_bool ponder;
+    Search::SearchManager* main_manager();
+    Thread*                main_thread() const { return threads.front(); }
+    uint64_t               nodes_searched() const;
+    uint64_t               tb_hits() const;
+    uint64_t               TT_saves() const;
+    Thread*                get_best_thread() const;
+    void                   start_searching();
+    void                   wait_for_search_finished() const;
+
+    std::atomic_bool stop, abortedSearch, increaseDepth;
+
+    auto cbegin() const noexcept { return threads.cbegin(); }
+    auto begin() noexcept { return threads.begin(); }
+    auto end() noexcept { return threads.end(); }
+    auto cend() const noexcept { return threads.cend(); }
+    auto size() const noexcept { return threads.size(); }
+    auto empty() const noexcept { return threads.empty(); }
+
+   private:
+    StateListPtr         setupStates;
+    std::vector<Thread*> threads;
+
+    uint64_t accumulate(std::atomic<uint64_t> Search::Worker::*member) const {
+
+        uint64_t sum = 0;
+        for (Thread* th : threads)
+            sum += (th->worker.get()->*member).load(std::memory_order_relaxed);
+        return sum;
+    }
 };
 
+}  // namespace Stockfish
 
-/// ThreadPool struct handles all the threads-related stuff like init, starting,
-/// parking and, most importantly, launching a thread. All the access to threads
-/// is done through this class.
-
-struct ThreadPool : public std::vector<Thread*> {
-
-  void start_thinking(Position&, StateListPtr&, const Search::LimitsType&, bool = false);
-  void clear();
-  void set(size_t);
-
-  MainThread* main()        const { return static_cast<MainThread*>(front()); }
-  uint64_t nodes_searched() const { return accumulate(&Thread::nodes); }
-  uint64_t tb_hits()        const { return accumulate(&Thread::tbHits); }
-  Thread* get_best_thread() const;
-  void start_searching();
-  void wait_for_search_finished() const;
-
-  std::atomic_bool stop, increaseDepth;
-
-private:
-  StateListPtr setupStates;
-
-  uint64_t accumulate(std::atomic<uint64_t> Thread::* member) const {
-
-    uint64_t sum = 0;
-    for (Thread* th : *this)
-        sum += (th->*member).load(std::memory_order_relaxed);
-    return sum;
-  }
-};
-
-extern ThreadPool Threads;
-
-#endif // #ifndef THREAD_H_INCLUDED
+#endif  // #ifndef THREAD_H_INCLUDED

src/thread_win32_osx.h

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -21,46 +21,58 @@
 
 #include <thread>
 
-/// On OSX threads other than the main thread are created with a reduced stack
-/// size of 512KB by default, this is too low for deep searches, which require
-/// somewhat more than 1MB stack, so adjust it to TH_STACK_SIZE.
-/// The implementation calls pthread_create() with the stack size parameter
-/// equal to the linux 8MB default, on platforms that support it.
+// On OSX threads other than the main thread are created with a reduced stack
+// size of 512KB by default, this is too low for deep searches, which require
+// somewhat more than 1MB stack, so adjust it to TH_STACK_SIZE.
+// The implementation calls pthread_create() with the stack size parameter
+// equal to the Linux 8MB default, on platforms that support it.
 
 #if defined(__APPLE__) || defined(__MINGW32__) || defined(__MINGW64__) || defined(USE_PTHREADS)
 
-#include <pthread.h>
+    #include <pthread.h>
+    #include <functional>
 
-static const size_t TH_STACK_SIZE = 8 * 1024 * 1024;
-
-template <class T, class P = std::pair<T*, void(T::*)()>>
-void* start_routine(void* ptr)
-{
-   P* p = reinterpret_cast<P*>(ptr);
-   (p->first->*(p->second))(); // Call member function pointer
-   delete p;
-   return NULL;
-}
+namespace Stockfish {
 
 class NativeThread {
+    pthread_t thread;
 
-   pthread_t thread;
+    static constexpr size_t TH_STACK_SIZE = 8 * 1024 * 1024;
 
-public:
-  template<class T, class P = std::pair<T*, void(T::*)()>>
-  explicit NativeThread(void(T::*fun)(), T* obj) {
-    pthread_attr_t attr_storage, *attr = &attr_storage;
-    pthread_attr_init(attr);
-    pthread_attr_setstacksize(attr, TH_STACK_SIZE);
-    pthread_create(&thread, attr, start_routine<T>, new P(obj, fun));
-  }
-  void join() { pthread_join(thread, NULL); }
+   public:
+    template<class Function, class... Args>
+    explicit NativeThread(Function&& fun, Args&&... args) {
+        auto func = new std::function<void()>(
+          std::bind(std::forward<Function>(fun), std::forward<Args>(args)...));
+
+        pthread_attr_t attr_storage, *attr = &attr_storage;
+        pthread_attr_init(attr);
+        pthread_attr_setstacksize(attr, TH_STACK_SIZE);
+
+        auto start_routine = [](void* ptr) -> void* {
+            auto f = reinterpret_cast<std::function<void()>*>(ptr);
+            // Call the function
+            (*f)();
+            delete f;
+            return nullptr;
+        };
+
+        pthread_create(&thread, attr, start_routine, func);
+    }
+
+    void join() { pthread_join(thread, nullptr); }
 };
 
-#else // Default case: use STL classes
+}  // namespace Stockfish
 
-typedef std::thread NativeThread;
+#else  // Default case: use STL classes
+
+namespace Stockfish {
+
+using NativeThread = std::thread;
+
+}  // namespace Stockfish
 
 #endif
 
-#endif // #ifndef THREAD_WIN32_OSX_H_INCLUDED
+#endif  // #ifndef THREAD_WIN32_OSX_H_INCLUDED

src/timeman.cpp

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -16,82 +16,117 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include "timeman.h"
+
 #include <algorithm>
-#include <cfloat>
+#include <cassert>
 #include <cmath>
+#include <cstdint>
 
 #include "search.h"
-#include "timeman.h"
-#include "uci.h"
+#include "ucioption.h"
 
-TimeManagement Time; // Our global time management object
+namespace Stockfish {
 
+TimePoint TimeManagement::optimum() const { return optimumTime; }
+TimePoint TimeManagement::maximum() const { return maximumTime; }
+TimePoint TimeManagement::elapsed(size_t nodes) const {
+    return useNodesTime ? TimePoint(nodes) : now() - startTime;
+}
 
-/// TimeManagement::init() is called at the beginning of the search and calculates
-/// the bounds of time allowed for the current game ply. We currently support:
+void TimeManagement::clear() {
+    availableNodes = 0;  // When in 'nodes as time' mode
+}
+
+void TimeManagement::advance_nodes_time(std::int64_t nodes) {
+    assert(useNodesTime);
+    availableNodes += nodes;
+}
+
+// Called at the beginning of the search and calculates
+// the bounds of time allowed for the current game ply. We currently support:
 //      1) x basetime (+ z increment)
 //      2) x moves in y seconds (+ z increment)
+void TimeManagement::init(Search::LimitsType& limits,
+                          Color               us,
+                          int                 ply,
+                          const OptionsMap&   options) {
+    // If we have no time, no need to initialize TM, except for the start time,
+    // which is used by movetime.
+    startTime = limits.startTime;
+    if (limits.time[us] == 0)
+        return;
 
-void TimeManagement::init(Search::LimitsType& limits, Color us, int ply) {
+    TimePoint moveOverhead = TimePoint(options["Move Overhead"]);
+    TimePoint npmsec       = TimePoint(options["nodestime"]);
 
-  TimePoint moveOverhead    = TimePoint(Options["Move Overhead"]);
-  TimePoint slowMover       = TimePoint(Options["Slow Mover"]);
-  TimePoint npmsec          = TimePoint(Options["nodestime"]);
+    // optScale is a percentage of available time to use for the current move.
+    // maxScale is a multiplier applied to optimumTime.
+    double optScale, maxScale;
 
-  // optScale is a percentage of available time to use for the current move.
-  // maxScale is a multiplier applied to optimumTime.
-  double optScale, maxScale;
+    // If we have to play in 'nodes as time' mode, then convert from time
+    // to nodes, and use resulting values in time management formulas.
+    // WARNING: to avoid time losses, the given npmsec (nodes per millisecond)
+    // must be much lower than the real engine speed.
+    if (npmsec)
+    {
+        useNodesTime = true;
 
-  // If we have to play in 'nodes as time' mode, then convert from time
-  // to nodes, and use resulting values in time management formulas.
-  // WARNING: to avoid time losses, the given npmsec (nodes per millisecond)
-  // must be much lower than the real engine speed.
-  if (npmsec)
-  {
-      if (!availableNodes) // Only once at game start
-          availableNodes = npmsec * limits.time[us]; // Time is in msec
+        if (!availableNodes)                            // Only once at game start
+            availableNodes = npmsec * limits.time[us];  // Time is in msec
 
-      // Convert from milliseconds to nodes
-      limits.time[us] = TimePoint(availableNodes);
-      limits.inc[us] *= npmsec;
-      limits.npmsec = npmsec;
-  }
+        // Convert from milliseconds to nodes
+        limits.time[us] = TimePoint(availableNodes);
+        limits.inc[us] *= npmsec;
+        limits.npmsec = npmsec;
+    }
 
-  startTime = limits.startTime;
+    // Maximum move horizon of 50 moves
+    int mtg = limits.movestogo ? std::min(limits.movestogo, 50) : 50;
 
-  // Maximum move horizon of 50 moves
-  int mtg = limits.movestogo ? std::min(limits.movestogo, 50) : 50;
+    // if less than one second, gradually reduce mtg
+    if (limits.time[us] < 1000 && (double(mtg) / limits.time[us] > 0.05))
+    {
+        mtg = limits.time[us] * 0.05;
+    }
 
-  // Make sure timeLeft is > 0 since we may use it as a divisor
-  TimePoint timeLeft =  std::max(TimePoint(1),
-      limits.time[us] + limits.inc[us] * (mtg - 1) - moveOverhead * (2 + mtg));
+    // Make sure timeLeft is > 0 since we may use it as a divisor
+    TimePoint timeLeft = std::max(TimePoint(1), limits.time[us] + limits.inc[us] * (mtg - 1)
+                                                  - moveOverhead * (2 + mtg));
 
-  // A user may scale time usage by setting UCI option "Slow Mover"
-  // Default is 100 and changing this value will probably lose elo.
-  timeLeft = slowMover * timeLeft / 100;
+    // x basetime (+ z increment)
+    // If there is a healthy increment, timeLeft can exceed the actual available
+    // game time for the current move, so also cap to a percentage of available game time.
+    if (limits.movestogo == 0)
+    {
+        // Use extra time with larger increments
+        double optExtra = limits.inc[us] < 500 ? 1.0 : 1.13;
 
-  // x basetime (+ z increment)
-  // If there is a healthy increment, timeLeft can exceed actual available
-  // game time for the current move, so also cap to 20% of available game time.
-  if (limits.movestogo == 0)
-  {
-      optScale = std::min(0.0084 + std::pow(ply + 3.0, 0.5) * 0.0042,
-                           0.2 * limits.time[us] / double(timeLeft));
-      maxScale = std::min(7.0, 4.0 + ply / 12.0);
-  }
+        // Calculate time constants based on current time left.
+        double optConstant =
+          std::min(0.00308 + 0.000319 * std::log10(limits.time[us] / 1000.0), 0.00506);
+        double maxConstant = std::max(3.39 + 3.01 * std::log10(limits.time[us] / 1000.0), 2.93);
 
-  // x moves in y seconds (+ z increment)
-  else
-  {
-      optScale = std::min((0.8 + ply / 128.0) / mtg,
-                            0.8 * limits.time[us] / double(timeLeft));
-      maxScale = std::min(6.3, 1.5 + 0.11 * mtg);
-  }
+        optScale = std::min(0.0122 + std::pow(ply + 2.95, 0.462) * optConstant,
+                            0.213 * limits.time[us] / double(timeLeft))
+                 * optExtra;
+        maxScale = std::min(6.64, maxConstant + ply / 12.0);
+    }
 
-  // Never use more than 80% of the available time for this move
-  optimumTime = TimePoint(optScale * timeLeft);
-  maximumTime = TimePoint(std::min(0.8 * limits.time[us] - moveOverhead, maxScale * optimumTime));
+    // x moves in y seconds (+ z increment)
+    else
+    {
+        optScale = std::min((0.88 + ply / 116.4) / mtg, 0.88 * limits.time[us] / double(timeLeft));
+        maxScale = std::min(6.3, 1.5 + 0.11 * mtg);
+    }
 
-  if (Options["Ponder"])
-      optimumTime += optimumTime / 4;
+    // Limit the maximum possible time for this move
+    optimumTime = TimePoint(optScale * timeLeft);
+    maximumTime =
+      TimePoint(std::min(0.825 * limits.time[us] - moveOverhead, maxScale * optimumTime)) - 10;
+
+    if (options["Ponder"])
+        optimumTime += optimumTime / 4;
 }
+
+}  // namespace Stockfish

src/timeman.h

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -19,29 +19,42 @@
 #ifndef TIMEMAN_H_INCLUDED
 #define TIMEMAN_H_INCLUDED
 
+#include <cstddef>
+#include <cstdint>
+
+#include "cluster.h"
 #include "misc.h"
-#include "search.h"
-#include "thread.h"
 
-/// The TimeManagement class computes the optimal time to think depending on
-/// the maximum available time, the game move number and other parameters.
+namespace Stockfish {
 
+class OptionsMap;
+
+namespace Search {
+struct LimitsType;
+}
+
+// The TimeManagement class computes the optimal time to think depending on
+// the maximum available time, the game move number, and other parameters.
 class TimeManagement {
-public:
-  void init(Search::LimitsType& limits, Color us, int ply);
-  TimePoint optimum() const { return optimumTime; }
-  TimePoint maximum() const { return maximumTime; }
-  TimePoint elapsed() const { return Search::Limits.npmsec ?
-                                     TimePoint(Threads.nodes_searched()) : now() - startTime; }
+   public:
+    void init(Search::LimitsType& limits, Color us, int ply, const OptionsMap& options);
 
-  int64_t availableNodes; // When in 'nodes as time' mode
+    TimePoint optimum() const;
+    TimePoint maximum() const;
+    TimePoint elapsed(std::size_t nodes) const;
 
-private:
-  TimePoint startTime;
-  TimePoint optimumTime;
-  TimePoint maximumTime;
+    void clear();
+    void advance_nodes_time(std::int64_t nodes);
+
+   private:
+    TimePoint startTime;
+    TimePoint optimumTime;
+    TimePoint maximumTime;
+
+    std::int64_t availableNodes = 0;      // When in 'nodes as time' mode
+    bool         useNodesTime   = false;  // True if we are in 'nodes as time' mode
 };
 
-extern TimeManagement Time;
+}  // namespace Stockfish
 
-#endif // #ifndef TIMEMAN_H_INCLUDED
+#endif  // #ifndef TIMEMAN_H_INCLUDED

src/tt.cpp

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -16,143 +16,144 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <cstring>   // For std::memset
+#include "tt.h"
+
+#include <cassert>
+#include <cstdint>
+#include <cstdlib>
+#include <cstring>
 #include <iostream>
 #include <thread>
+#include <vector>
 
-#include "bitboard.h"
 #include "misc.h"
-#include "thread.h"
-#include "tt.h"
-#include "uci.h"
 
-TranspositionTable TT; // Our global transposition table
+namespace Stockfish {
 
-/// TTEntry::save() populates the TTEntry with a new node's data, possibly
-/// overwriting an old position. Update is not atomic and can be racy.
+// Populates the TTEntry with a new node's data, possibly
+// overwriting an old position. The update is not atomic and can be racy.
+void TTEntry::save(
+  Key k, Value v, bool pv, Bound b, Depth d, Move m, Value ev, uint8_t generation8) {
 
-void TTEntry::save(Key k, Value v, bool pv, Bound b, Depth d, Move m, Value ev) {
+    // Preserve any existing move for the same position
+    if (m || uint16_t(k) != key16)
+        move16 = m;
 
-  // Preserve any existing move for the same position
-  if (m || (uint16_t)k != key16)
-      move16 = (uint16_t)m;
+    // Overwrite less valuable entries (cheapest checks first)
+    if (b == BOUND_EXACT || uint16_t(k) != key16 || d - DEPTH_OFFSET + 2 * pv > depth8 - 4)
+    {
+        assert(d > DEPTH_OFFSET);
+        assert(d < 256 + DEPTH_OFFSET);
 
-  // Overwrite less valuable entries (cheapest checks first)
-  if (b == BOUND_EXACT
-      || (uint16_t)k != key16
-      || d - DEPTH_OFFSET > depth8 - 4)
-  {
-      assert(d > DEPTH_OFFSET);
-      assert(d < 256 + DEPTH_OFFSET);
-
-      key16     = (uint16_t)k;
-      depth8    = (uint8_t)(d - DEPTH_OFFSET);
-      genBound8 = (uint8_t)(TT.generation8 | uint8_t(pv) << 2 | b);
-      value16   = (int16_t)v;
-      eval16    = (int16_t)ev;
-  }
+        key16     = uint16_t(k);
+        depth8    = uint8_t(d - DEPTH_OFFSET);
+        genBound8 = uint8_t(generation8 | uint8_t(pv) << 2 | b);
+        value16   = int16_t(v);
+        eval16    = int16_t(ev);
+    }
 }
 
 
-/// TranspositionTable::resize() sets the size of the transposition table,
-/// measured in megabytes. Transposition table consists of a power of 2 number
-/// of clusters and each cluster consists of ClusterSize number of TTEntry.
+uint8_t TTEntry::relative_age(const uint8_t generation8) const {
+    // Due to our packed storage format for generation and its cyclic
+    // nature we add GENERATION_CYCLE (256 is the modulus, plus what
+    // is needed to keep the unrelated lowest n bits from affecting
+    // the result) to calculate the entry age correctly even after
+    // generation8 overflows into the next cycle.
 
-void TranspositionTable::resize(size_t mbSize) {
-
-  Threads.main()->wait_for_search_finished();
-
-  aligned_large_pages_free(table);
-
-  clusterCount = mbSize * 1024 * 1024 / sizeof(Cluster);
-
-  table = static_cast<Cluster*>(aligned_large_pages_alloc(clusterCount * sizeof(Cluster)));
-  if (!table)
-  {
-      std::cerr << "Failed to allocate " << mbSize
-                << "MB for transposition table." << std::endl;
-      exit(EXIT_FAILURE);
-  }
-
-  clear();
+    return (TranspositionTable::GENERATION_CYCLE + generation8 - genBound8)
+         & TranspositionTable::GENERATION_MASK;
 }
 
 
-/// TranspositionTable::clear() initializes the entire transposition table to zero,
-//  in a multi-threaded way.
+// Sets the size of the transposition table,
+// measured in megabytes. Transposition table consists of a power of 2 number
+// of clusters and each cluster consists of ClusterSize number of TTEntry.
+void TranspositionTable::resize(size_t mbSize, int threadCount) {
+    aligned_large_pages_free(table);
 
-void TranspositionTable::clear() {
+    clusterCount = mbSize * 1024 * 1024 / sizeof(Cluster);
 
-  std::vector<std::thread> threads;
+    table = static_cast<Cluster*>(aligned_large_pages_alloc(clusterCount * sizeof(Cluster)));
+    if (!table)
+    {
+        std::cerr << "Failed to allocate " << mbSize << "MB for transposition table." << std::endl;
+        exit(EXIT_FAILURE);
+    }
 
-  for (size_t idx = 0; idx < Options["Threads"]; ++idx)
-  {
-      threads.emplace_back([this, idx]() {
-
-          // Thread binding gives faster search on systems with a first-touch policy
-          if (Options["Threads"] > 8)
-              WinProcGroup::bindThisThread(idx);
-
-          // Each thread will zero its part of the hash table
-          const size_t stride = size_t(clusterCount / Options["Threads"]),
-                       start  = size_t(stride * idx),
-                       len    = idx != Options["Threads"] - 1 ?
-                                stride : clusterCount - start;
-
-          std::memset(&table[start], 0, len * sizeof(Cluster));
-      });
-  }
-
-  for (std::thread& th : threads)
-      th.join();
+    clear(threadCount);
 }
 
 
-/// TranspositionTable::probe() looks up the current position in the transposition
-/// table. It returns true and a pointer to the TTEntry if the position is found.
-/// Otherwise, it returns false and a pointer to an empty or least valuable TTEntry
-/// to be replaced later. The replace value of an entry is calculated as its depth
-/// minus 8 times its relative age. TTEntry t1 is considered more valuable than
-/// TTEntry t2 if its replace value is greater than that of t2.
+// Initializes the entire transposition table to zero,
+// in a multi-threaded way.
+void TranspositionTable::clear(size_t threadCount) {
+    std::vector<std::thread> threads;
 
+    for (size_t idx = 0; idx < size_t(threadCount); ++idx)
+    {
+        threads.emplace_back([this, idx, threadCount]() {
+            // Thread binding gives faster search on systems with a first-touch policy
+            if (threadCount > 8)
+                WinProcGroup::bind_this_thread(idx);
+
+            // Each thread will zero its part of the hash table
+            const size_t stride = size_t(clusterCount / threadCount), start = size_t(stride * idx),
+                         len = idx != size_t(threadCount) - 1 ? stride : clusterCount - start;
+
+            std::memset(&table[start], 0, len * sizeof(Cluster));
+        });
+    }
+
+    for (std::thread& th : threads)
+        th.join();
+}
+
+
+// Looks up the current position in the transposition
+// table. It returns true and a pointer to the TTEntry if the position is found.
+// Otherwise, it returns false and a pointer to an empty or least valuable TTEntry
+// to be replaced later. The replace value of an entry is calculated as its depth
+// minus 8 times its relative age. TTEntry t1 is considered more valuable than
+// TTEntry t2 if its replace value is greater than that of t2.
 TTEntry* TranspositionTable::probe(const Key key, bool& found) const {
 
-  TTEntry* const tte = first_entry(key);
-  const uint16_t key16 = (uint16_t)key;  // Use the low 16 bits as key inside the cluster
+    TTEntry* const tte   = first_entry(key);
+    const uint16_t key16 = uint16_t(key);  // Use the low 16 bits as key inside the cluster
 
-  for (int i = 0; i < ClusterSize; ++i)
-      if (tte[i].key16 == key16 || !tte[i].depth8)
-      {
-          tte[i].genBound8 = uint8_t(generation8 | (tte[i].genBound8 & (GENERATION_DELTA - 1))); // Refresh
+    for (int i = 0; i < ClusterSize; ++i)
+        if (tte[i].key16 == key16 || !tte[i].depth8)
+        {
+            constexpr uint8_t lowerBits = GENERATION_DELTA - 1;
 
-          return found = (bool)tte[i].depth8, &tte[i];
-      }
+            // Refresh with new generation, keeping the lower bits the same.
+            tte[i].genBound8 = uint8_t(generation8 | (tte[i].genBound8 & lowerBits));
+            return found     = bool(tte[i].depth8), &tte[i];
+        }
 
-  // Find an entry to be replaced according to the replacement strategy
-  TTEntry* replace = tte;
-  for (int i = 1; i < ClusterSize; ++i)
-      // Due to our packed storage format for generation and its cyclic
-      // nature we add GENERATION_CYCLE (256 is the modulus, plus what
-      // is needed to keep the unrelated lowest n bits from affecting
-      // the result) to calculate the entry age correctly even after
-      // generation8 overflows into the next cycle.
-      if (  replace->depth8 - ((GENERATION_CYCLE + generation8 - replace->genBound8) & GENERATION_MASK)
-          >   tte[i].depth8 - ((GENERATION_CYCLE + generation8 -   tte[i].genBound8) & GENERATION_MASK))
-          replace = &tte[i];
+    // Find an entry to be replaced according to the replacement strategy
+    TTEntry* replace = tte;
+    for (int i = 1; i < ClusterSize; ++i)
+        if (replace->depth8 - replace->relative_age(generation8) * 2
+            > tte[i].depth8 - tte[i].relative_age(generation8) * 2)
+            replace = &tte[i];
 
-  return found = false, replace;
+    return found = false, replace;
 }
 
 
-/// TranspositionTable::hashfull() returns an approximation of the hashtable
-/// occupation during a search. The hash is x permill full, as per UCI protocol.
-
+// Returns an approximation of the hashtable
+// occupation during a search. The hash is x permill full, as per UCI protocol.
+// Only counts entries which match the current generation.
 int TranspositionTable::hashfull() const {
 
-  int cnt = 0;
-  for (int i = 0; i < 1000; ++i)
-      for (int j = 0; j < ClusterSize; ++j)
-          cnt += table[i].entry[j].depth8 && (table[i].entry[j].genBound8 & GENERATION_MASK) == generation8;
+    int cnt = 0;
+    for (int i = 0; i < 1000; ++i)
+        for (int j = 0; j < ClusterSize; ++j)
+            cnt += table[i].entry[j].depth8
+                && (table[i].entry[j].genBound8 & GENERATION_MASK) == generation8;
 
-  return cnt / ClusterSize;
+    return cnt / ClusterSize;
 }
+
+}  // namespace Stockfish

src/tt.h

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -19,9 +19,18 @@
 #ifndef TT_H_INCLUDED
 #define TT_H_INCLUDED
 
+#include <cstddef>
+#include <cstdint>
+
 #include "misc.h"
 #include "types.h"
 
+namespace Stockfish {
+
+namespace Cluster {
+void init();
+}
+
 /// TTEntry struct is the 10 bytes transposition table entry, defined as below:
 ///
 /// key        16 bit
@@ -35,69 +44,87 @@
 
 struct TTEntry {
 
-  Move  move()  const { return (Move )move16; }
-  Value value() const { return (Value)value16; }
-  Value eval()  const { return (Value)eval16; }
-  Depth depth() const { return (Depth)depth8 + DEPTH_OFFSET; }
-  bool is_pv()  const { return (bool)(genBound8 & 0x4); }
-  Bound bound() const { return (Bound)(genBound8 & 0x3); }
-  void save(Key k, Value v, bool pv, Bound b, Depth d, Move m, Value ev);
+    Move  move() const { return Move(move16); }
+    Value value() const { return Value(value16); }
+    Value eval() const { return Value(eval16); }
+    Depth depth() const { return Depth(depth8 + DEPTH_OFFSET); }
+    bool  is_pv() const { return bool(genBound8 & 0x4); }
+    Bound bound() const { return Bound(genBound8 & 0x3); }
+    void  save(Key k, Value v, bool pv, Bound b, Depth d, Move m, Value ev, uint8_t generation8);
+    // The returned age is a multiple of TranspositionTable::GENERATION_DELTA
+    uint8_t relative_age(const uint8_t generation8) const;
 
-private:
-  friend class TranspositionTable;
+   private:
+    friend class TranspositionTable;
+    friend void Cluster::init();
 
-  uint16_t key16;
-  uint8_t  depth8;
-  uint8_t  genBound8;
-  uint16_t move16;
-  int16_t  value16;
-  int16_t  eval16;
+
+    uint16_t key16;
+    uint8_t  depth8;
+    uint8_t  genBound8;
+    Move     move16;
+    int16_t  value16;
+    int16_t  eval16;
 };
 
 
-/// A TranspositionTable is an array of Cluster, of size clusterCount. Each
-/// cluster consists of ClusterSize number of TTEntry. Each non-empty TTEntry
-/// contains information on exactly one position. The size of a Cluster should
-/// divide the size of a cache line for best performance, as the cacheline is
-/// prefetched when possible.
-
+// A TranspositionTable is an array of Cluster, of size clusterCount. Each
+// cluster consists of ClusterSize number of TTEntry. Each non-empty TTEntry
+// contains information on exactly one position. The size of a Cluster should
+// divide the size of a cache line for best performance, as the cacheline is
+// prefetched when possible.
 class TranspositionTable {
 
-  static constexpr int ClusterSize = 3;
+    friend void Cluster::init();
 
-  struct Cluster {
-    TTEntry entry[ClusterSize];
-    char padding[2]; // Pad to 32 bytes
-  };
+    static constexpr int ClusterSize = 3;
 
-  static_assert(sizeof(Cluster) == 32, "Unexpected Cluster size");
+    struct Cluster {
+        TTEntry entry[ClusterSize];
+        char    padding[2];  // Pad to 32 bytes
+    };
 
-  // Constants used to refresh the hash table periodically
-  static constexpr unsigned GENERATION_BITS  = 3;                                // nb of bits reserved for other things
-  static constexpr int      GENERATION_DELTA = (1 << GENERATION_BITS);           // increment for generation field
-  static constexpr int      GENERATION_CYCLE = 255 + (1 << GENERATION_BITS);     // cycle length
-  static constexpr int      GENERATION_MASK  = (0xFF << GENERATION_BITS) & 0xFF; // mask to pull out generation number
+    static_assert(sizeof(Cluster) == 32, "Unexpected Cluster size");
 
-public:
- ~TranspositionTable() { aligned_large_pages_free(table); }
-  void new_search() { generation8 += GENERATION_DELTA; } // Lower bits are used for other things
-  TTEntry* probe(const Key key, bool& found) const;
-  int hashfull() const;
-  void resize(size_t mbSize);
-  void clear();
+    // Constants used to refresh the hash table periodically
 
-  TTEntry* first_entry(const Key key) const {
-    return &table[mul_hi64(key, clusterCount)].entry[0];
-  }
+    // We have 8 bits available where the lowest 3 bits are
+    // reserved for other things.
+    static constexpr unsigned GENERATION_BITS = 3;
+    // increment for generation field
+    static constexpr int GENERATION_DELTA = (1 << GENERATION_BITS);
+    // cycle length
+    static constexpr int GENERATION_CYCLE = 255 + GENERATION_DELTA;
+    // mask to pull out generation number
+    static constexpr int GENERATION_MASK = (0xFF << GENERATION_BITS) & 0xFF;
 
-private:
-  friend struct TTEntry;
+   public:
+    ~TranspositionTable() { aligned_large_pages_free(table); }
 
-  size_t clusterCount;
-  Cluster* table;
-  uint8_t generation8; // Size must be not bigger than TTEntry::genBound8
+    void new_search() {
+        // increment by delta to keep lower bits as is
+        generation8 += GENERATION_DELTA;
+    }
+
+    TTEntry* probe(const Key key, bool& found) const;
+    int      hashfull() const;
+    void     resize(size_t mbSize, int threadCount);
+    void     clear(size_t threadCount);
+
+    TTEntry* first_entry(const Key key) const {
+        return &table[mul_hi64(key, clusterCount)].entry[0];
+    }
+
+    uint8_t generation() const { return generation8; }
+
+   private:
+    friend struct TTEntry;
+
+    size_t   clusterCount;
+    Cluster* table       = nullptr;
+    uint8_t  generation8 = 0;  // Size must be not bigger than TTEntry::genBound8
 };
 
-extern TranspositionTable TT;
+}  // namespace Stockfish
 
-#endif // #ifndef TT_H_INCLUDED
+#endif  // #ifndef TT_H_INCLUDED

src/tune.cpp

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -16,116 +16,95 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include "tune.h"
+
 #include <algorithm>
 #include <iostream>
+#include <map>
 #include <sstream>
+#include <string>
 
-#include "types.h"
-#include "misc.h"
-#include "uci.h"
+#include "ucioption.h"
 
 using std::string;
 
-bool Tune::update_on_last;
-const UCI::Option* LastOption = nullptr;
-BoolConditions Conditions;
-static std::map<std::string, int> TuneResults;
+namespace Stockfish {
+
+bool          Tune::update_on_last;
+const Option* LastOption = nullptr;
+OptionsMap*   Tune::options;
+
+
+namespace {
+std::map<std::string, int> TuneResults;
+
+void on_tune(const Option& o) {
+
+    if (!Tune::update_on_last || LastOption == &o)
+        Tune::read_options();
+}
+
+
+void make_option(OptionsMap* options, const string& n, int v, const SetRange& r) {
+
+    // Do not generate option when there is nothing to tune (ie. min = max)
+    if (r(v).first == r(v).second)
+        return;
+
+    if (TuneResults.count(n))
+        v = TuneResults[n];
+
+    (*options)[n] << Option(v, r(v).first, r(v).second, on_tune);
+    LastOption = &((*options)[n]);
+
+    // Print formatted parameters, ready to be copy-pasted in Fishtest
+    std::cout << n << "," << v << "," << r(v).first << "," << r(v).second << ","
+              << (r(v).second - r(v).first) / 20.0 << ","
+              << "0.0020" << std::endl;
+}
+}
 
 string Tune::next(string& names, bool pop) {
 
-  string name;
+    string name;
 
-  do {
-      string token = names.substr(0, names.find(','));
+    do
+    {
+        string token = names.substr(0, names.find(','));
 
-      if (pop)
-          names.erase(0, token.size() + 1);
+        if (pop)
+            names.erase(0, token.size() + 1);
 
-      std::stringstream ws(token);
-      name += (ws >> token, token); // Remove trailing whitespace
+        std::stringstream ws(token);
+        name += (ws >> token, token);  // Remove trailing whitespace
 
-  } while (  std::count(name.begin(), name.end(), '(')
-           - std::count(name.begin(), name.end(), ')'));
+    } while (std::count(name.begin(), name.end(), '(') - std::count(name.begin(), name.end(), ')'));
 
-  return name;
+    return name;
 }
 
-static void on_tune(const UCI::Option& o) {
 
-  if (!Tune::update_on_last || LastOption == &o)
-      Tune::read_options();
+template<>
+void Tune::Entry<int>::init_option() {
+    make_option(options, name, value, range);
 }
 
-static void make_option(const string& n, int v, const SetRange& r) {
-
-  // Do not generate option when there is nothing to tune (ie. min = max)
-  if (r(v).first == r(v).second)
-      return;
-
-  if (TuneResults.count(n))
-      v = TuneResults[n];
-
-  Options[n] << UCI::Option(v, r(v).first, r(v).second, on_tune);
-  LastOption = &Options[n];
-
-  // Print formatted parameters, ready to be copy-pasted in Fishtest
-  std::cout << n << ","
-            << v << ","
-            << r(v).first << "," << r(v).second << ","
-            << (r(v).second - r(v).first) / 20.0 << ","
-            << "0.0020"
-            << std::endl;
-}
-
-template<> void Tune::Entry<int>::init_option() { make_option(name, value, range); }
-
-template<> void Tune::Entry<int>::read_option() {
-  if (Options.count(name))
-      value = int(Options[name]);
-}
-
-template<> void Tune::Entry<Value>::init_option() { make_option(name, value, range); }
-
-template<> void Tune::Entry<Value>::read_option() {
-  if (Options.count(name))
-      value = Value(int(Options[name]));
-}
-
-template<> void Tune::Entry<Score>::init_option() {
-  make_option("m" + name, mg_value(value), range);
-  make_option("e" + name, eg_value(value), range);
-}
-
-template<> void Tune::Entry<Score>::read_option() {
-  if (Options.count("m" + name))
-      value = make_score(int(Options["m" + name]), eg_value(value));
-
-  if (Options.count("e" + name))
-      value = make_score(mg_value(value), int(Options["e" + name]));
+template<>
+void Tune::Entry<int>::read_option() {
+    if (options->count(name))
+        value = int((*options)[name]);
 }
 
 // Instead of a variable here we have a PostUpdate function: just call it
-template<> void Tune::Entry<Tune::PostUpdate>::init_option() {}
-template<> void Tune::Entry<Tune::PostUpdate>::read_option() { value(); }
-
-
-// Set binary conditions according to a probability that depends
-// on the corresponding parameter value.
-
-void BoolConditions::set() {
-
-  static PRNG rng(now());
-  static bool startup = true; // To workaround fishtest bench
-
-  for (size_t i = 0; i < binary.size(); i++)
-      binary[i] = !startup && (values[i] + int(rng.rand<unsigned>() % variance) > threshold);
-
-  startup = false;
-
-  for (size_t i = 0; i < binary.size(); i++)
-      sync_cout << binary[i] << sync_endl;
+template<>
+void Tune::Entry<Tune::PostUpdate>::init_option() {}
+template<>
+void Tune::Entry<Tune::PostUpdate>::read_option() {
+    value();
 }
 
+}  // namespace Stockfish
+
 
 // Init options with tuning session results instead of default values. Useful to
 // get correct bench signature after a tuning session or to test tuned values.
@@ -136,9 +115,10 @@ void BoolConditions::set() {
 //
 // Then paste the output below, as the function body
 
-#include <cmath>
 
-void Tune::read_results() {
+namespace Stockfish {
 
-  /* ...insert your values here... */
+void Tune::read_results() { /* ...insert your values here... */
 }
+
+}  // namespace Stockfish

src/tune.h

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -19,175 +19,163 @@
 #ifndef TUNE_H_INCLUDED
 #define TUNE_H_INCLUDED
 
+#include <cstddef>
 #include <memory>
 #include <string>
-#include <type_traits>
+#include <type_traits>  // IWYU pragma: keep
+#include <utility>
 #include <vector>
 
-typedef std::pair<int, int> Range; // Option's min-max values
-typedef Range (RangeFun) (int);
+namespace Stockfish {
+
+class OptionsMap;
+
+using Range    = std::pair<int, int>;  // Option's min-max values
+using RangeFun = Range(int);
 
 // Default Range function, to calculate Option's min-max values
-inline Range default_range(int v) {
-  return v > 0 ? Range(0, 2 * v) : Range(2 * v, 0);
-}
+inline Range default_range(int v) { return v > 0 ? Range(0, 2 * v) : Range(2 * v, 0); }
 
 struct SetRange {
-  explicit SetRange(RangeFun f) : fun(f) {}
-  SetRange(int min, int max) : fun(nullptr), range(min, max) {}
-  Range operator()(int v) const { return fun ? fun(v) : range; }
+    explicit SetRange(RangeFun f) :
+        fun(f) {}
+    SetRange(int min, int max) :
+        fun(nullptr),
+        range(min, max) {}
+    Range operator()(int v) const { return fun ? fun(v) : range; }
 
-  RangeFun* fun;
-  Range range;
+    RangeFun* fun;
+    Range     range;
 };
 
 #define SetDefaultRange SetRange(default_range)
 
 
-/// BoolConditions struct is used to tune boolean conditions in the
-/// code by toggling them on/off according to a probability that
-/// depends on the value of a tuned integer parameter: for high
-/// values of the parameter condition is always disabled, for low
-/// values is always enabled, otherwise it is enabled with a given
-/// probability that depnends on the parameter under tuning.
-
-struct BoolConditions {
-  void init(size_t size) { values.resize(size, defaultValue), binary.resize(size, 0); }
-  void set();
-
-  std::vector<int> binary, values;
-  int defaultValue = 465, variance = 40, threshold = 500;
-  SetRange range = SetRange(0, 1000);
-};
-
-extern BoolConditions Conditions;
-
-inline void set_conditions() { Conditions.set(); }
-
-
-/// Tune class implements the 'magic' code that makes the setup of a fishtest
-/// tuning session as easy as it can be. Mainly you have just to remove const
-/// qualifiers from the variables you want to tune and flag them for tuning, so
-/// if you have:
-///
-///   const Score myScore = S(10, 15);
-///   const Value myValue[][2] = { { V(100), V(20) }, { V(7), V(78) } };
-///
-/// If you have a my_post_update() function to run after values have been updated,
-/// and a my_range() function to set custom Option's min-max values, then you just
-/// remove the 'const' qualifiers and write somewhere below in the file:
-///
-///   TUNE(SetRange(my_range), myScore, myValue, my_post_update);
-///
-/// You can also set the range directly, and restore the default at the end
-///
-///   TUNE(SetRange(-100, 100), myScore, SetDefaultRange);
-///
-/// In case update function is slow and you have many parameters, you can add:
-///
-///   UPDATE_ON_LAST();
-///
-/// And the values update, including post update function call, will be done only
-/// once, after the engine receives the last UCI option, that is the one defined
-/// and created as the last one, so the GUI should send the options in the same
-/// order in which have been defined.
+// Tune class implements the 'magic' code that makes the setup of a fishtest tuning
+// session as easy as it can be. Mainly you have just to remove const qualifiers
+// from the variables you want to tune and flag them for tuning, so if you have:
+//
+//   const Value myValue[][2] = { { V(100), V(20) }, { V(7), V(78) } };
+//
+// If you have a my_post_update() function to run after values have been updated,
+// and a my_range() function to set custom Option's min-max values, then you just
+// remove the 'const' qualifiers and write somewhere below in the file:
+//
+//   TUNE(SetRange(my_range), myValue, my_post_update);
+//
+// You can also set the range directly, and restore the default at the end
+//
+//   TUNE(SetRange(-100, 100), myValue, SetDefaultRange);
+//
+// In case update function is slow and you have many parameters, you can add:
+//
+//   UPDATE_ON_LAST();
+//
+// And the values update, including post update function call, will be done only
+// once, after the engine receives the last UCI option, that is the one defined
+// and created as the last one, so the GUI should send the options in the same
+// order in which have been defined.
 
 class Tune {
 
-  typedef void (PostUpdate) (); // Post-update function
+    using PostUpdate = void();  // Post-update function
 
-  Tune() { read_results(); }
-  Tune(const Tune&) = delete;
-  void operator=(const Tune&) = delete;
-  void read_results();
+    Tune() { read_results(); }
+    Tune(const Tune&)           = delete;
+    void operator=(const Tune&) = delete;
+    void read_results();
 
-  static Tune& instance() { static Tune t; return t; } // Singleton
+    static Tune& instance() {
+        static Tune t;
+        return t;
+    }  // Singleton
 
-  // Use polymorphism to accomodate Entry of different types in the same vector
-  struct EntryBase {
-    virtual ~EntryBase() = default;
-    virtual void init_option() = 0;
-    virtual void read_option() = 0;
-  };
+    // Use polymorphism to accommodate Entry of different types in the same vector
+    struct EntryBase {
+        virtual ~EntryBase()       = default;
+        virtual void init_option() = 0;
+        virtual void read_option() = 0;
+    };
 
-  template<typename T>
-  struct Entry : public EntryBase {
+    template<typename T>
+    struct Entry: public EntryBase {
 
-    static_assert(!std::is_const<T>::value, "Parameter cannot be const!");
+        static_assert(!std::is_const_v<T>, "Parameter cannot be const!");
 
-    static_assert(   std::is_same<T,   int>::value
-                  || std::is_same<T, Value>::value
-                  || std::is_same<T, Score>::value
-                  || std::is_same<T, PostUpdate>::value, "Parameter type not supported!");
+        static_assert(std::is_same_v<T, int> || std::is_same_v<T, PostUpdate>,
+                      "Parameter type not supported!");
 
-    Entry(const std::string& n, T& v, const SetRange& r) : name(n), value(v), range(r) {}
-    void operator=(const Entry&) = delete; // Because 'value' is a reference
-    void init_option() override;
-    void read_option() override;
+        Entry(const std::string& n, T& v, const SetRange& r) :
+            name(n),
+            value(v),
+            range(r) {}
+        void operator=(const Entry&) = delete;  // Because 'value' is a reference
+        void init_option() override;
+        void read_option() override;
 
-    std::string name;
-    T& value;
-    SetRange range;
-  };
+        std::string name;
+        T&          value;
+        SetRange    range;
+    };
 
-  // Our facility to fill the container, each Entry corresponds to a parameter
-  // to tune. We use variadic templates to deal with an unspecified number of
-  // entries, each one of a possible different type.
-  static std::string next(std::string& names, bool pop = true);
+    // Our facility to fill the container, each Entry corresponds to a parameter
+    // to tune. We use variadic templates to deal with an unspecified number of
+    // entries, each one of a possible different type.
+    static std::string next(std::string& names, bool pop = true);
 
-  int add(const SetRange&, std::string&&) { return 0; }
+    int add(const SetRange&, std::string&&) { return 0; }
 
-  template<typename T, typename... Args>
-  int add(const SetRange& range, std::string&& names, T& value, Args&&... args) {
-    list.push_back(std::unique_ptr<EntryBase>(new Entry<T>(next(names), value, range)));
-    return add(range, std::move(names), args...);
-  }
+    template<typename T, typename... Args>
+    int add(const SetRange& range, std::string&& names, T& value, Args&&... args) {
+        list.push_back(std::unique_ptr<EntryBase>(new Entry<T>(next(names), value, range)));
+        return add(range, std::move(names), args...);
+    }
 
-  // Template specialization for arrays: recursively handle multi-dimensional arrays
-  template<typename T, size_t N, typename... Args>
-  int add(const SetRange& range, std::string&& names, T (&value)[N], Args&&... args) {
-    for (size_t i = 0; i < N; i++)
-        add(range, next(names, i == N - 1) + "[" + std::to_string(i) + "]", value[i]);
-    return add(range, std::move(names), args...);
-  }
+    // Template specialization for arrays: recursively handle multi-dimensional arrays
+    template<typename T, size_t N, typename... Args>
+    int add(const SetRange& range, std::string&& names, T (&value)[N], Args&&... args) {
+        for (size_t i = 0; i < N; i++)
+            add(range, next(names, i == N - 1) + "[" + std::to_string(i) + "]", value[i]);
+        return add(range, std::move(names), args...);
+    }
 
-  // Template specialization for SetRange
-  template<typename... Args>
-  int add(const SetRange&, std::string&& names, SetRange& value, Args&&... args) {
-    return add(value, (next(names), std::move(names)), args...);
-  }
+    // Template specialization for SetRange
+    template<typename... Args>
+    int add(const SetRange&, std::string&& names, SetRange& value, Args&&... args) {
+        return add(value, (next(names), std::move(names)), args...);
+    }
 
-  // Template specialization for BoolConditions
-  template<typename... Args>
-  int add(const SetRange& range, std::string&& names, BoolConditions& cond, Args&&... args) {
-    for (size_t size = cond.values.size(), i = 0; i < size; i++)
-        add(cond.range, next(names, i == size - 1) + "_" + std::to_string(i), cond.values[i]);
-    return add(range, std::move(names), args...);
-  }
+    std::vector<std::unique_ptr<EntryBase>> list;
 
-  std::vector<std::unique_ptr<EntryBase>> list;
+   public:
+    template<typename... Args>
+    static int add(const std::string& names, Args&&... args) {
+        return instance().add(SetDefaultRange, names.substr(1, names.size() - 2),
+                              args...);  // Remove trailing parenthesis
+    }
+    static void init(OptionsMap& o) {
+        options = &o;
+        for (auto& e : instance().list)
+            e->init_option();
+        read_options();
+    }  // Deferred, due to UCI::Options access
+    static void read_options() {
+        for (auto& e : instance().list)
+            e->read_option();
+    }
 
-public:
-  template<typename... Args>
-  static int add(const std::string& names, Args&&... args) {
-    return instance().add(SetDefaultRange, names.substr(1, names.size() - 2), args...); // Remove trailing parenthesis
-  }
-  static void init() { for (auto& e : instance().list) e->init_option(); read_options(); } // Deferred, due to UCI::Options access
-  static void read_options() { for (auto& e : instance().list) e->read_option(); }
-  static bool update_on_last;
+    static bool        update_on_last;
+    static OptionsMap* options;
 };
 
-// Some macro magic :-) we define a dummy int variable that compiler initializes calling Tune::add()
+// Some macro magic :-) we define a dummy int variable that the compiler initializes calling Tune::add()
 #define STRINGIFY(x) #x
-#define UNIQUE2(x, y) x ## y
-#define UNIQUE(x, y) UNIQUE2(x, y) // Two indirection levels to expand __LINE__
+#define UNIQUE2(x, y) x##y
+#define UNIQUE(x, y) UNIQUE2(x, y)  // Two indirection levels to expand __LINE__
 #define TUNE(...) int UNIQUE(p, __LINE__) = Tune::add(STRINGIFY((__VA_ARGS__)), __VA_ARGS__)
 
 #define UPDATE_ON_LAST() bool UNIQUE(p, __LINE__) = Tune::update_on_last = true
 
-// Some macro to tune toggling of boolean conditions
-#define CONDITION(x) (Conditions.binary[__COUNTER__] || (x))
-#define TUNE_CONDITIONS() int UNIQUE(c, __LINE__) = (Conditions.init(__COUNTER__), 0); \
-                          TUNE(Conditions, set_conditions)
+}  // namespace Stockfish
 
-#endif // #ifndef TUNE_H_INCLUDED
+#endif  // #ifndef TUNE_H_INCLUDED

src/types.h

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -17,471 +17,395 @@
 */
 
 #ifndef TYPES_H_INCLUDED
-#define TYPES_H_INCLUDED
+    #define TYPES_H_INCLUDED
 
-/// When compiling with provided Makefile (e.g. for Linux and OSX), configuration
-/// is done automatically. To get started type 'make help'.
-///
-/// When Makefile is not used (e.g. with Microsoft Visual Studio) some switches
-/// need to be set manually:
-///
-/// -DNDEBUG      | Disable debugging mode. Always use this for release.
-///
-/// -DNO_PREFETCH | Disable use of prefetch asm-instruction. You may need this to
-///               | run on some very old machines.
-///
-/// -DUSE_POPCNT  | Add runtime support for use of popcnt asm-instruction. Works
-///               | only in 64-bit mode and requires hardware with popcnt support.
-///
-/// -DUSE_PEXT    | Add runtime support for use of pext asm-instruction. Works
-///               | only in 64-bit mode and requires hardware with pext support.
+// When compiling with provided Makefile (e.g. for Linux and OSX), configuration
+// is done automatically. To get started type 'make help'.
+//
+// When Makefile is not used (e.g. with Microsoft Visual Studio) some switches
+// need to be set manually:
+//
+// -DNDEBUG      | Disable debugging mode. Always use this for release.
+//
+// -DNO_PREFETCH | Disable use of prefetch asm-instruction. You may need this to
+//               | run on some very old machines.
+//
+// -DUSE_POPCNT  | Add runtime support for use of popcnt asm-instruction. Works
+//               | only in 64-bit mode and requires hardware with popcnt support.
+//
+// -DUSE_PEXT    | Add runtime support for use of pext asm-instruction. Works
+//               | only in 64-bit mode and requires hardware with pext support.
 
-#include <cassert>
-#include <cctype>
-#include <cstdint>
-#include <cstdlib>
-#include <algorithm>
+    #include <cassert>
+    #include <cstdint>
 
-#if defined(_MSC_VER)
-// Disable some silly and noisy warning from MSVC compiler
-#pragma warning(disable: 4127) // Conditional expression is constant
-#pragma warning(disable: 4146) // Unary minus operator applied to unsigned type
-#pragma warning(disable: 4800) // Forcing value to bool 'true' or 'false'
-#endif
+    #if defined(_MSC_VER)
+        // Disable some silly and noisy warnings from MSVC compiler
+        #pragma warning(disable: 4127)  // Conditional expression is constant
+        #pragma warning(disable: 4146)  // Unary minus operator applied to unsigned type
+        #pragma warning(disable: 4800)  // Forcing value to bool 'true' or 'false'
+    #endif
 
-/// Predefined macros hell:
-///
-/// __GNUC__           Compiler is gcc, Clang or Intel on Linux
-/// __INTEL_COMPILER   Compiler is Intel
-/// _MSC_VER           Compiler is MSVC or Intel on Windows
-/// _WIN32             Building on Windows (any)
-/// _WIN64             Building on Windows 64 bit
+// Predefined macros hell:
+//
+// __GNUC__                Compiler is GCC, Clang or ICX
+// __clang__               Compiler is Clang or ICX
+// __INTEL_LLVM_COMPILER   Compiler is ICX
+// _MSC_VER                Compiler is MSVC
+// _WIN32                  Building on Windows (any)
+// _WIN64                  Building on Windows 64 bit
 
-#if defined(__GNUC__ ) && (__GNUC__ < 9 || (__GNUC__ == 9 && __GNUC_MINOR__ <= 2)) && defined(_WIN32) && !defined(__clang__)
-#define ALIGNAS_ON_STACK_VARIABLES_BROKEN
-#endif
+    #if defined(__GNUC__) && (__GNUC__ < 9 || (__GNUC__ == 9 && __GNUC_MINOR__ <= 2)) \
+      && defined(_WIN32) && !defined(__clang__)
+        #define ALIGNAS_ON_STACK_VARIABLES_BROKEN
+    #endif
 
-#define ASSERT_ALIGNED(ptr, alignment) assert(reinterpret_cast<uintptr_t>(ptr) % alignment == 0)
+    #define ASSERT_ALIGNED(ptr, alignment) assert(reinterpret_cast<uintptr_t>(ptr) % alignment == 0)
 
-#if defined(_WIN64) && defined(_MSC_VER) // No Makefile used
-#  include <intrin.h> // Microsoft header for _BitScanForward64()
-#  define IS_64BIT
-#endif
+    #if defined(_WIN64) && defined(_MSC_VER)  // No Makefile used
+        #include <intrin.h>                   // Microsoft header for _BitScanForward64()
+        #define IS_64BIT
+    #endif
 
-#if defined(USE_POPCNT) && (defined(__INTEL_COMPILER) || defined(_MSC_VER))
-#  include <nmmintrin.h> // Intel and Microsoft header for _mm_popcnt_u64()
-#endif
+    #if defined(USE_POPCNT) && defined(_MSC_VER)
+        #include <nmmintrin.h>  // Microsoft header for _mm_popcnt_u64()
+    #endif
 
-#if !defined(NO_PREFETCH) && (defined(__INTEL_COMPILER) || defined(_MSC_VER))
-#  include <xmmintrin.h> // Intel and Microsoft header for _mm_prefetch()
-#endif
+    #if !defined(NO_PREFETCH) && defined(_MSC_VER)
+        #include <xmmintrin.h>  // Microsoft header for _mm_prefetch()
+    #endif
 
-#if defined(USE_PEXT)
-#  include <immintrin.h> // Header for _pext_u64() intrinsic
-#  define pext(b, m) _pext_u64(b, m)
-#else
-#  define pext(b, m) 0
-#endif
+    #if defined(USE_PEXT)
+        #include <immintrin.h>  // Header for _pext_u64() intrinsic
+        #define pext(b, m) _pext_u64(b, m)
+    #else
+        #define pext(b, m) 0
+    #endif
 
-#ifdef USE_POPCNT
+namespace Stockfish {
+
+    #ifdef USE_POPCNT
 constexpr bool HasPopCnt = true;
-#else
+    #else
 constexpr bool HasPopCnt = false;
-#endif
+    #endif
 
-#ifdef USE_PEXT
+    #ifdef USE_PEXT
 constexpr bool HasPext = true;
-#else
+    #else
 constexpr bool HasPext = false;
-#endif
+    #endif
 
-#ifdef IS_64BIT
+    #ifdef IS_64BIT
 constexpr bool Is64Bit = true;
-#else
+    #else
 constexpr bool Is64Bit = false;
-#endif
+    #endif
 
-typedef uint64_t Key;
-typedef uint64_t Bitboard;
+using Key      = uint64_t;
+using Bitboard = uint64_t;
 
 constexpr int MAX_MOVES = 256;
 constexpr int MAX_PLY   = 246;
 
-/// A move needs 16 bits to be stored
-///
-/// bit  0- 5: destination square (from 0 to 63)
-/// bit  6-11: origin square (from 0 to 63)
-/// bit 12-13: promotion piece type - 2 (from KNIGHT-2 to QUEEN-2)
-/// bit 14-15: special move flag: promotion (1), en passant (2), castling (3)
-/// NOTE: en passant bit is set only when a pawn can be captured
-///
-/// Special cases are MOVE_NONE and MOVE_NULL. We can sneak these in because in
-/// any normal move destination square is always different from origin square
-/// while MOVE_NONE and MOVE_NULL have the same origin and destination square.
-
-enum Move : int {
-  MOVE_NONE,
-  MOVE_NULL = 65
-};
-
-enum MoveType {
-  NORMAL,
-  PROMOTION = 1 << 14,
-  EN_PASSANT = 2 << 14,
-  CASTLING  = 3 << 14
-};
-
 enum Color {
-  WHITE, BLACK, COLOR_NB = 2
+    WHITE,
+    BLACK,
+    COLOR_NB = 2
 };
 
 enum CastlingRights {
-  NO_CASTLING,
-  WHITE_OO,
-  WHITE_OOO = WHITE_OO << 1,
-  BLACK_OO  = WHITE_OO << 2,
-  BLACK_OOO = WHITE_OO << 3,
+    NO_CASTLING,
+    WHITE_OO,
+    WHITE_OOO = WHITE_OO << 1,
+    BLACK_OO  = WHITE_OO << 2,
+    BLACK_OOO = WHITE_OO << 3,
 
-  KING_SIDE      = WHITE_OO  | BLACK_OO,
-  QUEEN_SIDE     = WHITE_OOO | BLACK_OOO,
-  WHITE_CASTLING = WHITE_OO  | WHITE_OOO,
-  BLACK_CASTLING = BLACK_OO  | BLACK_OOO,
-  ANY_CASTLING   = WHITE_CASTLING | BLACK_CASTLING,
+    KING_SIDE      = WHITE_OO | BLACK_OO,
+    QUEEN_SIDE     = WHITE_OOO | BLACK_OOO,
+    WHITE_CASTLING = WHITE_OO | WHITE_OOO,
+    BLACK_CASTLING = BLACK_OO | BLACK_OOO,
+    ANY_CASTLING   = WHITE_CASTLING | BLACK_CASTLING,
 
-  CASTLING_RIGHT_NB = 16
-};
-
-enum Phase {
-  PHASE_ENDGAME,
-  PHASE_MIDGAME = 128,
-  MG = 0, EG = 1, PHASE_NB = 2
-};
-
-enum ScaleFactor {
-  SCALE_FACTOR_DRAW    = 0,
-  SCALE_FACTOR_NORMAL  = 64,
-  SCALE_FACTOR_MAX     = 128,
-  SCALE_FACTOR_NONE    = 255
+    CASTLING_RIGHT_NB = 16
 };
 
 enum Bound {
-  BOUND_NONE,
-  BOUND_UPPER,
-  BOUND_LOWER,
-  BOUND_EXACT = BOUND_UPPER | BOUND_LOWER
+    BOUND_NONE,
+    BOUND_UPPER,
+    BOUND_LOWER,
+    BOUND_EXACT = BOUND_UPPER | BOUND_LOWER
 };
 
-enum Value : int {
-  VALUE_ZERO      = 0,
-  VALUE_DRAW      = 0,
-  VALUE_KNOWN_WIN = 10000,
-  VALUE_MATE      = 32000,
-  VALUE_INFINITE  = 32001,
-  VALUE_NONE      = 32002,
+// Value is used as an alias for int16_t, this is done to differentiate between
+// a search value and any other integer value. The values used in search are always
+// supposed to be in the range (-VALUE_NONE, VALUE_NONE] and should not exceed this range.
+using Value = int;
 
-  VALUE_TB_WIN_IN_MAX_PLY  =  VALUE_MATE - 2 * MAX_PLY,
-  VALUE_TB_LOSS_IN_MAX_PLY = -VALUE_TB_WIN_IN_MAX_PLY,
-  VALUE_MATE_IN_MAX_PLY  =  VALUE_MATE - MAX_PLY,
-  VALUE_MATED_IN_MAX_PLY = -VALUE_MATE_IN_MAX_PLY,
+constexpr Value VALUE_ZERO     = 0;
+constexpr Value VALUE_DRAW     = 0;
+constexpr Value VALUE_NONE     = 32002;
+constexpr Value VALUE_INFINITE = 32001;
 
-  PawnValueMg   = 126,   PawnValueEg   = 208,
-  KnightValueMg = 781,   KnightValueEg = 854,
-  BishopValueMg = 825,   BishopValueEg = 915,
-  RookValueMg   = 1276,  RookValueEg   = 1380,
-  QueenValueMg  = 2538,  QueenValueEg  = 2682,
-  Tempo = 28,
+constexpr Value VALUE_MATE             = 32000;
+constexpr Value VALUE_MATE_IN_MAX_PLY  = VALUE_MATE - MAX_PLY;
+constexpr Value VALUE_MATED_IN_MAX_PLY = -VALUE_MATE_IN_MAX_PLY;
 
-  MidgameLimit  = 15258, EndgameLimit  = 3915
-};
+constexpr Value VALUE_TB                 = VALUE_MATE_IN_MAX_PLY - 1;
+constexpr Value VALUE_TB_WIN_IN_MAX_PLY  = VALUE_TB - MAX_PLY;
+constexpr Value VALUE_TB_LOSS_IN_MAX_PLY = -VALUE_TB_WIN_IN_MAX_PLY;
 
+// In the code, we make the assumption that these values
+// are such that non_pawn_material() can be used to uniquely
+// identify the material on the board.
+constexpr Value PawnValue   = 208;
+constexpr Value KnightValue = 781;
+constexpr Value BishopValue = 825;
+constexpr Value RookValue   = 1276;
+constexpr Value QueenValue  = 2538;
+
+
+// clang-format off
 enum PieceType {
-  NO_PIECE_TYPE, PAWN, KNIGHT, BISHOP, ROOK, QUEEN, KING,
-  ALL_PIECES = 0,
-  PIECE_TYPE_NB = 8
+    NO_PIECE_TYPE, PAWN, KNIGHT, BISHOP, ROOK, QUEEN, KING,
+    ALL_PIECES = 0,
+    PIECE_TYPE_NB = 8
 };
 
 enum Piece {
-  NO_PIECE,
-  W_PAWN = PAWN,     W_KNIGHT, W_BISHOP, W_ROOK, W_QUEEN, W_KING,
-  B_PAWN = PAWN + 8, B_KNIGHT, B_BISHOP, B_ROOK, B_QUEEN, B_KING,
-  PIECE_NB = 16
+    NO_PIECE,
+    W_PAWN = PAWN,     W_KNIGHT, W_BISHOP, W_ROOK, W_QUEEN, W_KING,
+    B_PAWN = PAWN + 8, B_KNIGHT, B_BISHOP, B_ROOK, B_QUEEN, B_KING,
+    PIECE_NB = 16
 };
+// clang-format on
 
-constexpr Value PieceValue[PHASE_NB][PIECE_NB] = {
-  { VALUE_ZERO, PawnValueMg, KnightValueMg, BishopValueMg, RookValueMg, QueenValueMg, VALUE_ZERO, VALUE_ZERO,
-    VALUE_ZERO, PawnValueMg, KnightValueMg, BishopValueMg, RookValueMg, QueenValueMg, VALUE_ZERO, VALUE_ZERO },
-  { VALUE_ZERO, PawnValueEg, KnightValueEg, BishopValueEg, RookValueEg, QueenValueEg, VALUE_ZERO, VALUE_ZERO,
-    VALUE_ZERO, PawnValueEg, KnightValueEg, BishopValueEg, RookValueEg, QueenValueEg, VALUE_ZERO, VALUE_ZERO }
-};
+constexpr Value PieceValue[PIECE_NB] = {
+  VALUE_ZERO, PawnValue, KnightValue, BishopValue, RookValue, QueenValue, VALUE_ZERO, VALUE_ZERO,
+  VALUE_ZERO, PawnValue, KnightValue, BishopValue, RookValue, QueenValue, VALUE_ZERO, VALUE_ZERO};
 
-typedef int Depth;
+using Depth = int;
 
 enum : int {
-  DEPTH_QS_CHECKS     =  0,
-  DEPTH_QS_NO_CHECKS  = -1,
-  DEPTH_QS_RECAPTURES = -5,
+    DEPTH_QS_CHECKS    = 0,
+    DEPTH_QS_NO_CHECKS = -1,
 
-  DEPTH_NONE   = -6,
+    DEPTH_NONE = -6,
 
-  DEPTH_OFFSET = -7 // value used only for TT entry occupancy check
+    DEPTH_OFFSET = -7  // value used only for TT entry occupancy check
 };
 
+// clang-format off
 enum Square : int {
-  SQ_A1, SQ_B1, SQ_C1, SQ_D1, SQ_E1, SQ_F1, SQ_G1, SQ_H1,
-  SQ_A2, SQ_B2, SQ_C2, SQ_D2, SQ_E2, SQ_F2, SQ_G2, SQ_H2,
-  SQ_A3, SQ_B3, SQ_C3, SQ_D3, SQ_E3, SQ_F3, SQ_G3, SQ_H3,
-  SQ_A4, SQ_B4, SQ_C4, SQ_D4, SQ_E4, SQ_F4, SQ_G4, SQ_H4,
-  SQ_A5, SQ_B5, SQ_C5, SQ_D5, SQ_E5, SQ_F5, SQ_G5, SQ_H5,
-  SQ_A6, SQ_B6, SQ_C6, SQ_D6, SQ_E6, SQ_F6, SQ_G6, SQ_H6,
-  SQ_A7, SQ_B7, SQ_C7, SQ_D7, SQ_E7, SQ_F7, SQ_G7, SQ_H7,
-  SQ_A8, SQ_B8, SQ_C8, SQ_D8, SQ_E8, SQ_F8, SQ_G8, SQ_H8,
-  SQ_NONE,
+    SQ_A1, SQ_B1, SQ_C1, SQ_D1, SQ_E1, SQ_F1, SQ_G1, SQ_H1,
+    SQ_A2, SQ_B2, SQ_C2, SQ_D2, SQ_E2, SQ_F2, SQ_G2, SQ_H2,
+    SQ_A3, SQ_B3, SQ_C3, SQ_D3, SQ_E3, SQ_F3, SQ_G3, SQ_H3,
+    SQ_A4, SQ_B4, SQ_C4, SQ_D4, SQ_E4, SQ_F4, SQ_G4, SQ_H4,
+    SQ_A5, SQ_B5, SQ_C5, SQ_D5, SQ_E5, SQ_F5, SQ_G5, SQ_H5,
+    SQ_A6, SQ_B6, SQ_C6, SQ_D6, SQ_E6, SQ_F6, SQ_G6, SQ_H6,
+    SQ_A7, SQ_B7, SQ_C7, SQ_D7, SQ_E7, SQ_F7, SQ_G7, SQ_H7,
+    SQ_A8, SQ_B8, SQ_C8, SQ_D8, SQ_E8, SQ_F8, SQ_G8, SQ_H8,
+    SQ_NONE,
 
-  SQUARE_ZERO = 0,
-  SQUARE_NB   = 64
+    SQUARE_ZERO = 0,
+    SQUARE_NB   = 64
 };
+// clang-format on
 
 enum Direction : int {
-  NORTH =  8,
-  EAST  =  1,
-  SOUTH = -NORTH,
-  WEST  = -EAST,
+    NORTH = 8,
+    EAST  = 1,
+    SOUTH = -NORTH,
+    WEST  = -EAST,
 
-  NORTH_EAST = NORTH + EAST,
-  SOUTH_EAST = SOUTH + EAST,
-  SOUTH_WEST = SOUTH + WEST,
-  NORTH_WEST = NORTH + WEST
+    NORTH_EAST = NORTH + EAST,
+    SOUTH_EAST = SOUTH + EAST,
+    SOUTH_WEST = SOUTH + WEST,
+    NORTH_WEST = NORTH + WEST
 };
 
 enum File : int {
-  FILE_A, FILE_B, FILE_C, FILE_D, FILE_E, FILE_F, FILE_G, FILE_H, FILE_NB
+    FILE_A,
+    FILE_B,
+    FILE_C,
+    FILE_D,
+    FILE_E,
+    FILE_F,
+    FILE_G,
+    FILE_H,
+    FILE_NB
 };
 
 enum Rank : int {
-  RANK_1, RANK_2, RANK_3, RANK_4, RANK_5, RANK_6, RANK_7, RANK_8, RANK_NB
+    RANK_1,
+    RANK_2,
+    RANK_3,
+    RANK_4,
+    RANK_5,
+    RANK_6,
+    RANK_7,
+    RANK_8,
+    RANK_NB
 };
 
 // Keep track of what a move changes on the board (used by NNUE)
 struct DirtyPiece {
 
-  // Number of changed pieces
-  int dirty_num;
+    // Number of changed pieces
+    int dirty_num;
 
-  // Max 3 pieces can change in one move. A promotion with capture moves
-  // both the pawn and the captured piece to SQ_NONE and the piece promoted
-  // to from SQ_NONE to the capture square.
-  Piece piece[3];
+    // Max 3 pieces can change in one move. A promotion with capture moves
+    // both the pawn and the captured piece to SQ_NONE and the piece promoted
+    // to from SQ_NONE to the capture square.
+    Piece piece[3];
 
-  // From and to squares, which may be SQ_NONE
-  Square from[3];
-  Square to[3];
+    // From and to squares, which may be SQ_NONE
+    Square from[3];
+    Square to[3];
 };
 
-/// Score enum stores a middlegame and an endgame value in a single integer (enum).
-/// The least significant 16 bits are used to store the middlegame value and the
-/// upper 16 bits are used to store the endgame value. We have to take care to
-/// avoid left-shifting a signed int to avoid undefined behavior.
-enum Score : int { SCORE_ZERO };
+    #define ENABLE_INCR_OPERATORS_ON(T) \
+        inline T& operator++(T& d) { return d = T(int(d) + 1); } \
+        inline T& operator--(T& d) { return d = T(int(d) - 1); }
 
-constexpr Score make_score(int mg, int eg) {
-  return Score((int)((unsigned int)eg << 16) + mg);
-}
-
-/// Extracting the signed lower and upper 16 bits is not so trivial because
-/// according to the standard a simple cast to short is implementation defined
-/// and so is a right shift of a signed integer.
-inline Value eg_value(Score s) {
-  union { uint16_t u; int16_t s; } eg = { uint16_t(unsigned(s + 0x8000) >> 16) };
-  return Value(eg.s);
-}
-
-inline Value mg_value(Score s) {
-  union { uint16_t u; int16_t s; } mg = { uint16_t(unsigned(s)) };
-  return Value(mg.s);
-}
-
-#define ENABLE_BASE_OPERATORS_ON(T)                                \
-constexpr T operator+(T d1, int d2) { return T(int(d1) + d2); }    \
-constexpr T operator-(T d1, int d2) { return T(int(d1) - d2); }    \
-constexpr T operator-(T d) { return T(-int(d)); }                  \
-inline T& operator+=(T& d1, int d2) { return d1 = d1 + d2; }       \
-inline T& operator-=(T& d1, int d2) { return d1 = d1 - d2; }
-
-#define ENABLE_INCR_OPERATORS_ON(T)                                \
-inline T& operator++(T& d) { return d = T(int(d) + 1); }           \
-inline T& operator--(T& d) { return d = T(int(d) - 1); }
-
-#define ENABLE_FULL_OPERATORS_ON(T)                                \
-ENABLE_BASE_OPERATORS_ON(T)                                        \
-constexpr T operator*(int i, T d) { return T(i * int(d)); }        \
-constexpr T operator*(T d, int i) { return T(int(d) * i); }        \
-constexpr T operator/(T d, int i) { return T(int(d) / i); }        \
-constexpr int operator/(T d1, T d2) { return int(d1) / int(d2); }  \
-inline T& operator*=(T& d, int i) { return d = T(int(d) * i); }    \
-inline T& operator/=(T& d, int i) { return d = T(int(d) / i); }
-
-ENABLE_FULL_OPERATORS_ON(Value)
-ENABLE_FULL_OPERATORS_ON(Direction)
-
-ENABLE_INCR_OPERATORS_ON(Piece)
 ENABLE_INCR_OPERATORS_ON(PieceType)
 ENABLE_INCR_OPERATORS_ON(Square)
 ENABLE_INCR_OPERATORS_ON(File)
 ENABLE_INCR_OPERATORS_ON(Rank)
 
-ENABLE_BASE_OPERATORS_ON(Score)
+    #undef ENABLE_INCR_OPERATORS_ON
 
-#undef ENABLE_FULL_OPERATORS_ON
-#undef ENABLE_INCR_OPERATORS_ON
-#undef ENABLE_BASE_OPERATORS_ON
+constexpr Direction operator+(Direction d1, Direction d2) { return Direction(int(d1) + int(d2)); }
+constexpr Direction operator*(int i, Direction d) { return Direction(i * int(d)); }
 
-/// Additional operators to add a Direction to a Square
+// Additional operators to add a Direction to a Square
 constexpr Square operator+(Square s, Direction d) { return Square(int(s) + int(d)); }
 constexpr Square operator-(Square s, Direction d) { return Square(int(s) - int(d)); }
-inline Square& operator+=(Square& s, Direction d) { return s = s + d; }
-inline Square& operator-=(Square& s, Direction d) { return s = s - d; }
+inline Square&   operator+=(Square& s, Direction d) { return s = s + d; }
+inline Square&   operator-=(Square& s, Direction d) { return s = s - d; }
 
-/// Only declared but not defined. We don't want to multiply two scores due to
-/// a very high risk of overflow. So user should explicitly convert to integer.
-Score operator*(Score, Score) = delete;
+// Toggle color
+constexpr Color operator~(Color c) { return Color(c ^ BLACK); }
 
-/// Division of a Score must be handled separately for each term
-inline Score operator/(Score s, int i) {
-  return make_score(mg_value(s) / i, eg_value(s) / i);
-}
+// Swap A1 <-> A8
+constexpr Square flip_rank(Square s) { return Square(s ^ SQ_A8); }
 
-/// Multiplication of a Score by an integer. We check for overflow in debug mode.
-inline Score operator*(Score s, int i) {
+// Swap A1 <-> H1
+constexpr Square flip_file(Square s) { return Square(s ^ SQ_H1); }
 
-  Score result = Score(int(s) * i);
-
-  assert(eg_value(result) == (i * eg_value(s)));
-  assert(mg_value(result) == (i * mg_value(s)));
-  assert((i == 0) || (result / i) == s);
-
-  return result;
-}
-
-/// Multiplication of a Score by a boolean
-inline Score operator*(Score s, bool b) {
-  return b ? s : SCORE_ZERO;
-}
-
-constexpr Color operator~(Color c) {
-  return Color(c ^ BLACK); // Toggle color
-}
-
-constexpr Square flip_rank(Square s) { // Swap A1 <-> A8
-  return Square(s ^ SQ_A8);
-}
-
-constexpr Square flip_file(Square s) { // Swap A1 <-> H1
-  return Square(s ^ SQ_H1);
-}
-
-constexpr Piece operator~(Piece pc) {
-  return Piece(pc ^ 8); // Swap color of piece B_KNIGHT <-> W_KNIGHT
-}
+// Swap color of piece B_KNIGHT <-> W_KNIGHT
+constexpr Piece operator~(Piece pc) { return Piece(pc ^ 8); }
 
 constexpr CastlingRights operator&(Color c, CastlingRights cr) {
-  return CastlingRights((c == WHITE ? WHITE_CASTLING : BLACK_CASTLING) & cr);
+    return CastlingRights((c == WHITE ? WHITE_CASTLING : BLACK_CASTLING) & cr);
 }
 
-constexpr Value mate_in(int ply) {
-  return VALUE_MATE - ply;
-}
+constexpr Value mate_in(int ply) { return VALUE_MATE - ply; }
 
-constexpr Value mated_in(int ply) {
-  return -VALUE_MATE + ply;
-}
+constexpr Value mated_in(int ply) { return -VALUE_MATE + ply; }
 
-constexpr Square make_square(File f, Rank r) {
-  return Square((r << 3) + f);
-}
+constexpr Square make_square(File f, Rank r) { return Square((r << 3) + f); }
 
-constexpr Piece make_piece(Color c, PieceType pt) {
-  return Piece((c << 3) + pt);
-}
+constexpr Piece make_piece(Color c, PieceType pt) { return Piece((c << 3) + pt); }
 
-constexpr PieceType type_of(Piece pc) {
-  return PieceType(pc & 7);
-}
+constexpr PieceType type_of(Piece pc) { return PieceType(pc & 7); }
 
 inline Color color_of(Piece pc) {
-  assert(pc != NO_PIECE);
-  return Color(pc >> 3);
+    assert(pc != NO_PIECE);
+    return Color(pc >> 3);
 }
 
-constexpr bool is_ok(Square s) {
-  return s >= SQ_A1 && s <= SQ_H8;
-}
+constexpr bool is_ok(Square s) { return s >= SQ_A1 && s <= SQ_H8; }
 
-constexpr File file_of(Square s) {
-  return File(s & 7);
-}
+constexpr File file_of(Square s) { return File(s & 7); }
 
-constexpr Rank rank_of(Square s) {
-  return Rank(s >> 3);
-}
+constexpr Rank rank_of(Square s) { return Rank(s >> 3); }
 
-constexpr Square relative_square(Color c, Square s) {
-  return Square(s ^ (c * 56));
-}
+constexpr Square relative_square(Color c, Square s) { return Square(s ^ (c * 56)); }
 
-constexpr Rank relative_rank(Color c, Rank r) {
-  return Rank(r ^ (c * 7));
-}
+constexpr Rank relative_rank(Color c, Rank r) { return Rank(r ^ (c * 7)); }
 
-constexpr Rank relative_rank(Color c, Square s) {
-  return relative_rank(c, rank_of(s));
-}
+constexpr Rank relative_rank(Color c, Square s) { return relative_rank(c, rank_of(s)); }
 
-constexpr Direction pawn_push(Color c) {
-  return c == WHITE ? NORTH : SOUTH;
-}
+constexpr Direction pawn_push(Color c) { return c == WHITE ? NORTH : SOUTH; }
 
-constexpr Square from_sq(Move m) {
-  return Square((m >> 6) & 0x3F);
-}
 
-constexpr Square to_sq(Move m) {
-  return Square(m & 0x3F);
-}
-
-constexpr int from_to(Move m) {
- return m & 0xFFF;
-}
-
-constexpr MoveType type_of(Move m) {
-  return MoveType(m & (3 << 14));
-}
-
-constexpr PieceType promotion_type(Move m) {
-  return PieceType(((m >> 12) & 3) + KNIGHT);
-}
-
-constexpr Move make_move(Square from, Square to) {
-  return Move((from << 6) + to);
-}
-
-constexpr Move reverse_move(Move m) {
-  return make_move(to_sq(m), from_sq(m));
-}
-
-template<MoveType T>
-constexpr Move make(Square from, Square to, PieceType pt = KNIGHT) {
-  return Move(T + ((pt - KNIGHT) << 12) + (from << 6) + to);
-}
-
-constexpr bool is_ok(Move m) {
-  return from_sq(m) != to_sq(m); // Catch MOVE_NULL and MOVE_NONE
-}
-
-/// Based on a congruential pseudo random number generator
+// Based on a congruential pseudo-random number generator
 constexpr Key make_key(uint64_t seed) {
-  return seed * 6364136223846793005ULL + 1442695040888963407ULL;
+    return seed * 6364136223846793005ULL + 1442695040888963407ULL;
 }
 
-#endif // #ifndef TYPES_H_INCLUDED
 
-#include "tune.h" // Global visibility to tuning setup
+enum MoveType {
+    NORMAL,
+    PROMOTION  = 1 << 14,
+    EN_PASSANT = 2 << 14,
+    CASTLING   = 3 << 14
+};
+
+// A move needs 16 bits to be stored
+//
+// bit  0- 5: destination square (from 0 to 63)
+// bit  6-11: origin square (from 0 to 63)
+// bit 12-13: promotion piece type - 2 (from KNIGHT-2 to QUEEN-2)
+// bit 14-15: special move flag: promotion (1), en passant (2), castling (3)
+// NOTE: en passant bit is set only when a pawn can be captured
+//
+// Special cases are Move::none() and Move::null(). We can sneak these in because in
+// any normal move destination square is always different from origin square
+// while Move::none() and Move::null() have the same origin and destination square.
+class Move {
+   public:
+    Move() = default;
+    constexpr explicit Move(std::uint16_t d) :
+        data(d) {}
+
+    constexpr Move(Square from, Square to) :
+        data((from << 6) + to) {}
+
+    template<MoveType T>
+    static constexpr Move make(Square from, Square to, PieceType pt = KNIGHT) {
+        return Move(T + ((pt - KNIGHT) << 12) + (from << 6) + to);
+    }
+
+    constexpr Square from_sq() const {
+        assert(is_ok());
+        return Square((data >> 6) & 0x3F);
+    }
+
+    constexpr Square to_sq() const {
+        assert(is_ok());
+        return Square(data & 0x3F);
+    }
+
+    constexpr int from_to() const { return data & 0xFFF; }
+
+    constexpr MoveType type_of() const { return MoveType(data & (3 << 14)); }
+
+    constexpr PieceType promotion_type() const { return PieceType(((data >> 12) & 3) + KNIGHT); }
+
+    constexpr bool is_ok() const { return none().data != data && null().data != data; }
+
+    static constexpr Move null() { return Move(65); }
+    static constexpr Move none() { return Move(0); }
+
+    constexpr bool operator==(const Move& m) const { return data == m.data; }
+    constexpr bool operator!=(const Move& m) const { return data != m.data; }
+
+    constexpr explicit operator bool() const { return data != 0; }
+
+    constexpr std::uint16_t raw() const { return data; }
+
+    struct MoveHash {
+        std::size_t operator()(const Move& m) const { return make_key(m.data); }
+    };
+
+   protected:
+    std::uint16_t data;
+};
+
+}  // namespace Stockfish
+
+#endif  // #ifndef TYPES_H_INCLUDED
+
+#include "tune.h"  // Global visibility to tuning setup

src/uci.cpp

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -16,48 +16,321 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <cassert>
-#include <cmath>
-#include <iostream>
-#include <sstream>
-#include <string>
+#include "uci.h"
 
+#include <algorithm>
+#include <cassert>
+#include <cctype>
+#include <cmath>
+#include <cstdint>
+#include <cstdlib>
+#include <deque>
+#include <memory>
+#include <optional>
+#include <sstream>
+#include <utility>
+#include <vector>
+
+#include "benchmark.h"
+#include "cluster.h"
 #include "evaluate.h"
 #include "movegen.h"
+#include "nnue/network.h"
+#include "nnue/nnue_common.h"
+#include "perft.h"
 #include "position.h"
 #include "search.h"
-#include "thread.h"
-#include "timeman.h"
-#include "tt.h"
-#include "uci.h"
 #include "syzygy/tbprobe.h"
+#include "types.h"
+#include "ucioption.h"
 
-using namespace std;
+namespace Stockfish {
 
-extern vector<string> setup_bench(const Position&, istream&);
-
-namespace {
-
-  // FEN string of the initial position, normal chess
-  const char* StartFEN = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
+constexpr auto StartFEN  = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
+constexpr int  MaxHashMB = Is64Bit ? 33554432 : 2048;
 
 
-  // position() is called when engine receives the "position" UCI command.
-  // The function sets up the position described in the given FEN string ("fen")
-  // or the starting position ("startpos") and then makes the moves given in the
-  // following move list ("moves").
+namespace NN = Eval::NNUE;
 
-  void position(Position& pos, istringstream& is, StateListPtr& states) {
 
-    Move m;
-    string token, fen;
+UCI::UCI(int argc, char** argv) :
+    networks(NN::Networks(
+      NN::NetworkBig({EvalFileDefaultNameBig, "None", ""}, NN::EmbeddedNNUEType::BIG),
+      NN::NetworkSmall({EvalFileDefaultNameSmall, "None", ""}, NN::EmbeddedNNUEType::SMALL))),
+    cli(argc, argv) {
+
+    options["Debug Log File"] << Option("", [](const Option& o) { start_logger(o); });
+
+    options["Threads"] << Option(1, 1, 1024, [this](const Option&) {
+        threads.set({options, threads, tt, networks});
+    });
+
+    options["Hash"] << Option(16, 1, MaxHashMB, [this](const Option& o) {
+        threads.main_thread()->wait_for_search_finished();
+        tt.resize(o, options["Threads"]);
+    });
+
+    options["Clear Hash"] << Option([this](const Option&) { search_clear(); });
+    options["Ponder"] << Option(false);
+    options["MultiPV"] << Option(1, 1, MAX_MOVES);
+    options["Skill Level"] << Option(20, 0, 20);
+    options["Move Overhead"] << Option(10, 0, 5000);
+    options["nodestime"] << Option(0, 0, 10000);
+    options["UCI_Chess960"] << Option(false);
+    options["UCI_LimitStrength"] << Option(false);
+    options["UCI_Elo"] << Option(1320, 1320, 3190);
+    options["UCI_ShowWDL"] << Option(false);
+    options["SyzygyPath"] << Option("<empty>", [](const Option& o) { Tablebases::init(o); });
+    options["SyzygyProbeDepth"] << Option(1, 1, 100);
+    options["Syzygy50MoveRule"] << Option(true);
+    options["SyzygyProbeLimit"] << Option(7, 0, 7);
+    options["EvalFile"] << Option(EvalFileDefaultNameBig, [this](const Option& o) {
+        networks.big.load(cli.binaryDirectory, o);
+    });
+    options["EvalFileSmall"] << Option(EvalFileDefaultNameSmall, [this](const Option& o) {
+        networks.small.load(cli.binaryDirectory, o);
+    });
+
+    networks.big.load(cli.binaryDirectory, options["EvalFile"]);
+    networks.small.load(cli.binaryDirectory, options["EvalFileSmall"]);
+
+    threads.set({options, threads, tt, networks});
+
+    search_clear();  // After threads are up
+}
+
+void UCI::loop() {
+
+    Position     pos;
+    std::string  token, cmd;
+    StateListPtr states(new std::deque<StateInfo>(1));
+
+    pos.set(StartFEN, false, &states->back());
+
+    for (int i = 1; i < cli.argc; ++i)
+        cmd += std::string(cli.argv[i]) + " ";
+
+    do
+    {
+        if (cli.argc == 1
+            && !Cluster::getline(std::cin,
+                                 cmd))  // Wait for an input or an end-of-file (EOF) indication
+            cmd = "quit";
+
+        std::istringstream is(cmd);
+
+        token.clear();  // Avoid a stale if getline() returns nothing or a blank line
+        is >> std::skipws >> token;
+
+        if (token == "quit" || token == "stop")
+            threads.stop = true;
+
+        // The GUI sends 'ponderhit' to tell that the user has played the expected move.
+        // So, 'ponderhit' is sent if pondering was done on the same move that the user
+        // has played. The search should continue, but should also switch from pondering
+        // to the normal search.
+        else if (token == "ponderhit")
+            threads.main_manager()->ponder = false;  // Switch to the normal search
+
+        else if (token == "uci" && Cluster::is_root())
+            sync_cout << "id name " << engine_info(true) << "\n"
+                      << options << "\nuciok" << sync_endl;
+
+        else if (token == "setoption")
+            setoption(is);
+        else if (token == "go")
+            go(pos, is, states);
+        else if (token == "position")
+            position(pos, is, states);
+        else if (token == "ucinewgame")
+            search_clear();
+        else if (token == "isready" && Cluster::is_root())
+            sync_cout << "readyok" << sync_endl;
+
+        // Add custom non-UCI commands, mainly for debugging purposes.
+        // These commands must not be used during a search!
+        else if (token == "flip")
+            pos.flip();
+        else if (token == "bench")
+            bench(pos, is, states);
+        else if (token == "d" && Cluster::is_root())
+            sync_cout << pos << sync_endl;
+        else if (token == "eval" && Cluster::is_root())
+            trace_eval(pos);
+        else if (token == "compiler" && Cluster::is_root())
+            sync_cout << compiler_info() << sync_endl;
+        else if (token == "export_net" && Cluster::is_root())
+        {
+            std::pair<std::optional<std::string>, std::string> files[2];
+
+            if (is >> std::skipws >> files[0].second)
+                files[0].first = files[0].second;
+
+            if (is >> std::skipws >> files[1].second)
+                files[1].first = files[1].second;
+
+            networks.big.save(files[0].first);
+            networks.small.save(files[1].first);
+        }
+        else if ((token == "--help" || token == "help" || token == "--license"
+                  || token == "license")
+                 && Cluster::is_root())
+            sync_cout
+              << "\nStockfish is a powerful chess engine for playing and analyzing."
+                 "\nIt is released as free software licensed under the GNU GPLv3 License."
+                 "\nStockfish is normally used with a graphical user interface (GUI) and implements"
+                 "\nthe Universal Chess Interface (UCI) protocol to communicate with a GUI, an API, etc."
+                 "\nFor any further information, visit https://github.com/official-stockfish/Stockfish#readme"
+                 "\nor read the corresponding README.md and Copying.txt files distributed along with this program.\n"
+              << sync_endl;
+        else if (!token.empty() && token[0] != '#' && Cluster::is_root())
+            sync_cout << "Unknown command: '" << cmd << "'. Type help for more information."
+                      << sync_endl;
+
+    } while (token != "quit" && cli.argc == 1);  // The command-line arguments are one-shot
+}
+
+Search::LimitsType UCI::parse_limits(const Position& pos, std::istream& is) {
+    Search::LimitsType limits;
+    std::string        token;
+
+    limits.startTime = now();  // The search starts as early as possible
+
+    while (is >> token)
+        if (token == "searchmoves")  // Needs to be the last command on the line
+            while (is >> token)
+                limits.searchmoves.push_back(to_move(pos, token));
+
+        else if (token == "wtime")
+            is >> limits.time[WHITE];
+        else if (token == "btime")
+            is >> limits.time[BLACK];
+        else if (token == "winc")
+            is >> limits.inc[WHITE];
+        else if (token == "binc")
+            is >> limits.inc[BLACK];
+        else if (token == "movestogo")
+            is >> limits.movestogo;
+        else if (token == "depth")
+            is >> limits.depth;
+        else if (token == "nodes")
+            is >> limits.nodes;
+        else if (token == "movetime")
+            is >> limits.movetime;
+        else if (token == "mate")
+            is >> limits.mate;
+        else if (token == "perft")
+            is >> limits.perft;
+        else if (token == "infinite")
+            limits.infinite = 1;
+        else if (token == "ponder")
+            limits.ponderMode = true;
+
+    return limits;
+}
+
+void UCI::go(Position& pos, std::istringstream& is, StateListPtr& states) {
+
+    Search::LimitsType limits = parse_limits(pos, is);
+
+    networks.big.verify(options["EvalFile"]);
+    networks.small.verify(options["EvalFileSmall"]);
+
+    if (limits.perft)
+    {
+        perft(pos.fen(), limits.perft, options["UCI_Chess960"]);
+        return;
+    }
+
+    threads.start_thinking(options, pos, states, limits);
+}
+
+void UCI::bench(Position& pos, std::istream& args, StateListPtr& states) {
+    std::string token;
+    uint64_t    num, nodes = 0, cnt = 1;
+
+    std::vector<std::string> list = setup_bench(pos, args);
+
+    num = count_if(list.begin(), list.end(),
+                   [](const std::string& s) { return s.find("go ") == 0 || s.find("eval") == 0; });
+
+    TimePoint elapsed = now();
+
+    for (const auto& cmd : list)
+    {
+        std::istringstream is(cmd);
+        is >> std::skipws >> token;
+
+        if (token == "go" || token == "eval")
+        {
+            if (Cluster::is_root())
+                std::cerr << "\nPosition: " << cnt++ << '/' << num << " (" << pos.fen() << ")"
+                          << std::endl;
+            if (token == "go")
+            {
+                go(pos, is, states);
+                threads.main_thread()->wait_for_search_finished();
+                nodes += Cluster::nodes_searched(threads);
+            }
+            else if (Cluster::is_root())
+                trace_eval(pos);
+        }
+        else if (token == "setoption")
+            setoption(is);
+        else if (token == "position")
+            position(pos, is, states);
+        else if (token == "ucinewgame")
+        {
+            search_clear();  // Search::clear() may take a while
+            elapsed = now();
+        }
+    }
+
+    elapsed = now() - elapsed + 1;  // Ensure positivity to avoid a 'divide by zero'
+
+    dbg_print();
+
+    if (Cluster::is_root())
+        std::cerr << "\n==========================="
+                  << "\nTotal time (ms) : " << elapsed << "\nNodes searched  : " << nodes
+                  << "\nNodes/second    : " << 1000 * nodes / elapsed << std::endl;
+}
+
+void UCI::trace_eval(Position& pos) {
+    StateListPtr states(new std::deque<StateInfo>(1));
+    Position     p;
+    p.set(pos.fen(), options["UCI_Chess960"], &states->back());
+
+    networks.big.verify(options["EvalFile"]);
+    networks.small.verify(options["EvalFileSmall"]);
+
+
+    sync_cout << "\n" << Eval::trace(p, networks) << sync_endl;
+}
+
+void UCI::search_clear() {
+    threads.main_thread()->wait_for_search_finished();
+
+    tt.clear(options["Threads"]);
+    threads.clear();
+    Tablebases::init(options["SyzygyPath"]);  // Free mapped files
+}
+
+void UCI::setoption(std::istringstream& is) {
+    threads.main_thread()->wait_for_search_finished();
+    options.setoption(is);
+}
+
+void UCI::position(Position& pos, std::istringstream& is, StateListPtr& states) {
+    Move        m;
+    std::string token, fen;
 
     is >> token;
 
     if (token == "startpos")
     {
         fen = StartFEN;
-        is >> token; // Consume "moves" token if any
+        is >> token;  // Consume the "moves" token, if any
     }
     else if (token == "fen")
         while (is >> token && token != "moves")
@@ -65,307 +338,130 @@ namespace {
     else
         return;
 
-    states = StateListPtr(new std::deque<StateInfo>(1)); // Drop old and create a new one
-    pos.set(fen, Options["UCI_Chess960"], &states->back(), Threads.main());
+    states = StateListPtr(new std::deque<StateInfo>(1));  // Drop the old state and create a new one
+    pos.set(fen, options["UCI_Chess960"], &states->back());
 
-    // Parse move list (if any)
-    while (is >> token && (m = UCI::to_move(pos, token)) != MOVE_NONE)
+    // Parse the move list, if any
+    while (is >> token && (m = to_move(pos, token)) != Move::none())
     {
         states->emplace_back();
         pos.do_move(m, states->back());
     }
-  }
+}
 
-  // trace_eval() prints the evaluation for the current position, consistent with the UCI
-  // options set so far.
+namespace {
 
-  void trace_eval(Position& pos) {
+struct WinRateParams {
+    double a;
+    double b;
+};
 
-    StateListPtr states(new std::deque<StateInfo>(1));
-    Position p;
-    p.set(pos.fen(), Options["UCI_Chess960"], &states->back(), Threads.main());
+WinRateParams win_rate_params(const Position& pos) {
 
-    Eval::NNUE::verify();
+    int material = pos.count<PAWN>() + 3 * pos.count<KNIGHT>() + 3 * pos.count<BISHOP>()
+                 + 5 * pos.count<ROOK>() + 9 * pos.count<QUEEN>();
 
-    sync_cout << "\n" << Eval::trace(p) << sync_endl;
-  }
+    // The fitted model only uses data for material counts in [10, 78], and is anchored at count 58.
+    double m = std::clamp(material, 10, 78) / 58.0;
 
+    // Return a = p_a(material) and b = p_b(material), see github.com/official-stockfish/WDL_model
+    constexpr double as[] = {-185.71965483, 504.85014385, -438.58295743, 474.04604627};
+    constexpr double bs[] = {89.23542728, -137.02141296, 73.28669021, 47.53376190};
 
-  // setoption() is called when engine receives the "setoption" UCI command. The
-  // function updates the UCI option ("name") to the given value ("value").
+    double a = (((as[0] * m + as[1]) * m + as[2]) * m) + as[3];
+    double b = (((bs[0] * m + bs[1]) * m + bs[2]) * m) + bs[3];
 
-  void setoption(istringstream& is) {
+    return {a, b};
+}
 
-    string token, name, value;
+// The win rate model is 1 / (1 + exp((a - eval) / b)), where a = p_a(material) and b = p_b(material).
+// It fits the LTC fishtest statistics rather accurately.
+int win_rate_model(Value v, const Position& pos) {
 
-    is >> token; // Consume "name" token
+    auto [a, b] = win_rate_params(pos);
 
-    // Read option name (can contain spaces)
-    while (is >> token && token != "value")
-        name += (name.empty() ? "" : " ") + token;
+    // Return the win rate in per mille units, rounded to the nearest integer.
+    return int(0.5 + 1000 / (1 + std::exp((a - double(v)) / b)));
+}
+}
 
-    // Read option value (can contain spaces)
-    while (is >> token)
-        value += (value.empty() ? "" : " ") + token;
+std::string UCI::to_score(Value v, const Position& pos) {
+    assert(-VALUE_INFINITE < v && v < VALUE_INFINITE);
 
-    if (Options.count(name))
-        Options[name] = value;
-    else
-        sync_cout << "No such option: " << name << sync_endl;
-  }
+    std::stringstream ss;
 
-
-  // go() is called when engine receives the "go" UCI command. The function sets
-  // the thinking time and other parameters from the input string, then starts
-  // the search.
-
-  void go(Position& pos, istringstream& is, StateListPtr& states) {
-
-    Search::LimitsType limits;
-    string token;
-    bool ponderMode = false;
-
-    limits.startTime = now(); // As early as possible!
-
-    while (is >> token)
-        if (token == "searchmoves") // Needs to be the last command on the line
-            while (is >> token)
-                limits.searchmoves.push_back(UCI::to_move(pos, token));
-
-        else if (token == "wtime")     is >> limits.time[WHITE];
-        else if (token == "btime")     is >> limits.time[BLACK];
-        else if (token == "winc")      is >> limits.inc[WHITE];
-        else if (token == "binc")      is >> limits.inc[BLACK];
-        else if (token == "movestogo") is >> limits.movestogo;
-        else if (token == "depth")     is >> limits.depth;
-        else if (token == "nodes")     is >> limits.nodes;
-        else if (token == "movetime")  is >> limits.movetime;
-        else if (token == "mate")      is >> limits.mate;
-        else if (token == "perft")     is >> limits.perft;
-        else if (token == "infinite")  limits.infinite = 1;
-        else if (token == "ponder")    ponderMode = true;
-
-    Threads.start_thinking(pos, states, limits, ponderMode);
-  }
-
-
-  // bench() is called when engine receives the "bench" command. Firstly
-  // a list of UCI commands is setup according to bench parameters, then
-  // it is run one by one printing a summary at the end.
-
-  void bench(Position& pos, istream& args, StateListPtr& states) {
-
-    string token;
-    uint64_t num, nodes = 0, cnt = 1;
-
-    vector<string> list = setup_bench(pos, args);
-    num = count_if(list.begin(), list.end(), [](string s) { return s.find("go ") == 0 || s.find("eval") == 0; });
-
-    TimePoint elapsed = now();
-
-    for (const auto& cmd : list)
+    if (std::abs(v) < VALUE_TB_WIN_IN_MAX_PLY)
+        ss << "cp " << to_cp(v, pos);
+    else if (std::abs(v) <= VALUE_TB)
     {
-        istringstream is(cmd);
-        is >> skipws >> token;
-
-        if (token == "go" || token == "eval")
-        {
-            cerr << "\nPosition: " << cnt++ << '/' << num << " (" << pos.fen() << ")" << endl;
-            if (token == "go")
-            {
-               go(pos, is, states);
-               Threads.main()->wait_for_search_finished();
-               nodes += Threads.nodes_searched();
-            }
-            else
-               trace_eval(pos);
-        }
-        else if (token == "setoption")  setoption(is);
-        else if (token == "position")   position(pos, is, states);
-        else if (token == "ucinewgame") { Search::clear(); elapsed = now(); } // Search::clear() may take some while
+        const int ply = VALUE_TB - std::abs(v);  // recompute ss->ply
+        ss << "cp " << (v > 0 ? 20000 - ply : -20000 + ply);
     }
+    else
+        ss << "mate " << (v > 0 ? VALUE_MATE - v + 1 : -VALUE_MATE - v) / 2;
 
-    elapsed = now() - elapsed + 1; // Ensure positivity to avoid a 'divide by zero'
-
-    dbg_print(); // Just before exiting
-
-    cerr << "\n==========================="
-         << "\nTotal time (ms) : " << elapsed
-         << "\nNodes searched  : " << nodes
-         << "\nNodes/second    : " << 1000 * nodes / elapsed << endl;
-  }
-
-  // The win rate model returns the probability (per mille) of winning given an eval
-  // and a game-ply. The model fits rather accurately the LTC fishtest statistics.
-  int win_rate_model(Value v, int ply) {
-
-     // The model captures only up to 240 plies, so limit input (and rescale)
-     double m = std::min(240, ply) / 64.0;
-
-     // Coefficients of a 3rd order polynomial fit based on fishtest data
-     // for two parameters needed to transform eval to the argument of a
-     // logistic function.
-     double as[] = {-8.24404295, 64.23892342, -95.73056462, 153.86478679};
-     double bs[] = {-3.37154371, 28.44489198, -56.67657741,  72.05858751};
-     double a = (((as[0] * m + as[1]) * m + as[2]) * m) + as[3];
-     double b = (((bs[0] * m + bs[1]) * m + bs[2]) * m) + bs[3];
-
-     // Transform eval to centipawns with limited range
-     double x = std::clamp(double(100 * v) / PawnValueEg, -1000.0, 1000.0);
-
-     // Return win rate in per mille (rounded to nearest)
-     return int(0.5 + 1000 / (1 + std::exp((a - x) / b)));
-  }
-
-} // namespace
-
-
-/// UCI::loop() waits for a command from stdin, parses it and calls the appropriate
-/// function. Also intercepts EOF from stdin to ensure gracefully exiting if the
-/// GUI dies unexpectedly. When called with some command line arguments, e.g. to
-/// run 'bench', once the command is executed the function returns immediately.
-/// In addition to the UCI ones, also some additional debug commands are supported.
-
-void UCI::loop(int argc, char* argv[]) {
-
-  Position pos;
-  string token, cmd;
-  StateListPtr states(new std::deque<StateInfo>(1));
-
-  pos.set(StartFEN, false, &states->back(), Threads.main());
-
-  for (int i = 1; i < argc; ++i)
-      cmd += std::string(argv[i]) + " ";
-
-  do {
-      if (argc == 1 && !getline(cin, cmd)) // Block here waiting for input or EOF
-          cmd = "quit";
-
-      istringstream is(cmd);
-
-      token.clear(); // Avoid a stale if getline() returns empty or blank line
-      is >> skipws >> token;
-
-      if (    token == "quit"
-          ||  token == "stop")
-          Threads.stop = true;
-
-      // The GUI sends 'ponderhit' to tell us the user has played the expected move.
-      // So 'ponderhit' will be sent if we were told to ponder on the same move the
-      // user has played. We should continue searching but switch from pondering to
-      // normal search.
-      else if (token == "ponderhit")
-          Threads.main()->ponder = false; // Switch to normal search
-
-      else if (token == "uci")
-          sync_cout << "id name " << engine_info(true)
-                    << "\n"       << Options
-                    << "\nuciok"  << sync_endl;
-
-      else if (token == "setoption")  setoption(is);
-      else if (token == "go")         go(pos, is, states);
-      else if (token == "position")   position(pos, is, states);
-      else if (token == "ucinewgame") Search::clear();
-      else if (token == "isready")    sync_cout << "readyok" << sync_endl;
-
-      // Additional custom non-UCI commands, mainly for debugging.
-      // Do not use these commands during a search!
-      else if (token == "flip")     pos.flip();
-      else if (token == "bench")    bench(pos, is, states);
-      else if (token == "d")        sync_cout << pos << sync_endl;
-      else if (token == "eval")     trace_eval(pos);
-      else if (token == "compiler") sync_cout << compiler_info() << sync_endl;
-      else
-          sync_cout << "Unknown command: " << cmd << sync_endl;
-
-  } while (token != "quit" && argc == 1); // Command line args are one-shot
+    return ss.str();
 }
 
+// Turns a Value to an integer centipawn number,
+// without treatment of mate and similar special scores.
+int UCI::to_cp(Value v, const Position& pos) {
 
-/// UCI::value() converts a Value to a string suitable for use with the UCI
-/// protocol specification:
-///
-/// cp <x>    The score from the engine's point of view in centipawns.
-/// mate <y>  Mate in y moves, not plies. If the engine is getting mated
-///           use negative values for y.
+    // In general, the score can be defined via the the WDL as
+    // (log(1/L - 1) - log(1/W - 1)) / ((log(1/L - 1) + log(1/W - 1))
+    // Based on our win_rate_model, this simply yields v / a.
 
-string UCI::value(Value v) {
+    auto [a, b] = win_rate_params(pos);
 
-  assert(-VALUE_INFINITE < v && v < VALUE_INFINITE);
-
-  stringstream ss;
-
-  if (abs(v) < VALUE_MATE_IN_MAX_PLY)
-      ss << "cp " << v * 100 / PawnValueEg;
-  else
-      ss << "mate " << (v > 0 ? VALUE_MATE - v + 1 : -VALUE_MATE - v) / 2;
-
-  return ss.str();
+    return std::round(100 * int(v) / a);
 }
 
+std::string UCI::wdl(Value v, const Position& pos) {
+    std::stringstream ss;
 
-/// UCI::wdl() report WDL statistics given an evaluation and a game ply, based on
-/// data gathered for fishtest LTC games.
+    int wdl_w = win_rate_model(v, pos);
+    int wdl_l = win_rate_model(-v, pos);
+    int wdl_d = 1000 - wdl_w - wdl_l;
+    ss << " wdl " << wdl_w << " " << wdl_d << " " << wdl_l;
 
-string UCI::wdl(Value v, int ply) {
-
-  stringstream ss;
-
-  int wdl_w = win_rate_model( v, ply);
-  int wdl_l = win_rate_model(-v, ply);
-  int wdl_d = 1000 - wdl_w - wdl_l;
-  ss << " wdl " << wdl_w << " " << wdl_d << " " << wdl_l;
-
-  return ss.str();
+    return ss.str();
 }
 
-
-/// UCI::square() converts a Square to a string in algebraic notation (g1, a7, etc.)
-
 std::string UCI::square(Square s) {
-  return std::string{ char('a' + file_of(s)), char('1' + rank_of(s)) };
+    return std::string{char('a' + file_of(s)), char('1' + rank_of(s))};
+}
+
+std::string UCI::move(Move m, bool chess960) {
+    if (m == Move::none())
+        return "(none)";
+
+    if (m == Move::null())
+        return "0000";
+
+    Square from = m.from_sq();
+    Square to   = m.to_sq();
+
+    if (m.type_of() == CASTLING && !chess960)
+        to = make_square(to > from ? FILE_G : FILE_C, rank_of(from));
+
+    std::string move = square(from) + square(to);
+
+    if (m.type_of() == PROMOTION)
+        move += " pnbrqk"[m.promotion_type()];
+
+    return move;
 }
 
 
-/// UCI::move() converts a Move to a string in coordinate notation (g1f3, a7a8q).
-/// The only special case is castling, where we print in the e1g1 notation in
-/// normal chess mode, and in e1h1 notation in chess960 mode. Internally all
-/// castling moves are always encoded as 'king captures rook'.
+Move UCI::to_move(const Position& pos, std::string& str) {
+    if (str.length() == 5)
+        str[4] = char(tolower(str[4]));  // The promotion piece character must be lowercased
 
-string UCI::move(Move m, bool chess960) {
+    for (const auto& m : MoveList<LEGAL>(pos))
+        if (str == move(m, pos.is_chess960()))
+            return m;
 
-  Square from = from_sq(m);
-  Square to = to_sq(m);
-
-  if (m == MOVE_NONE)
-      return "(none)";
-
-  if (m == MOVE_NULL)
-      return "0000";
-
-  if (type_of(m) == CASTLING && !chess960)
-      to = make_square(to > from ? FILE_G : FILE_C, rank_of(from));
-
-  string move = UCI::square(from) + UCI::square(to);
-
-  if (type_of(m) == PROMOTION)
-      move += " pnbrqk"[promotion_type(m)];
-
-  return move;
+    return Move::none();
 }
 
-
-/// UCI::to_move() converts a string representing a move in coordinate notation
-/// (g1f3, a7a8q) to the corresponding legal Move, if any.
-
-Move UCI::to_move(const Position& pos, string& str) {
-
-  if (str.length() == 5) // Junior could send promotion piece in uppercase
-      str[4] = char(tolower(str[4]));
-
-  for (const auto& m : MoveList<LEGAL>(pos))
-      if (str == UCI::move(m, pos.is_chess960()))
-          return m;
-
-  return MOVE_NONE;
-}
+}  // namespace Stockfish

src/uci.h

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -19,63 +19,56 @@
 #ifndef UCI_H_INCLUDED
 #define UCI_H_INCLUDED
 
-#include <map>
+#include <iostream>
 #include <string>
 
-#include "types.h"
+#include "misc.h"
+#include "nnue/network.h"
+#include "position.h"
+#include "search.h"
+#include "thread.h"
+#include "tt.h"
+#include "ucioption.h"
 
-class Position;
+namespace Stockfish {
 
-namespace UCI {
+class Move;
+enum Square : int;
+using Value = int;
 
-class Option;
+class UCI {
+   public:
+    UCI(int argc, char** argv);
 
-/// Custom comparator because UCI options should be case insensitive
-struct CaseInsensitiveLess {
-  bool operator() (const std::string&, const std::string&) const;
+    void loop();
+
+    static int         to_cp(Value v, const Position& pos);
+    static std::string to_score(Value v, const Position& pos);
+    static std::string square(Square s);
+    static std::string move(Move m, bool chess960);
+    static std::string wdl(Value v, const Position& pos);
+    static Move        to_move(const Position& pos, std::string& str);
+
+    static Search::LimitsType parse_limits(const Position& pos, std::istream& is);
+
+    const std::string& working_directory() const { return cli.workingDirectory; }
+
+    OptionsMap           options;
+    Eval::NNUE::Networks networks;
+
+   private:
+    TranspositionTable tt;
+    ThreadPool         threads;
+    CommandLine        cli;
+
+    void go(Position& pos, std::istringstream& is, StateListPtr& states);
+    void bench(Position& pos, std::istream& args, StateListPtr& states);
+    void position(Position& pos, std::istringstream& is, StateListPtr& states);
+    void trace_eval(Position& pos);
+    void search_clear();
+    void setoption(std::istringstream& is);
 };
 
-/// Our options container is actually a std::map
-typedef std::map<std::string, Option, CaseInsensitiveLess> OptionsMap;
+}  // namespace Stockfish
 
-/// Option class implements an option as defined by UCI protocol
-class Option {
-
-  typedef void (*OnChange)(const Option&);
-
-public:
-  Option(OnChange = nullptr);
-  Option(bool v, OnChange = nullptr);
-  Option(const char* v, OnChange = nullptr);
-  Option(double v, int minv, int maxv, OnChange = nullptr);
-  Option(const char* v, const char* cur, OnChange = nullptr);
-
-  Option& operator=(const std::string&);
-  void operator<<(const Option&);
-  operator double() const;
-  operator std::string() const;
-  bool operator==(const char*) const;
-
-private:
-  friend std::ostream& operator<<(std::ostream&, const OptionsMap&);
-
-  std::string defaultValue, currentValue, type;
-  int min, max;
-  size_t idx;
-  OnChange on_change;
-};
-
-void init(OptionsMap&);
-void loop(int argc, char* argv[]);
-std::string value(Value v);
-std::string square(Square s);
-std::string move(Move m, bool chess960);
-std::string pv(const Position& pos, Depth depth, Value alpha, Value beta);
-std::string wdl(Value v, int ply);
-Move to_move(const Position& pos, std::string& str);
-
-} // namespace UCI
-
-extern UCI::OptionsMap Options;
-
-#endif // #ifndef UCI_H_INCLUDED
+#endif  // #ifndef UCI_H_INCLUDED

src/ucioption.cpp

@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -16,177 +16,171 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include "ucioption.h"
+
 #include <algorithm>
 #include <cassert>
-#include <ostream>
+#include <cctype>
+#include <iostream>
 #include <sstream>
+#include <utility>
 
-#include "evaluate.h"
+#include "cluster.h"
 #include "misc.h"
-#include "search.h"
-#include "thread.h"
-#include "tt.h"
-#include "uci.h"
-#include "syzygy/tbprobe.h"
 
-using std::string;
+namespace Stockfish {
 
-UCI::OptionsMap Options; // Global object
+bool CaseInsensitiveLess::operator()(const std::string& s1, const std::string& s2) const {
 
-namespace UCI {
-
-/// 'On change' actions, triggered by an option's value change
-void on_clear_hash(const Option&) { Search::clear(); }
-void on_hash_size(const Option& o) { TT.resize(size_t(o)); }
-void on_logger(const Option& o) { start_logger(o); }
-void on_threads(const Option& o) { Threads.set(size_t(o)); }
-void on_tb_path(const Option& o) { Tablebases::init(o); }
-void on_use_NNUE(const Option& ) { Eval::NNUE::init(); }
-void on_eval_file(const Option& ) { Eval::NNUE::init(); }
-
-/// Our case insensitive less() function as required by UCI protocol
-bool CaseInsensitiveLess::operator() (const string& s1, const string& s2) const {
-
-  return std::lexicographical_compare(s1.begin(), s1.end(), s2.begin(), s2.end(),
-         [](char c1, char c2) { return tolower(c1) < tolower(c2); });
+    return std::lexicographical_compare(
+      s1.begin(), s1.end(), s2.begin(), s2.end(),
+      [](char c1, char c2) { return std::tolower(c1) < std::tolower(c2); });
 }
 
+void OptionsMap::setoption(std::istringstream& is) {
+    std::string token, name, value;
 
-/// UCI::init() initializes the UCI options to their hard-coded default values
+    is >> token;  // Consume the "name" token
 
-void init(OptionsMap& o) {
+    // Read the option name (can contain spaces)
+    while (is >> token && token != "value")
+        name += (name.empty() ? "" : " ") + token;
 
-  constexpr int MaxHashMB = Is64Bit ? 33554432 : 2048;
+    // Read the option value (can contain spaces)
+    while (is >> token)
+        value += (value.empty() ? "" : " ") + token;
 
-  o["Debug Log File"]        << Option("", on_logger);
-  o["Contempt"]              << Option(24, -100, 100);
-  o["Analysis Contempt"]     << Option("Both var Off var White var Black var Both", "Both");
-  o["Threads"]               << Option(1, 1, 512, on_threads);
-  o["Hash"]                  << Option(16, 1, MaxHashMB, on_hash_size);
-  o["Clear Hash"]            << Option(on_clear_hash);
-  o["Ponder"]                << Option(false);
-  o["MultiPV"]               << Option(1, 1, 500);
-  o["Skill Level"]           << Option(20, 0, 20);
-  o["Move Overhead"]         << Option(10, 0, 5000);
-  o["Slow Mover"]            << Option(100, 10, 1000);
-  o["nodestime"]             << Option(0, 0, 10000);
-  o["UCI_Chess960"]          << Option(false);
-  o["UCI_AnalyseMode"]       << Option(false);
-  o["UCI_LimitStrength"]     << Option(false);
-  o["UCI_Elo"]               << Option(1350, 1350, 2850);
-  o["UCI_ShowWDL"]           << Option(false);
-  o["SyzygyPath"]            << Option("<empty>", on_tb_path);
-  o["SyzygyProbeDepth"]      << Option(1, 1, 100);
-  o["Syzygy50MoveRule"]      << Option(true);
-  o["SyzygyProbeLimit"]      << Option(7, 0, 7);
-  o["Use NNUE"]              << Option(true, on_use_NNUE);
-  o["EvalFile"]              << Option(EvalFileDefaultName, on_eval_file);
+    if (options_map.count(name))
+        options_map[name] = value;
+    else if (Cluster::is_root())
+        sync_cout << "No such option: " << name << sync_endl;
 }
 
-
-/// operator<<() is used to print all the options default values in chronological
-/// insertion order (the idx field) and in the format defined by the UCI protocol.
-
-std::ostream& operator<<(std::ostream& os, const OptionsMap& om) {
-
-  for (size_t idx = 0; idx < om.size(); ++idx)
-      for (const auto& it : om)
-          if (it.second.idx == idx)
-          {
-              const Option& o = it.second;
-              os << "\noption name " << it.first << " type " << o.type;
-
-              if (o.type == "string" || o.type == "check" || o.type == "combo")
-                  os << " default " << o.defaultValue;
-
-              if (o.type == "spin")
-                  os << " default " << int(stof(o.defaultValue))
-                     << " min "     << o.min
-                     << " max "     << o.max;
-
-              break;
-          }
-
-  return os;
+Option OptionsMap::operator[](const std::string& name) const {
+    auto it = options_map.find(name);
+    return it != options_map.end() ? it->second : Option();
 }
 
+Option& OptionsMap::operator[](const std::string& name) { return options_map[name]; }
 
-/// Option class constructors and conversion operators
+std::size_t OptionsMap::count(const std::string& name) const { return options_map.count(name); }
 
-Option::Option(const char* v, OnChange f) : type("string"), min(0), max(0), on_change(f)
-{ defaultValue = currentValue = v; }
+Option::Option(const char* v, OnChange f) :
+    type("string"),
+    min(0),
+    max(0),
+    on_change(std::move(f)) {
+    defaultValue = currentValue = v;
+}
 
-Option::Option(bool v, OnChange f) : type("check"), min(0), max(0), on_change(f)
-{ defaultValue = currentValue = (v ? "true" : "false"); }
+Option::Option(bool v, OnChange f) :
+    type("check"),
+    min(0),
+    max(0),
+    on_change(std::move(f)) {
+    defaultValue = currentValue = (v ? "true" : "false");
+}
 
-Option::Option(OnChange f) : type("button"), min(0), max(0), on_change(f)
-{}
+Option::Option(OnChange f) :
+    type("button"),
+    min(0),
+    max(0),
+    on_change(std::move(f)) {}
 
-Option::Option(double v, int minv, int maxv, OnChange f) : type("spin"), min(minv), max(maxv), on_change(f)
-{ defaultValue = currentValue = std::to_string(v); }
+Option::Option(double v, int minv, int maxv, OnChange f) :
+    type("spin"),
+    min(minv),
+    max(maxv),
+    on_change(std::move(f)) {
+    defaultValue = currentValue = std::to_string(v);
+}
 
-Option::Option(const char* v, const char* cur, OnChange f) : type("combo"), min(0), max(0), on_change(f)
-{ defaultValue = v; currentValue = cur; }
+Option::Option(const char* v, const char* cur, OnChange f) :
+    type("combo"),
+    min(0),
+    max(0),
+    on_change(std::move(f)) {
+    defaultValue = v;
+    currentValue = cur;
+}
 
-Option::operator double() const {
-  assert(type == "check" || type == "spin");
-  return (type == "spin" ? stof(currentValue) : currentValue == "true");
+Option::operator int() const {
+    assert(type == "check" || type == "spin");
+    return (type == "spin" ? std::stoi(currentValue) : currentValue == "true");
 }
 
 Option::operator std::string() const {
-  assert(type == "string");
-  return currentValue;
+    assert(type == "string");
+    return currentValue;
 }
 
 bool Option::operator==(const char* s) const {
-  assert(type == "combo");
-  return   !CaseInsensitiveLess()(currentValue, s)
-        && !CaseInsensitiveLess()(s, currentValue);
+    assert(type == "combo");
+    return !CaseInsensitiveLess()(currentValue, s) && !CaseInsensitiveLess()(s, currentValue);
 }
 
 
-/// operator<<() inits options and assigns idx in the correct printing order
+// Inits options and assigns idx in the correct printing order
 
 void Option::operator<<(const Option& o) {
 
-  static size_t insert_order = 0;
+    static size_t insert_order = 0;
 
-  *this = o;
-  idx = insert_order++;
+    *this = o;
+    idx   = insert_order++;
 }
 
 
-/// operator=() updates currentValue and triggers on_change() action. It's up to
-/// the GUI to check for option's limits, but we could receive the new value
-/// from the user by console window, so let's check the bounds anyway.
+// Updates currentValue and triggers on_change() action. It's up to
+// the GUI to check for option's limits, but we could receive the new value
+// from the user by console window, so let's check the bounds anyway.
+Option& Option::operator=(const std::string& v) {
 
-Option& Option::operator=(const string& v) {
+    assert(!type.empty());
 
-  assert(!type.empty());
+    if ((type != "button" && type != "string" && v.empty())
+        || (type == "check" && v != "true" && v != "false")
+        || (type == "spin" && (std::stof(v) < min || std::stof(v) > max)))
+        return *this;
 
-  if (   (type != "button" && v.empty())
-      || (type == "check" && v != "true" && v != "false")
-      || (type == "spin" && (stof(v) < min || stof(v) > max)))
-      return *this;
+    if (type == "combo")
+    {
+        OptionsMap         comboMap;  // To have case insensitive compare
+        std::string        token;
+        std::istringstream ss(defaultValue);
+        while (ss >> token)
+            comboMap[token] << Option();
+        if (!comboMap.count(v) || v == "var")
+            return *this;
+    }
 
-  if (type == "combo")
-  {
-      OptionsMap comboMap; // To have case insensitive compare
-      string token;
-      std::istringstream ss(defaultValue);
-      while (ss >> token)
-          comboMap[token] << Option();
-      if (!comboMap.count(v) || v == "var")
-          return *this;
-  }
+    if (type != "button")
+        currentValue = v;
 
-  if (type != "button")
-      currentValue = v;
+    if (on_change)
+        on_change(*this);
 
-  if (on_change)
-      on_change(*this);
-
-  return *this;
+    return *this;
 }
 
-} // namespace UCI
+std::ostream& operator<<(std::ostream& os, const OptionsMap& om) {
+    for (size_t idx = 0; idx < om.options_map.size(); ++idx)
+        for (const auto& it : om.options_map)
+            if (it.second.idx == idx)
+            {
+                const Option& o = it.second;
+                os << "\noption name " << it.first << " type " << o.type;
+
+                if (o.type == "string" || o.type == "check" || o.type == "combo")
+                    os << " default " << o.defaultValue;
+
+                if (o.type == "spin")
+                    os << " default " << int(stof(o.defaultValue)) << " min " << o.min << " max "
+                       << o.max;
+
+                break;
+            }
+
+    return os;
+}
+}

src/ucioption.h

@@ -0,0 +1,81 @@
+/*
+  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)
+
+  Stockfish is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  Stockfish is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef UCIOPTION_H_INCLUDED
+#define UCIOPTION_H_INCLUDED
+
+#include <cstddef>
+#include <functional>
+#include <iosfwd>
+#include <map>
+#include <string>
+
+namespace Stockfish {
+// Define a custom comparator, because the UCI options should be case-insensitive
+struct CaseInsensitiveLess {
+    bool operator()(const std::string&, const std::string&) const;
+};
+
+class Option;
+
+class OptionsMap {
+   public:
+    void setoption(std::istringstream&);
+
+    friend std::ostream& operator<<(std::ostream&, const OptionsMap&);
+
+    Option  operator[](const std::string&) const;
+    Option& operator[](const std::string&);
+
+    std::size_t count(const std::string&) const;
+
+   private:
+    // The options container is defined as a std::map
+    using OptionsStore = std::map<std::string, Option, CaseInsensitiveLess>;
+
+    OptionsStore options_map;
+};
+
+// The Option class implements each option as specified by the UCI protocol
+class Option {
+   public:
+    using OnChange = std::function<void(const Option&)>;
+
+    Option(OnChange = nullptr);
+    Option(bool v, OnChange = nullptr);
+    Option(const char* v, OnChange = nullptr);
+    Option(double v, int minv, int maxv, OnChange = nullptr);
+    Option(const char* v, const char* cur, OnChange = nullptr);
+
+    Option& operator=(const std::string&);
+    void    operator<<(const Option&);
+    operator int() const;
+    operator std::string() const;
+    bool operator==(const char*) const;
+
+    friend std::ostream& operator<<(std::ostream&, const OptionsMap&);
+
+   private:
+    std::string defaultValue, currentValue, type;
+    int         min, max;
+    size_t      idx;
+    OnChange    on_change;
+};
+
+}
+#endif  // #ifndef UCIOPTION_H_INCLUDED

tests/instrumented.sh

@@ -1,5 +1,5 @@
 #!/bin/bash
-# check for errors under valgrind or sanitizers.
+# check for errors under Valgrind or sanitizers.
 
 error()
 {
@@ -8,12 +8,19 @@ error()
 }
 trap 'error ${LINENO}' ERR
 
+# Since Linux Kernel 6.5 we are getting false positives from the ci,
+# lower the ALSR entropy to disable ALSR, which works as a temporary workaround.
+# https://github.com/google/sanitizers/issues/1716
+# https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2056762
+sudo sysctl -w vm.mmap_rnd_bits=28
+
+
 # define suitable post and prefixes for testing options
 case $1 in
   --valgrind)
     echo "valgrind testing started"
     prefix=''
-    exeprefix='valgrind --error-exitcode=42'
+    exeprefix='valgrind --error-exitcode=42 --errors-for-leak-kinds=all --leak-check=full'
     postfix='1>/dev/null'
     threads="1"
   ;;
@@ -39,16 +46,16 @@ case $1 in
     threads="2"
 
 cat << EOF > tsan.supp
-race:TTEntry::move
-race:TTEntry::depth
-race:TTEntry::bound
-race:TTEntry::save
-race:TTEntry::value
-race:TTEntry::eval
-race:TTEntry::is_pv
+race:Stockfish::TTEntry::move
+race:Stockfish::TTEntry::depth
+race:Stockfish::TTEntry::bound
+race:Stockfish::TTEntry::save
+race:Stockfish::TTEntry::value
+race:Stockfish::TTEntry::eval
+race:Stockfish::TTEntry::is_pv
 
-race:TranspositionTable::probe
-race:TranspositionTable::hashfull
+race:Stockfish::TranspositionTable::probe
+race:Stockfish::TranspositionTable::hashfull
 
 EOF
 
@@ -64,13 +71,32 @@ EOF
   ;;
 esac
 
+cat << EOF > bench_tmp.epd
+Rn6/1rbq1bk1/2p2n1p/2Bp1p2/3Pp1pP/1N2P1P1/2Q1NPB1/6K1 w - - 2 26
+rnbqkb1r/ppp1pp2/5n1p/3p2p1/P2PP3/5P2/1PP3PP/RNBQKBNR w KQkq - 0 3
+3qnrk1/4bp1p/1p2p1pP/p2bN3/1P1P1B2/P2BQ3/5PP1/4R1K1 w - - 9 28
+r4rk1/1b2ppbp/pq4pn/2pp1PB1/1p2P3/1P1P1NN1/1PP3PP/R2Q1RK1 w - - 0 13
+EOF
+
 # simple command line testing
 for args in "eval" \
             "go nodes 1000" \
             "go depth 10" \
+            "go perft 4" \
             "go movetime 1000" \
             "go wtime 8000 btime 8000 winc 500 binc 500" \
-            "bench 128 $threads 8 default depth"
+            "go wtime 1000 btime 1000 winc 0 binc 0" \
+            "go wtime 1000 btime 1000 winc 0 binc 0" \
+            "go wtime 1000 btime 1000 winc 0 binc 0 movestogo 5" \
+            "go movetime 200" \
+            "go nodes 20000 searchmoves e2e4 d2d4" \
+            "bench 128 $threads 8 default depth" \
+            "bench 128 $threads 3 bench_tmp.epd depth" \
+            "export_net verify.nnue" \
+            "d" \
+            "compiler" \
+            "license" \
+            "uci"
 do
 
    echo "$prefix $exeprefix ./stockfish $args $postfix"
@@ -78,6 +104,11 @@ do
 
 done
 
+# verify the generated net equals the base net
+network=`./stockfish uci | grep 'option name EvalFile type string default' | awk '{print $NF}'`
+echo "Comparing $network to the written verify.nnue"
+diff $network verify.nnue
+
 # more general testing, following an uci protocol exchange
 cat << EOF > game.exp
  set timeout 240
@@ -86,6 +117,7 @@ cat << EOF > game.exp
  send "uci\n"
  expect "uciok"
 
+ # send "setoption name Debug Log File value debug.log\n"
  send "setoption name Threads value $threads\n"
 
  send "ucinewgame\n"
@@ -98,13 +130,35 @@ cat << EOF > game.exp
  expect "bestmove"
 
  send "position fen 5rk1/1K4p1/8/8/3B4/8/8/8 b - - 0 1\n"
- send "go depth 20\n"
+ send "go depth 10\n"
  expect "bestmove"
 
+ send "setoption name UCI_ShowWDL value true\n"
+ send "position startpos\n"
+ send "flip\n"
+ send "go depth 5\n"
+ expect "bestmove"
+
+ send "setoption name Skill Level value 10\n"
+ send "position startpos\n"
+ send "go depth 5\n"
+ expect "bestmove"
+
+ send "setoption name Clear Hash\n"
+
+ send "setoption name EvalFile value verify.nnue\n"
+ send "position startpos\n"
+ send "go depth 5\n"
+ expect "bestmove"
+
+ send "setoption name MultiPV value 4\n"
+ send "position startpos\n"
+ send "go depth 5\n"
+
  send "quit\n"
  expect eof
 
- # return error code of the spawned program, useful for valgrind
+ # return error code of the spawned program, useful for Valgrind
  lassign [wait] pid spawnid os_error_flag value
  exit \$value
 EOF
@@ -122,10 +176,17 @@ cat << EOF > syzygy.exp
  send "setoption name SyzygyPath value ../tests/syzygy/\n"
  expect "info string Found 35 tablebases" {} timeout {exit 1}
  send "bench 128 1 8 default depth\n"
+ send "ucinewgame\n"
+ send "position fen 4k3/PP6/8/8/8/8/8/4K3 w - - 0 1\n"
+ send "go depth 5\n"
+ expect "bestmove"
+ send "position fen 8/1P6/2B5/8/4K3/8/6k1/8 w - - 0 1\n"
+ send "go depth 5\n"
+ expect "bestmove"
  send "quit\n"
  expect eof
 
- # return error code of the spawned program, useful for valgrind
+ # return error code of the spawned program, useful for Valgrind
  lassign [wait] pid spawnid os_error_flag value
  exit \$value
 EOF
@@ -140,6 +201,6 @@ do
 
 done
 
-rm -f tsan.supp
+rm -f tsan.supp bench_tmp.epd
 
 echo "instrumented testing OK"

tests/reprosearch.sh

@@ -43,7 +43,7 @@ cat << EOF > repeat.exp
  expect eof
 EOF
 
-# to increase the likelyhood of finding a non-reproducible case,
+# to increase the likelihood of finding a non-reproducible case,
 # the allowed number of nodes are varied systematically
 for i in `seq 1 20`
 do

tests/signature.sh

@@ -11,7 +11,7 @@ trap 'error ${LINENO}' ERR
 
 # obtain
 
-signature=`./stockfish bench 2>&1 | grep "Nodes searched  : " | awk '{print $4}'`
+signature=`eval "$WINE_PATH ./stockfish bench 2>&1" | grep "Nodes searched  : " | awk '{print $4}'`
 
 if [ $# -gt 0 ]; then
    # compare to given reference