Stockfish 15.1

Official release version of Stockfish 15.1

Bench: 3467381

---

Today, we have the pleasure to announce Stockfish 15.1.

As usual, downloads will be freely available at stockfishchess.org/download

*Elo gain and competition results*

With this release, version 5 of the NNUE neural net architecture has
been introduced, and the training data has been extended to include
Fischer random chess (FRC) positions. As a result, Elo gains are largest
for FRC, reaching up to 50 Elo for doubly randomized FRC[1] (DFRC).
More importantly, also for standard chess this release progressed and
will win two times more game pairs than it loses[2] against
Stockfish 15. Stockfish continues to win in a dominating way[3] all
chess engine tournaments, including the TCEC Superfinal, Cup, FRC, DFRC,
and Swiss as well as the CCC Bullet, Blitz, and Rapid events.

*New evaluation*

This release also introduces a new convention for the evaluation that
is reported by search. An evaluation of +1 is now no longer tied to the
value of one pawn, but to the likelihood of winning the game. With
a +1 evaluation, Stockfish has now a 50% chance of winning the game
against an equally strong opponent. This convention scales down
evaluations a bit compared to Stockfish 15 and allows for consistent
evaluations in the future.

*ChessBase settlement*

In this release period, the Stockfish team has successfully enforced
its GPL license against ChessBase. This has been an intense process that
included filing a lawsuit[4], a court hearing[5], and finally
negotiating a settlement[6] that established that ChessBase infringed on
the license by not distributing the Stockfish derivatives Fat Fritz 2
and Houdini 6 as free software, and that ensures ChessBase will respect
the Free Software principles in the future. This settlement has been
covered by major chess sites (see e.g. lichess.org[7] and chess.com[8]),
and we are proud that it has been hailed as a ‘historic violation
settlement[9]’ by the Software Freedom Conservancy.

*Thank you*

The Stockfish project builds on a thriving community of enthusiasts
(thanks everybody!) that contribute their expertise, time, and resources
to build a free and open-source chess engine that is robust, widely
available, and very strong. We invite our chess fans to join the
fishtest testing framework and programmers to contribute to the
project[10].

The Stockfish team

[1] https://tests.stockfishchess.org/tests/view/638a6170d2b9c924c4c62cb4
[2] https://tests.stockfishchess.org/tests/view/638a4dd7d2b9c924c4c6297b
[3] https://en.wikipedia.org/wiki/Stockfish_(chess)#Competition_results
[4] https://stockfishchess.org/blog/2021/our-lawsuit-against-chessbase/
[5] https://stockfishchess.org/blog/2022/public-court-hearing-soon/
[6] https://stockfishchess.org/blog/2022/chessbase-stockfish-agreement/
[7] https://lichess.org/blog/Y3u1mRAAACIApBVn/settlement-reached-in-stockfish-v-chessbase
[8] https://www.chess.com/news/view/chessbase-stockfish-reach-settlement
[9] https://sfconservancy.org/news/2022/nov/28/sfc-named-trusted-party-in-gpl-case/
[10] https://stockfishchess.org/get-involved/

.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 in 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/workflows/stockfish.yml

@@ -10,268 +10,12 @@ on:
       - master
       - tools
 jobs:
-  Stockfish:
+  Sanitizers:
-    name: ${{ matrix.config.name }}
+    uses: ./.github/workflows/stockfish_sanitizers.yml
-    runs-on: ${{ matrix.config.os }}
+  Tests:
-    env:
+    uses: ./.github/workflows/stockfish_test.yml
-      COMPILER: ${{ matrix.config.compiler }}
+  Compiles:
-      COMP: ${{ matrix.config.comp }}
+    uses: ./.github/workflows/stockfish_compile_test.yml
-      CXXFLAGS: "-Werror"
+  Binaries:
-    strategy:
+    if: github.ref == 'refs/heads/master'
-      matrix:
+    uses: ./.github/workflows/stockfish_binaries.yml
-        config:
-          - {
-              name: "Ubuntu 20.04 GCC",
-              os: ubuntu-20.04,
-              compiler: g++,
-              comp: gcc,
-              run_expensive_tests: true,
-              run_32bit_tests: true,
-              run_64bit_tests: true,
-              shell: 'bash {0}'
-            }
-          - {
-              name: "Ubuntu 20.04 Clang",
-              os: ubuntu-20.04,
-              compiler: clang++,
-              comp: clang,
-              run_expensive_tests: false,
-              run_32bit_tests: true,
-              run_64bit_tests: true,
-              shell: 'bash {0}'
-            }
-          - {
-              name: "MacOS 10.15 Apple Clang",
-              os: macos-10.15,
-              compiler: clang++,
-              comp: clang,
-              run_expensive_tests: false,
-              run_32bit_tests: false,
-              run_64bit_tests: true,
-              shell: 'bash {0}'
-            }
-          - {
-              name: "MacOS 10.15 GCC 10",
-              os: macos-10.15,
-              compiler: g++-10,
-              comp: gcc,
-              run_expensive_tests: false,
-              run_32bit_tests: false,
-              run_64bit_tests: true,
-              shell: 'bash {0}'
-            }
-          - {
-              name: "Windows 2019 Mingw-w64 GCC x86_64",
-              os: windows-2019,
-              compiler: g++,
-              comp: gcc,
-              run_expensive_tests: false,
-              run_32bit_tests: false,
-              run_64bit_tests: true,
-              msys_sys: 'mingw64',
-              msys_env: 'x86_64',
-              shell: 'msys2 {0}'
-            }
-          - {
-              name: "Windows 2019 Mingw-w64 GCC i686",
-              os: windows-2019,
-              compiler: g++,
-              comp: gcc,
-              run_expensive_tests: false,
-              run_32bit_tests: true,
-              run_64bit_tests: false,
-              msys_sys: 'mingw32',
-              msys_env: 'i686',
-              shell: 'msys2 {0}'
-            }
-
-    defaults:
-      run:
-        working-directory: src
-        shell: ${{ matrix.config.shell }}
-    steps:
-      - uses: actions/checkout@v2
-        with:
-          fetch-depth: 0
-
-      - name: Download required linux packages
-        if: runner.os == 'Linux'
-        run: |
-          sudo apt update
-          sudo apt install expect valgrind g++-multilib
-
-      - 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}}-gcc 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: |
-          git log HEAD | grep "\b[Bb]ench[ :]\+[0-9]\{7\}" | head -n 1 | sed "s/[^0-9]*\([0-9]*\).*/\1/g" > git_sig
-          [ -s git_sig ] && echo "benchref=$(cat git_sig)" >> $GITHUB_ENV && echo "Reference bench:" $(cat git_sig) || echo "No bench found"
-
-      - name: Check compiler
-        run: |
-          $COMPILER -v
-
-      - name: Test help target
-        run: |
-          make help
-
-      # 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 -j2 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 -j2 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 -j2 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 -j2 ARCH=x86-32-sse2 build
-          ../tests/signature.sh $benchref
-
-      - name: Test general-32 build
-        if: ${{ matrix.config.run_32bit_tests }}
-        run: |
-          make clean
-          make -j2 ARCH=general-32 build
-          ../tests/signature.sh $benchref
-
-      # x86-64 tests
-
-      - name: Test debug x86-64-modern build
-        if: ${{ matrix.config.run_64bit_tests }}
-        run: |
-          export CXXFLAGS="-Werror -D_GLIBCXX_DEBUG"
-          make clean
-          make -j2 ARCH=x86-64-modern optimize=no debug=yes build
-          ../tests/signature.sh $benchref
-
-      - name: Test x86-64-modern build
-        if: ${{ matrix.config.run_64bit_tests }}
-        run: |
-          make clean
-          make -j2 ARCH=x86-64-modern build
-          ../tests/signature.sh $benchref
-
-      - name: Test x86-64-ssse3 build
-        if: ${{ matrix.config.run_64bit_tests }}
-        run: |
-          make clean
-          make -j2 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 -j2 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 -j2 ARCH=x86-64 build
-          ../tests/signature.sh $benchref
-
-      - name: Test general-64 build
-        if: matrix.config.run_64bit_tests
-        run: |
-          make clean
-          make -j2 ARCH=general-64 build
-          ../tests/signature.sh $benchref
-
-      # x86-64 with newer extensions tests
-
-      - name: Compile x86-64-avx2 build
-        if: ${{ matrix.config.run_64bit_tests }}
-        run: |
-          make clean
-          make -j2 ARCH=x86-64-avx2 build
-
-      - name: Compile x86-64-bmi2 build
-        if: ${{ matrix.config.run_64bit_tests }}
-        run: |
-          make clean
-          make -j2 ARCH=x86-64-bmi2 build
-
-      - name: Compile x86-64-avx512 build
-        if: ${{ matrix.config.run_64bit_tests }}
-        run: |
-          make clean
-          make -j2 ARCH=x86-64-avx512 build
-
-      - name: Compile x86-64-vnni512 build
-        if: ${{ matrix.config.run_64bit_tests }}
-        run: |
-          make clean
-          make -j2 ARCH=x86-64-vnni512 build
-
-      - name: Compile x86-64-vnni256 build
-        if: ${{ matrix.config.run_64bit_tests }}
-        run: |
-          make clean
-          make -j2 ARCH=x86-64-vnni256 build
-
-      # Other tests
-
-      - name: Check perft and search reproducibility
-        if: ${{ matrix.config.run_64bit_tests }}
-        run: |
-          make clean
-          make -j2 ARCH=x86-64-modern build
-          ../tests/perft.sh
-          ../tests/reprosearch.sh
-
-      # Sanitizers
-
-      - name: Run under valgrind
-        if: ${{ matrix.config.run_expensive_tests }}
-        run: |
-          export CXXFLAGS="-O1 -fno-inline"
-          make clean
-          make -j2 ARCH=x86-64-modern debug=yes optimize=no build > /dev/null
-          ../tests/instrumented.sh --valgrind
-          ../tests/instrumented.sh --valgrind-thread
-
-      - name: Run with UB sanitizer
-        if: ${{ matrix.config.run_expensive_tests }}
-        run: |
-          export CXXFLAGS="-O1 -fno-inline"
-          make clean
-          make -j2 ARCH=x86-64-modern sanitize=undefined optimize=no debug=yes build > /dev/null
-          ../tests/instrumented.sh --sanitizer-undefined
-
-      - name: Run with thread sanitizer
-        if: ${{ matrix.config.run_expensive_tests }}
-        run: |
-          export CXXFLAGS="-O1 -fno-inline"
-          make clean
-          make -j2 ARCH=x86-64-modern sanitize=thread optimize=no debug=yes build > /dev/null
-          ../tests/instrumented.sh --sanitizer-thread

.github/workflows/stockfish_binaries.yml

@@ -0,0 +1,110 @@
+name: Stockfish
+on:
+  workflow_call:
+jobs:
+  Stockfish:
+    name: ${{ matrix.config.name }} ${{ matrix.binaries }}
+    runs-on: ${{ matrix.config.os }}
+    env:
+      COMPILER: ${{ matrix.config.compiler }}
+      COMP: ${{ matrix.config.comp }}
+      EXT: ${{ matrix.config.ext }}
+      OS: ${{ matrix.config.os }}
+      BINARY: ${{ matrix.binaries }}
+    strategy:
+      matrix:
+        config:
+          - {
+              name: "Ubuntu 20.04 GCC",
+              os: ubuntu-20.04,
+              compiler: g++,
+              comp: gcc,
+              shell: 'bash {0}'
+            }
+          - {
+              name: "MacOS 12 Apple Clang",
+              os: macos-12,
+              compiler: clang++,
+              comp: clang,
+              shell: 'bash {0}'
+            }
+          - {
+              name: "Windows 2022 Mingw-w64 GCC x86_64",
+              os: windows-2022,
+              compiler: g++,
+              comp: mingw,
+              msys_sys: 'mingw64',
+              msys_env: 'x86_64-gcc',
+              shell: 'msys2 {0}',
+              ext: .exe
+            }
+        binaries:
+          - x86-64
+          - x86-64-modern
+          - x86-64-avx2
+        exclude:
+          - binaries: x86-64-avx2
+            config: {os: macos-12}
+    defaults:
+      run:
+        working-directory: src
+        shell: ${{ matrix.config.shell }}
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+
+      - name: Download required linux packages
+        if: runner.os == 'Linux'
+        run: |
+          sudo apt update
+
+      - 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: Check compiler
+        run: |
+          export PATH=$PATH:$ANDROID_NDK_HOME/toolchains/llvm/prebuilt/linux-x86_64/bin
+          $COMPILER -v
+
+      - name: Test help target
+        run: |
+          make help
+
+      # Compile profile guided builds
+
+      - name: Compile ${{ matrix.binaries }} build
+        run: |
+          make clean
+          make -j2 profile-build ARCH=$BINARY COMP=$COMP
+          strip ./stockfish$EXT
+          mv ./stockfish$EXT ../stockfish-$OS-$BINARY$EXT
+
+      - name: Remove non src files
+        run: rm -f *.o .depend *.nnue
+
+      - name: Create tar archive.
+        run: |
+          cd ..
+          mkdir stockfish
+          cp -r src stockfish/
+          cp stockfish-$OS-$BINARY$EXT stockfish/
+          cp "Top CPU Contributors.txt" stockfish/
+          cp Copying.txt stockfish/
+          cp AUTHORS stockfish/
+          tar -cvf stockfish-$OS-$BINARY.tar stockfish
+
+      - name: Upload binaries
+        uses: actions/upload-artifact@v3
+        with:
+          name: stockfish-${{ matrix.config.os }}-${{ matrix.binaries }}
+          path: |
+            stockfish-${{ matrix.config.os }}-${{ matrix.binaries }}.tar

.github/workflows/stockfish_compile_test.yml

@@ -0,0 +1,115 @@
+name: Stockfish
+on:
+  workflow_call:
+jobs:
+  Stockfish:
+    name: ${{ matrix.config.name }}
+    runs-on: ${{ matrix.config.os }}
+    env:
+      COMPILER: ${{ matrix.config.compiler }}
+      COMP: ${{ matrix.config.comp }}
+    strategy:
+      matrix:
+        config:
+          - {
+              name: "Ubuntu 20.04 GCC",
+              os: ubuntu-20.04,
+              compiler: g++,
+              comp: gcc,
+              shell: 'bash {0}'
+            }
+          - {
+              name: "Ubuntu 20.04 Clang",
+              os: ubuntu-20.04,
+              compiler: clang++,
+              comp: clang,
+              shell: 'bash {0}'
+            }
+          - {
+              name: "MacOS 12 Apple Clang",
+              os: macos-12,
+              compiler: clang++,
+              comp: clang,
+              shell: 'bash {0}'
+            }
+          - {
+              name: "MacOS 12 GCC 11",
+              os: macos-12,
+              compiler: g++-11,
+              comp: gcc,
+              shell: 'bash {0}'
+            }
+          - {
+              name: "Windows 2022 Mingw-w64 GCC x86_64",
+              os: windows-2022,
+              compiler: g++,
+              comp: mingw,
+              msys_sys: 'mingw64',
+              msys_env: 'x86_64-gcc',
+              shell: 'msys2 {0}'
+            }
+          - {
+              name: "Windows 2022 Mingw-w64 Clang x86_64",
+              os: windows-2022,
+              compiler: clang++,
+              comp: clang,
+              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@v3
+        with:
+          fetch-depth: 0
+
+      - 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: Check compiler
+        run: |
+          export PATH=$PATH:$ANDROID_NDK_HOME/toolchains/llvm/prebuilt/linux-x86_64/bin
+          $COMPILER -v
+
+      - name: Test help target
+        run: |
+          make help
+
+      # x86-64 with newer extensions tests
+
+      - name: Compile x86-64-avx2 build
+        run: |
+          make clean
+          make -j2 ARCH=x86-64-avx2 build
+
+      - name: Compile x86-64-bmi2 build
+        run: |
+          make clean
+          make -j2 ARCH=x86-64-bmi2 build
+
+      - name: Compile x86-64-avx512 build
+        run: |
+          make clean
+          make -j2 ARCH=x86-64-avx512 build
+
+      - name: Compile x86-64-vnni512 build
+        run: |
+          make clean
+          make -j2 ARCH=x86-64-vnni512 build
+
+      - name: Compile x86-64-vnni256 build
+        run: |
+          make clean
+          make -j2 ARCH=x86-64-vnni256 build

.github/workflows/stockfish_sanitizers.yml

@@ -0,0 +1,77 @@
+name: Stockfish
+on:
+  workflow_call:
+jobs:
+  Stockfish:
+    name: ${{ matrix.sanitizers.name }}
+    runs-on: ${{ matrix.config.os }}
+    env:
+      COMPILER: ${{ matrix.config.compiler }}
+      COMP: ${{ matrix.config.comp }}
+      CXXFLAGS: "-Werror"
+    strategy:
+      matrix:
+        config:
+          - {
+              name: "Ubuntu 20.04 GCC",
+              os: ubuntu-20.04,
+              compiler: g++,
+              comp: gcc,
+              shell: 'bash {0}'
+            }
+        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: ${{ matrix.config.shell }}
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+
+      - name: Download required linux packages
+        run: |
+          sudo apt update
+          sudo apt install expect valgrind g++-multilib qemu-user
+
+      - name: Download the used network from the fishtest framework
+        run: |
+          make net
+
+      - name: Check compiler
+        run: |
+          export PATH=$PATH:$ANDROID_NDK_HOME/toolchains/llvm/prebuilt/linux-x86_64/bin
+          $COMPILER -v
+
+      - name: Test help target
+        run: |
+          make help
+
+      # Sanitizers
+
+      - name: ${{ matrix.sanitizers.name }}
+        run: |
+          export CXXFLAGS="-O1 -fno-inline"
+          make clean
+          make -j2 ARCH=x86-64-modern ${{ matrix.sanitizers.make_option }} debug=yes optimize=no build > /dev/null
+          ../tests/instrumented.sh --${{ matrix.sanitizers.instrumented_option }}

.github/workflows/stockfish_test.yml

@@ -0,0 +1,284 @@
+name: Stockfish
+on:
+  workflow_call:
+jobs:
+  Stockfish:
+    name: ${{ matrix.config.name }}
+    runs-on: ${{ matrix.config.os }}
+    env:
+      COMPILER: ${{ matrix.config.compiler }}
+      COMP: ${{ matrix.config.comp }}
+      CXXFLAGS: "-Werror"
+    strategy:
+      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 {0}'
+            }
+          - {
+              name: "Ubuntu 20.04 Clang",
+              os: ubuntu-20.04,
+              compiler: clang++,
+              comp: clang,
+              run_32bit_tests: true,
+              run_64bit_tests: true,
+              shell: 'bash {0}'
+            }
+          - {
+              name: "Ubuntu 20.04 NDK armv8",
+              os: ubuntu-20.04,
+              compiler: aarch64-linux-android21-clang++,
+              comp: ndk,
+              run_armv8_tests: false,
+              shell: 'bash {0}'
+            }
+          - {
+              name: "Ubuntu 20.04 NDK armv7",
+              os: ubuntu-20.04,
+              compiler: armv7a-linux-androideabi21-clang++,
+              comp: ndk,
+              run_armv7_tests: false,
+              shell: 'bash {0}'
+            }
+          - {
+              name: "MacOS 12 Apple Clang",
+              os: macos-12,
+              compiler: clang++,
+              comp: clang,
+              run_64bit_tests: true,
+              shell: 'bash {0}'
+            }
+          - {
+              name: "MacOS 12 GCC 11",
+              os: macos-12,
+              compiler: g++-11,
+              comp: gcc,
+              run_64bit_tests: true,
+              shell: 'bash {0}'
+            }
+          - {
+              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}'
+            }
+        exclude:
+          - config: 
+              {
+                name: "Ubuntu 20.04 NDK armv7"
+              }
+          - config:
+              {
+                name: "Ubuntu 20.04 NDK armv8"
+              }
+    defaults:
+      run:
+        working-directory: src
+        shell: ${{ matrix.config.shell }}
+    steps:
+      - uses: actions/checkout@v3
+        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
+
+      - 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: |
+          git log HEAD | grep "\b[Bb]ench[ :]\+[0-9]\{7\}" | head -n 1 | sed "s/[^0-9]*\([0-9]*\).*/\1/g" > git_sig
+          [ -s git_sig ] && echo "benchref=$(cat git_sig)" >> $GITHUB_ENV && echo "Reference bench:" $(cat git_sig) || echo "No bench found"
+
+      - name: Check compiler
+        run: |
+          export PATH=$PATH:$ANDROID_NDK_HOME/toolchains/llvm/prebuilt/linux-x86_64/bin
+          $COMPILER -v
+
+      - name: Test help target
+        run: |
+          make help
+
+      # 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 -j2 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 -j2 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 -j2 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 -j2 ARCH=x86-32-sse2 build
+          ../tests/signature.sh $benchref
+
+      - name: Test general-32 build
+        if: ${{ matrix.config.run_32bit_tests }}
+        run: |
+          make clean
+          make -j2 ARCH=general-32 build
+          ../tests/signature.sh $benchref
+
+      # x86-64 tests
+
+      - name: Test debug x86-64-modern build
+        if: ${{ matrix.config.run_64bit_tests }}
+        run: |
+          export CXXFLAGS="-Werror -D_GLIBCXX_DEBUG"
+          make clean
+          make -j2 ARCH=x86-64-modern optimize=no debug=yes build
+          ../tests/signature.sh $benchref
+
+      - name: Test x86-64-modern build
+        if: ${{ matrix.config.run_64bit_tests }}
+        run: |
+          make clean
+          make -j2 ARCH=x86-64-modern build
+          ../tests/signature.sh $benchref
+
+      - name: Test x86-64-ssse3 build
+        if: ${{ matrix.config.run_64bit_tests }}
+        run: |
+          make clean
+          make -j2 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 -j2 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 -j2 ARCH=x86-64 build
+          ../tests/signature.sh $benchref
+
+      - name: Test general-64 build
+        if: matrix.config.run_64bit_tests
+        run: |
+          make clean
+          make -j2 ARCH=general-64 build
+          ../tests/signature.sh $benchref
+
+      # armv8 tests
+
+      - name: Test armv8 build
+        if: ${{ matrix.config.run_armv8_tests }}
+        run: |
+          ANDROID_ROOT=/usr/local/lib/android
+          ANDROID_SDK_ROOT=${ANDROID_ROOT}/sdk
+          SDKMANAGER=${ANDROID_SDK_ROOT}/cmdline-tools/latest/bin/sdkmanager
+          echo "y" | $SDKMANAGER "ndk;21.4.7075529"
+          ANDROID_NDK_ROOT=${ANDROID_SDK_ROOT}/ndk-bundle
+          ln -sfn $ANDROID_SDK_ROOT/ndk/21.4.7075529 $ANDROID_NDK_ROOT
+          export PATH=$ANDROID_NDK_HOME/toolchains/llvm/prebuilt/linux-x86_64/bin:$PATH
+          export LDFLAGS="-static -Wno-unused-command-line-argument"
+          make clean
+          make -j2 ARCH=armv8 build
+          ../tests/signature.sh $benchref
+
+      # armv7 tests
+
+      - name: Test armv7 build
+        if: ${{ matrix.config.run_armv7_tests }}
+        run: |
+          ANDROID_ROOT=/usr/local/lib/android
+          ANDROID_SDK_ROOT=${ANDROID_ROOT}/sdk
+          SDKMANAGER=${ANDROID_SDK_ROOT}/cmdline-tools/latest/bin/sdkmanager
+          echo "y" | $SDKMANAGER "ndk;21.4.7075529"
+          ANDROID_NDK_ROOT=${ANDROID_SDK_ROOT}/ndk-bundle
+          ln -sfn $ANDROID_SDK_ROOT/ndk/21.4.7075529 $ANDROID_NDK_ROOT
+          export PATH=$ANDROID_NDK_HOME/toolchains/llvm/prebuilt/linux-x86_64/bin:$PATH
+          export LDFLAGS="-static -Wno-unused-command-line-argument"
+          make clean
+          make -j2 ARCH=armv7 build
+          ../tests/signature.sh $benchref
+
+      - name: Test armv7-neon build
+        if: ${{ matrix.config.run_armv7_tests }}
+        run: |
+          ANDROID_ROOT=/usr/local/lib/android
+          ANDROID_SDK_ROOT=${ANDROID_ROOT}/sdk
+          SDKMANAGER=${ANDROID_SDK_ROOT}/cmdline-tools/latest/bin/sdkmanager
+          echo "y" | $SDKMANAGER "ndk;21.4.7075529"
+          ANDROID_NDK_ROOT=${ANDROID_SDK_ROOT}/ndk-bundle
+          ln -sfn $ANDROID_SDK_ROOT/ndk/21.4.7075529 $ANDROID_NDK_ROOT
+          export PATH=$ANDROID_NDK_HOME/toolchains/llvm/prebuilt/linux-x86_64/bin:$PATH
+          export LDFLAGS="-static -Wno-unused-command-line-argument"
+          make clean
+          make -j2 ARCH=armv7-neon build
+          ../tests/signature.sh $benchref
+
+      # Other tests
+
+      - name: Check perft and search reproducibility
+        if: ${{ matrix.config.run_64bit_tests }}
+        run: |
+          make clean
+          make -j2 ARCH=x86-64-modern build
+          ../tests/perft.sh
+          ../tests/reprosearch.sh

AUTHORS

@@ -31,22 +31,27 @@ Arjun Temurnikar
 Artem Solopiy (EntityFX)
 Auguste Pop
 Balint Pfliegel
+Ben Chaney (Chaneybenjamini)
 Ben Koshy (BKSpurgeon)
 Bill Henry (VoyagerOne)
 Bojun Guo (noobpwnftw, Nooby)
+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
 Dale Weiler (graphitemaster)
 Dan Schmidt (dfannius)
 Daniel Axtens (daxtens)
 Daniel Dugovic (ddugovic)
 Dariusz Orzechowski (dorzechowski)
 David Zar
+David (dav1312)
 Daylen Yang (daylen)
 Deshawn Mohan-Smith (GoldenRare)
 Dieter Dobbelaere (ddobbelaere)
@@ -54,6 +59,7 @@ DiscanX
 Dominik Schlösser (domschl)
 double-beep
 Douglas Matos Gomes (dsmsgms)
+Dubslow
 Eduardo Cáceres (eduherminio)
 Eelco de Groot (KingDefender)
 Elvin Liu (solarlight2)
@@ -85,7 +91,7 @@ Hongzhi Cheng
 Ivan Ivec (IIvec)
 Jacques B. (Timshel)
 Jan Ondruš (hxim)
-Jared Kish (Kurtbusch)
+Jared Kish (Kurtbusch, kurt22i)
 Jarrod Torriero (DU-jdto)
 Jean Gauthier (OuaisBla)
 Jean-Francois Romang (jromang)
@@ -103,6 +109,7 @@ jundery
 Justin Blanchard (UncombedCoconut)
 Kelly Wilson
 Ken Takusagawa
+Kian E (KJE-98)
 kinderchocolate
 Kiran Panditrao (Krgp)
 Kojirion
@@ -123,6 +130,7 @@ marotear
 Matt Ginsberg (mattginsberg)
 Matthew Lai (matthewlai)
 Matthew Sullivan (Matt14916)
+Max A. (Disservin)
 Maxim Molchanov (Maxim)
 Michael An (man)
 Michael Byrne (MichaelB7)
@@ -132,6 +140,7 @@ 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)
@@ -152,19 +161,21 @@ Panthee
 Pascal Romaret
 Pasquale Pigazzini (ppigazzini)
 Patrick Jansen (mibere)
-pellanda
+Peter Schneider (pschneider1968)
 Peter Zsifkovits (CoffeeOne)
 Praveen Kumar Tummala (praveentml)
 Rahul Dsilva (silversolver1)
 Ralph Stößer (Ralph Stoesser)
 Raminder Singh
 renouve
-Reuven Peleg
+Reuven Peleg (R-Peleg)
-Richard Lloyd
+Richard Lloyd (Richard-Lloyd)
 Rodrigo Exterckötter Tjäder
+Rodrigo Roim (roim)
 Ron Britvich (Britvich)
 Ronald de Man (syzygy1, syzygy)
 rqs
+Rui Coelho (ruicoelhopedro)
 Ryan Schmitt
 Ryan Takker
 Sami Kiminki (skiminki)
@@ -180,6 +191,7 @@ Stefan Geschwentner (locutus2)
 Stefano Cardanobile (Stefano80)
 Steinar Gunderson (sesse)
 Stéphane Nicolet (snicolet)
+Syine Mineta (MinetaS)
 Prokop Randáček (ProkopRandacek)
 Thanar2
 thaspel
@@ -194,6 +206,7 @@ tttak
 Unai Corzo (unaiic)
 Uri Blass (uriblass)
 Vince Negri (cuddlestmonkey)
+xefoci7612
 zz4032
 
 

README.md

@@ -1,44 +1,58 @@
+<div align="center">
+
+  [![Stockfish][stockfish128-logo]][website-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://github.com/official-stockfish/Stockfish/actions/workflows/stockfish.yml/badge.svg)](https://github.com/official-stockfish/Stockfish/actions)
+[Stockfish][website-link] is a free, powerful UCI chess engine derived from
-[![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)
+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,
-[Stockfish](https://stockfishchess.org) is a free, powerful UCI chess engine
+Arena, Sigma Chess, Shredder, Chess Partner or Fritz) in order to be used comfortably.
-derived from Glaurung 2.1. Stockfish is not a complete chess program and requires a
+Read the documentation for your GUI of choice for information about how to use
-UCI-compatible graphical user interface (GUI) (e.g. XBoard with PolyGlot, Scid,
+Stockfish with it.
-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).
 
+The Stockfish engine features two evaluation functions for chess. The efficiently
+updatable neural network (NNUE) based evaluation is the default and by far the strongest.
+The classical evaluation based on handcrafted terms remains available. The strongest
+network is integrated in the binary and downloaded automatically during the build process.
+The NNUE evaluation benefits from the vector intrinsics available on most CPUs (sse2,
+avx2, neon, or similar).
 
 ## Files
 
 This distribution of Stockfish consists of the following files:
 
-  * [Readme.md](https://github.com/official-stockfish/Stockfish/blob/master/README.md), the file you are currently reading.
+  * [README.md][readme-link], the file you are currently reading.
 
-  * [Copying.txt](https://github.com/official-stockfish/Stockfish/blob/master/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](https://github.com/official-stockfish/Stockfish/blob/master/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](https://github.com/official-stockfish/Stockfish/tree/master/src), a subdirectory containing the full source code, including a Makefile
+  * [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
+  * a file with the .nnue extension, storing the neural network for the NNUE evaluation.
-    evaluation. Binary distributions will have this file embedded.
+    Binary distributions will have this file embedded.
 
 ## The UCI protocol and available options
 
 The Universal Chess Interface (UCI) is a standard protocol used to communicate with
 a chess engine, and is the recommended way to do so for typical graphical user interfaces
-(GUI) or chess tools. Stockfish implements the majority of it options as described
+(GUI) or chess tools. Stockfish implements the majority of its options as described
-in [the UCI protocol](https://www.shredderchess.com/download/div/uci.zip).
+in [the UCI protocol][uci-link].
 
 Developers can see the default values for UCI options available in Stockfish by typing
 `./stockfish uci` in a terminal, but the majority of users will typically see them and
@@ -68,9 +82,9 @@ change them via a chess GUI. This is a list of available UCI options in Stockfis
 
   * #### 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.
+    filename might have to include the full path to the folder/directory that contains
-    Other locations, such as the directory that contains the binary and the working directory,
+    the file. Other locations, such as the directory that contains the binary and the
-    are also searched.
+    working directory, are also searched.
 
   * #### UCI_AnalyseMode
     An option handled by your GUI.
@@ -103,7 +117,7 @@ change them via a chess GUI. This is a list of available UCI options in Stockfis
     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
+    the .rtbz files on a regular HDD. It is recommended to verify all md5 checksums
     of the downloaded tablebase files (`md5sum -c checksum.md5`) as corruption will
     lead to engine crashes.
 
@@ -138,8 +152,9 @@ change them via a chess GUI. This is a list of available UCI options in Stockfis
 For developers the following non-standard commands might be of interest, mainly useful for debugging:
 
   * #### bench *ttSize threads limit fenFile limitType evalType*
-    Performs a standard benchmark using various options. The signature of a version (standard node
+    Performs a standard benchmark using various options. The signature of a version
-    count) is obtained using all defaults. `bench` is currently `bench 16 1 13 default depth mixed`.
+    (standard node count) is obtained using all defaults. `bench` is currently
+    `bench 16 1 13 default depth mixed`.
 
   * #### compiler
     Give information about the compiler and environment used for building a binary.
@@ -175,22 +190,25 @@ 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
+[The nodchip repository][nodchip-link] provided the first version of the needed tools
-tools to train and develop the NNUE networks. On CPUs supporting modern vector instructions
+to train and develop the NNUE networks. Today, more advanced training tools are
-(avx2 and similar), the NNUE evaluation results in much stronger playing strength, even
+available in [the nnue-pytorch repository][pytorch-link], while data generation tools
-if the nodes per second computed by the engine is somewhat lower (roughly 80% of nps
+are available in [a dedicated branch][tools-link].
-is typical).
+
+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
+1) the NNUE evaluation depends on the Stockfish binary and the network parameter file
-file (see the EvalFile UCI option). Not every parameter file is compatible with a given
+(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
+Stockfish binary, but the default value of the EvalFile UCI option is the name of a
-that is guaranteed to be compatible with that binary.
+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
+needs to be available. Normally, this file is already embedded in the binary or it can
-can be downloaded. The filename for the default (recommended) net can be found as the default
+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
 ```
@@ -241,8 +259,8 @@ 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)
+[Enable the Lock Pages in Memory Option (Windows)][lockpages-link]
-on how to enable this privilege, then run [RAMMap](https://docs.microsoft.com/en-us/sysinternals/downloads/rammap)
+on how to enable this privilege, then run [RAMMap][rammap-link]
 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
@@ -285,26 +303,26 @@ effort. There are a few ways to help contribute to its growth.
 ### 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)
+your hardware resources by installing the [Fishtest Worker][worker-link]
-and view the current tests on [Fishtest](https://tests.stockfishchess.org/tests).
+and view 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 this wiki,][programming-link] many techniques used in
 Stockfish are explained with a lot of background information.
 
-* [The section on Stockfish](https://www.chessprogramming.org/Stockfish)
+* [The section on Stockfish][programmingsf-link]
 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).
+* The latest source can always be found on [GitHub][github-link].
-Discussions about Stockfish take place these days mainly in the [FishCooking](https://groups.google.com/forum/#!forum/fishcooking)
+Discussions about Stockfish take place these days mainly in the [FishCooking][fishcooking-link]
-group and on the [Stockfish Discord channel](https://discord.gg/nv8gDtt).
+group and on the [Stockfish Discord channel][discord-link].
-The engine testing is done on [Fishtest](https://tests.stockfishchess.org/tests).
+The engine testing is done on [Fishtest][fishtest-link].
-If you want to help improve Stockfish, please read this [guideline](https://github.com/glinscott/fishtest/wiki/Creating-my-first-test)
+If you want to help improve Stockfish, please read this [guideline][guideline-link]
 first, where the basics of Stockfish development are explained.
 
 
@@ -318,10 +336,43 @@ 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
+some way, you MUST always include the license and the full source code
-to where the source code can be found, to generate the exact binary
+(or a pointer to where the source code can be found) to generate the
-you are distributing. If you make any changes to the source code,
+exact binary you are distributing. If you make any changes to the
-these changes must also be made available under the GPL.
+source code, these changes must also be made available under the GPL v3.
 
 For full details, read the copy of the GPL v3 found in the file named
-[*Copying.txt*](https://github.com/official-stockfish/Stockfish/blob/master/Copying.txt).
+[*Copying.txt*][license-link].
+
+
+[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
+[fishcooking-link]:   https://groups.google.com/g/fishcooking
+[fishtest-link]:      https://tests.stockfishchess.org/tests
+[github-link]:        https://github.com/official-stockfish/Stockfish
+[guideline-link]:     https://github.com/glinscott/fishtest/wiki/Creating-my-first-test
+[license-link]:       https://github.com/official-stockfish/Stockfish/blob/master/Copying.txt
+[lockpages-link]:     https://docs.microsoft.com/en-us/sql/database-engine/configure-windows/enable-the-lock-pages-in-memory-option-windows
+[nodchip-link]:       https://github.com/nodchip/Stockfish
+[programming-link]:   https://www.chessprogramming.org/Main_Page
+[programmingsf-link]: https://www.chessprogramming.org/Stockfish
+[pytorch-link]:       https://github.com/glinscott/nnue-pytorch
+[rammap-link]:        https://docs.microsoft.com/en-us/sysinternals/downloads/rammap
+[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
+[tools-link]:         https://github.com/official-stockfish/Stockfish/tree/tools
+[uci-link]:           https://www.shredderchess.com/download/div/uci.zip
+[website-link]:       https://stockfishchess.org
+[worker-link]:        https://github.com/glinscott/fishtest/wiki/Running-the-worker:-overview
+
+[build-badge]:        https://img.shields.io/github/workflow/status/official-stockfish/Stockfish/Stockfish?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

@@ -1,205 +1,260 @@
-Contributors to Fishtest with >10,000 CPU hours, as of Jun 29, 2021.
+Contributors to Fishtest with >10,000 CPU hours, as of 2022-11-19.
 Thank you!
 
-Username                 CPU Hours       Games played
+Username                                CPU Hours     Games played
------------------------------------------------------
+------------------------------------------------------------------
-noobpwnftw                27649494         1834734733
+noobpwnftw                               36475307       2748033975
-mlang                      1426107           89454622
+technologov                              14570711        760073590
-dew                        1380910           82831648
+mlang                                     3026000        200065824
-mibere                      703840           46867607
+dew                                       1689222        100034318
-grandphish2                 692707           41737913
+grandphish2                               1442171         86798057
-tvijlbrief                  669642           42371594
+okrout                                    1439985        133471766
-JojoM                       597778           35297180
+pemo                                      1405374         44189811
-TueRens                     519226           31823562
+linrock                                   1299003         28382783
-cw                          458421           30307421
+TueRens                                   1163420         71159522
-fastgm                      439667           25950040
+JojoM                                      897158         55177114
-gvreuls                     436599           28177460
+tvijlbrief                                 796125         51897690
-crunchy                     427035           27344275
+mibere                                     703840         46867607
-CSU_Dynasty                 374765           25106278
+gvreuls                                    635982         40652394
-Fisherman                   326901           21822979
+oz                                         590763         41201352
-ctoks                       325477           21767943
+sebastronomy                               581517         23307132
-velislav                    295343           18844324
+cw                                         517915         34865769
-linrock                     292789           10624427
+fastgm                                     504266         30264740
-bcross                      278584           19488961
+CSU_Dynasty                                479901         31846710
-okrout                      262818           13803272
+ctoks                                      433503         28180725
-pemo                        245982           11376085
+crunchy                                    427035         27344275
-glinscott                   217799           13780820
+leszek                                     416883         27493447
-leszek                      212346           12959025
+bcross                                     409982         28062127
-nordlandia                  211692           13484886
+velislav                                   345954         22232274
-bking_US                    198894           11876016
+Fisherman                                  327231         21829379
-drabel                      196463           13450602
+Dantist                                    296386         18031762
-robal                       195473           12375650
+mgrabiak                                   288928         18869896
-mgrabiak                    187226           12016564
+rpngn                                      259965         16281463
-Dantist                     183202           10990484
+robal                                      237653         15148350
-Thanar                      179852           12365359
+ncfish1                                    231764         15275003
-vdv                         175274            9889046
+nordlandia                                 226923         14624832
-spams                       157128           10319326
+glinscott                                  208125         13277240
-marrco                      150295            9402141
+drabel                                     204167         13930674
-sqrt2                       147963            9724586
+mhoram                                     202894         12601997
-mhoram                      141278            8901241
+bking_US                                   198894         11876016
-CoffeeOne                   137100            5024116
+thirdlife                                  198844          5453268
-vdbergh                     137041            8926915
+Thanar                                     179852         12365359
-malala                      136182            8002293
+vdv                                        175544          9904472
-xoto                        133702            9156676
+armo9494                                   168201         11136452
-davar                       122092            7960001
+spams                                      157128         10319326
-dsmith                      122059            7570238
+marrco                                     151599          9551115
-Data                        113305            8220352
+sqrt2                                      147963          9724586
-BrunoBanani                 112960            7436849
+vdbergh                                    137690          8971569
-MaZePallas                  102823            6633619
+CoffeeOne                                  137100          5024116
-sterni1971                  100532            5880772
+malala                                     136182          8002293
-ElbertoOne                   99028            7023771
+DesolatedDodo                              135276          8657464
-brabos                       92118            6186135
+xoto                                       133759          9159372
-oz                           92100            6486640
+davar                                      129023          8376525
-psk                          89957            5984901
+dsmith                                     122059          7570238
-amicic                       89156            5392305
+amicic                                     119661          7938029
-sunu                         88851            6028873
+Data                                       113305          8220352
-Vizvezdenec                  83761            5344740
+BrunoBanani                                112960          7436849
-0x3C33                       82614            5271253
+CypressChess                               108331          7759788
-BRAVONE                      81239            5054681
+skiminki                                   106518          7062598
-racerschmacer                80899            5759262
+MaZePallas                                 102823          6633619
-cuistot                      80300            4606144
+sterni1971                                 100532          5880772
-nssy                         76497            5259388
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-teddybaer                    75125            5407666
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-Pking_cda                    73776            5293873
+ElbertoOne                                  99028          7023771
-jromang                      72192            5057715
+DMBK                                        97572          6950312
-solarlight                   70517            5028306
+Calis007                                    96779          5611552
-dv8silencer                  70287            3883992
+cuistot                                     93111          5536500
-Bobo1239                     68515            4652287
+brabos                                      92118          6186135
-manap                        66273            4121774
+Wolfgang                                    91769          5720158
-skiminki                     65088            4023328
+psk                                         89957          5984901
-tinker                       64333            4268790
+racerschmacer                               85805          6122790
-sschnee                      60767            3500800
+jcAEie                                      85527          5630616
-qurashee                     57344            3168264
+Vizvezdenec                                 83761          5344740
-robnjr                       57262            4053117
+sschnee                                     83557          4853690
-Freja                        56938            3733019
+0x3C33                                      82614          5271253
-ttruscott                    56010            3680085
+BRAVONE                                     81239          5054681
-rkl                          55132            4164467
+Dubslow                                     78461          5042980
-renouve                      53811            3501516
+nssy                                        76497          5259388
-finfish                      51360            3370515
+jromang                                     76106          5236025
-eva42                        51272            3599691
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-rap                          49985            3219146
+yurikvelo                                   73933          5031096
-pb00067                      49727            3298270
+tolkki963                                   73885          4721430
-ronaldjerum                  47654            3240695
+Pking_cda                                   73776          5293873
-bigpen0r                     47653            3335327
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-eastorwest                   47585            3221629
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-biffhero                     46564            3111352
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-VoyagerOne                   45476            3452465
+Gelma                                       69304          3980932
-yurikvelo                    44834            3034550
+manap                                       66273          4121774
-speedycpu                    43842            3003273
+megaman7de                                  65419          4120200
-jbwiebe                      43305            2805433
+markkulix                                   65331          4114860
-Spprtr                       42279            2680153
+bigpen0r                                    64932          4683883
-DesolatedDodo                42007            2447516
+tinker                                      64333          4268790
-Antihistamine                41788            2761312
+qurashee                                    61208          3429862
-mhunt                        41735            2691355
+AGI                                         58325          4258646
-homyur                       39893            2850481
+robnjr                                      57262          4053117
-gri                          39871            2515779
+Freja                                       56938          3733019
-Fifis                        38776            2529121
+MaxKlaxxMiner                               56879          3423958
-oryx                         38724            2966648
+ttruscott                                   56010          3680085
-SC                           37290            2731014
+rkl                                         55132          4164467
-csnodgrass                   36207            2688994
+renouve                                     53811          3501516
-jmdana                       36157            2210661
+Spprtr                                      52736          3410019
-strelock                     34716            2074055
+finfish                                     51360          3370515
-rpngn                        33951            2057395
+eva42                                       51272          3599691
-Garf                         33922            2751802
+eastorwest                                  51117          3454811
-EthanOConnor                 33370            2090311
+rap                                         49985          3219146
-slakovv                      32915            2021889
+unixwizard                                  49734          2536230
-manapbk                      30987            1810399
+pb00067                                     49727          3298270
-Prcuvu                       30377            2170122
+ronaldjerum                                 47654          3240695
-anst                         30301            2190091
+biffhero                                    46564          3111352
-jkiiski                      30136            1904470
+GPUex                                       45861          2926502
-hyperbolic.tom               29840            2017394
+Fifis                                       45843          3088497
-Pyafue                       29650            1902349
+oryx                                        45578          3493978
-Wolfgang                     29260            1658936
+VoyagerOne                                  45476          3452465
-zeryl                        28156            1579911
+Wencey                                      44943          2654490
-OuaisBla                     27636            1578800
+speedycpu                                   43842          3003273
-DMBK                         27051            1999456
+jbwiebe                                     43305          2805433
-chriswk                      26902            1868317
+Antihistamine                               41788          2761312
-achambord                    26582            1767323
+mhunt                                       41735          2691355
-Patrick_G                    26276            1801617
+olafm                                       41277          3284344
-yorkman                      26193            1992080
+homyur                                      39893          2850481
-SFTUser                      25182            1675689
+gri                                         39871          2515779
-nabildanial                  24942            1519409
+MarcusTullius                               38303          2251097
-Sharaf_DG                    24765            1786697
+Garf                                        37741          2999686
-ncfish1                      24411            1520927
+kdave                                       37424          2557406
-rodneyc                      24227            1409514
+SC                                          37299          2731694
-agg177                       23890            1395014
+csnodgrass                                  36207          2688994
-JanErik                      23408            1703875
+jmdana                                      36157          2210661
-Isidor                       23388            1680691
+strelock                                    34716          2074055
-Norabor                      23164            1591830
+EthanOConnor                                33370          2090311
-cisco2015                    22897            1762669
+slakovv                                     32915          2021889
-Zirie                        22542            1472937
+gopeto                                      31669          2060958
-team-oh                      22272            1636708
+manapbk                                     30987          1810399
-MazeOfGalious                21978            1629593
+Prcuvu                                      30377          2170122
-sg4032                       21947            1643265
+anst                                        30301          2190091
-ianh2105                     21725            1632562
+jkiiski                                     30136          1904470
-xor12                        21628            1680365
+spcc                                        30135          1903728
-dex                          21612            1467203
+hyperbolic.tom                              29840          2017394
-nesoneg                      21494            1463031
+xwziegtm                                    29763          2347412
-sphinx                       21211            1384728
+chuckstablers                               29659          2093438
-jjoshua2                     21001            1423089
+Pyafue                                      29650          1902349
-horst.prack                  20878            1465656
+belzedar94                                  28846          1811530
-Ente                         20865            1477066
+OuaisBla                                    27636          1578800
-0xB00B1ES                    20590            1208666
+chriswk                                     26902          1868317
-j3corre                      20405             941444
+achambord                                   26582          1767323
-Adrian.Schmidt123            20316            1281436
+Patrick_G                                   26276          1801617
-wei                          19973            1745989
+yorkman                                     26193          1992080
-MaxKlaxxMiner                19850            1009176
+Ulysses                                     25289          1674274
-rstoesser                    19569            1293588
+SFTUser                                     25182          1675689
-gopeto                       19491            1174952
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-eudhan                       19274            1283717
+Sharaf_DG                                   24765          1786697
-jundery                      18445            1115855
+rodneyc                                     24376          1416402
-megaman7de                   18377            1067540
+agg177                                      23890          1395014
-iisiraider                   18247            1101015
+Ente                                        23747          1674582
-ville                        17883            1384026
+Karpovbot                                   23629          1313186
-chris                        17698            1487385
+JanErik                                     23408          1703875
-purplefishies                17595            1092533
+Isidor                                      23388          1680691
-dju                          17353             978595
+Norabor                                     23371          1603244
-DragonLord                   17014            1162790
+cisco2015                                   22934          1763773
-IgorLeMasson                 16064            1147232
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-ako027ako                    15671            1173203
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-chuckstablers                15289             891576
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-Nikolay.IT                   15154            1068349
+MazeOfGalious                               21978          1629593
-Andrew Grant                 15114             895539
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-OssumOpossum                 14857            1007129
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-Karby                        14808             867120
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-enedene                      14476             905279
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-bpfliegel                    14298             884523
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-Hjax                         13535             915487
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-jsys14                       13459             785000
+0xB00B1ES                                   20590          1208666
-Dark_wizzie                  13422            1007152
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-mabichito                    12903             749391
+Adrian.Schmidt123                           20316          1281436
-thijsk                       12886             722107
+bonsi                                       20022          1300682
-AdrianSA                     12860             804972
+wei                                         19973          1745989
-Flopzee                      12698             894821
+dapper                                      19754          1167758
-fatmurphy                    12547             853210
+Zake9298                                    19745          1458416
-Rudolphous                   12520             832340
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-scuzzi                       12511             845761
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-SapphireBrand                12416             969604
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-modolief                     12386             896470
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-Machariel                    12335             810784
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-mschmidt                     11941             803401
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-Maxim                        11543             836024
+chris                                       17698          1487385
-infinity                     11470             727027
+dju                                         17697           994333
-torbjo                       11395             729145
+purplefishies                               17595          1092533
-Thomas A. Anderson           11372             732094
+iisiraider                                  17275          1049015
-savage84                     11358             670860
+DragonLord                                  17014          1162790
-d64                          11263             789184
+Karby                                       16457          1010138
-MooTheCow                    11237             720174
+Goatminola                                  16278          1145026
-snicolet                     11106             869170
+IgorLeMasson                                16064          1147232
-ali-al-zhrani                11086             767926
+Gaster319                                   16056          1109070
-AndreasKrug                  10875             887457
+redstone59                                  15953          1161664
-pirt                         10806             836519
+scuzzi                                      15757           968735
-basepi                       10637             744851
+ako027ako                                   15671          1173203
-michaelrpg                   10508             739039
+Nikolay.IT                                  15154          1068349
-dzjp                         10343             732529
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-aga                          10302             622975
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-ols                          10259             570669
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-lbraesch                     10252             647825
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-FormazChar                   10059             757283
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+mbeier                                      13650          1044928
+Hjax                                        13535           915487
+Dark_wizzie                                 13422          1007152
+Rudolphous                                  13244           883140
+Machariel                                   13010           863104
+infinigon                                   12991           943216
+pirt                                        12925           985437
+Skiff84                                     12923           649994
+mabichito                                   12903           749391
+thijsk                                      12886           722107
+AdrianSA                                    12860           804972
+Flopzee                                     12698           894821
+fatmurphy                                   12547           853210
+woutboat                                    12419           836696
+SapphireBrand                               12416           969604
+Oakwen                                      12406           840961
+deflectooor                                 12386           579392
+modolief                                    12386           896470
+Farseer                                     12249           694108
+pgontarz                                    12151           848794
+stocky                                      11954           699440
+mschmidt                                    11941           803401
+MooTheCow                                   11871           773654
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+dbernier                                    11705           821780
+whelanh                                     11557           245188
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+michaelrpg                                  10509           739239
+OIVAS7572                                   10420           995586
+Garruk                                      10348           704905
+dzjp                                        10343           732529
+ols                                         10259           570669

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 }

src/Makefile

@@ -1,5 +1,5 @@
 # Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-# Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+# Copyright (C) 2004-2022 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
@@ -19,11 +19,29 @@
 ### Section 1. General Configuration
 ### ==========================================================================
 
+### Establish the operating system name
+KERNEL = $(shell uname -s)
+ifeq ($(KERNEL),Linux)
+	OS = $(shell uname -o)
+endif
+
+### Target Windows OS
+ifeq ($(OS),Windows_NT)
+	ifneq ($(COMP),ndk)
+		target_windows = yes
+	endif
+else ifeq ($(COMP),mingw)
+	target_windows = yes
+	ifeq ($(WINE_PATH),)
+		WINE_PATH = $(shell which wine)
+	endif
+endif
+
 ### Executable name
-ifeq ($(COMP),mingw)
+ifeq ($(target_windows),yes)
-EXE = stockfish.exe
+	EXE = stockfish.exe
 else
-EXE = stockfish
+	EXE = stockfish
 endif
 
 ### Installation dir definitions
@@ -32,9 +50,9 @@ BINDIR = $(PREFIX)/bin
 
 ### Built-in benchmark for pgo-builds
 ifeq ($(SDE_PATH),)
-	PGOBENCH = ./$(EXE) bench
+	PGOBENCH = $(WINE_PATH) ./$(EXE) bench
 else
-	PGOBENCH = $(SDE_PATH) -- ./$(EXE) bench
+	PGOBENCH = $(SDE_PATH) -- $(WINE_PATH) ./$(EXE) bench
 endif
 
 ### Source and object files
@@ -47,12 +65,6 @@ OBJS = $(notdir $(SRCS:.cpp=.o))
 
 VPATH = syzygy:nnue:nnue/features
 
-### Establish the operating system name
-KERNEL = $(shell uname -s)
-ifeq ($(KERNEL),Linux)
-	OS = $(shell uname -o)
-endif
-
 ### ==========================================================================
 ### Section 2. High-level Configuration
 ### ==========================================================================
@@ -78,6 +90,7 @@ endif
 # ssse3 = yes/no      --- -mssse3          --- Use Intel Supplemental Streaming SIMD Extensions 3
 # sse41 = yes/no      --- -msse4.1         --- Use Intel Streaming SIMD Extensions 4.1
 # avx2 = yes/no       --- -mavx2           --- Use Intel Advanced Vector Extensions 2
+# avxvnni = yes/no    --- -mavxvnni        --- Use Intel Vector Neural Network Instructions AVX
 # avx512 = yes/no     --- -mavx512bw       --- Use Intel Advanced Vector Extensions 512
 # vnni256 = yes/no    --- -mavx512vnni     --- Use Intel Vector Neural Network Instructions 256
 # vnni512 = yes/no    --- -mavx512vnni     --- Use Intel Vector Neural Network Instructions 512
@@ -100,10 +113,10 @@ endif
 # explicitly check for the list of supported architectures (as listed with make help),
 # the user can override with `make ARCH=x86-32-vnni256 SUPPORTED_ARCH=true`
 ifeq ($(ARCH), $(filter $(ARCH), \
-                 x86-64-vnni512 x86-64-vnni256 x86-64-avx512 x86-64-bmi2 x86-64-avx2 \
+                 x86-64-vnni512 x86-64-vnni256 x86-64-avx512 x86-64-avxvnni x86-64-bmi2 \
-                 x86-64-sse41-popcnt x86-64-modern x86-64-ssse3 x86-64-sse3-popcnt \
+                 x86-64-avx2 x86-64-sse41-popcnt x86-64-modern x86-64-ssse3 x86-64-sse3-popcnt \
                  x86-64 x86-32-sse41-popcnt x86-32-sse2 x86-32 ppc-64 ppc-32 e2k \
-                 armv7 armv7-neon armv8 apple-silicon general-64 general-32))
+                 armv7 armv7-neon armv8 apple-silicon general-64 general-32 riscv64))
    SUPPORTED_ARCH=true
 else
    SUPPORTED_ARCH=false
@@ -122,10 +135,12 @@ sse2 = no
 ssse3 = no
 sse41 = no
 avx2 = no
+avxvnni = no
 avx512 = no
 vnni256 = no
 vnni512 = no
 neon = no
+arm_version = 0
 STRIP = strip
 
 ### 2.2 Architecture specific
@@ -137,7 +152,7 @@ ifeq ($(findstring x86,$(ARCH)),x86)
 ifeq ($(findstring x86-32,$(ARCH)),x86-32)
 	arch = i386
 	bits = 32
-	sse = yes
+	sse = no
 	mmx = yes
 else
 	arch = x86_64
@@ -192,6 +207,17 @@ ifeq ($(findstring -avx2,$(ARCH)),-avx2)
 	avx2 = yes
 endif
 
+ifeq ($(findstring -avxvnni,$(ARCH)),-avxvnni)
+	popcnt = yes
+	sse = yes
+	sse2 = yes
+	ssse3 = yes
+	sse41 = yes
+	avx2 = yes
+	avxvnni = yes
+	pext = yes
+endif
+
 ifeq ($(findstring -bmi2,$(ARCH)),-bmi2)
 	popcnt = yes
 	sse = yes
@@ -262,6 +288,7 @@ ifeq ($(ARCH),armv7)
 	arch = armv7
 	prefetch = yes
 	bits = 32
+	arm_version = 7
 endif
 
 ifeq ($(ARCH),armv7-neon)
@@ -270,6 +297,7 @@ ifeq ($(ARCH),armv7-neon)
 	popcnt = yes
 	neon = yes
 	bits = 32
+	arm_version = 7
 endif
 
 ifeq ($(ARCH),armv8)
@@ -277,6 +305,7 @@ ifeq ($(ARCH),armv8)
 	prefetch = yes
 	popcnt = yes
 	neon = yes
+	arm_version = 8
 endif
 
 ifeq ($(ARCH),apple-silicon)
@@ -284,6 +313,7 @@ ifeq ($(ARCH),apple-silicon)
 	prefetch = yes
 	popcnt = yes
 	neon = yes
+	arm_version = 8
 endif
 
 ifeq ($(ARCH),ppc-32)
@@ -308,16 +338,26 @@ ifeq ($(findstring e2k,$(ARCH)),e2k)
 	popcnt = yes
 endif
 
+ifeq ($(ARCH),riscv64)
+	arch = riscv64
 endif
+endif
+
 
 ### ==========================================================================
 ### Section 3. Low-level Configuration
 ### ==========================================================================
 
 ### 3.1 Selecting compiler (default = gcc)
-CXXFLAGS += -Wall -Wcast-qual -fno-exceptions -std=c++17 $(EXTRACXXFLAGS)
+ifeq ($(MAKELEVEL),0)
-DEPENDFLAGS += -std=c++17
+       export ENV_CXXFLAGS := $(CXXFLAGS)
-LDFLAGS += $(EXTRALDFLAGS)
+       export ENV_DEPENDFLAGS := $(DEPENDFLAGS)
+       export ENV_LDFLAGS := $(LDFLAGS)
+endif
+
+CXXFLAGS = $(ENV_CXXFLAGS) -Wall -Wcast-qual -fno-exceptions -std=c++17 $(EXTRACXXFLAGS)
+DEPENDFLAGS = $(ENV_DEPENDFLAGS) -std=c++17
+LDFLAGS = $(ENV_LDFLAGS) $(EXTRALDFLAGS)
 
 ifeq ($(COMP),)
 	COMP=gcc
@@ -328,11 +368,14 @@ ifeq ($(COMP),gcc)
 	CXX=g++
 	CXXFLAGS += -pedantic -Wextra -Wshadow
 
-	ifeq ($(arch),$(filter $(arch),armv7 armv8))
+	ifeq ($(arch),$(filter $(arch),armv7 armv8 riscv64))
 		ifeq ($(OS),Android)
 			CXXFLAGS += -m$(bits)
 			LDFLAGS += -m$(bits)
 		endif
+		ifeq ($(ARCH),riscv64)
+			CXXFLAGS += -latomic
+		endif
 	else
 		CXXFLAGS += -m$(bits)
 		LDFLAGS += -m$(bits)
@@ -347,29 +390,27 @@ ifeq ($(COMP),gcc)
 	endif
 endif
 
+ifeq ($(target_windows),yes)
+	LDFLAGS += -static
+endif
+
 ifeq ($(COMP),mingw)
 	comp=mingw
 
-	ifeq ($(KERNEL),Linux)
+	ifeq ($(bits),64)
-		ifeq ($(bits),64)
+		ifeq ($(shell which x86_64-w64-mingw32-c++-posix 2> /dev/null),)
-			ifeq ($(shell which x86_64-w64-mingw32-c++-posix),)
+			CXX=x86_64-w64-mingw32-c++
-				CXX=x86_64-w64-mingw32-c++
-			else
-				CXX=x86_64-w64-mingw32-c++-posix
-			endif
 		else
-			ifeq ($(shell which i686-w64-mingw32-c++-posix),)
+			CXX=x86_64-w64-mingw32-c++-posix
-				CXX=i686-w64-mingw32-c++
-			else
-				CXX=i686-w64-mingw32-c++-posix
-			endif
 		endif
 	else
-		CXX=g++
+		ifeq ($(shell which i686-w64-mingw32-c++-posix 2> /dev/null),)
+			CXX=i686-w64-mingw32-c++
+		else
+			CXX=i686-w64-mingw32-c++-posix
+		endif
 	endif
-
 	CXXFLAGS += -pedantic -Wextra -Wshadow
-	LDFLAGS += -static
 endif
 
 ifeq ($(COMP),icc)
@@ -381,23 +422,28 @@ endif
 ifeq ($(COMP),clang)
 	comp=clang
 	CXX=clang++
+	ifeq ($(target_windows),yes)
+		CXX=x86_64-w64-mingw32-clang++
+	endif
+
 	CXXFLAGS += -pedantic -Wextra -Wshadow
 
-	ifneq ($(KERNEL),Darwin)
+	ifeq ($(filter $(KERNEL),Darwin OpenBSD FreeBSD),)
-	ifneq ($(KERNEL),OpenBSD)
+	ifeq ($(target_windows),)
-	ifneq ($(KERNEL),FreeBSD)
 	ifneq ($(RTLIB),compiler-rt)
 		LDFLAGS += -latomic
 	endif
 	endif
 	endif
-	endif
 
-	ifeq ($(arch),$(filter $(arch),armv7 armv8))
+	ifeq ($(arch),$(filter $(arch),armv7 armv8 riscv64))
 		ifeq ($(OS),Android)
 			CXXFLAGS += -m$(bits)
 			LDFLAGS += -m$(bits)
 		endif
+		ifeq ($(ARCH),riscv64)
+			CXXFLAGS += -latomic
+		endif
 	else
 		CXXFLAGS += -m$(bits)
 		LDFLAGS += -m$(bits)
@@ -423,11 +469,19 @@ ifeq ($(COMP),ndk)
 	ifeq ($(arch),armv7)
 		CXX=armv7a-linux-androideabi16-clang++
 		CXXFLAGS += -mthumb -march=armv7-a -mfloat-abi=softfp -mfpu=neon
-		STRIP=arm-linux-androideabi-strip
+		ifneq ($(shell which arm-linux-androideabi-strip 2>/dev/null),)
+			STRIP=arm-linux-androideabi-strip
+		else
+			STRIP=llvm-strip
+		endif
 	endif
 	ifeq ($(arch),armv8)
 		CXX=aarch64-linux-android21-clang++
-		STRIP=aarch64-linux-android-strip
+		ifneq ($(shell which aarch64-linux-android-strip 2>/dev/null),)
+			STRIP=aarch64-linux-android-strip
+		else
+			STRIP=llvm-strip
+		endif
 	endif
 	LDFLAGS += -static-libstdc++ -pie -lm -latomic
 endif
@@ -441,6 +495,9 @@ else ifeq ($(comp),clang)
 else
 	profile_make = gcc-profile-make
 	profile_use = gcc-profile-use
+	ifeq ($(KERNEL),Darwin)
+		EXTRAPROFILEFLAGS = -fvisibility=hidden
+	endif
 endif
 
 ### Travis CI script uses COMPILER to overwrite CXX
@@ -501,10 +558,16 @@ ifeq ($(optimize),yes)
 		endif
 	endif
 
-	ifeq ($(comp),$(filter $(comp),gcc clang icc))
+	ifeq ($(KERNEL),Darwin)
-		ifeq ($(KERNEL),Darwin)
+		ifeq ($(comp),$(filter $(comp),clang icc))
 			CXXFLAGS += -mdynamic-no-pic
 		endif
+
+		ifeq ($(comp),gcc)
+			ifneq ($(arch),arm64)
+				CXXFLAGS += -mdynamic-no-pic
+			endif
+		endif
 	endif
 
 	ifeq ($(comp),clang)
@@ -540,7 +603,14 @@ endif
 ifeq ($(avx2),yes)
 	CXXFLAGS += -DUSE_AVX2
 	ifeq ($(comp),$(filter $(comp),gcc clang mingw))
-		CXXFLAGS += -mavx2
+		CXXFLAGS += -mavx2 -mbmi
+	endif
+endif
+
+ifeq ($(avxvnni),yes)
+	CXXFLAGS += -DUSE_VNNI -DUSE_AVXVNNI
+	ifeq ($(comp),$(filter $(comp),gcc clang mingw))
+		CXXFLAGS += -mavxvnni
 	endif
 endif
 
@@ -594,7 +664,7 @@ ifeq ($(mmx),yes)
 endif
 
 ifeq ($(neon),yes)
-	CXXFLAGS += -DUSE_NEON
+	CXXFLAGS += -DUSE_NEON=$(arm_version)
 	ifeq ($(KERNEL),Linux)
 	ifneq ($(COMP),ndk)
 	ifneq ($(arch),armv8)
@@ -612,16 +682,26 @@ ifeq ($(pext),yes)
 	endif
 endif
 
+### 3.7.1 Try to include git commit sha for versioning
+GIT_SHA = $(shell git rev-parse --short HEAD 2>/dev/null)
+ifneq ($(GIT_SHA), )
+	CXXFLAGS += -DGIT_SHA=\"$(GIT_SHA)\"
+endif
+
+### 3.7.2 Try to include git commit date for versioning
+GIT_DATE = $(shell git show -s --date=format:'%Y%m%d' --format=%cd HEAD 2>/dev/null)
+ifneq ($(GIT_DATE), )
+	CXXFLAGS += -DGIT_DATE=\"$(GIT_DATE)\"
+endif
+
 ### 3.8 Link Time Optimization
 ### This is a mix of compile and link time options because the lto link phase
 ### needs access to the optimization flags.
 ifeq ($(optimize),yes)
 ifeq ($(debug), no)
 	ifeq ($(comp),clang)
-		CXXFLAGS += -flto
+		CXXFLAGS += -flto=full
-		ifneq ($(findstring MINGW,$(KERNEL)),)
+		ifeq ($(target_windows),yes)
-			CXXFLAGS += -fuse-ld=lld
-		else ifneq ($(findstring MSYS,$(KERNEL)),)
 			CXXFLAGS += -fuse-ld=lld
 		endif
 		LDFLAGS += $(CXXFLAGS)
@@ -630,28 +710,18 @@ ifeq ($(debug), no)
 # GCC on some systems.
 	else ifeq ($(comp),gcc)
 	ifeq ($(gccisclang),)
-		CXXFLAGS += -flto
+		CXXFLAGS += -flto -flto-partition=one
 		LDFLAGS += $(CXXFLAGS) -flto=jobserver
-		ifneq ($(findstring MINGW,$(KERNEL)),)
-			LDFLAGS += -save-temps
-		else ifneq ($(findstring MSYS,$(KERNEL)),)
-			LDFLAGS += -save-temps
-		endif
 	else
-		CXXFLAGS += -flto
+		CXXFLAGS += -flto=full
 		LDFLAGS += $(CXXFLAGS)
 	endif
 
-# To use LTO and static linking on windows, the tool chain requires a recent gcc:
+# To use LTO and static linking on Windows,
-# gcc version 10.1 in msys2 or TDM-GCC version 9.2 are known to work, older might not.
+# the tool chain requires gcc version 10.1 or later.
-# So, only enable it for a cross from Linux by default.
 	else ifeq ($(comp),mingw)
-	ifeq ($(KERNEL),Linux)
+		CXXFLAGS += -flto -flto-partition=one
-	ifneq ($(arch),i386)
+		LDFLAGS += $(CXXFLAGS) -save-temps
-		CXXFLAGS += -flto
-		LDFLAGS += $(CXXFLAGS) -flto=jobserver
-	endif
-	endif
 	endif
 endif
 endif
@@ -689,6 +759,7 @@ help:
 	@echo "x86-64-vnni512          > x86 64-bit with vnni support 512bit wide"
 	@echo "x86-64-vnni256          > x86 64-bit with vnni support 256bit wide"
 	@echo "x86-64-avx512           > x86 64-bit with avx512 support"
+	@echo "x86-64-avxvnni          > x86 64-bit with avxvnni support"
 	@echo "x86-64-bmi2             > x86 64-bit with bmi2 support"
 	@echo "x86-64-avx2             > x86 64-bit with avx2 support"
 	@echo "x86-64-sse41-popcnt     > x86 64-bit with sse41 and popcnt support"
@@ -708,6 +779,7 @@ help:
 	@echo "apple-silicon           > Apple silicon ARM64"
 	@echo "general-64              > unspecified 64-bit"
 	@echo "general-32              > unspecified 32-bit"
+	@echo "riscv64                 > RISC-V 64-bit"
 	@echo ""
 	@echo "Supported compilers:"
 	@echo ""
@@ -740,7 +812,7 @@ endif
 
 .PHONY: help build profile-build strip install clean net objclean profileclean \
         config-sanity icc-profile-use icc-profile-make gcc-profile-use gcc-profile-make \
-        clang-profile-use clang-profile-make
+        clang-profile-use clang-profile-make FORCE
 
 build: net config-sanity
 	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) all
@@ -751,7 +823,7 @@ profile-build: net config-sanity objclean profileclean
 	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) $(profile_make)
 	@echo ""
 	@echo "Step 2/4. Running benchmark for pgo-build ..."
-	$(PGOBENCH) > /dev/null
+	$(PGOBENCH) 2>&1 | tail -n 4
 	@echo ""
 	@echo "Step 3/4. Building optimized executable ..."
 	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) objclean
@@ -766,7 +838,7 @@ strip:
 install:
 	-mkdir -p -m 755 $(BINDIR)
 	-cp $(EXE) $(BINDIR)
-	-strip $(BINDIR)/$(EXE)
+	$(STRIP) $(BINDIR)/$(EXE)
 
 # clean all
 clean: objclean profileclean
@@ -776,37 +848,48 @@ clean: objclean profileclean
 net:
 	$(eval nnuenet := $(shell grep EvalFileDefaultName evaluate.h | grep define | sed 's/.*\(nn-[a-z0-9]\{12\}.nnue\).*/\1/'))
 	@echo "Default net: $(nnuenet)"
-	$(eval nnuedownloadurl := https://tests.stockfishchess.org/api/nn/$(nnuenet))
+	$(eval nnuedownloadurl1 := https://tests.stockfishchess.org/api/nn/$(nnuenet))
+	$(eval nnuedownloadurl2 := https://github.com/official-stockfish/networks/raw/master/$(nnuenet))
 	$(eval curl_or_wget := $(shell if hash curl 2>/dev/null; then echo "curl -skL"; elif hash wget 2>/dev/null; then echo "wget -qO-"; fi))
-	@if test -f "$(nnuenet)"; then \
+	@if [ "x$(curl_or_wget)" = "x" ]; then \
-            echo "Already available."; \
+	    echo "Automatic download failed: neither curl nor wget is installed. Install one of these tools or download the net manually"; exit 1; \
-         else \
+        fi
-            if [ "x$(curl_or_wget)" = "x" ]; then \
-               echo "Automatic download failed: neither curl nor wget is installed. Install one of these tools or download the net manually"; exit 1; \
-            else \
-               echo "Downloading $(nnuedownloadurl)"; $(curl_or_wget) $(nnuedownloadurl) > $(nnuenet);\
-            fi; \
-        fi;
 	$(eval shasum_command := $(shell if hash shasum 2>/dev/null; then echo "shasum -a 256 "; elif hash sha256sum 2>/dev/null; then echo "sha256sum "; fi))
-	@if [ "x$(shasum_command)" != "x" ]; then \
+	@if [ "x$(shasum_command)" = "x" ]; then \
-	    if [ "$(nnuenet)" != "nn-"`$(shasum_command) $(nnuenet) | cut -c1-12`".nnue" ]; then \
-                echo "Failed download or $(nnuenet) corrupted, please delete!"; exit 1; \
-            fi \
-         else \
             echo "shasum / sha256sum not found, skipping net validation"; \
         fi
+	@for nnuedownloadurl in "$(nnuedownloadurl1)" "$(nnuedownloadurl2)"; do \
+	   if test -f "$(nnuenet)"; then \
+	      echo "$(nnuenet) available."; \
+	   else \
+	      if [ "x$(curl_or_wget)" != "x" ]; then \
+	         echo "Downloading $${nnuedownloadurl}"; $(curl_or_wget) $${nnuedownloadurl} > $(nnuenet);\
+	      fi; \
+	   fi; \
+	   if [ "x$(shasum_command)" != "x" ]; then \
+	      if [ "$(nnuenet)" != "nn-"`$(shasum_command) $(nnuenet) | cut -c1-12`".nnue" ]; then \
+	         echo "Removing failed download"; rm -f $(nnuenet); \
+	      else \
+	         echo "Network validated"; break; \
+	      fi; \
+	   fi; \
+	done
+	@if ! test -f "$(nnuenet)"; then \
+	    echo "Failed to download $(nnuenet)."; \
+	fi
 
 # clean binaries and objects
 objclean:
-	@rm -f $(EXE) *.o ./syzygy/*.o ./nnue/*.o ./nnue/features/*.o
+	@rm -f stockfish stockfish.exe *.o ./syzygy/*.o ./nnue/*.o ./nnue/features/*.o
 
 # clean auxiliary profiling files
 profileclean:
 	@rm -rf profdir
 	@rm -f bench.txt *.gcda *.gcno ./syzygy/*.gcda ./nnue/*.gcda ./nnue/features/*.gcda *.s
 	@rm -f stockfish.profdata *.profraw
-	@rm -f stockfish.exe.lto_wrapper_args
+	@rm -f stockfish.*args*
-	@rm -f stockfish.exe.ltrans.out
+	@rm -f stockfish.*lt*
+	@rm -f stockfish.res
 	@rm -f ./-lstdc++.res
 
 default:
@@ -837,10 +920,12 @@ config-sanity: net
 	@echo "ssse3: '$(ssse3)'"
 	@echo "sse41: '$(sse41)'"
 	@echo "avx2: '$(avx2)'"
+	@echo "avxvnni: '$(avxvnni)'"
 	@echo "avx512: '$(avx512)'"
 	@echo "vnni256: '$(vnni256)'"
 	@echo "vnni512: '$(vnni512)'"
 	@echo "neon: '$(neon)'"
+	@echo "arm_version: '$(arm_version)'"
 	@echo ""
 	@echo "Flags:"
 	@echo "CXX: $(CXX)"
@@ -854,7 +939,7 @@ config-sanity: net
 	@test "$(SUPPORTED_ARCH)" = "true"
 	@test "$(arch)" = "any" || test "$(arch)" = "x86_64" || test "$(arch)" = "i386" || \
 	 test "$(arch)" = "ppc64" || test "$(arch)" = "ppc" || test "$(arch)" = "e2k" || \
-	 test "$(arch)" = "armv7" || test "$(arch)" = "armv8" || test "$(arch)" = "arm64"
+	 test "$(arch)" = "armv7" || test "$(arch)" = "armv8" || test "$(arch)" = "arm64" || test "$(arch)" = "riscv64"
 	@test "$(bits)" = "32" || test "$(bits)" = "64"
 	@test "$(prefetch)" = "yes" || test "$(prefetch)" = "no"
 	@test "$(popcnt)" = "yes" || test "$(popcnt)" = "no"
@@ -875,6 +960,10 @@ config-sanity: net
 $(EXE): $(OBJS)
 	+$(CXX) -o $@ $(OBJS) $(LDFLAGS)
 
+# Force recompilation to ensure version info is up-to-date
+misc.o: FORCE
+FORCE:
+
 clang-profile-make:
 	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) \
 	EXTRACXXFLAGS='-fprofile-instr-generate ' \
@@ -892,12 +981,14 @@ gcc-profile-make:
 	@mkdir -p profdir
 	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) \
 	EXTRACXXFLAGS='-fprofile-generate=profdir' \
+	EXTRACXXFLAGS+=$(EXTRAPROFILEFLAGS) \
 	EXTRALDFLAGS='-lgcov' \
 	all
 
 gcc-profile-use:
 	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) \
 	EXTRACXXFLAGS='-fprofile-use=profdir -fno-peel-loops -fno-tracer' \
+	EXTRACXXFLAGS+=$(EXTRAPROFILEFLAGS) \
 	EXTRALDFLAGS='-lgcov' \
 	all
 

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) 2004-2022 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
@@ -87,6 +87,7 @@ 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"
 };
 

src/bitbase.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) 2004-2022 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

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) 2004-2022 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

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) 2004-2022 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

src/endgame.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) 2004-2022 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

src/endgame.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) 2004-2022 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

src/evaluate.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) 2004-2022 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
@@ -108,6 +108,7 @@ namespace Eval {
 
                 MemoryBuffer buffer(const_cast<char*>(reinterpret_cast<const char*>(gEmbeddedNNUEData)),
                                     size_t(gEmbeddedNNUESize));
+                (void) gEmbeddedNNUEEnd; // Silence warning on unused variable
 
                 istream stream(&buffer);
                 if (load_eval(eval_file, stream))
@@ -158,7 +159,7 @@ namespace Trace {
 
   Score scores[TERM_NB][COLOR_NB];
 
-  double to_cp(Value v) { return double(v) / PawnValueEg; }
+  double to_cp(Value v) { return double(v) / UCI::NormalizeToPawnValue; }
 
   void add(int idx, Color c, Score s) {
     scores[idx][c] = s;
@@ -192,17 +193,17 @@ using namespace Trace;
 namespace {
 
   // Threshold for lazy and space evaluation
-  constexpr Value LazyThreshold1    =  Value(3130);
+  constexpr Value LazyThreshold1    =  Value(3631);
-  constexpr Value LazyThreshold2    =  Value(2204);
+  constexpr Value LazyThreshold2    =  Value(2084);
   constexpr Value SpaceThreshold    =  Value(11551);
 
   // KingAttackWeights[PieceType] contains king attack weights by piece type
-  constexpr int KingAttackWeights[PIECE_TYPE_NB] = { 0, 0, 81, 52, 44, 10 };
+  constexpr int KingAttackWeights[PIECE_TYPE_NB] = { 0, 0, 76, 46, 45, 14 };
 
   // SafeCheck[PieceType][single/multiple] contains safe check bonus by piece type,
   // higher if multiple safe checks are possible for that piece type.
   constexpr int SafeCheck[][2] = {
-      {}, {}, {803, 1292}, {639, 974}, {1087, 1878}, {759, 1132}
+      {}, {}, {805, 1292}, {650, 984}, {1071, 1886}, {730, 1128}
   };
 
 #define S(mg, eg) make_score(mg, eg)
@@ -228,58 +229,58 @@ namespace {
   // BishopPawns[distance from edge] contains a file-dependent penalty for pawns on
   // squares of the same color as our bishop.
   constexpr Score BishopPawns[int(FILE_NB) / 2] = {
-    S(3, 8), S(3, 9), S(2, 8), S(3, 8)
+    S(3, 8), S(3, 9), S(2, 7), S(3, 7)
   };
 
   // KingProtector[knight/bishop] contains penalty for each distance unit to own king
-  constexpr Score KingProtector[] = { S(8, 9), S(6, 9) };
+  constexpr Score KingProtector[] = { S(9, 9), S(7, 9) };
 
   // Outpost[knight/bishop] contains bonuses for each knight or bishop occupying a
   // pawn protected square on rank 4 to 6 which is also safe from a pawn attack.
-  constexpr Score Outpost[] = { S(57, 38), S(31, 24) };
+  constexpr Score Outpost[] = { S(54, 34), S(31, 25) };
 
   // PassedRank[Rank] contains a bonus according to the rank of a passed pawn
   constexpr Score PassedRank[RANK_NB] = {
-    S(0, 0), S(7, 27), S(16, 32), S(17, 40), S(64, 71), S(170, 174), S(278, 262)
+    S(0, 0), S(2, 38), S(15, 36), S(22, 50), S(64, 81), S(166, 184), S(284, 269)
   };
 
   constexpr Score RookOnClosedFile = S(10, 5);
-  constexpr Score RookOnOpenFile[] = { S(19, 6), S(47, 26) };
+  constexpr Score RookOnOpenFile[] = { S(18, 8), S(49, 26) };
 
   // ThreatByMinor/ByRook[attacked PieceType] contains bonuses according to
   // which piece type attacks which one. Attacks on lesser pieces which are
   // pawn-defended are not considered.
   constexpr Score ThreatByMinor[PIECE_TYPE_NB] = {
-    S(0, 0), S(5, 32), S(55, 41), S(77, 56), S(89, 119), S(79, 162)
+    S(0, 0), S(6, 37), S(64, 50), S(82, 57), S(103, 130), S(81, 163)
   };
 
   constexpr Score ThreatByRook[PIECE_TYPE_NB] = {
-    S(0, 0), S(3, 44), S(37, 68), S(42, 60), S(0, 39), S(58, 43)
+    S(0, 0), S(3, 44), S(36, 71), S(44, 59), S(0, 39), S(60, 39)
   };
 
   constexpr Value CorneredBishop = Value(50);
 
   // Assorted bonuses and penalties
-  constexpr Score UncontestedOutpost  = S(  1, 10);
+  constexpr Score UncontestedOutpost  = S(  0, 10);
   constexpr Score BishopOnKingRing    = S( 24,  0);
   constexpr Score BishopXRayPawns     = S(  4,  5);
   constexpr Score FlankAttacks        = S(  8,  0);
-  constexpr Score Hanging             = S( 69, 36);
+  constexpr Score Hanging             = S( 72, 40);
   constexpr Score KnightOnQueen       = S( 16, 11);
   constexpr Score LongDiagonalBishop  = S( 45,  0);
   constexpr Score MinorBehindPawn     = S( 18,  3);
-  constexpr Score PassedFile          = S( 11,  8);
+  constexpr Score PassedFile          = S( 13,  8);
-  constexpr Score PawnlessFlank       = S( 17, 95);
+  constexpr Score PawnlessFlank       = S( 19, 97);
-  constexpr Score ReachableOutpost    = S( 31, 22);
+  constexpr Score ReachableOutpost    = S( 33, 19);
-  constexpr Score RestrictedPiece     = S(  7,  7);
+  constexpr Score RestrictedPiece     = S(  6,  7);
   constexpr Score RookOnKingRing      = S( 16,  0);
-  constexpr Score SliderOnQueen       = S( 60, 18);
+  constexpr Score SliderOnQueen       = S( 62, 21);
-  constexpr Score ThreatByKing        = S( 24, 89);
+  constexpr Score ThreatByKing        = S( 24, 87);
   constexpr Score ThreatByPawnPush    = S( 48, 39);
-  constexpr Score ThreatBySafePawn    = S(173, 94);
+  constexpr Score ThreatBySafePawn    = S(167, 99);
   constexpr Score TrappedRook         = S( 55, 13);
   constexpr Score WeakQueenProtection = S( 14,  0);
-  constexpr Score WeakQueen           = S( 56, 15);
+  constexpr Score WeakQueen           = S( 57, 19);
 
 
 #undef S
@@ -980,7 +981,7 @@ namespace {
     // Initialize score by reading the incrementally updated scores included in
     // the position object (material + piece square tables) and the material
     // imbalance. Score is computed internally from the white point of view.
-    Score score = pos.psq_score() + me->imbalance() + pos.this_thread()->trend;
+    Score score = pos.psq_score() + me->imbalance();
 
     // Probe the pawn hash table
     pe = Pawns::probe(pos);
@@ -988,7 +989,9 @@ namespace {
 
     // Early exit if score is high
     auto lazy_skip = [&](Value lazyThreshold) {
-        return abs(mg_value(score) + eg_value(score)) > lazyThreshold + pos.non_pawn_material() / 32;
+        return abs(mg_value(score) + eg_value(score)) >   lazyThreshold
+                                                        + std::abs(pos.this_thread()->bestValue) * 5 / 4
+                                                        + pos.non_pawn_material() / 32;
     };
 
     if (lazy_skip(LazyThreshold1))
@@ -1039,72 +1042,58 @@ make_v:
     return v;
   }
 
-
-  /// Fisher Random Chess: correction for cornered bishops, to fix chess960 play with NNUE
-
-  Value fix_FRC(const Position& pos) {
-
-    constexpr Bitboard Corners =  1ULL << SQ_A1 | 1ULL << SQ_H1 | 1ULL << SQ_A8 | 1ULL << SQ_H8;
-
-    if (!(pos.pieces(BISHOP) & Corners))
-        return VALUE_ZERO;
-
-    int correction = 0;
-
-    if (   pos.piece_on(SQ_A1) == W_BISHOP
-        && pos.piece_on(SQ_B2) == W_PAWN)
-        correction -= CorneredBishop;
-
-    if (   pos.piece_on(SQ_H1) == W_BISHOP
-        && pos.piece_on(SQ_G2) == W_PAWN)
-        correction -= CorneredBishop;
-
-    if (   pos.piece_on(SQ_A8) == B_BISHOP
-        && pos.piece_on(SQ_B7) == B_PAWN)
-        correction += CorneredBishop;
-
-    if (   pos.piece_on(SQ_H8) == B_BISHOP
-        && pos.piece_on(SQ_G7) == B_PAWN)
-        correction += CorneredBishop;
-
-    return pos.side_to_move() == WHITE ?  Value(5 * correction)
-                                       : -Value(5 * correction);
-  }
-
 } // namespace Eval
 
 
 /// evaluate() is the evaluator for the outer world. It returns a static
 /// evaluation of the position from the point of view of the side to move.
 
-Value Eval::evaluate(const Position& pos) {
+Value Eval::evaluate(const Position& pos, int* complexity) {
 
   Value v;
+  Value psq = pos.psq_eg_stm();
 
-  // Deciding between classical and NNUE eval: for high PSQ imbalance we use classical,
+  // We use the much less accurate but faster Classical eval when the NNUE
-  // but we switch to NNUE during long shuffling or with high material on the board.
+  // option is set to false. Otherwise we use the NNUE eval unless the
+  // PSQ advantage is decisive and several pieces remain. (~3 Elo)
+  bool useClassical = !useNNUE || (pos.count<ALL_PIECES>() > 7 && abs(psq) > 1760);
 
-  if (  !useNNUE
+  if (useClassical)
-      || abs(eg_value(pos.psq_score())) * 5 > (850 + pos.non_pawn_material() / 64) * (5 + pos.rule50_count()))
+      v = Evaluation<NO_TRACE>(pos).value();
-      v = Evaluation<NO_TRACE>(pos).value();          // classical
   else
   {
-      int scale =   883
+      int nnueComplexity;
-                  + 32 * pos.count<PAWN>()
+      int scale = 1064 + 106 * pos.non_pawn_material() / 5120;
-                  + 32 * pos.non_pawn_material() / 1024;
 
-       v = NNUE::evaluate(pos, true) * scale / 1024;  // NNUE
+      Color stm = pos.side_to_move();
+      Value optimism = pos.this_thread()->optimism[stm];
 
-       if (pos.is_chess960())
+      Value nnue = NNUE::evaluate(pos, true, &nnueComplexity);
-           v += fix_FRC(pos);
+
+      // Blend nnue complexity with (semi)classical complexity
+      nnueComplexity = (  416 * nnueComplexity
+                        + 424 * abs(psq - nnue)
+                        + (optimism  > 0 ? int(optimism) * int(psq - nnue) : 0)
+                        ) / 1024;
+
+      // Return hybrid NNUE complexity to caller
+      if (complexity)
+          *complexity = nnueComplexity;
+
+      optimism = optimism * (269 + nnueComplexity) / 256;
+      v = (nnue * scale + optimism * (scale - 754)) / 1024;
   }
 
   // Damp down the evaluation linearly when shuffling
-  v = v * (100 - pos.rule50_count()) / 100;
+  v = v * (195 - pos.rule50_count()) / 211;
 
   // Guarantee evaluation does not hit the tablebase range
   v = std::clamp(v, VALUE_TB_LOSS_IN_MAX_PLY + 1, VALUE_TB_WIN_IN_MAX_PLY - 1);
 
+  // When not using NNUE, return classical complexity to caller
+  if (complexity && (!useNNUE || useClassical))
+      *complexity = abs(v - psq);
+
   return v;
 }
 
@@ -1125,7 +1114,10 @@ std::string Eval::trace(Position& pos) {
 
   std::memset(scores, 0, sizeof(scores));
 
-  pos.this_thread()->trend = SCORE_ZERO; // Reset any dynamic contempt
+  // Reset any global variable used in eval
+  pos.this_thread()->bestValue       = VALUE_ZERO;
+  pos.this_thread()->optimism[WHITE] = VALUE_ZERO;
+  pos.this_thread()->optimism[BLACK] = VALUE_ZERO;
 
   v = Evaluation<TRACE>(pos).value();
 

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) 2004-2022 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
@@ -31,7 +31,7 @@ class Position;
 namespace Eval {
 
   std::string trace(Position& pos);
-  Value evaluate(const Position& pos);
+  Value evaluate(const Position& pos, int* complexity = nullptr);
 
   extern bool useNNUE;
   extern std::string currentEvalFileName;
@@ -39,12 +39,12 @@ namespace Eval {
   // 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-13406b1dcbe0.nnue"
+  #define EvalFileDefaultName   "nn-ad9b42354671.nnue"
 
   namespace NNUE {
 
     std::string trace(Position& pos);
-    Value evaluate(const Position& pos, bool adjusted = false);
+    Value evaluate(const Position& pos, bool adjusted = false, int* complexity = nullptr);
 
     void init();
     void verify();

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) 2004-2022 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

src/material.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) 2004-2022 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

src/material.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) 2004-2022 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

src/misc.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) 2004-2022 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
@@ -36,6 +36,8 @@ typedef bool(*fun1_t)(LOGICAL_PROCESSOR_RELATIONSHIP,
                       PSYSTEM_LOGICAL_PROCESSOR_INFORMATION_EX, PDWORD);
 typedef bool(*fun2_t)(USHORT, PGROUP_AFFINITY);
 typedef bool(*fun3_t)(HANDLE, CONST GROUP_AFFINITY*, PGROUP_AFFINITY);
+typedef bool(*fun4_t)(USHORT, PGROUP_AFFINITY, USHORT, PUSHORT);
+typedef WORD(*fun5_t)();
 }
 #endif
 
@@ -65,9 +67,8 @@ namespace Stockfish {
 
 namespace {
 
-/// Version number. If Version is left empty, then compile date in the format
+/// Version number or dev.
-/// DD-MM-YY and show in engine_info.
+const string version = "15.1";
-const string Version = "14.1";
 
 /// Our fancy logging facility. The trick here is to replace cin.rdbuf() and
 /// cout.rdbuf() with two Tie objects that tie cin and cout to a file stream. We
@@ -136,23 +137,41 @@ public:
 } // namespace
 
 
-/// engine_info() returns the full name of the current Stockfish version. This
+/// engine_info() returns the full name of the current Stockfish version.
-/// will be either "Stockfish <Tag> DD-MM-YY" (where DD-MM-YY is the date when
+/// For local dev compiles we try to append the commit sha and commit date
-/// the program was compiled) or "Stockfish <Version>", depending on whether
+/// from git if that fails only the local compilation date is set and "nogit" is specified:
-/// Version is empty.
+/// Stockfish dev-YYYYMMDD-SHA
+/// or
+/// Stockfish dev-YYYYMMDD-nogit
+///
+/// For releases (non dev builds) we only include the version number:
+/// Stockfish version
 
 string engine_info(bool to_uci) {
+  stringstream ss;
+  ss << "Stockfish " << version << setfill('0');
 
-  const string months("Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec");
+  if (version == "dev")
-  string month, day, year;
-  stringstream ss, date(__DATE__); // From compiler, format is "Sep 21 2008"
-
-  ss << "Stockfish " << Version << setfill('0');
-
-  if (Version.empty())
   {
+      ss << "-";
+      #ifdef GIT_DATE
+      ss << GIT_DATE;
+      #else
+      const string months("Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec");
+      string month, day, year;
+      stringstream date(__DATE__); // From compiler, format is "Sep 21 2008"
+
       date >> month >> day >> year;
-      ss << setw(2) << day << setw(2) << (1 + months.find(month) / 4) << year.substr(2);
+      ss << year << setw(2) << setfill('0') << (1 + months.find(month) / 4) << setw(2) << setfill('0') << day;
+      #endif
+
+      ss << "-";
+
+      #ifdef GIT_SHA
+      ss << GIT_SHA;
+      #else
+      ss << "nogit";
+      #endif
   }
 
   ss << (to_uci  ? "\nid author ": " by ")
@@ -376,10 +395,9 @@ void std_aligned_free(void* ptr) {
 
 #if defined(_WIN32)
 
-static void* aligned_large_pages_alloc_windows(size_t allocSize) {
+static void* aligned_large_pages_alloc_windows([[maybe_unused]] size_t allocSize) {
 
   #if !defined(_WIN64)
-    (void)allocSize; // suppress unused-parameter compiler warning
     return nullptr;
   #else
 
@@ -495,11 +513,11 @@ void bindThisThread(size_t) {}
 
 #else
 
-/// best_group() retrieves logical processor information using Windows specific
+/// best_node() retrieves logical processor information using Windows specific
-/// API and returns the best group id for the thread with index idx. Original
+/// API and returns the best node id for the thread with index idx. Original
 /// code from Texel by Peter Österlund.
 
-int best_group(size_t idx) {
+int best_node(size_t idx) {
 
   int threads = 0;
   int nodes = 0;
@@ -513,7 +531,8 @@ int best_group(size_t idx) {
   if (!fun1)
       return -1;
 
-  // First call to get returnLength. We expect it to fail due to null buffer
+  // First call to GetLogicalProcessorInformationEx() to get returnLength.
+  // We expect the call to fail due to null buffer.
   if (fun1(RelationAll, nullptr, &returnLength))
       return -1;
 
@@ -521,7 +540,7 @@ int best_group(size_t idx) {
   SYSTEM_LOGICAL_PROCESSOR_INFORMATION_EX *buffer, *ptr;
   ptr = buffer = (SYSTEM_LOGICAL_PROCESSOR_INFORMATION_EX*)malloc(returnLength);
 
-  // Second call, now we expect to succeed
+  // Second call to GetLogicalProcessorInformationEx(), now we expect to succeed
   if (!fun1(RelationAll, buffer, &returnLength))
   {
       free(buffer);
@@ -571,22 +590,38 @@ int best_group(size_t idx) {
 void bindThisThread(size_t idx) {
 
   // Use only local variables to be thread-safe
-  int group = best_group(idx);
+  int node = best_node(idx);
 
-  if (group == -1)
+  if (node == -1)
       return;
 
   // Early exit if the needed API are not available at runtime
   HMODULE k32 = GetModuleHandle("Kernel32.dll");
   auto fun2 = (fun2_t)(void(*)())GetProcAddress(k32, "GetNumaNodeProcessorMaskEx");
   auto fun3 = (fun3_t)(void(*)())GetProcAddress(k32, "SetThreadGroupAffinity");
+  auto fun4 = (fun4_t)(void(*)())GetProcAddress(k32, "GetNumaNodeProcessorMask2");
+  auto fun5 = (fun5_t)(void(*)())GetProcAddress(k32, "GetMaximumProcessorGroupCount");
 
   if (!fun2 || !fun3)
       return;
 
-  GROUP_AFFINITY affinity;
+  if (!fun4 || !fun5)
-  if (fun2(group, &affinity))
+  {
-      fun3(GetCurrentThread(), &affinity, nullptr);
+      GROUP_AFFINITY affinity;
+      if (fun2(node, &affinity))                                                 // GetNumaNodeProcessorMaskEx
+          fun3(GetCurrentThread(), &affinity, nullptr);                          // SetThreadGroupAffinity
+  }
+  else
+  {
+      // If a numa node has more than one processor group, we assume they are
+      // sized equal and we spread threads evenly across the groups.
+      USHORT elements, returnedElements;
+      elements = fun5();                                                         // GetMaximumProcessorGroupCount
+      GROUP_AFFINITY *affinity = (GROUP_AFFINITY*)malloc(elements * sizeof(GROUP_AFFINITY));
+      if (fun4(node, affinity, elements, &returnedElements))                     // GetNumaNodeProcessorMask2
+          fun3(GetCurrentThread(), &affinity[idx % returnedElements], nullptr);  // SetThreadGroupAffinity
+      free(affinity);
+  }
 }
 
 #endif
@@ -607,8 +642,7 @@ string argv0;            // path+name of the executable binary, as given by argv
 string binaryDirectory;  // path of the executable directory
 string workingDirectory; // path of the working directory
 
-void init(int argc, char* argv[]) {
+void init([[maybe_unused]] int argc, char* argv[]) {
-    (void)argc;
     string pathSeparator;
 
     // extract the path+name of the executable binary

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) 2004-2022 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
@@ -90,9 +90,6 @@ static inline const bool IsLittleEndian = (Le.c[0] == 4);
 class RunningAverage {
   public:
 
-      // Constructor
-      RunningAverage() {}
-
       // Reset the running average to rational value p / q
       void set(int64_t p, int64_t q)
         { average = p * PERIOD * RESOLUTION / q; }
@@ -102,8 +99,11 @@ class RunningAverage {
         { average = RESOLUTION * v + (PERIOD - 1) * average / PERIOD; }
 
       // Test if average is strictly greater than rational a / b
-      bool is_greater(int64_t a, int64_t b)
+      bool is_greater(int64_t a, int64_t b) const
-        { return b * average > a * PERIOD * RESOLUTION ; }
+        { return b * average > a * (PERIOD * RESOLUTION); }
+
+      int64_t value() const
+        { return average / (PERIOD * RESOLUTION); }
 
   private :
       static constexpr int64_t PERIOD     = 4096;
@@ -116,28 +116,16 @@ class ValueList {
 
 public:
   std::size_t size() const { return size_; }
-  void resize(std::size_t newSize) { size_ = newSize; }
   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 maxSize = std::max(size_, other.size_);
-    for (std::size_t i = 0; i < maxSize; ++i) {
-      std::swap(values_[i], other.values_[i]);
-    }
-    std::swap(size_, other.size_);
-  }
-
 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).

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) 2004-2022 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

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) 2004-2022 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

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) 2004-2022 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
@@ -18,6 +18,7 @@
 
 #include <cassert>
 
+#include "bitboard.h"
 #include "movepick.h"
 
 namespace Stockfish {
@@ -56,35 +57,40 @@ namespace {
 /// 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,
+MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh,
-                       const CapturePieceToHistory* cph, const PieceToHistory** ch, Move cm, const Move* killers, int pl)
+                                                             const CapturePieceToHistory* cph,
-           : pos(p), mainHistory(mh), lowPlyHistory(lp), captureHistory(cph), continuationHistory(ch),
+                                                             const PieceToHistory** ch,
-             ttMove(ttm), refutations{{killers[0], 0}, {killers[1], 0}, {cm, 0}}, depth(d), ply(pl) {
+                                                             Move cm,
-
+                                                             const Move* killers)
+           : pos(p), mainHistory(mh), captureHistory(cph), continuationHistory(ch),
+             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));
+  threatenedPieces = 0;
 }
 
 /// 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)
+                                                             const CapturePieceToHistory* cph,
-           : pos(p), mainHistory(mh), captureHistory(cph), continuationHistory(ch), ttMove(ttm), recaptureSquare(rs), depth(d) {
+                                                             const PieceToHistory** ch,
-
+                                                             Square rs)
+           : pos(p), mainHistory(mh), captureHistory(cph), continuationHistory(ch), ttMove(ttm), recaptureSquare(rs), depth(d)
+{
   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));
 }
 
 /// 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) {
+           : pos(p), captureHistory(cph), ttMove(ttm), threshold(th)
-
+{
   assert(!pos.checkers());
 
   stage = PROBCUT_TT + !(ttm && pos.capture(ttm)
@@ -100,28 +106,48 @@ void MovePicker::score() {
 
   static_assert(Type == CAPTURES || Type == QUIETS || Type == EVASIONS, "Wrong type");
 
+  [[maybe_unused]] Bitboard threatenedByPawn, threatenedByMinor, threatenedByRook;
+  if constexpr (Type == QUIETS)
+  {
+      Color us = pos.side_to_move();
+
+      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;
+
+      // 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 =  int(PieceValue[MG][pos.piece_on(to_sq(m))]) * 6
+          m.value =  6 * int(PieceValue[MG][pos.piece_on(to_sq(m))])
-                   + (*captureHistory)[pos.moved_piece(m)][to_sq(m)][type_of(pos.piece_on(to_sq(m)))];
+                   +     (*captureHistory)[pos.moved_piece(m)][to_sq(m)][type_of(pos.piece_on(to_sq(m)))];
 
       else if constexpr (Type == QUIETS)
-          m.value =      (*mainHistory)[pos.side_to_move()][from_to(m)]
+          m.value =  2 * (*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 ? 6 * (*lowPlyHistory)[ply][from_to(m)] : 0);
+                   +     (threatenedPieces & from_sq(m) ?
-
+                           (type_of(pos.moved_piece(m)) == QUEEN && !(to_sq(m) & threatenedByRook)  ? 50000
+                          : type_of(pos.moved_piece(m)) == ROOK  && !(to_sq(m) & threatenedByMinor) ? 25000
+                          :                                         !(to_sq(m) & threatenedByPawn)  ? 15000
+                          :                                                                           0)
+                          :                                                                           0)
+                   +     bool(pos.check_squares(type_of(pos.moved_piece(m))) & to_sq(m)) * 16384;
       else // Type == EVASIONS
       {
           if (pos.capture(m))
               m.value =  PieceValue[MG][pos.piece_on(to_sq(m))]
-                       - Value(type_of(pos.moved_piece(m)));
+                       - Value(type_of(pos.moved_piece(m)))
+                       + (1 << 28);
           else
-              m.value =      (*mainHistory)[pos.side_to_move()][from_to(m)]
+              m.value =  (*mainHistory)[pos.side_to_move()][from_to(m)]
-                       + 2 * (*continuationHistory[0])[pos.moved_piece(m)][to_sq(m)]
+                       + (*continuationHistory[0])[pos.moved_piece(m)][to_sq(m)];
-                       - (1 << 28);
       }
 }
 
@@ -165,11 +191,12 @@ top:
       endMoves = generate<CAPTURES>(pos, cur);
 
       score<CAPTURES>();
+      partial_insertion_sort(cur, endMoves, std::numeric_limits<int>::min());
       ++stage;
       goto top;
 
   case GOOD_CAPTURE:
-      if (select<Best>([&](){
+      if (select<Next>([&](){
                        return pos.see_ge(*cur, Value(-69 * cur->value / 1024)) ?
                               // Move losing capture to endBadCaptures to be tried later
                               true : (*endBadCaptures++ = *cur, false); }))
@@ -237,10 +264,10 @@ top:
       return select<Best>([](){ return true; });
 
   case PROBCUT:
-      return select<Best>([&](){ return pos.see_ge(*cur, threshold); });
+      return select<Next>([&](){ return pos.see_ge(*cur, threshold); });
 
   case QCAPTURE:
-      if (select<Best>([&](){ return   depth > DEPTH_QS_RECAPTURES
+      if (select<Next>([&](){ return   depth > DEPTH_QS_RECAPTURES
                                     || to_sq(*cur) == recaptureSquare; }))
           return *(cur - 1);
 

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) 2004-2022 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
@@ -86,13 +86,8 @@ enum StatsType { NoCaptures, Captures };
 /// 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, 14365, COLOR_NB, int(SQUARE_NB) * int(SQUARE_NB)> ButterflyHistory;
+/// (~11 elo)
-
+typedef Stats<int16_t, 7183, COLOR_NB, int(SQUARE_NB) * int(SQUARE_NB)> ButterflyHistory;
-/// At higher depths LowPlyHistory records successful quiet moves near the root
-/// and quiet moves which are/were in the PV (ttPv). LowPlyHistory is populated during
-/// iterative deepening and at each new search the data is shifted down by 2 plies
-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
@@ -107,6 +102,7 @@ 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)
 typedef Stats<PieceToHistory, NOT_USED, PIECE_NB, SQUARE_NB> ContinuationHistory;
 
 
@@ -123,20 +119,20 @@ class MovePicker {
 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**,
+                                           Move,
+                                           const Move*);
   MovePicker(const Position&, Move, Depth, const ButterflyHistory*,
                                            const CapturePieceToHistory*,
                                            const PieceToHistory**,
                                            Square);
-  MovePicker(const Position&, Move, Depth, const ButterflyHistory*,
+  MovePicker(const Position&, Move, Value, const CapturePieceToHistory*);
-                                           const LowPlyHistory*,
-                                           const CapturePieceToHistory*,
-                                           const PieceToHistory**,
-                                           Move,
-                                           const Move*,
-                                           int);
   Move next_move(bool skipQuiets = false);
 
+  Bitboard threatenedPieces;
+
 private:
   template<PickType T, typename Pred> Move select(Pred);
   template<GenType> void score();
@@ -145,7 +141,6 @@ private:
 
   const Position& pos;
   const ButterflyHistory* mainHistory;
-  const LowPlyHistory* lowPlyHistory;
   const CapturePieceToHistory* captureHistory;
   const PieceToHistory** continuationHistory;
   Move ttMove;
@@ -154,7 +149,6 @@ private:
   Square recaptureSquare;
   Value threshold;
   Depth depth;
-  int ply;
   ExtMove moves[MAX_MOVES];
 };
 

src/nnue/evaluate_nnue.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) 2004-2022 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
@@ -109,7 +109,7 @@ namespace Stockfish::Eval::NNUE {
   {
     write_little_endian<std::uint32_t>(stream, Version);
     write_little_endian<std::uint32_t>(stream, hashValue);
-    write_little_endian<std::uint32_t>(stream, desc.size());
+    write_little_endian<std::uint32_t>(stream, (std::uint32_t)desc.size());
     stream.write(&desc[0], desc.size());
     return !stream.fail();
   }
@@ -137,40 +137,38 @@ namespace Stockfish::Eval::NNUE {
   }
 
   // Evaluation function. Perform differential calculation.
-  Value evaluate(const Position& pos, bool adjusted) {
+  Value evaluate(const Position& pos, bool adjusted, int* complexity) {
 
     // 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;
-    int delta = 7;
+    int delta = 24 - pos.non_pawn_material() / 9560;
 
 #if defined(ALIGNAS_ON_STACK_VARIABLES_BROKEN)
     TransformedFeatureType transformedFeaturesUnaligned[
       FeatureTransformer::BufferSize + alignment / sizeof(TransformedFeatureType)];
-    char bufferUnaligned[Network::BufferSize + alignment];
 
     auto* transformedFeatures = align_ptr_up<alignment>(&transformedFeaturesUnaligned[0]);
-    auto* buffer = align_ptr_up<alignment>(&bufferUnaligned[0]);
 #else
     alignas(alignment)
       TransformedFeatureType transformedFeatures[FeatureTransformer::BufferSize];
-    alignas(alignment) char buffer[Network::BufferSize];
 #endif
 
     ASSERT_ALIGNED(transformedFeatures, alignment);
-    ASSERT_ALIGNED(buffer, alignment);
 
-    const std::size_t bucket = (pos.count<ALL_PIECES>() - 1) / 4;
+    const int bucket = (pos.count<ALL_PIECES>() - 1) / 4;
     const auto psqt = featureTransformer->transform(pos, transformedFeatures, bucket);
-    const auto positional = network[bucket]->propagate(transformedFeatures, buffer)[0];
+    const auto positional = network[bucket]->propagate(transformedFeatures);
 
-    // Give more value to positional evaluation when material is balanced
+    if (complexity)
-    if (   adjusted
+        *complexity = abs(psqt - positional) / OutputScale;
-        && abs(pos.non_pawn_material(WHITE) - pos.non_pawn_material(BLACK)) <= RookValueMg - BishopValueMg)
+
-      return  static_cast<Value>(((128 - delta) * psqt + (128 + delta) * positional) / 128 / OutputScale);
+    // 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);
+        return static_cast<Value>((psqt + positional) / OutputScale);
   }
 
   struct NnueEvalTrace {
@@ -191,27 +189,20 @@ namespace Stockfish::Eval::NNUE {
 #if defined(ALIGNAS_ON_STACK_VARIABLES_BROKEN)
     TransformedFeatureType transformedFeaturesUnaligned[
       FeatureTransformer::BufferSize + alignment / sizeof(TransformedFeatureType)];
-    char bufferUnaligned[Network::BufferSize + alignment];
 
     auto* transformedFeatures = align_ptr_up<alignment>(&transformedFeaturesUnaligned[0]);
-    auto* buffer = align_ptr_up<alignment>(&bufferUnaligned[0]);
 #else
     alignas(alignment)
       TransformedFeatureType transformedFeatures[FeatureTransformer::BufferSize];
-    alignas(alignment) char buffer[Network::BufferSize];
 #endif
 
     ASSERT_ALIGNED(transformedFeatures, alignment);
-    ASSERT_ALIGNED(buffer, alignment);
 
     NnueEvalTrace t{};
     t.correctBucket = (pos.count<ALL_PIECES>() - 1) / 4;
-    for (std::size_t bucket = 0; bucket < LayerStacks; ++bucket) {
+    for (IndexType bucket = 0; bucket < LayerStacks; ++bucket) {
-      const auto psqt = featureTransformer->transform(pos, transformedFeatures, bucket);
+      const auto materialist = featureTransformer->transform(pos, transformedFeatures, bucket);
-      const auto output = network[bucket]->propagate(transformedFeatures, buffer);
+      const auto positional = network[bucket]->propagate(transformedFeatures);
-
-      int materialist = psqt;
-      int positional  = output[0];
 
       t.psqt[bucket] = static_cast<Value>( materialist / OutputScale );
       t.positional[bucket] = static_cast<Value>( positional / OutputScale );
@@ -229,12 +220,12 @@ namespace Stockfish::Eval::NNUE {
 
     buffer[0] = (v < 0 ? '-' : v > 0 ? '+' : ' ');
 
-    int cp = std::abs(100 * v / PawnValueEg);
+    int cp = std::abs(100 * v / UCI::NormalizeToPawnValue);
     if (cp >= 10000)
     {
         buffer[1] = '0' + cp / 10000; cp %= 10000;
         buffer[2] = '0' + cp / 1000; cp %= 1000;
-        buffer[3] = '0' + cp / 100; cp %= 100;
+        buffer[3] = '0' + cp / 100;
         buffer[4] = ' ';
     }
     else if (cp >= 1000)
@@ -260,7 +251,7 @@ namespace Stockfish::Eval::NNUE {
 
     buffer[0] = (v < 0 ? '-' : v > 0 ? '+' : ' ');
 
-    double cp = 1.0 * std::abs(int(v)) / PawnValueEg;
+    double cp = 1.0 * std::abs(int(v)) / UCI::NormalizeToPawnValue;
     sprintf(&buffer[1], "%6.2f", cp);
   }
 

src/nnue/evaluate_nnue.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) 2004-2022 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

src/nnue/features/half_ka_v2_hm.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) 2004-2022 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
@@ -24,50 +24,51 @@
 
 namespace Stockfish::Eval::NNUE::Features {
 
-  // Orient a square according to perspective (rotates by 180 for black)
-  inline Square HalfKAv2_hm::orient(Color perspective, Square s, Square ksq) {
-    return Square(int(s) ^ (bool(perspective) * SQ_A8) ^ ((file_of(ksq) < FILE_E) * SQ_H1));
-  }
-
   // Index of a feature for a given king position and another piece on some square
-  inline IndexType HalfKAv2_hm::make_index(Color perspective, Square s, Piece pc, Square ksq) {
+  template<Color Perspective>
-    Square o_ksq = orient(perspective, ksq, ksq);
+  inline IndexType HalfKAv2_hm::make_index(Square s, Piece pc, Square ksq) {
-    return IndexType(orient(perspective, s, ksq) + PieceSquareIndex[perspective][pc] + PS_NB * KingBuckets[o_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,
-    Color perspective,
     IndexList& active
   ) {
-    Square ksq = pos.square<KING>(perspective);
+    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));
+      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);
 
   // append_changed_indices() : get a list of indices for recently changed features
-
+  template<Color Perspective>
   void HalfKAv2_hm::append_changed_indices(
     Square ksq,
     const DirtyPiece& dp,
-    Color perspective,
     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));
+        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));
+        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;
   }

src/nnue/features/half_ka_v2_hm.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) 2004-2022 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
@@ -49,8 +49,8 @@ namespace Stockfish::Eval::NNUE::Features {
       PS_B_ROOK   =  7 * SQUARE_NB,
       PS_W_QUEEN  =  8 * SQUARE_NB,
       PS_B_QUEEN  =  9 * SQUARE_NB,
-      PS_KING     =  10 * SQUARE_NB,
+      PS_KING     = 10 * SQUARE_NB,
-      PS_NB       =  11 * SQUARE_NB
+      PS_NB       = 11 * SQUARE_NB
     };
 
     static constexpr IndexType PieceSquareIndex[COLOR_NB][PIECE_NB] = {
@@ -62,11 +62,9 @@ namespace Stockfish::Eval::NNUE::Features {
         PS_NONE, PS_W_PAWN, PS_W_KNIGHT, PS_W_BISHOP, PS_W_ROOK, PS_W_QUEEN, PS_KING, PS_NONE }
     };
 
-    // Orient a square according to perspective (rotates by 180 for black)
-    static Square orient(Color perspective, Square s, Square ksq);
-
     // Index of a feature for a given king position and another piece on some square
-    static IndexType make_index(Color perspective, Square s, Piece pc, Square ksq);
+    template<Color Perspective>
+    static IndexType make_index(Square s, Piece pc, Square ksq);
 
    public:
     // Feature name
@@ -79,15 +77,45 @@ namespace Stockfish::Eval::NNUE::Features {
     static constexpr IndexType Dimensions =
         static_cast<IndexType>(SQUARE_NB) * static_cast<IndexType>(PS_NB) / 2;
 
-    static constexpr int KingBuckets[64] = {
+#define B(v) (v * PS_NB)
-      -1, -1, -1, -1, 31, 30, 29, 28,
+    static constexpr int KingBuckets[COLOR_NB][SQUARE_NB] = {
-      -1, -1, -1, -1, 27, 26, 25, 24,
+      { B(28), B(29), B(30), B(31), B(31), B(30), B(29), B(28),
-      -1, -1, -1, -1, 23, 22, 21, 20,
+        B(24), B(25), B(26), B(27), B(27), B(26), B(25), B(24),
-      -1, -1, -1, -1, 19, 18, 17, 16,
+        B(20), B(21), B(22), B(23), B(23), B(22), B(21), B(20),
-      -1, -1, -1, -1, 15, 14, 13, 12,
+        B(16), B(17), B(18), B(19), B(19), B(18), B(17), B(16),
-      -1, -1, -1, -1, 11, 10,  9,  8,
+        B(12), B(13), B(14), B(15), B(15), B(14), B(13), B(12),
-      -1, -1, -1, -1,  7,  6,  5,  4,
+        B( 8), B( 9), B(10), B(11), B(11), B(10), B( 9), B( 8),
-      -1, -1, -1, -1,  3,  2,  1,  0
+        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) }
+    };
+#undef B
+
+    // 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 }
     };
 
     // Maximum number of simultaneously active features.
@@ -95,16 +123,16 @@ namespace Stockfish::Eval::NNUE::Features {
     using IndexList = ValueList<IndexType, MaxActiveDimensions>;
 
     // Get a list of indices for active features
+    template<Color Perspective>
     static void append_active_indices(
       const Position& pos,
-      Color perspective,
       IndexList& active);
 
     // Get a list of indices for recently changed features
+    template<Color Perspective>
     static void append_changed_indices(
       Square ksq,
       const DirtyPiece& dp,
-      Color perspective,
       IndexList& removed,
       IndexList& added
     );

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) 2004-2022 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
@@ -25,7 +25,7 @@
 #include <algorithm>
 #include <type_traits>
 #include "../nnue_common.h"
-#include "../../simd.h"
+#include "simd.h"
 
 /*
   This file contains the definition for a fully connected layer (aka affine transform).
@@ -63,20 +63,17 @@ namespace Stockfish::Eval::NNUE::Layers {
   {
 # if defined(USE_SSE2)
     // At least a multiple of 16, with SSE2.
-    static_assert(PaddedInputDimensions % 16 == 0);
+    constexpr IndexType NumChunks = ceil_to_multiple<IndexType>(InputDimensions, 16) / 16;
-    constexpr IndexType NumChunks = PaddedInputDimensions / 16;
     const __m128i Zeros = _mm_setzero_si128();
     const auto inputVector = reinterpret_cast<const __m128i*>(input);
 
 # elif defined(USE_MMX)
-    static_assert(InputDimensions % 8 == 0);
+    constexpr IndexType NumChunks = ceil_to_multiple<IndexType>(InputDimensions, 8) / 8;
-    constexpr IndexType NumChunks = InputDimensions / 8;
     const __m64 Zeros = _mm_setzero_si64();
     const auto inputVector = reinterpret_cast<const __m64*>(input);
 
 # elif defined(USE_NEON)
-    static_assert(PaddedInputDimensions % 16 == 0);
+    constexpr IndexType NumChunks = ceil_to_multiple<IndexType>(InputDimensions, 16) / 16;
-    constexpr IndexType NumChunks = PaddedInputDimensions / 16;
     const auto inputVector = reinterpret_cast<const int8x8_t*>(input);
 # endif
 
@@ -151,26 +148,35 @@ namespace Stockfish::Eval::NNUE::Layers {
   }
 #endif
 
-  template <typename PreviousLayer, IndexType OutDims, typename Enabled = void>
+  template <IndexType InDims, IndexType OutDims, typename Enabled = void>
   class AffineTransform;
 
+#if defined (USE_AVX512)
+  constexpr IndexType LargeInputSize = 2 * 64;
+#else
+  constexpr IndexType LargeInputSize = std::numeric_limits<IndexType>::max();
+#endif
+
   // A specialization for large inputs.
-  template <typename PreviousLayer, IndexType OutDims>
+  template <IndexType InDims, IndexType OutDims>
-  class AffineTransform<PreviousLayer, OutDims, std::enable_if_t<(PreviousLayer::OutputDimensions >= 2*64-1)>> {
+  class AffineTransform<InDims, OutDims, std::enable_if_t<(ceil_to_multiple<IndexType>(InDims, MaxSimdWidth) >= LargeInputSize)>> {
    public:
     // Input/output type
-    using InputType = typename PreviousLayer::OutputType;
+    using InputType = std::uint8_t;
     using OutputType = std::int32_t;
-    static_assert(std::is_same<InputType, std::uint8_t>::value, "");
 
     // Number of input/output dimensions
-    static constexpr IndexType InputDimensions = PreviousLayer::OutputDimensions;
+    static constexpr IndexType InputDimensions = InDims;
     static constexpr IndexType OutputDimensions = OutDims;
 
     static constexpr IndexType PaddedInputDimensions =
       ceil_to_multiple<IndexType>(InputDimensions, MaxSimdWidth);
+    static constexpr IndexType PaddedOutputDimensions =
+      ceil_to_multiple<IndexType>(OutputDimensions, MaxSimdWidth);
 
-    static_assert(PaddedInputDimensions >= 128, "Something went wrong. This specialization should not have been chosen.");
+    using OutputBuffer = OutputType[PaddedOutputDimensions];
+
+    static_assert(PaddedInputDimensions >= LargeInputSize, "Something went wrong. This specialization should not have been chosen.");
 
 #if defined (USE_AVX512)
     static constexpr const IndexType InputSimdWidth = 64;
@@ -181,6 +187,9 @@ namespace Stockfish::Eval::NNUE::Layers {
 #elif defined (USE_SSSE3)
     static constexpr const IndexType InputSimdWidth = 16;
     static constexpr const IndexType MaxNumOutputRegs = 8;
+#elif defined (USE_NEON)
+    static constexpr const IndexType InputSimdWidth = 8;
+    static constexpr const IndexType MaxNumOutputRegs = 8;
 #else
     // The fallback implementation will not have permuted weights.
     // We define these to avoid a lot of ifdefs later.
@@ -200,20 +209,12 @@ namespace Stockfish::Eval::NNUE::Layers {
 
     static_assert(OutputDimensions % NumOutputRegs == 0);
 
-    // Size of forward propagation buffer used in this layer
-    static constexpr std::size_t SelfBufferSize =
-      ceil_to_multiple(OutputDimensions * sizeof(OutputType), CacheLineSize);
-
-    // Size of the forward propagation buffer used from the input layer to this layer
-    static constexpr std::size_t BufferSize =
-      PreviousLayer::BufferSize + SelfBufferSize;
-
     // Hash value embedded in the evaluation file
-    static constexpr std::uint32_t get_hash_value() {
+    static constexpr std::uint32_t get_hash_value(std::uint32_t prevHash) {
       std::uint32_t hashValue = 0xCC03DAE4u;
       hashValue += OutputDimensions;
-      hashValue ^= PreviousLayer::get_hash_value() >> 1;
+      hashValue ^= prevHash >> 1;
-      hashValue ^= PreviousLayer::get_hash_value() << 31;
+      hashValue ^= prevHash << 31;
       return hashValue;
     }
 
@@ -240,11 +241,10 @@ namespace Stockfish::Eval::NNUE::Layers {
 
     // Read network parameters
     bool read_parameters(std::istream& stream) {
-      if (!previousLayer.read_parameters(stream)) return false;
+      for (IndexType i = 0; i < OutputDimensions; ++i)
-      for (std::size_t i = 0; i < OutputDimensions; ++i)
         biases[i] = read_little_endian<BiasType>(stream);
 
-      for (std::size_t i = 0; i < OutputDimensions * PaddedInputDimensions; ++i)
+      for (IndexType i = 0; i < OutputDimensions * PaddedInputDimensions; ++i)
         weights[get_weight_index(i)] = read_little_endian<WeightType>(stream);
 
       return !stream.fail();
@@ -252,11 +252,10 @@ namespace Stockfish::Eval::NNUE::Layers {
 
     // Write network parameters
     bool write_parameters(std::ostream& stream) const {
-      if (!previousLayer.write_parameters(stream)) return false;
+      for (IndexType i = 0; i < OutputDimensions; ++i)
-      for (std::size_t i = 0; i < OutputDimensions; ++i)
           write_little_endian<BiasType>(stream, biases[i]);
 
-      for (std::size_t i = 0; i < OutputDimensions * PaddedInputDimensions; ++i)
+      for (IndexType i = 0; i < OutputDimensions * PaddedInputDimensions; ++i)
         write_little_endian<WeightType>(stream, weights[get_weight_index(i)]);
 
       return !stream.fail();
@@ -264,58 +263,66 @@ namespace Stockfish::Eval::NNUE::Layers {
 
     // Forward propagation
     const OutputType* propagate(
-        const TransformedFeatureType* transformedFeatures, char* buffer) const {
+        const InputType* input, OutputType* output) const {
-      const auto input = previousLayer.propagate(
-        transformedFeatures, buffer + SelfBufferSize);
-      OutputType* output = reinterpret_cast<OutputType*>(buffer);
 
 #if defined (USE_AVX512)
-      using vec_t = __m512i;
+      using acc_vec_t = __m512i;
-      #define vec_setzero _mm512_setzero_si512
+      using bias_vec_t = __m128i;
-      #define vec_set_32 _mm512_set1_epi32
+      using weight_vec_t = __m512i;
-      #define vec_add_dpbusd_32 Simd::m512_add_dpbusd_epi32
+      using in_vec_t = __m512i;
+      #define vec_zero _mm512_setzero_si512()
       #define vec_add_dpbusd_32x2 Simd::m512_add_dpbusd_epi32x2
       #define vec_hadd Simd::m512_hadd
       #define vec_haddx4 Simd::m512_haddx4
 #elif defined (USE_AVX2)
-      using vec_t = __m256i;
+      using acc_vec_t = __m256i;
-      #define vec_setzero _mm256_setzero_si256
+      using bias_vec_t = __m128i;
-      #define vec_set_32 _mm256_set1_epi32
+      using weight_vec_t = __m256i;
-      #define vec_add_dpbusd_32 Simd::m256_add_dpbusd_epi32
+      using in_vec_t = __m256i;
+      #define vec_zero _mm256_setzero_si256()
       #define vec_add_dpbusd_32x2 Simd::m256_add_dpbusd_epi32x2
       #define vec_hadd Simd::m256_hadd
       #define vec_haddx4 Simd::m256_haddx4
 #elif defined (USE_SSSE3)
-      using vec_t = __m128i;
+      using acc_vec_t = __m128i;
-      #define vec_setzero _mm_setzero_si128
+      using bias_vec_t = __m128i;
-      #define vec_set_32 _mm_set1_epi32
+      using weight_vec_t = __m128i;
-      #define vec_add_dpbusd_32 Simd::m128_add_dpbusd_epi32
+      using in_vec_t = __m128i;
+      #define vec_zero _mm_setzero_si128()
       #define vec_add_dpbusd_32x2 Simd::m128_add_dpbusd_epi32x2
       #define vec_hadd Simd::m128_hadd
       #define vec_haddx4 Simd::m128_haddx4
+#elif defined (USE_NEON)
+      using acc_vec_t = int32x4_t;
+      using bias_vec_t = int32x4_t;
+      using weight_vec_t = int8x8_t;
+      using in_vec_t = int8x8_t;
+      #define vec_zero {0}
+      #define vec_add_dpbusd_32x2 Simd::neon_m128_add_dpbusd_epi32x2
+      #define vec_hadd Simd::neon_m128_hadd
+      #define vec_haddx4 Simd::neon_m128_haddx4
 #endif
 
-#if defined (USE_SSSE3)
+#if defined (USE_SSSE3) || defined (USE_NEON)
-      const vec_t* invec = reinterpret_cast<const vec_t*>(input);
+      const in_vec_t* invec = reinterpret_cast<const in_vec_t*>(input);
-
 
       // Perform accumulation to registers for each big block
       for (IndexType bigBlock = 0; bigBlock < NumBigBlocks; ++bigBlock)
       {
-        vec_t acc[NumOutputRegs] = { vec_setzero() };
+        acc_vec_t acc[NumOutputRegs] = { vec_zero };
 
         // Each big block has NumOutputRegs small blocks in each "row", one per register.
         // We process two small blocks at a time to save on one addition without VNNI.
         for (IndexType smallBlock = 0; smallBlock < NumSmallBlocksPerOutput; smallBlock += 2)
         {
-          const vec_t* weightvec =
+          const weight_vec_t* weightvec =
-            reinterpret_cast<const vec_t*>(
+            reinterpret_cast<const weight_vec_t*>(
                 weights
               + bigBlock * BigBlockSize
               + smallBlock * SmallBlockSize * NumOutputRegs);
 
-          const vec_t in0 = invec[smallBlock + 0];
+          const in_vec_t in0 = invec[smallBlock + 0];
-          const vec_t in1 = invec[smallBlock + 1];
+          const in_vec_t in1 = invec[smallBlock + 1];
 
           for (IndexType k = 0; k < NumOutputRegs; ++k)
             vec_add_dpbusd_32x2(acc[k], in0, weightvec[k], in1, weightvec[k + NumOutputRegs]);
@@ -324,8 +331,8 @@ namespace Stockfish::Eval::NNUE::Layers {
         // Horizontally add all accumulators.
         if constexpr (NumOutputRegs % 4 == 0)
         {
-          __m128i* outputvec = reinterpret_cast<__m128i*>(output);
+          bias_vec_t* outputvec = reinterpret_cast<bias_vec_t*>(output);
-          const __m128i* biasvec = reinterpret_cast<const __m128i*>(biases);
+          const bias_vec_t* biasvec = reinterpret_cast<const bias_vec_t*>(biases);
 
           for (IndexType k = 0; k < NumOutputRegs; k += 4)
           {
@@ -343,9 +350,7 @@ namespace Stockfish::Eval::NNUE::Layers {
         }
       }
 
-# undef vec_setzero
+# undef vec_zero
-# undef vec_set_32
-# undef vec_add_dpbusd_32
 # undef vec_add_dpbusd_32x2
 # undef vec_hadd
 # undef vec_haddx4
@@ -365,48 +370,42 @@ namespace Stockfish::Eval::NNUE::Layers {
     using BiasType = OutputType;
     using WeightType = std::int8_t;
 
-    PreviousLayer previousLayer;
-
     alignas(CacheLineSize) BiasType biases[OutputDimensions];
     alignas(CacheLineSize) WeightType weights[OutputDimensions * PaddedInputDimensions];
   };
 
-  template <typename PreviousLayer, IndexType OutDims>
+  template <IndexType InDims, IndexType OutDims>
-  class AffineTransform<PreviousLayer, OutDims, std::enable_if_t<(PreviousLayer::OutputDimensions < 2*64-1)>> {
+  class AffineTransform<InDims, OutDims, std::enable_if_t<(ceil_to_multiple<IndexType>(InDims, MaxSimdWidth) < LargeInputSize)>> {
    public:
     // Input/output type
-    using InputType = typename PreviousLayer::OutputType;
+    // Input/output type
+    using InputType = std::uint8_t;
     using OutputType = std::int32_t;
-    static_assert(std::is_same<InputType, std::uint8_t>::value, "");
 
     // Number of input/output dimensions
-    static constexpr IndexType InputDimensions =
+    static constexpr IndexType InputDimensions = InDims;
-        PreviousLayer::OutputDimensions;
     static constexpr IndexType OutputDimensions = OutDims;
-    static constexpr IndexType PaddedInputDimensions =
-        ceil_to_multiple<IndexType>(InputDimensions, MaxSimdWidth);
 
-    static_assert(PaddedInputDimensions < 128, "Something went wrong. This specialization should not have been chosen.");
+    static constexpr IndexType PaddedInputDimensions =
+      ceil_to_multiple<IndexType>(InputDimensions, MaxSimdWidth);
+    static constexpr IndexType PaddedOutputDimensions =
+      ceil_to_multiple<IndexType>(OutputDimensions, MaxSimdWidth);
+
+    using OutputBuffer = OutputType[PaddedOutputDimensions];
+
+    static_assert(PaddedInputDimensions < LargeInputSize, "Something went wrong. This specialization should not have been chosen.");
 
 #if defined (USE_SSSE3)
     static constexpr const IndexType OutputSimdWidth = SimdWidth / 4;
     static constexpr const IndexType InputSimdWidth = SimdWidth;
 #endif
 
-    // Size of forward propagation buffer used in this layer
-    static constexpr std::size_t SelfBufferSize =
-      ceil_to_multiple(OutputDimensions * sizeof(OutputType), CacheLineSize);
-
-    // Size of the forward propagation buffer used from the input layer to this layer
-    static constexpr std::size_t BufferSize =
-      PreviousLayer::BufferSize + SelfBufferSize;
-
     // Hash value embedded in the evaluation file
-    static constexpr std::uint32_t get_hash_value() {
+    static constexpr std::uint32_t get_hash_value(std::uint32_t prevHash) {
       std::uint32_t hashValue = 0xCC03DAE4u;
       hashValue += OutputDimensions;
-      hashValue ^= PreviousLayer::get_hash_value() >> 1;
+      hashValue ^= prevHash >> 1;
-      hashValue ^= PreviousLayer::get_hash_value() << 31;
+      hashValue ^= prevHash << 31;
       return hashValue;
     }
 
@@ -429,10 +428,9 @@ namespace Stockfish::Eval::NNUE::Layers {
 
     // Read network parameters
     bool read_parameters(std::istream& stream) {
-      if (!previousLayer.read_parameters(stream)) return false;
+      for (IndexType i = 0; i < OutputDimensions; ++i)
-      for (std::size_t i = 0; i < OutputDimensions; ++i)
         biases[i] = read_little_endian<BiasType>(stream);
-      for (std::size_t i = 0; i < OutputDimensions * PaddedInputDimensions; ++i)
+      for (IndexType i = 0; i < OutputDimensions * PaddedInputDimensions; ++i)
         weights[get_weight_index(i)] = read_little_endian<WeightType>(stream);
 
       return !stream.fail();
@@ -440,21 +438,17 @@ namespace Stockfish::Eval::NNUE::Layers {
 
     // Write network parameters
     bool write_parameters(std::ostream& stream) const {
-      if (!previousLayer.write_parameters(stream)) return false;
+      for (IndexType i = 0; i < OutputDimensions; ++i)
-      for (std::size_t i = 0; i < OutputDimensions; ++i)
         write_little_endian<BiasType>(stream, biases[i]);
 
-      for (std::size_t i = 0; i < OutputDimensions * PaddedInputDimensions; ++i)
+      for (IndexType i = 0; i < OutputDimensions * PaddedInputDimensions; ++i)
         write_little_endian<WeightType>(stream, weights[get_weight_index(i)]);
 
       return !stream.fail();
     }
     // Forward propagation
     const OutputType* propagate(
-        const TransformedFeatureType* transformedFeatures, char* buffer) const {
+        const InputType* input, OutputType* output) const {
-      const auto input = previousLayer.propagate(
-        transformedFeatures, buffer + SelfBufferSize);
-      const auto output = reinterpret_cast<OutputType*>(buffer);
 
 #if defined (USE_AVX2)
       using vec_t = __m256i;
@@ -479,12 +473,11 @@ namespace Stockfish::Eval::NNUE::Layers {
 #if defined (USE_SSSE3)
       const auto inputVector = reinterpret_cast<const vec_t*>(input);
 
-      static_assert(InputDimensions % 8 == 0);
       static_assert(OutputDimensions % OutputSimdWidth == 0 || OutputDimensions == 1);
 
       if constexpr (OutputDimensions % OutputSimdWidth == 0)
       {
-        constexpr IndexType NumChunks = InputDimensions / 4;
+        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);
@@ -543,8 +536,6 @@ namespace Stockfish::Eval::NNUE::Layers {
     using BiasType = OutputType;
     using WeightType = std::int8_t;
 
-    PreviousLayer previousLayer;
-
     alignas(CacheLineSize) BiasType biases[OutputDimensions];
     alignas(CacheLineSize) WeightType weights[OutputDimensions * PaddedInputDimensions];
   };

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) 2004-2022 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
@@ -26,51 +26,41 @@
 namespace Stockfish::Eval::NNUE::Layers {
 
   // Clipped ReLU
-  template <typename PreviousLayer>
+  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 InputDimensions = PreviousLayer::OutputDimensions;
+    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
+    using OutputBuffer = OutputType[PaddedOutputDimensions];
-    static constexpr std::size_t SelfBufferSize =
-        ceil_to_multiple(OutputDimensions * sizeof(OutputType), CacheLineSize);
-
-    // Size of the forward propagation buffer used from the input layer to this layer
-    static constexpr std::size_t BufferSize =
-        PreviousLayer::BufferSize + SelfBufferSize;
 
     // Hash value embedded in the evaluation file
-    static constexpr std::uint32_t get_hash_value() {
+    static constexpr std::uint32_t get_hash_value(std::uint32_t prevHash) {
       std::uint32_t hashValue = 0x538D24C7u;
-      hashValue += PreviousLayer::get_hash_value();
+      hashValue += prevHash;
       return hashValue;
     }
 
     // Read network parameters
-    bool read_parameters(std::istream& stream) {
+    bool read_parameters(std::istream&) {
-      return previousLayer.read_parameters(stream);
+      return true;
     }
 
     // Write network parameters
-    bool write_parameters(std::ostream& stream) const {
+    bool write_parameters(std::ostream&) const {
-      return previousLayer.write_parameters(stream);
+      return true;
     }
 
     // Forward propagation
     const OutputType* propagate(
-        const TransformedFeatureType* transformedFeatures, char* buffer) const {
+        const InputType* input, OutputType* output) const {
-      const auto input = previousLayer.propagate(
-          transformedFeatures, buffer + SelfBufferSize);
-      const auto output = reinterpret_cast<OutputType*>(buffer);
 
   #if defined(USE_AVX2)
       if constexpr (InputDimensions % SimdWidth == 0) {
@@ -181,19 +171,8 @@ namespace Stockfish::Eval::NNUE::Layers {
             std::max(0, std::min(127, input[i] >> WeightScaleBits)));
       }
 
-      // Affine transform layers expect that there is at least
-      // ceil_to_multiple(OutputDimensions, 32) initialized values.
-      // We cannot do this in the affine transform because it requires
-      // preallocating space here.
-      for (IndexType i = OutputDimensions; i < PaddedOutputDimensions; ++i) {
-        output[i] = 0;
-      }
-
       return output;
     }
-
-   private:
-    PreviousLayer previousLayer;
   };
 
 }  // namespace Stockfish::Eval::NNUE::Layers

src/nnue/layers/input_slice.h

@@ -1,73 +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 Stockfish::Eval::NNUE::Layers {
-
-// Input layer
-template <IndexType OutDims, IndexType Offset = 0>
-class InputSlice {
- public:
-  // Need to maintain alignment
-  static_assert(Offset % MaxSimdWidth == 0, "");
-
-  // Output type
-  using OutputType = TransformedFeatureType;
-
-  // Output dimensionality
-  static constexpr IndexType OutputDimensions = OutDims;
-
-  // Size of forward propagation buffer used from the input layer to this layer
-  static constexpr std::size_t BufferSize = 0;
-
-  // Hash value embedded in the evaluation file
-  static constexpr std::uint32_t get_hash_value() {
-    std::uint32_t hashValue = 0xEC42E90Du;
-    hashValue ^= OutputDimensions ^ (Offset << 10);
-    return hashValue;
-  }
-
-  // Read network parameters
-  bool read_parameters(std::istream& /*stream*/) {
-    return true;
-  }
-
-  // Write network parameters
-  bool write_parameters(std::ostream& /*stream*/) const {
-    return true;
-  }
-
-  // Forward propagation
-  const OutputType* propagate(
-      const TransformedFeatureType* transformedFeatures,
-      char* /*buffer*/) const {
-    return transformedFeatures + Offset;
-  }
-
- private:
-};
-
-}  // namespace Stockfish::Eval::NNUE::Layers
-
-#endif // #ifndef NNUE_LAYERS_INPUT_SLICE_H_INCLUDED

src/nnue/layers/simd.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) 2004-2022 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
@@ -46,6 +46,13 @@
 #define USE_INLINE_ASM
 #endif
 
+// Use either the AVX512 or AVX-VNNI version of the VNNI instructions.
+#if defined(USE_AVXVNNI)
+#define VNNI_PREFIX "%{vex%} "
+#else
+#define VNNI_PREFIX ""
+#endif
+
 namespace Stockfish::Simd {
 
 #if defined (USE_AVX512)
@@ -208,7 +215,7 @@ namespace Stockfish::Simd {
 # if defined (USE_VNNI)
 #   if defined (USE_INLINE_ASM)
       asm(
-        "vpdpbusd %[b], %[a], %[acc]\n\t"
+        VNNI_PREFIX "vpdpbusd %[b], %[a], %[acc]\n\t"
         : [acc]"+v"(acc)
         : [a]"v"(a), [b]"vm"(b)
       );
@@ -240,8 +247,8 @@ namespace Stockfish::Simd {
 # if defined (USE_VNNI)
 #   if defined (USE_INLINE_ASM)
       asm(
-        "vpdpbusd %[b0], %[a0], %[acc]\n\t"
+        VNNI_PREFIX "vpdpbusd %[b0], %[a0], %[acc]\n\t"
-        "vpdpbusd %[b1], %[a1], %[acc]\n\t"
+        VNNI_PREFIX "vpdpbusd %[b1], %[a1], %[acc]\n\t"
         : [acc]"+v"(acc)
         : [a0]"v"(a0), [b0]"vm"(b0), [a1]"v"(a1), [b1]"vm"(b1)
       );
@@ -336,6 +343,45 @@ namespace Stockfish::Simd {
 
 #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;
+    }
+
+    [[maybe_unused]] static int32x4_t neon_m128_haddx4(
+        int32x4_t sum0, int32x4_t sum1, int32x4_t sum2, int32x4_t sum3,
+        int32x4_t bias) {
+
+      int32x4_t hsums {
+        neon_m128_reduce_add_epi32(sum0),
+        neon_m128_reduce_add_epi32(sum1),
+        neon_m128_reduce_add_epi32(sum2),
+        neon_m128_reduce_add_epi32(sum3)
+      };
+      return vaddq_s32(hsums, bias);
+    }
+
+    [[maybe_unused]] static void neon_m128_add_dpbusd_epi32x2(
+        int32x4_t& acc,
+        int8x8_t a0, int8x8_t b0,
+        int8x8_t a1, int8x8_t b1) {
+
+      int16x8_t product = vmull_s8(a0, b0);
+      product = vmlal_s8(product, a1, b1);
+      acc = vpadalq_s16(acc, product);
+    }
+
+#endif
+
 }
 
 #endif // STOCKFISH_SIMD_H_INCLUDED

src/nnue/layers/sqr_clipped_relu.h

@@ -0,0 +1,120 @@
+/*
+  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+  Copyright (C) 2004-2022 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 "../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
+    const OutputType* propagate(
+        const InputType* input, OutputType* output) const {
+
+  #if defined(USE_SSE2)
+      constexpr IndexType NumChunks = InputDimensions / 16;
+
+  #ifdef USE_SSE41
+      const __m128i Zero = _mm_setzero_si128();
+  #else
+      const __m128i k0x80s = _mm_set1_epi8(-128);
+  #endif
+
+      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]));
+
+        // Not sure if
+        words0 = _mm_srli_epi16(_mm_mulhi_epi16(words0, words0), 3);
+        words1 = _mm_srli_epi16(_mm_mulhi_epi16(words1, words1), 3);
+
+        const __m128i packedbytes = _mm_packs_epi16(words0, words1);
+
+        _mm_store_si128(&out[i],
+
+  #ifdef USE_SSE41
+          _mm_max_epi8(packedbytes, Zero)
+  #else
+          _mm_subs_epi8(_mm_adds_epi8(packedbytes, k0x80s), k0x80s)
+  #endif
+
+        );
+      }
+      constexpr IndexType Start = NumChunks * 16;
+
+  #else
+      constexpr IndexType Start = 0;
+  #endif
+
+      for (IndexType i = Start; i < InputDimensions; ++i) {
+        output[i] = static_cast<OutputType>(
+            // realy should be /127 but we need to make it fast
+            // needs to be accounted for in the trainer
+            std::max(0ll, std::min(127ll, (((long long)input[i] * input[i]) >> (2 * WeightScaleBits)) / 128)));
+      }
+
+      return output;
+    }
+  };
+
+}  // namespace Stockfish::Eval::NNUE::Layers
+
+#endif // NNUE_LAYERS_SQR_CLIPPED_RELU_H_INCLUDED

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) 2004-2022 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

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) 2004-2022 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
@@ -21,39 +21,117 @@
 #ifndef NNUE_ARCHITECTURE_H_INCLUDED
 #define NNUE_ARCHITECTURE_H_INCLUDED
 
+#include <memory>
+
 #include "nnue_common.h"
 
 #include "features/half_ka_v2_hm.h"
 
-#include "layers/input_slice.h"
 #include "layers/affine_transform.h"
 #include "layers/clipped_relu.h"
+#include "layers/sqr_clipped_relu.h"
+
+#include "../misc.h"
 
 namespace Stockfish::Eval::NNUE {
 
-  // Input features used in evaluation function
+// Input features used in evaluation function
-  using FeatureSet = Features::HalfKAv2_hm;
+using FeatureSet = Features::HalfKAv2_hm;
 
-  // Number of input feature dimensions after conversion
+// Number of input feature dimensions after conversion
-  constexpr IndexType TransformedFeatureDimensions = 1024;
+constexpr IndexType TransformedFeatureDimensions = 1024;
-  constexpr IndexType PSQTBuckets = 8;
+constexpr IndexType PSQTBuckets = 8;
-  constexpr IndexType LayerStacks = 8;
+constexpr IndexType LayerStacks = 8;
 
-  namespace Layers {
+struct Network
+{
+  static constexpr int FC_0_OUTPUTS = 15;
+  static constexpr int FC_1_OUTPUTS = 32;
 
-    // Define network structure
+  Layers::AffineTransform<TransformedFeatureDimensions, FC_0_OUTPUTS + 1> fc_0;
-    using InputLayer = InputSlice<TransformedFeatureDimensions * 2>;
+  Layers::SqrClippedReLU<FC_0_OUTPUTS + 1> ac_sqr_0;
-    using HiddenLayer1 = ClippedReLU<AffineTransform<InputLayer, 8>>;
+  Layers::ClippedReLU<FC_0_OUTPUTS + 1> ac_0;
-    using HiddenLayer2 = ClippedReLU<AffineTransform<HiddenLayer1, 32>>;
+  Layers::AffineTransform<FC_0_OUTPUTS * 2, FC_1_OUTPUTS> fc_1;
-    using OutputLayer = AffineTransform<HiddenLayer2, 1>;
+  Layers::ClippedReLU<FC_1_OUTPUTS> ac_1;
+  Layers::AffineTransform<FC_1_OUTPUTS, 1> fc_2;
 
-  }  // namespace Layers
+  // 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;
 
-  using Network = Layers::OutputLayer;
+    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);
 
-  static_assert(TransformedFeatureDimensions % MaxSimdWidth == 0, "");
+    return hashValue;
-  static_assert(Network::OutputDimensions == 1, "");
+  }
-  static_assert(std::is_same<Network::OutputType, std::int32_t>::value, "");
+
+  // Read network parameters
+  bool read_parameters(std::istream& stream) {
+    if (!fc_0.read_parameters(stream)) return false;
+    if (!ac_0.read_parameters(stream)) return false;
+    if (!fc_1.read_parameters(stream)) return false;
+    if (!ac_1.read_parameters(stream)) return false;
+    if (!fc_2.read_parameters(stream)) return false;
+    return true;
+  }
+
+  // Read network parameters
+  bool write_parameters(std::ostream& stream) const {
+    if (!fc_0.write_parameters(stream)) return false;
+    if (!ac_0.write_parameters(stream)) return false;
+    if (!fc_1.write_parameters(stream)) return false;
+    if (!ac_1.write_parameters(stream)) return false;
+    if (!fc_2.write_parameters(stream)) return false;
+    return true;
+  }
+
+  std::int32_t propagate(const TransformedFeatureType* transformedFeatures)
+  {
+    struct alignas(CacheLineSize) Buffer
+    {
+      alignas(CacheLineSize) decltype(fc_0)::OutputBuffer fc_0_out;
+      alignas(CacheLineSize) decltype(ac_sqr_0)::OutputType ac_sqr_0_out[ceil_to_multiple<IndexType>(FC_0_OUTPUTS * 2, 32)];
+      alignas(CacheLineSize) decltype(ac_0)::OutputBuffer ac_0_out;
+      alignas(CacheLineSize) decltype(fc_1)::OutputBuffer fc_1_out;
+      alignas(CacheLineSize) decltype(ac_1)::OutputBuffer ac_1_out;
+      alignas(CacheLineSize) 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(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 = int(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
 

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) 2004-2022 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
@@ -109,7 +109,7 @@ namespace Stockfish::Eval::NNUE {
 
   // write_little_endian() is our 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, independantly of the byte
+  // 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) {
@@ -127,11 +127,11 @@ namespace Stockfish::Eval::NNUE {
           {
             for (; i + 1 < sizeof(IntType); ++i)
             {
-                u[i] = v;
+                u[i] = (std::uint8_t)v;
                 v >>= 8;
             }
           }
-          u[i] = v;
+          u[i] = (std::uint8_t)v;
 
           stream.write(reinterpret_cast<char*>(u), sizeof(IntType));
       }

src/nnue/nnue_feature_transformer.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) 2004-2022 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
@@ -47,12 +47,22 @@ namespace Stockfish::Eval::NNUE {
   #define vec_store(a,b) _mm512_store_si512(a,b)
   #define vec_add_16(a,b) _mm512_add_epi16(a,b)
   #define vec_sub_16(a,b) _mm512_sub_epi16(a,b)
+  #define vec_mul_16(a,b) _mm512_mullo_epi16(a,b)
+  #define vec_zero() _mm512_setzero_epi32()
+  #define vec_set_16(a) _mm512_set1_epi16(a)
+  #define vec_max_16(a,b) _mm512_max_epi16(a,b)
+  #define vec_min_16(a,b) _mm512_min_epi16(a,b)
+  inline vec_t vec_msb_pack_16(vec_t a, vec_t b){
+    vec_t compacted = _mm512_packs_epi16(_mm512_srli_epi16(a,7),_mm512_srli_epi16(b,7));
+    return _mm512_permutexvar_epi64(_mm512_setr_epi64(0, 2, 4, 6, 1, 3, 5, 7), compacted);
+  }
   #define vec_load_psqt(a) _mm256_load_si256(a)
   #define vec_store_psqt(a,b) _mm256_store_si256(a,b)
   #define vec_add_psqt_32(a,b) _mm256_add_epi32(a,b)
   #define vec_sub_psqt_32(a,b) _mm256_sub_epi32(a,b)
   #define vec_zero_psqt() _mm256_setzero_si256()
   #define NumRegistersSIMD 32
+  #define MaxChunkSize 64
 
   #elif USE_AVX2
   typedef __m256i vec_t;
@@ -61,12 +71,22 @@ namespace Stockfish::Eval::NNUE {
   #define vec_store(a,b) _mm256_store_si256(a,b)
   #define vec_add_16(a,b) _mm256_add_epi16(a,b)
   #define vec_sub_16(a,b) _mm256_sub_epi16(a,b)
+  #define vec_mul_16(a,b) _mm256_mullo_epi16(a,b)
+  #define vec_zero() _mm256_setzero_si256()
+  #define vec_set_16(a) _mm256_set1_epi16(a)
+  #define vec_max_16(a,b) _mm256_max_epi16(a,b)
+  #define vec_min_16(a,b) _mm256_min_epi16(a,b)
+  inline vec_t vec_msb_pack_16(vec_t a, vec_t b){
+    vec_t compacted = _mm256_packs_epi16(_mm256_srli_epi16(a,7), _mm256_srli_epi16(b,7));
+    return _mm256_permute4x64_epi64(compacted, 0b11011000);
+  }
   #define vec_load_psqt(a) _mm256_load_si256(a)
   #define vec_store_psqt(a,b) _mm256_store_si256(a,b)
   #define vec_add_psqt_32(a,b) _mm256_add_epi32(a,b)
   #define vec_sub_psqt_32(a,b) _mm256_sub_epi32(a,b)
   #define vec_zero_psqt() _mm256_setzero_si256()
   #define NumRegistersSIMD 16
+  #define MaxChunkSize 32
 
   #elif USE_SSE2
   typedef __m128i vec_t;
@@ -75,12 +95,19 @@ namespace Stockfish::Eval::NNUE {
   #define vec_store(a,b) *(a)=(b)
   #define vec_add_16(a,b) _mm_add_epi16(a,b)
   #define vec_sub_16(a,b) _mm_sub_epi16(a,b)
+  #define vec_mul_16(a,b) _mm_mullo_epi16(a,b)
+  #define vec_zero() _mm_setzero_si128()
+  #define vec_set_16(a) _mm_set1_epi16(a)
+  #define vec_max_16(a,b) _mm_max_epi16(a,b)
+  #define vec_min_16(a,b) _mm_min_epi16(a,b)
+  #define vec_msb_pack_16(a,b) _mm_packs_epi16(_mm_srli_epi16(a,7),_mm_srli_epi16(b,7))
   #define vec_load_psqt(a) (*(a))
   #define vec_store_psqt(a,b) *(a)=(b)
   #define vec_add_psqt_32(a,b) _mm_add_epi32(a,b)
   #define vec_sub_psqt_32(a,b) _mm_sub_epi32(a,b)
   #define vec_zero_psqt() _mm_setzero_si128()
   #define NumRegistersSIMD (Is64Bit ? 16 : 8)
+  #define MaxChunkSize 16
 
   #elif USE_MMX
   typedef __m64 vec_t;
@@ -89,12 +116,26 @@ namespace Stockfish::Eval::NNUE {
   #define vec_store(a,b) *(a)=(b)
   #define vec_add_16(a,b) _mm_add_pi16(a,b)
   #define vec_sub_16(a,b) _mm_sub_pi16(a,b)
+  #define vec_mul_16(a,b) _mm_mullo_pi16(a,b)
+  #define vec_zero() _mm_setzero_si64()
+  #define vec_set_16(a) _mm_set1_pi16(a)
+  inline vec_t vec_max_16(vec_t a,vec_t b){
+    vec_t comparison = _mm_cmpgt_pi16(a,b);
+    return _mm_or_si64(_mm_and_si64(comparison, a), _mm_andnot_si64(comparison, b));
+  }
+  inline vec_t vec_min_16(vec_t a,vec_t b){
+    vec_t comparison = _mm_cmpgt_pi16(a,b);
+    return _mm_or_si64(_mm_and_si64(comparison, b), _mm_andnot_si64(comparison, a));
+  }
+  #define vec_msb_pack_16(a,b) _mm_packs_pi16(_mm_srli_pi16(a,7),_mm_srli_pi16(b,7))
   #define vec_load_psqt(a) (*(a))
   #define vec_store_psqt(a,b) *(a)=(b)
   #define vec_add_psqt_32(a,b) _mm_add_pi32(a,b)
   #define vec_sub_psqt_32(a,b) _mm_sub_pi32(a,b)
   #define vec_zero_psqt() _mm_setzero_si64()
+  #define vec_cleanup() _mm_empty()
   #define NumRegistersSIMD 8
+  #define MaxChunkSize 8
 
   #elif USE_NEON
   typedef int16x8_t vec_t;
@@ -103,12 +144,24 @@ namespace Stockfish::Eval::NNUE {
   #define vec_store(a,b) *(a)=(b)
   #define vec_add_16(a,b) vaddq_s16(a,b)
   #define vec_sub_16(a,b) vsubq_s16(a,b)
+  #define vec_mul_16(a,b) vmulq_s16(a,b)
+  #define vec_zero() vec_t{0}
+  #define vec_set_16(a) vdupq_n_s16(a)
+  #define vec_max_16(a,b) vmaxq_s16(a,b)
+  #define vec_min_16(a,b) vminq_s16(a,b)
+  inline vec_t vec_msb_pack_16(vec_t a, vec_t b){
+    const int8x8_t shifta = vshrn_n_s16(a, 7);
+    const int8x8_t shiftb = vshrn_n_s16(b, 7);
+    const int8x16_t compacted = vcombine_s8(shifta,shiftb);
+    return *reinterpret_cast<const vec_t*> (&compacted);
+  }
   #define vec_load_psqt(a) (*(a))
   #define vec_store_psqt(a,b) *(a)=(b)
   #define vec_add_psqt_32(a,b) vaddq_s32(a,b)
   #define vec_sub_psqt_32(a,b) vsubq_s32(a,b)
   #define vec_zero_psqt() psqt_vec_t{0}
   #define NumRegistersSIMD 16
+  #define MaxChunkSize 16
 
   #else
   #undef VECTOR
@@ -123,8 +176,10 @@ namespace Stockfish::Eval::NNUE {
       // We use __m* types as template arguments, which causes GCC to emit warnings
       // about losing some attribute information. This is irrelevant to us as we
       // only take their size, so the following pragma are harmless.
+      #if defined(__GNUC__)
       #pragma GCC diagnostic push
       #pragma GCC diagnostic ignored "-Wignored-attributes"
+      #endif
 
       template <typename SIMDRegisterType,
                 typename LaneType,
@@ -156,9 +211,9 @@ namespace Stockfish::Eval::NNUE {
 
       static constexpr int NumRegs     = BestRegisterCount<vec_t, WeightType, TransformedFeatureDimensions, NumRegistersSIMD>();
       static constexpr int NumPsqtRegs = BestRegisterCount<psqt_vec_t, PSQTWeightType, PSQTBuckets, NumRegistersSIMD>();
-
+      #if defined(__GNUC__)
       #pragma GCC diagnostic pop
-
+      #endif
   #endif
 
 
@@ -183,7 +238,7 @@ namespace Stockfish::Eval::NNUE {
 
     // Number of input/output dimensions
     static constexpr IndexType InputDimensions = FeatureSet::Dimensions;
-    static constexpr IndexType OutputDimensions = HalfDimensions * 2;
+    static constexpr IndexType OutputDimensions = HalfDimensions;
 
     // Size of forward propagation buffer
     static constexpr std::size_t BufferSize =
@@ -191,7 +246,7 @@ namespace Stockfish::Eval::NNUE {
 
     // Hash value embedded in the evaluation file
     static constexpr std::uint32_t get_hash_value() {
-      return FeatureSet::HashValue ^ OutputDimensions;
+      return FeatureSet::HashValue ^ (OutputDimensions * 2);
     }
 
     // Read network parameters
@@ -216,8 +271,8 @@ namespace Stockfish::Eval::NNUE {
 
     // Convert input features
     std::int32_t transform(const Position& pos, OutputType* output, int bucket) const {
-      update_accumulator(pos, WHITE);
+      update_accumulator<WHITE>(pos);
-      update_accumulator(pos, BLACK);
+      update_accumulator<BLACK>(pos);
 
       const Color perspectives[2] = {pos.side_to_move(), ~pos.side_to_move()};
       const auto& accumulation = pos.state()->accumulator.accumulation;
@@ -229,142 +284,62 @@ namespace Stockfish::Eval::NNUE {
         ) / 2;
 
 
-  #if defined(USE_AVX512)
-
-      constexpr IndexType NumChunks = HalfDimensions / (SimdWidth * 2);
-      static_assert(HalfDimensions % (SimdWidth * 2) == 0);
-      const __m512i Control = _mm512_setr_epi64(0, 2, 4, 6, 1, 3, 5, 7);
-      const __m512i Zero = _mm512_setzero_si512();
-
       for (IndexType p = 0; p < 2; ++p)
       {
-          const IndexType offset = HalfDimensions * p;
+          const IndexType offset = (HalfDimensions / 2) * p;
-          auto out = reinterpret_cast<__m512i*>(&output[offset]);
+
-          for (IndexType j = 0; j < NumChunks; ++j)
+#if defined(VECTOR)
+
+          constexpr IndexType OutputChunkSize = MaxChunkSize;
+          static_assert((HalfDimensions / 2) % OutputChunkSize == 0);
+          constexpr IndexType NumOutputChunks = HalfDimensions / 2 / OutputChunkSize;
+
+          vec_t Zero = vec_zero();
+          vec_t One = vec_set_16(127);
+
+          const vec_t* in0 = reinterpret_cast<const vec_t*>(&(accumulation[perspectives[p]][0]));
+          const vec_t* in1 = reinterpret_cast<const vec_t*>(&(accumulation[perspectives[p]][HalfDimensions / 2]));
+                vec_t* out = reinterpret_cast<      vec_t*>(output + offset);
+
+          for (IndexType j = 0; j < NumOutputChunks; j += 1)
           {
-              __m512i sum0 = _mm512_load_si512(&reinterpret_cast<const __m512i*>
+              const vec_t sum0a = vec_max_16(vec_min_16(in0[j * 2 + 0], One), Zero);
-                                              (accumulation[perspectives[p]])[j * 2 + 0]);
+              const vec_t sum0b = vec_max_16(vec_min_16(in0[j * 2 + 1], One), Zero);
-              __m512i sum1 = _mm512_load_si512(&reinterpret_cast<const __m512i*>
+              const vec_t sum1a = vec_max_16(vec_min_16(in1[j * 2 + 0], One), Zero);
-                                              (accumulation[perspectives[p]])[j * 2 + 1]);
+              const vec_t sum1b = vec_max_16(vec_min_16(in1[j * 2 + 1], One), Zero);
 
-              _mm512_store_si512(&out[j], _mm512_permutexvar_epi64(Control,
+              const vec_t pa = vec_mul_16(sum0a, sum1a);
-                                 _mm512_max_epi8(_mm512_packs_epi16(sum0, sum1), Zero)));
+              const vec_t pb = vec_mul_16(sum0b, sum1b);
+
+              out[j] = vec_msb_pack_16(pa, pb);
           }
-      }
-      return psqt;
 
-  #elif defined(USE_AVX2)
+#else
 
-      constexpr IndexType NumChunks = HalfDimensions / SimdWidth;
+          for (IndexType j = 0; j < HalfDimensions / 2; ++j) {
-      constexpr int Control = 0b11011000;
+              BiasType sum0 = accumulation[static_cast<int>(perspectives[p])][j + 0];
-      const __m256i Zero = _mm256_setzero_si256();
+              BiasType sum1 = accumulation[static_cast<int>(perspectives[p])][j + HalfDimensions / 2];
-
+              sum0 = std::max<int>(0, std::min<int>(127, sum0));
-      for (IndexType p = 0; p < 2; ++p)
+              sum1 = std::max<int>(0, std::min<int>(127, sum1));
-      {
+              output[offset + j] = static_cast<OutputType>(sum0 * sum1 / 128);
-          const IndexType offset = HalfDimensions * p;
-          auto out = reinterpret_cast<__m256i*>(&output[offset]);
-          for (IndexType j = 0; j < NumChunks; ++j)
-          {
-              __m256i sum0 = _mm256_load_si256(&reinterpret_cast<const __m256i*>
-                                              (accumulation[perspectives[p]])[j * 2 + 0]);
-              __m256i sum1 = _mm256_load_si256(&reinterpret_cast<const __m256i*>
-                                              (accumulation[perspectives[p]])[j * 2 + 1]);
-
-              _mm256_store_si256(&out[j], _mm256_permute4x64_epi64(
-                                 _mm256_max_epi8(_mm256_packs_epi16(sum0, sum1), Zero), Control));
           }
+
+#endif
       }
+
+#if defined(vec_cleanup)
+      vec_cleanup();
+#endif
+
       return psqt;
 
-  #elif defined(USE_SSE2)
-
-      #ifdef USE_SSE41
-      constexpr IndexType NumChunks = HalfDimensions / SimdWidth;
-      const __m128i Zero = _mm_setzero_si128();
-      #else
-      constexpr IndexType NumChunks = HalfDimensions / SimdWidth;
-      const __m128i k0x80s = _mm_set1_epi8(-128);
-      #endif
-
-      for (IndexType p = 0; p < 2; ++p)
-      {
-          const IndexType offset = HalfDimensions * p;
-          auto out = reinterpret_cast<__m128i*>(&output[offset]);
-          for (IndexType j = 0; j < NumChunks; ++j)
-          {
-              __m128i sum0 = _mm_load_si128(&reinterpret_cast<const __m128i*>
-                                           (accumulation[perspectives[p]])[j * 2 + 0]);
-              __m128i sum1 = _mm_load_si128(&reinterpret_cast<const __m128i*>
-                                           (accumulation[perspectives[p]])[j * 2 + 1]);
-              const __m128i packedbytes = _mm_packs_epi16(sum0, sum1);
-
-              #ifdef USE_SSE41
-              _mm_store_si128(&out[j], _mm_max_epi8(packedbytes, Zero));
-              #else
-              _mm_store_si128(&out[j], _mm_subs_epi8(_mm_adds_epi8(packedbytes, k0x80s), k0x80s));
-              #endif
-          }
-      }
-      return psqt;
-
-  #elif defined(USE_MMX)
-
-      constexpr IndexType NumChunks = HalfDimensions / SimdWidth;
-      const __m64 k0x80s = _mm_set1_pi8(-128);
-
-      for (IndexType p = 0; p < 2; ++p)
-      {
-          const IndexType offset = HalfDimensions * p;
-          auto out = reinterpret_cast<__m64*>(&output[offset]);
-          for (IndexType j = 0; j < NumChunks; ++j)
-          {
-              __m64 sum0 = *(&reinterpret_cast<const __m64*>(accumulation[perspectives[p]])[j * 2 + 0]);
-              __m64 sum1 = *(&reinterpret_cast<const __m64*>(accumulation[perspectives[p]])[j * 2 + 1]);
-              const __m64 packedbytes = _mm_packs_pi16(sum0, sum1);
-              out[j] = _mm_subs_pi8(_mm_adds_pi8(packedbytes, k0x80s), k0x80s);
-          }
-      }
-      _mm_empty();
-      return psqt;
-
-  #elif defined(USE_NEON)
-
-      constexpr IndexType NumChunks = HalfDimensions / (SimdWidth / 2);
-      const int8x8_t Zero = {0};
-
-      for (IndexType p = 0; p < 2; ++p)
-      {
-          const IndexType offset = HalfDimensions * p;
-          const auto out = reinterpret_cast<int8x8_t*>(&output[offset]);
-          for (IndexType j = 0; j < NumChunks; ++j)
-          {
-              int16x8_t sum = reinterpret_cast<const int16x8_t*>(accumulation[perspectives[p]])[j];
-              out[j] = vmax_s8(vqmovn_s16(sum), Zero);
-          }
-      }
-      return psqt;
-
-  #else
-
-      for (IndexType p = 0; p < 2; ++p)
-      {
-          const IndexType offset = HalfDimensions * p;
-          for (IndexType j = 0; j < HalfDimensions; ++j)
-          {
-              BiasType sum = accumulation[perspectives[p]][j];
-              output[offset + j] = static_cast<OutputType>(std::max<int>(0, std::min<int>(127, sum)));
-          }
-      }
-      return psqt;
-
-  #endif
-
    } // end of function transform()
 
 
 
    private:
-    void update_accumulator(const Position& pos, const Color perspective) const {
+    template<Color Perspective>
+    void update_accumulator(const Position& pos) const {
 
       // The size must be enough to contain the largest possible update.
       // That might depend on the feature set and generally relies on the
@@ -382,18 +357,18 @@ namespace Stockfish::Eval::NNUE {
       // of the estimated gain in terms of features to be added/subtracted.
       StateInfo *st = pos.state(), *next = nullptr;
       int gain = FeatureSet::refresh_cost(pos);
-      while (st->previous && !st->accumulator.computed[perspective])
+      while (st->previous && !st->accumulator.computed[Perspective])
       {
         // This governs when a full feature refresh is needed and how many
         // updates are better than just one full refresh.
-        if (   FeatureSet::requires_refresh(st, perspective)
+        if (   FeatureSet::requires_refresh(st, Perspective)
             || (gain -= FeatureSet::update_cost(st) + 1) < 0)
           break;
         next = st;
         st = st->previous;
       }
 
-      if (st->accumulator.computed[perspective])
+      if (st->accumulator.computed[Perspective])
       {
         if (next == nullptr)
           return;
@@ -402,17 +377,17 @@ namespace Stockfish::Eval::NNUE {
         // accumulator. Then, we update the current accumulator (pos.state()).
 
         // Gather all features to be updated.
-        const Square ksq = pos.square<KING>(perspective);
+        const Square ksq = pos.square<KING>(Perspective);
         FeatureSet::IndexList removed[2], added[2];
-        FeatureSet::append_changed_indices(
+        FeatureSet::append_changed_indices<Perspective>(
-          ksq, next->dirtyPiece, perspective, removed[0], added[0]);
+          ksq, next->dirtyPiece, removed[0], added[0]);
         for (StateInfo *st2 = pos.state(); st2 != next; st2 = st2->previous)
-          FeatureSet::append_changed_indices(
+          FeatureSet::append_changed_indices<Perspective>(
-            ksq, st2->dirtyPiece, perspective, removed[1], added[1]);
+            ksq, st2->dirtyPiece, removed[1], added[1]);
 
         // Mark the accumulators as computed.
-        next->accumulator.computed[perspective] = true;
+        next->accumulator.computed[Perspective] = true;
-        pos.state()->accumulator.computed[perspective] = true;
+        pos.state()->accumulator.computed[Perspective] = true;
 
         // Now update the accumulators listed in states_to_update[], where the last element is a sentinel.
         StateInfo *states_to_update[3] =
@@ -422,7 +397,7 @@ namespace Stockfish::Eval::NNUE {
         {
           // Load accumulator
           auto accTile = reinterpret_cast<vec_t*>(
-            &st->accumulator.accumulation[perspective][j * TileHeight]);
+            &st->accumulator.accumulation[Perspective][j * TileHeight]);
           for (IndexType k = 0; k < NumRegs; ++k)
             acc[k] = vec_load(&accTile[k]);
 
@@ -448,7 +423,7 @@ namespace Stockfish::Eval::NNUE {
 
             // Store accumulator
             accTile = reinterpret_cast<vec_t*>(
-              &states_to_update[i]->accumulator.accumulation[perspective][j * TileHeight]);
+              &states_to_update[i]->accumulator.accumulation[Perspective][j * TileHeight]);
             for (IndexType k = 0; k < NumRegs; ++k)
               vec_store(&accTile[k], acc[k]);
           }
@@ -458,7 +433,7 @@ namespace Stockfish::Eval::NNUE {
         {
           // Load accumulator
           auto accTilePsqt = reinterpret_cast<psqt_vec_t*>(
-            &st->accumulator.psqtAccumulation[perspective][j * PsqtTileHeight]);
+            &st->accumulator.psqtAccumulation[Perspective][j * PsqtTileHeight]);
           for (std::size_t k = 0; k < NumPsqtRegs; ++k)
             psqt[k] = vec_load_psqt(&accTilePsqt[k]);
 
@@ -484,7 +459,7 @@ namespace Stockfish::Eval::NNUE {
 
             // Store accumulator
             accTilePsqt = reinterpret_cast<psqt_vec_t*>(
-              &states_to_update[i]->accumulator.psqtAccumulation[perspective][j * PsqtTileHeight]);
+              &states_to_update[i]->accumulator.psqtAccumulation[Perspective][j * PsqtTileHeight]);
             for (std::size_t k = 0; k < NumPsqtRegs; ++k)
               vec_store_psqt(&accTilePsqt[k], psqt[k]);
           }
@@ -493,12 +468,12 @@ namespace Stockfish::Eval::NNUE {
   #else
         for (IndexType i = 0; states_to_update[i]; ++i)
         {
-          std::memcpy(states_to_update[i]->accumulator.accumulation[perspective],
+          std::memcpy(states_to_update[i]->accumulator.accumulation[Perspective],
-              st->accumulator.accumulation[perspective],
+              st->accumulator.accumulation[Perspective],
               HalfDimensions * sizeof(BiasType));
 
           for (std::size_t k = 0; k < PSQTBuckets; ++k)
-            states_to_update[i]->accumulator.psqtAccumulation[perspective][k] = st->accumulator.psqtAccumulation[perspective][k];
+            states_to_update[i]->accumulator.psqtAccumulation[Perspective][k] = st->accumulator.psqtAccumulation[Perspective][k];
 
           st = states_to_update[i];
 
@@ -508,10 +483,10 @@ namespace Stockfish::Eval::NNUE {
             const IndexType offset = HalfDimensions * index;
 
             for (IndexType j = 0; j < HalfDimensions; ++j)
-              st->accumulator.accumulation[perspective][j] -= weights[offset + j];
+              st->accumulator.accumulation[Perspective][j] -= weights[offset + j];
 
             for (std::size_t k = 0; k < PSQTBuckets; ++k)
-              st->accumulator.psqtAccumulation[perspective][k] -= psqtWeights[index * PSQTBuckets + k];
+              st->accumulator.psqtAccumulation[Perspective][k] -= psqtWeights[index * PSQTBuckets + k];
           }
 
           // Difference calculation for the activated features
@@ -520,10 +495,10 @@ namespace Stockfish::Eval::NNUE {
             const IndexType offset = HalfDimensions * index;
 
             for (IndexType j = 0; j < HalfDimensions; ++j)
-              st->accumulator.accumulation[perspective][j] += weights[offset + j];
+              st->accumulator.accumulation[Perspective][j] += weights[offset + j];
 
             for (std::size_t k = 0; k < PSQTBuckets; ++k)
-              st->accumulator.psqtAccumulation[perspective][k] += psqtWeights[index * PSQTBuckets + k];
+              st->accumulator.psqtAccumulation[Perspective][k] += psqtWeights[index * PSQTBuckets + k];
           }
         }
   #endif
@@ -532,9 +507,9 @@ namespace Stockfish::Eval::NNUE {
       {
         // Refresh the accumulator
         auto& accumulator = pos.state()->accumulator;
-        accumulator.computed[perspective] = true;
+        accumulator.computed[Perspective] = true;
         FeatureSet::IndexList active;
-        FeatureSet::append_active_indices(pos, perspective, active);
+        FeatureSet::append_active_indices<Perspective>(pos, active);
 
   #ifdef VECTOR
         for (IndexType j = 0; j < HalfDimensions / TileHeight; ++j)
@@ -554,7 +529,7 @@ namespace Stockfish::Eval::NNUE {
           }
 
           auto accTile = reinterpret_cast<vec_t*>(
-              &accumulator.accumulation[perspective][j * TileHeight]);
+              &accumulator.accumulation[Perspective][j * TileHeight]);
           for (unsigned k = 0; k < NumRegs; k++)
             vec_store(&accTile[k], acc[k]);
         }
@@ -574,27 +549,27 @@ namespace Stockfish::Eval::NNUE {
           }
 
           auto accTilePsqt = reinterpret_cast<psqt_vec_t*>(
-            &accumulator.psqtAccumulation[perspective][j * PsqtTileHeight]);
+            &accumulator.psqtAccumulation[Perspective][j * PsqtTileHeight]);
           for (std::size_t k = 0; k < NumPsqtRegs; ++k)
             vec_store_psqt(&accTilePsqt[k], psqt[k]);
         }
 
   #else
-        std::memcpy(accumulator.accumulation[perspective], biases,
+        std::memcpy(accumulator.accumulation[Perspective], biases,
             HalfDimensions * sizeof(BiasType));
 
         for (std::size_t k = 0; k < PSQTBuckets; ++k)
-          accumulator.psqtAccumulation[perspective][k] = 0;
+          accumulator.psqtAccumulation[Perspective][k] = 0;
 
         for (const auto index : active)
         {
           const IndexType offset = HalfDimensions * index;
 
           for (IndexType j = 0; j < HalfDimensions; ++j)
-            accumulator.accumulation[perspective][j] += weights[offset + j];
+            accumulator.accumulation[Perspective][j] += weights[offset + j];
 
           for (std::size_t k = 0; k < PSQTBuckets; ++k)
-            accumulator.psqtAccumulation[perspective][k] += psqtWeights[index * PSQTBuckets + k];
+            accumulator.psqtAccumulation[Perspective][k] += psqtWeights[index * PSQTBuckets + k];
         }
   #endif
       }

src/pawns.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) 2004-2022 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
@@ -32,30 +32,30 @@ namespace {
   #define S(mg, eg) make_score(mg, eg)
 
   // Pawn penalties
-  constexpr Score Backward      = S( 9, 22);
+  constexpr Score Backward      = S( 6, 19);
-  constexpr Score Doubled       = S(13, 51);
+  constexpr Score Doubled       = S(11, 51);
-  constexpr Score DoubledEarly  = S(20,  7);
+  constexpr Score DoubledEarly  = S(17,  7);
-  constexpr Score Isolated      = S( 3, 15);
+  constexpr Score Isolated      = S( 1, 20);
-  constexpr Score WeakLever     = S( 4, 58);
+  constexpr Score WeakLever     = S( 2, 57);
-  constexpr Score WeakUnopposed = S(13, 24);
+  constexpr Score WeakUnopposed = S(15, 18);
 
   // Bonus for blocked pawns at 5th or 6th rank
-  constexpr Score BlockedPawn[2] = { S(-17, -6), S(-9, 2) };
+  constexpr Score BlockedPawn[2] = { S(-19, -8), S(-7, 3) };
 
   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)
+    S(0, 0), S(0, 0), S(64, 75), S(-3, 14), S(-12, 19), S(-7, 4), S(-10, 5)
   };
 
   // Connected pawn bonus
-  constexpr int Connected[RANK_NB] = { 0, 5, 7, 11, 23, 48, 87 };
+  constexpr int Connected[RANK_NB] = { 0, 3, 7, 7, 15, 54, 86 };
 
   // 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(-2), V(85), V(95), V(53), V(39), V(23), V(25) },
-    { V(-44), V( 63), V( 33), V(-50), V(-30), V(-12), V( -62) },
+    { V(-55), V(64), V(32), V(-55), V(-30), V(-11), V(-61) },
-    { V(-11), V( 77), V( 22), V( -6), V( 31), V(  8), V( -45) },
+    { V(-11), V(75), V(19), V(-6), V(26), V(9), V(-47) },
-    { V(-39), V(-12), V(-29), V(-50), V(-43), V(-68), V(-164) }
+    { V(-41), V(-11), V(-27), V(-58), V(-42), V(-66), V(-163) }
   };
 
   // Danger of enemy pawns moving toward our king by [distance from edge][rank].
@@ -63,17 +63,17 @@ namespace {
   // 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(94), V(-280), V(-170), V(90), V(59), V(47), V(53) },
-    { V( 42), V( -25), V( 120), V( 45), V( 34), V( -9), V( 24) },
+    { V(43), V(-17), V(128), V(39), V(26), V(-17), V(15) },
-    { V( -8), V(  51), V( 167), V( 35), V( -4), V(-16), V(-12) },
+    { V(-9), V(62), V(170), V(34), V(-5), V(-20), V(-11) },
-    { V(-17), V( -13), V( 100), V(  4), V(  9), V(-16), V(-31) }
+    { V(-27), V(-19), V(106), V(10), V(2), V(-13), V(-24) }
   };
 
 
   // 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)  },
+  constexpr Score KingOnFile[2][2] = {{ S(-18,11), S(-6,-3)  },
-                                     {  S(  0,-3), S( 9,-4) }};
+                                     {  S(  0, 0), S( 5,-4) }};
 
   #undef S
   #undef V

src/pawns.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) 2004-2022 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

src/position.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) 2004-2022 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
@@ -129,7 +129,7 @@ void Position::init() {
   // Prepare the cuckoo tables
   std::memset(cuckoo, 0, sizeof(cuckoo));
   std::memset(cuckooMove, 0, sizeof(cuckooMove));
-  int count = 0;
+  [[maybe_unused]] int count = 0;
   for (Piece pc : Pieces)
       for (Square s1 = SQ_A1; s1 <= SQ_H8; ++s1)
           for (Square s2 = Square(s1 + 1); s2 <= SQ_H8; ++s2)
@@ -1054,7 +1054,10 @@ Key Position::key_after(Move m) const {
   if (captured)
       k ^= Zobrist::psq[captured][to];
 
-  return k ^ Zobrist::psq[pc][to] ^ Zobrist::psq[pc][from];
+  k ^= Zobrist::psq[pc][to] ^ Zobrist::psq[pc][from];
+
+  return (captured || type_of(pc) == PAWN)
+      ? k : adjust_key50<true>(k);
 }
 
 
@@ -1099,10 +1102,12 @@ bool Position::see_ge(Move m, Value threshold) const {
       // Don't allow pinned pieces to attack as long as there are
       // pinners on their original square.
       if (pinners(~stm) & occupied)
+      {
           stmAttackers &= ~blockers_for_king(stm);
 
-      if (!stmAttackers)
+          if (!stmAttackers)
-          break;
+              break;
+      }
 
       res ^= 1;
 

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) 2004-2022 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
@@ -120,12 +120,12 @@ public:
   Bitboard attackers_to(Square s) const;
   Bitboard attackers_to(Square s, Bitboard occupied) const;
   Bitboard slider_blockers(Bitboard sliders, Square s, Bitboard& pinners) 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;
   Piece moved_piece(Move m) const;
   Piece captured_piece() const;
@@ -161,6 +161,7 @@ public:
   bool has_repeated() const;
   int rule50_count() const;
   Score psq_score() const;
+  Value psq_eg_stm() const;
   Value non_pawn_material(Color c) const;
   Value non_pawn_material() const;
 
@@ -184,6 +185,8 @@ private:
   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];
@@ -285,6 +288,22 @@ 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;
 }
@@ -310,8 +329,14 @@ inline int Position::pawns_on_same_color_squares(Color c, Square s) const {
 }
 
 inline Key Position::key() const {
-  return st->rule50 < 14 ? st->key
+  return adjust_key50<false>(st->key);
-                         : st->key ^ make_key((st->rule50 - 14) / 8);
+}
+
+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 Key Position::pawn_key() const {
@@ -326,6 +351,10 @@ inline Score Position::psq_score() const {
   return psq;
 }
 
+inline Value Position::psq_eg_stm() const {
+  return (sideToMove == WHITE ? 1 : -1) * eg_value(psq);
+}
+
 inline Value Position::non_pawn_material(Color c) const {
   return st->nonPawnMaterial[c];
 }
@@ -352,11 +381,6 @@ 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::capture(Move m) const {
   assert(is_ok(m));
   // Castling is encoded as "king captures rook"

src/psqt.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) 2004-2022 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

src/psqt.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) 2004-2022 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

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) 2004-2022 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
@@ -31,9 +31,6 @@ class Position;
 
 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
@@ -47,13 +44,13 @@ struct Stack {
   Move excludedMove;
   Move killers[2];
   Value staticEval;
-  Depth depth;
   int statScore;
   int moveCount;
   bool inCheck;
   bool ttPv;
   bool ttHit;
   int doubleExtensions;
+  int cutoffCnt;
 };
 
 
@@ -73,6 +70,9 @@ struct RootMove {
 
   Value score = -VALUE_INFINITE;
   Value previousScore = -VALUE_INFINITE;
+  Value averageScore = -VALUE_INFINITE;
+  bool scoreLowerbound = false;
+  bool scoreUpperbound = false;
   int selDepth = 0;
   int tbRank = 0;
   Value tbScore;

src/syzygy/tbprobe.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) 2004-2022 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
@@ -59,6 +59,7 @@ namespace Stockfish {
 namespace {
 
 constexpr int TBPIECES = 7; // Max number of supported pieces
+constexpr int MAX_DTZ = 1 << 18; // Max DTZ supported, large enough to deal with the syzygy TB limit.
 
 enum { BigEndian, LittleEndian };
 enum TBType { WDL, DTZ }; // Used as template parameter
@@ -769,7 +770,7 @@ Ret do_probe_table(const Position& pos, T* entry, WDLScore wdl, ProbeState* resu
         goto encode_remaining; // With pawns we have finished special treatments
     }
 
-    // In positions withouth pawns, we further flip the squares to ensure leading
+    // In positions without pawns, we further flip the squares to ensure leading
     // piece is below RANK_5.
     if (rank_of(squares[0]) > RANK_4)
         for (int i = 0; i < size; ++i)
@@ -812,7 +813,7 @@ Ret do_probe_table(const Position& pos, T* entry, WDLScore wdl, ProbeState* resu
     // Rs "together" in 62 * 61 / 2 ways (we divide by 2 because rooks can be
     // swapped and still get the same position.)
     //
-    // In case we have at least 3 unique pieces (inlcuded kings) we encode them
+    // In case we have at least 3 unique pieces (included kings) we encode them
     // together.
     if (entry->hasUniquePieces) {
 
@@ -827,7 +828,7 @@ Ret do_probe_table(const Position& pos, T* entry, WDLScore wdl, ProbeState* resu
                    + (squares[1] - adjust1)) * 62
                    +  squares[2] - adjust2;
 
-        // First piece is on a1-h8 diagonal, second below: map this occurence to
+        // First piece is on a1-h8 diagonal, second below: map this occurrence to
         // 6 to differentiate from the above case, rank_of() maps a1-d4 diagonal
         // to 0...3 and finally MapB1H1H7[] maps the b1-h1-h7 triangle to 0..27.
         else if (off_A1H8(squares[1]))
@@ -857,7 +858,7 @@ encode_remaining:
     idx *= d->groupIdx[0];
     Square* groupSq = squares + d->groupLen[0];
 
-    // Encode remainig pawns then pieces according to square, in ascending order
+    // Encode remaining pawns then pieces according to square, in ascending order
     bool remainingPawns = entry->hasPawns && entry->pawnCount[1];
 
     while (d->groupLen[++next])
@@ -885,7 +886,7 @@ encode_remaining:
 
 // Group together pieces that will be encoded together. The general rule is that
 // a group contains pieces of same type and color. The exception is the leading
-// group that, in case of positions withouth pawns, can be formed by 3 different
+// group that, in case of positions without pawns, can be formed by 3 different
 // pieces (default) or by the king pair when there is not a unique piece apart
 // from the kings. When there are pawns, pawns are always first in pieces[].
 //
@@ -917,7 +918,7 @@ void set_groups(T& e, PairsData* d, int order[], File f) {
     //
     // This ensures unique encoding for the whole position. The order of the
     // groups is a per-table parameter and could not follow the canonical leading
-    // pawns/pieces -> remainig pawns -> remaining pieces. In particular the
+    // pawns/pieces -> remaining pawns -> remaining pieces. In particular the
     // first group is at order[0] position and the remaining pawns, when present,
     // are at order[1] position.
     bool pp = e.hasPawns && e.pawnCount[1]; // Pawns on both sides
@@ -937,7 +938,7 @@ void set_groups(T& e, PairsData* d, int order[], File f) {
             d->groupIdx[1] = idx;
             idx *= Binomial[d->groupLen[1]][48 - d->groupLen[0]];
         }
-        else // Remainig pieces
+        else // Remaining pieces
         {
             d->groupIdx[next] = idx;
             idx *= Binomial[d->groupLen[next]][freeSquares];
@@ -947,7 +948,7 @@ void set_groups(T& e, PairsData* d, int order[], File f) {
     d->groupIdx[n] = idx;
 }
 
-// In Recursive Pairing each symbol represents a pair of childern symbols. So
+// In Recursive Pairing each symbol represents a pair of children symbols. So
 // read d->btree[] symbols data and expand each one in his left and right child
 // symbol until reaching the leafs that represent the symbol value.
 uint8_t set_symlen(PairsData* d, Sym s, std::vector<bool>& visited) {
@@ -1290,7 +1291,7 @@ void Tablebases::init(const std::string& paths) {
     for (auto s : diagonal)
         MapA1D1D4[s] = code++;
 
-    // MapKK[] encodes all the 461 possible legal positions of two kings where
+    // MapKK[] encodes all the 462 possible legal positions of two kings where
     // the first is in the a1-d1-d4 triangle. If the first king is on the a1-d4
     // diagonal, the other one shall not to be above the a1-h8 diagonal.
     std::vector<std::pair<int, Square>> bothOnDiagonal;
@@ -1317,7 +1318,7 @@ void Tablebases::init(const std::string& paths) {
     for (auto p : bothOnDiagonal)
         MapKK[p.first][p.second] = code++;
 
-    // Binomial[] stores the Binomial Coefficents using Pascal rule. There
+    // Binomial[] stores the Binomial Coefficients using Pascal rule. There
     // are Binomial[k][n] ways to choose k elements from a set of n elements.
     Binomial[0][0] = 1;
 
@@ -1337,7 +1338,7 @@ void Tablebases::init(const std::string& paths) {
     for (int leadPawnsCnt = 1; leadPawnsCnt <= 5; ++leadPawnsCnt)
         for (File f = FILE_A; f <= FILE_D; ++f)
         {
-            // Restart the index at every file because TB table is splitted
+            // Restart the index at every file because TB table is split
             // by file, so we can reuse the same index for different files.
             int idx = 0;
 
@@ -1522,7 +1523,7 @@ bool Tablebases::root_probe(Position& pos, Search::RootMoves& rootMoves) {
     // Check whether a position was repeated since the last zeroing move.
     bool rep = pos.has_repeated();
 
-    int dtz, bound = Options["Syzygy50MoveRule"] ? 900 : 1;
+    int dtz, bound = Options["Syzygy50MoveRule"] ? (MAX_DTZ - 100) : 1;
 
     // Probe and rank each move
     for (auto& m : rootMoves)
@@ -1565,8 +1566,8 @@ bool Tablebases::root_probe(Position& pos, Search::RootMoves& rootMoves) {
 
         // Better moves are ranked higher. Certain wins are ranked equally.
         // Losing moves are ranked equally unless a 50-move draw is in sight.
-        int r =  dtz > 0 ? (dtz + cnt50 <= 99 && !rep ? 1000 : 1000 - (dtz + cnt50))
+        int r =  dtz > 0 ? (dtz + cnt50 <= 99 && !rep ? MAX_DTZ : MAX_DTZ - (dtz + cnt50))
-               : dtz < 0 ? (-dtz * 2 + cnt50 < 100 ? -1000 : -1000 + (-dtz + cnt50))
+               : dtz < 0 ? (-dtz * 2 + cnt50 < 100 ? -MAX_DTZ : -MAX_DTZ + (-dtz + cnt50))
                : 0;
         m.tbRank = r;
 
@@ -1574,9 +1575,9 @@ bool Tablebases::root_probe(Position& pos, Search::RootMoves& rootMoves) {
         // 1 cp to cursed wins and let it grow to 49 cp as the positions gets
         // closer to a real win.
         m.tbScore =  r >= bound ? VALUE_MATE - MAX_PLY - 1
-                   : r >  0     ? Value((std::max( 3, r - 800) * int(PawnValueEg)) / 200)
+                   : r >  0     ? Value((std::max( 3, r - (MAX_DTZ - 200)) * int(PawnValueEg)) / 200)
                    : r == 0     ? VALUE_DRAW
-                   : r > -bound ? Value((std::min(-3, r + 800) * int(PawnValueEg)) / 200)
+                   : r > -bound ? Value((std::min(-3, r + (MAX_DTZ - 200)) * int(PawnValueEg)) / 200)
                    :             -VALUE_MATE + MAX_PLY + 1;
     }
 
@@ -1590,7 +1591,7 @@ bool Tablebases::root_probe(Position& pos, Search::RootMoves& rootMoves) {
 // A return value false indicates that not all probes were successful.
 bool Tablebases::root_probe_wdl(Position& pos, Search::RootMoves& rootMoves) {
 
-    static const int WDL_to_rank[] = { -1000, -899, 0, 899, 1000 };
+    static const int WDL_to_rank[] = { -MAX_DTZ, -MAX_DTZ + 101, 0, MAX_DTZ - 101, MAX_DTZ };
 
     ProbeState result;
     StateInfo st;

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) 2004-2022 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
@@ -31,14 +31,12 @@ enum WDLScore {
     WDLDraw        =  0, // Draw
     WDLCursedWin   =  1, // Win, but draw under 50-move rule
     WDLWin         =  2, // Win
-
-    WDLScoreNone  = -1000
 };
 
 // Possible states after a probing operation
 enum ProbeState {
     FAIL              =  0, // Probe failed (missing file table)
-    OK                =  1, // Probe succesful
+    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)
 };

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) 2004-2022 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
@@ -59,17 +59,14 @@ void Thread::clear() {
 
   counterMoves.fill(MOVE_NONE);
   mainHistory.fill(0);
-  lowPlyHistory.fill(0);
   captureHistory.fill(0);
+  previousDepth = 0;
 
   for (bool inCheck : { false, true })
       for (StatsType c : { NoCaptures, Captures })
-      {
           for (auto& to : continuationHistory[inCheck][c])
-                for (auto& h : to)
+              for (auto& h : to)
-                      h->fill(0);
+                  h->fill(-71);
-          continuationHistory[inCheck][c][NO_PIECE][0]->fill(Search::CounterMovePruneThreshold - 1);
-      }
 }
 
 
@@ -162,6 +159,7 @@ void ThreadPool::clear() {
 
   main()->callsCnt = 0;
   main()->bestPreviousScore = VALUE_INFINITE;
+  main()->bestPreviousAverageScore = VALUE_INFINITE;
   main()->previousTimeReduction = 1.0;
 }
 
@@ -223,11 +221,14 @@ Thread* ThreadPool::get_best_thread() const {
         minScore = std::min(minScore, th->rootMoves[0].score);
 
     // Vote according to score and depth, and select the best thread
-    for (Thread* th : *this)
+    auto thread_value = [minScore](Thread* th) {
-    {
+            return (th->rootMoves[0].score - minScore + 14) * int(th->completedDepth);
-        votes[th->rootMoves[0].pv[0]] +=
+        };
-            (th->rootMoves[0].score - minScore + 14) * int(th->completedDepth);
 
+    for (Thread* th : *this)
+        votes[th->rootMoves[0].pv[0]] += thread_value(th);
+
+    for (Thread* th : *this)
         if (abs(bestThread->rootMoves[0].score) >= VALUE_TB_WIN_IN_MAX_PLY)
         {
             // Make sure we pick the shortest mate / TB conversion or stave off mate the longest
@@ -236,9 +237,10 @@ Thread* ThreadPool::get_best_thread() const {
         }
         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]]))
+                     && (   votes[th->rootMoves[0].pv[0]] > votes[bestThread->rootMoves[0].pv[0]]
+                         || (   votes[th->rootMoves[0].pv[0]] == votes[bestThread->rootMoves[0].pv[0]]
+                             && thread_value(th) > thread_value(bestThread)))))
             bestThread = th;
-    }
 
     return bestThread;
 }

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) 2004-2022 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
@@ -60,24 +60,21 @@ public:
   Pawns::Table pawnsTable;
   Material::Table materialTable;
   size_t pvIdx, pvLast;
-  RunningAverage doubleExtensionAverage[COLOR_NB];
+  RunningAverage complexityAverage;
-  uint64_t nodesLastExplosive;
-  uint64_t nodesLastNormal;
   std::atomic<uint64_t> nodes, tbHits, bestMoveChanges;
   int selDepth, nmpMinPly;
   Color nmpColor;
-  ExplosionState state;
+  Value bestValue, optimism[COLOR_NB];
 
   Position rootPos;
   StateInfo rootState;
   Search::RootMoves rootMoves;
-  Depth rootDepth, completedDepth;
+  Depth rootDepth, completedDepth, previousDepth;
+  Value rootDelta;
   CounterMoveHistory counterMoves;
   ButterflyHistory mainHistory;
-  LowPlyHistory lowPlyHistory;
   CapturePieceToHistory captureHistory;
   ContinuationHistory continuationHistory[2][2];
-  Score trend;
 };
 
 
@@ -92,6 +89,7 @@ struct MainThread : public Thread {
 
   double previousTimeReduction;
   Value bestPreviousScore;
+  Value bestPreviousAverageScore;
   Value iterValue[4];
   int callsCnt;
   bool stopOnPonderhit;

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) 2004-2022 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

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) 2004-2022 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
@@ -80,7 +80,7 @@ void TimeManagement::init(Search::LimitsType& limits, Color us, int ply) {
   // 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,
+      optScale = std::min(0.0120 + std::pow(ply + 3.0, 0.45) * 0.0039,
                            0.2 * limits.time[us] / double(timeLeft))
                  * optExtra;
       maxScale = std::min(7.0, 4.0 + ply / 12.0);

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) 2004-2022 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

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) 2004-2022 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
@@ -40,9 +40,9 @@ void TTEntry::save(Key k, Value v, bool pv, Bound b, Depth d, Move m, Value ev)
       move16 = (uint16_t)m;
 
   // Overwrite less valuable entries (cheapest checks first)
-  if (b == BOUND_EXACT
+  if (   b == BOUND_EXACT
       || (uint16_t)k != key16
-      || d - DEPTH_OFFSET > depth8 - 4)
+      || d - DEPTH_OFFSET + 2 * pv > depth8 - 4)
   {
       assert(d > DEPTH_OFFSET);
       assert(d < 256 + DEPTH_OFFSET);

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) 2004-2022 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

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) 2004-2022 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

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) 2004-2022 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
@@ -84,7 +84,7 @@ class Tune {
 
   static Tune& instance() { static Tune t; return t; } // Singleton
 
-  // Use polymorphism to accomodate Entry of different types in the same vector
+  // Use polymorphism to accommodate Entry of different types in the same vector
   struct EntryBase {
     virtual ~EntryBase() = default;
     virtual void init_option() = 0;

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) 2004-2022 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
@@ -173,11 +173,6 @@ enum Bound {
   BOUND_EXACT = BOUND_UPPER | BOUND_LOWER
 };
 
-enum ExplosionState {
-  EXPLOSION_NONE,
-  MUST_CALM_DOWN
-};
-
 enum Value : int {
   VALUE_ZERO      = 0,
   VALUE_DRAW      = 0,
@@ -455,7 +450,7 @@ constexpr Square to_sq(Move m) {
 }
 
 constexpr int from_to(Move m) {
- return m & 0xFFF;
+  return m & 0xFFF;
 }
 
 constexpr MoveType type_of(Move m) {
@@ -470,10 +465,6 @@ 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);

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) 2004-2022 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
@@ -40,14 +40,14 @@ extern vector<string> setup_bench(const Position&, istream&);
 
 namespace {
 
-  // FEN string of the initial position, normal chess
+  // FEN string for the initial position in standard chess
   const char* StartFEN = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
 
 
-  // position() is called when engine receives the "position" UCI command.
+  // position() is called when the engine receives the "position" UCI command.
-  // The function sets up the position described in the given FEN string ("fen")
+  // It sets up the position that is described in the given FEN string ("fen") or
-  // or the starting position ("startpos") and then makes the moves given in the
+  // the initial position ("startpos") and then makes the moves given in the following
-  // following move list ("moves").
+  // move list ("moves").
 
   void position(Position& pos, istringstream& is, StateListPtr& states) {
 
@@ -59,7 +59,7 @@ namespace {
     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")
@@ -67,10 +67,10 @@ namespace {
     else
         return;
 
-    states = StateListPtr(new std::deque<StateInfo>(1)); // Drop old and create a new one
+    states = StateListPtr(new std::deque<StateInfo>(1)); // Drop the old state and create a new one
     pos.set(fen, Options["UCI_Chess960"], &states->back(), Threads.main());
 
-    // Parse move list (if any)
+    // Parse the move list, if any
     while (is >> token && (m = UCI::to_move(pos, token)) != MOVE_NONE)
     {
         states->emplace_back();
@@ -78,8 +78,8 @@ namespace {
     }
   }
 
-  // trace_eval() prints the evaluation for the current position, consistent with the UCI
+  // trace_eval() prints the evaluation of the current position, consistent with
-  // options set so far.
+  // the UCI options set so far.
 
   void trace_eval(Position& pos) {
 
@@ -93,20 +93,20 @@ namespace {
   }
 
 
-  // setoption() is called when engine receives the "setoption" UCI command. The
+  // setoption() is called when the engine receives the "setoption" UCI command.
-  // function updates the UCI option ("name") to the given value ("value").
+  // The function updates the UCI option ("name") to the given value ("value").
 
   void setoption(istringstream& is) {
 
     string token, name, value;
 
-    is >> token; // Consume "name" token
+    is >> token; // Consume the "name" token
 
-    // Read option name (can contain spaces)
+    // Read the option name (can contain spaces)
     while (is >> token && token != "value")
         name += (name.empty() ? "" : " ") + token;
 
-    // Read option value (can contain spaces)
+    // Read the option value (can contain spaces)
     while (is >> token)
         value += (value.empty() ? "" : " ") + token;
 
@@ -117,9 +117,9 @@ namespace {
   }
 
 
-  // go() is called when engine receives the "go" UCI command. The function sets
+  // go() is called when the engine receives the "go" UCI command. The function
-  // the thinking time and other parameters from the input string, then starts
+  // sets the thinking time and other parameters from the input string, then starts
-  // the search.
+  // with a search.
 
   void go(Position& pos, istringstream& is, StateListPtr& states) {
 
@@ -127,7 +127,7 @@ namespace {
     string token;
     bool ponderMode = false;
 
-    limits.startTime = now(); // As early as possible!
+    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
@@ -151,9 +151,9 @@ namespace {
   }
 
 
-  // bench() is called when engine receives the "bench" command. Firstly
+  // bench() is called when the engine receives the "bench" command.
-  // a list of UCI commands is setup according to bench parameters, then
+  // Firstly, a list of UCI commands is set up according to the bench
-  // it is run one by one printing a summary at the end.
+  // parameters, then it is run one by one, printing a summary at the end.
 
   void bench(Position& pos, istream& args, StateListPtr& states) {
 
@@ -184,12 +184,12 @@ namespace {
         }
         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
+        else if (token == "ucinewgame") { Search::clear(); elapsed = now(); } // Search::clear() may take a while
     }
 
     elapsed = now() - elapsed + 1; // Ensure positivity to avoid a 'divide by zero'
 
-    dbg_print(); // Just before exiting
+    dbg_print();
 
     cerr << "\n==========================="
          << "\nTotal time (ms) : " << elapsed
@@ -197,36 +197,40 @@ namespace {
          << "\nNodes/second    : " << 1000 * nodes / elapsed << endl;
   }
 
-  // The win rate model returns the probability (per mille) of winning given an eval
+  // The win rate model returns the probability of winning (in per mille units) given an
-  // and a game-ply. The model fits rather accurately the LTC fishtest statistics.
+  // eval and a game ply. It fits the LTC fishtest statistics rather accurately.
   int win_rate_model(Value v, int ply) {
 
-     // The model captures only up to 240 plies, so limit input (and rescale)
+     // The model only captures up to 240 plies, so limit the input and then rescale
      double m = std::min(240, ply) / 64.0;
 
-     // Coefficients of a 3rd order polynomial fit based on fishtest data
+     // The coefficients of a third-order polynomial fit is based on the fishtest data
-     // for two parameters needed to transform eval to the argument of a
+     // for two parameters that need to transform eval to the argument of a logistic
-     // logistic function.
+     // function.
-     double as[] = {-3.68389304,  30.07065921, -60.52878723, 149.53378557};
+     constexpr double as[] = {  -0.58270499,    2.68512549,   15.24638015,  344.49745382};
-     double bs[] = {-2.0181857,   15.85685038, -29.83452023,  47.59078827};
+     constexpr double bs[] = {  -2.65734562,   15.96509799,  -20.69040836,   73.61029937 };
+
+     // Enforce that NormalizeToPawnValue corresponds to a 50% win rate at ply 64
+     static_assert(UCI::NormalizeToPawnValue == int(as[0] + as[1] + as[2] + as[3]));
+
      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
+     // Transform the eval to centipawns with limited range
-     double x = std::clamp(double(100 * v) / PawnValueEg, -2000.0, 2000.0);
+     double x = std::clamp(double(v), -4000.0, 4000.0);
 
-     // Return win rate in per mille (rounded to nearest)
+     // Return the win rate in per mille units rounded to the nearest value
      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
+/// UCI::loop() waits for a command from the stdin, parses it and then calls the appropriate
-/// function. Also intercepts EOF from stdin to ensure gracefully exiting if the
+/// function. It also intercepts an end-of-file (EOF) indication from the stdin to ensure a
-/// GUI dies unexpectedly. When called with some command line arguments, e.g. to
+/// graceful exit if the GUI dies unexpectedly. When called with some command-line arguments,
-/// run 'bench', once the command is executed the function returns immediately.
+/// like running 'bench', the function returns immediately after the command is executed.
-/// In addition to the UCI ones, also some additional debug commands are supported.
+/// In addition to the UCI ones, some additional debug commands are also supported.
 
 void UCI::loop(int argc, char* argv[]) {
 
@@ -240,24 +244,24 @@ void UCI::loop(int argc, char* argv[]) {
       cmd += std::string(argv[i]) + " ";
 
   do {
-      if (argc == 1 && !getline(cin, cmd)) // Block here waiting for input or EOF
+      if (argc == 1 && !getline(cin, cmd)) // Wait for an input or an end-of-file (EOF) indication
           cmd = "quit";
 
       istringstream is(cmd);
 
-      token.clear(); // Avoid a stale if getline() returns empty or blank line
+      token.clear(); // Avoid a stale if getline() returns nothing or a 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.
+      // The GUI sends 'ponderhit' to tell that the user has played the expected move.
-      // So 'ponderhit' will be sent if we were told to ponder on the same move the
+      // So, 'ponderhit' is sent if pondering was done on the same move that the user
-      // user has played. We should continue searching but switch from pondering to
+      // has played. The search should continue, but should also switch from pondering
-      // normal search.
+      // to the normal search.
       else if (token == "ponderhit")
-          Threads.main()->ponder = false; // Switch to normal search
+          Threads.main()->ponder = false; // Switch to the normal search
 
       else if (token == "uci")
           sync_cout << "id name " << engine_info(true)
@@ -270,8 +274,8 @@ void UCI::loop(int argc, char* argv[]) {
       else if (token == "ucinewgame") Search::clear();
       else if (token == "isready")    sync_cout << "readyok" << sync_endl;
 
-      // Additional custom non-UCI commands, mainly for debugging.
+      // Add custom non-UCI commands, mainly for debugging purposes.
-      // Do not use these commands during a search!
+      // 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")        sync_cout << pos << sync_endl;
@@ -285,19 +289,25 @@ void UCI::loop(int argc, char* argv[]) {
               filename = f;
           Eval::NNUE::save_eval(filename);
       }
+      else if (token == "--help" || token == "help" || token == "--license" || token == "license")
+          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] != '#')
-          sync_cout << "Unknown command: " << cmd << sync_endl;
+          sync_cout << "Unknown command: '" << cmd << "'. Type help for more information." << sync_endl;
 
-  } while (token != "quit" && argc == 1); // Command line args are one-shot
+  } while (token != "quit" && argc == 1); // The command-line arguments are one-shot
 }
 
 
-/// UCI::value() converts a Value to a string suitable for use with the UCI
+/// UCI::value() converts a Value to a string by adhering to the UCI protocol specification:
-/// 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
+/// mate <y>  Mate in 'y' moves (not plies). If the engine is getting mated,
-///           use negative values for y.
+///           uses negative values for 'y'.
 
 string UCI::value(Value v) {
 
@@ -306,7 +316,7 @@ string UCI::value(Value v) {
   stringstream ss;
 
   if (abs(v) < VALUE_MATE_IN_MAX_PLY)
-      ss << "cp " << v * 100 / PawnValueEg;
+      ss << "cp " << v * 100 / NormalizeToPawnValue;
   else
       ss << "mate " << (v > 0 ? VALUE_MATE - v + 1 : -VALUE_MATE - v) / 2;
 
@@ -314,8 +324,8 @@ string UCI::value(Value v) {
 }
 
 
-/// UCI::wdl() report WDL statistics given an evaluation and a game ply, based on
+/// UCI::wdl() reports the win-draw-loss (WDL) statistics given an evaluation
-/// data gathered for fishtest LTC games.
+/// and a game ply based on the data gathered for fishtest LTC games.
 
 string UCI::wdl(Value v, int ply) {
 
@@ -338,9 +348,9 @@ std::string UCI::square(Square s) {
 
 
 /// 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
+/// The only special case is castling where the e1g1 notation is printed in
-/// normal chess mode, and in e1h1 notation in chess960 mode. Internally all
+/// standard chess mode and in e1h1 notation it is printed in Chess960 mode.
-/// castling moves are always encoded as 'king captures rook'.
+/// Internally, all castling moves are always encoded as 'king captures rook'.
 
 string UCI::move(Move m, bool chess960) {
 
@@ -370,8 +380,8 @@ string UCI::move(Move m, bool chess960) {
 
 Move UCI::to_move(const Position& pos, string& str) {
 
-  if (str.length() == 5) // Junior could send promotion piece in uppercase
+  if (str.length() == 5)
-      str[4] = char(tolower(str[4]));
+      str[4] = char(tolower(str[4])); // The promotion piece character must be lowercased
 
   for (const auto& m : MoveList<LEGAL>(pos))
       if (str == UCI::move(m, pos.is_chess960()))

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) 2004-2022 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
@@ -30,17 +30,24 @@ class Position;
 
 namespace UCI {
 
+// Normalizes the internal value as reported by evaluate or search
+// to the UCI centipawn result used in output. This value is derived from
+// the win_rate_model() such that Stockfish outputs an advantage of
+// "100 centipawns" for a position if the engine has a 50% probability to win
+// from this position in selfplay at fishtest LTC time control.
+const int NormalizeToPawnValue = 361;
+
 class Option;
 
-/// Custom comparator because UCI options should be case insensitive
+/// Define a custom comparator, because the UCI options should be case-insensitive
 struct CaseInsensitiveLess {
   bool operator() (const std::string&, const std::string&) const;
 };
 
-/// Our options container is actually a std::map
+/// The options container is defined as a std::map
 typedef std::map<std::string, Option, CaseInsensitiveLess> OptionsMap;
 
-/// Option class implements an option as defined by UCI protocol
+/// The Option class implements each option as specified by the UCI protocol
 class Option {
 
   typedef void (*OnChange)(const Option&);
@@ -72,7 +79,7 @@ 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 pv(const Position& pos, Depth depth);
 std::string wdl(Value v, int ply);
 Move to_move(const Position& pos, std::string& str);
 

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) 2004-2022 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
@@ -61,7 +61,7 @@ void init(OptionsMap& o) {
   constexpr int MaxHashMB = Is64Bit ? 33554432 : 2048;
 
   o["Debug Log File"]        << Option("", on_logger);
-  o["Threads"]               << Option(1, 1, 512, on_threads);
+  o["Threads"]               << Option(1, 1, 1024, on_threads);
   o["Hash"]                  << Option(16, 1, MaxHashMB, on_hash_size);
   o["Clear Hash"]            << Option(on_clear_hash);
   o["Ponder"]                << Option(false);

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