Stockfish 10

Official release version of Stockfish 10.

This is also the 10th anniversary version of the Stockfish project, which
started exactly ten years ago! I wish to extend a huge thank you to
all contributors and authors in our amazing community :-)

Bench: 3939338

.travis.yml

@@ -0,0 +1,74 @@
+language: cpp
+sudo: required
+dist: trusty
+
+matrix:
+  include:
+    - os: linux
+      compiler: gcc
+      addons:
+        apt:
+          sources: ['ubuntu-toolchain-r-test']
+          packages: ['g++-7', 'g++-7-multilib', 'g++-multilib', 'valgrind', 'expect', 'curl']
+      env:
+        - COMPILER=g++-7
+        - COMP=gcc
+
+    - os: linux
+      compiler: clang
+      addons:
+        apt:
+          sources: ['ubuntu-toolchain-r-test', 'llvm-toolchain-trusty-5.0']
+          packages: ['clang-5.0', 'llvm-5.0-dev', 'g++-multilib', 'valgrind', 'expect', 'curl']
+      env:
+        - COMPILER=clang++-5.0
+        - COMP=clang
+        - LDFLAGS=-fuse-ld=gold
+
+    - os: osx
+      compiler: gcc
+      env:
+        - COMPILER=g++
+        - COMP=gcc
+
+    - os: osx
+      compiler: clang
+      env:
+        - COMPILER=clang++ V='Apple LLVM 6.0' # Apple LLVM version 6.0 (clang-600.0.54) (based on LLVM 3.5svn)
+        - COMP=clang
+
+branches:
+  only:
+   - master
+
+before_script:
+  - cd src
+
+script:
+  # Obtain bench reference from git log
+  - git log HEAD | grep "\b[Bb]ench[ :]\+[0-9]\{7\}" | head -n 1 | sed "s/[^0-9]*\([0-9]*\).*/\1/g" > git_sig
+  - export benchref=$(cat git_sig)
+  - echo "Reference bench:" $benchref
+  #
+  # Verify bench number against various builds
+  - export CXXFLAGS=-Werror
+  - make clean && make -j2 ARCH=x86-64 optimize=no debug=yes build && ../tests/signature.sh $benchref
+  - make clean && make -j2 ARCH=x86-32 optimize=no debug=yes build && ../tests/signature.sh $benchref
+  - make clean && make -j2 ARCH=x86-32 build && ../tests/signature.sh $benchref
+  - make clean && make -j2 ARCH=x86-64 build && ../tests/signature.sh $benchref
+  #
+  # Check perft and reproducible search
+  - ../tests/perft.sh
+  - ../tests/reprosearch.sh
+  #
+  # Valgrind
+  #
+  - export CXXFLAGS=-O1
+  - if [ -x "$(command -v valgrind )" ]; then make clean && make -j2 ARCH=x86-64 debug=yes optimize=no build > /dev/null && ../tests/instrumented.sh --valgrind; fi
+  - if [ -x "$(command -v valgrind )" ]; then ../tests/instrumented.sh --valgrind-thread; fi
+  #
+  # Sanitizer
+  #
+  # Use g++-7 as a proxy for having sanitizers, might need revision as they become available for more recent versions of clang/gcc
+  - if [[ "$COMPILER" == "g++-7" ]]; then make clean && make -j2 ARCH=x86-64 sanitize=undefined optimize=no debug=yes build > /dev/null && ../tests/instrumented.sh --sanitizer-undefined; fi
+  - if [[ "$COMPILER" == "g++-7" ]]; then make clean && make -j2 ARCH=x86-64 sanitize=thread    optimize=no debug=yes build > /dev/null && ../tests/instrumented.sh --sanitizer-thread; fi

AUTHORS

@@ -1,64 +1,129 @@
-# Generated with git shortlog -sn | cut -c8-', which sorts by commits (manually moved Tord to top)
+# List of authors for Stockfish, updated for version 10
 
-Tord Romstad
-Marco Costalba
-Joona Kiiski
-Gary Linscott
-Lucas Braesch
-Reuven Peleg
-Chris Caino
-homoSapiensSapiens
-Jean-Francois Romang
-jundery
-Arjun Temurnikar
-Uri Blass
-Ralph Stößer
-Stefan Geschwentner
-Tom Vijlbrief
-Daylen Yang
-Henri Wiechers
-Leonid Pechenik
-mstembera
-Eelco de Groot
-Jerry Donald
-Jörg Oster
-Ryan Schmitt
-mcostalba
+Tord Romstad (romstad)
+Marco Costalba (mcostalba)
+Joona Kiiski (zamar)
+Gary Linscott (glinscott)
+
+Aditya (absimaldata)
+Ajith Chandy Jose (ajithcj)
+Alain Savard (Rocky640)
 Alexander Kure
-Dan Schmidt
-H. Felix Wittmann
-Justin Blanchard
-Linus Arver
-RyanTaker
-ceebo
-Joseph H Ellis
-Stephane Nicolet
-Ajith
+Ali AlZhrani (Cooffe)
+Andrew Grant (AndyGrant)
+Andrey Neporada (nepal)
 Andy Duplain
+Aram Tumanian (atumanian)
+Arjun Temurnikar
 Auguste Pop
 Balint Pfliegel
-Chris Cain
+Ben Koshy (BKSpurgeon)
+Bill Henry (VoyagerOne)
+braich
+Brian Sheppard (SapphireBrand)
+Bryan Cross (crossbr)
+Bujun Guo (noobpwnftw)
+Chris Cain (ceebo)
+Dan Schmidt
+Daniel Dugovic (ddugovic)
 Dariusz Orzechowski
+David Zar
+Daylen Yang (daylen)
+DiscanX
+Eelco de Groot
+ElbertoOne
+erbsenzaehler
+Ernesto Gatti
+Fabian Beuke (madnight)
+Fabian Fichter (ianfab)
+fanon
+Fauzi Akram Dabat (FauziAkram)
+Felix Wittmann
+gamander
+gguliash
+Gian-Carlo Pascutto (gcp)
+Gontran Lemaire (gonlem)
+Goodkov Vasiliy Aleksandrovich (goodkov)
 Gregor Cramer
-Hiraoka Takuya
+GuardianRM
+Günther Demetz (pb00067, pb00068)
+Guy Vreuls (gvreuls)
+Henri Wiechers
+Hiraoka Takuya (HiraokaTakuya)
+homoSapiensSapiens
 Hongzhi Cheng
-Jonathan Calovski
+Ivan Ivec (IIvec)
+Jacques B. (Timshel)
+Jan Ondruš (hxim)
+Jared Kish (Kurtbusch)
+Jarrod Torriero (DU-jdto)
+Jean-Francois Romang (jromang)
+Jerry Donald Watson (jerrydonaldwatson)
+Jonathan Calovski (Mysseno)
+Jonathan D. (SFisGOD)
+Joost VandeVondele (vondele)
+Jörg Oster (joergoster)
+Joseph Ellis (jhellis3)
 Joseph R. Prostko
+jundery
+Justin Blanchard
 Kelly Wilson
-Kojirion
-Matt Sullivan
-Matthew Sullivan
-Michel Van den Bergh
-Mysseno
-Pablo Vazquez
-Raminder Singh
-Richard Lloyd
-Ron Britvich
-Ronald de Man
-Ryan Takker
-Thanar2
+Ken Takusagawa
 kinderchocolate
+Kiran Panditrao (Krgp)
+Kojirion
+Leonardo Ljubičić (ICCF World Champion)
+Leonid Pechenik (lp--)
+Linus Arver
+loco-loco
+Luca Brivio (lucabrivio)
+Lucas Braesch (lucasart)
+Lyudmil Antonov (lantonov)
+Matthew Lai (matthewlai)
+Matthew Sullivan
+Mark Tenzer (31m059)
+Michael Byrne (MichaelB7)
+Michael Stembera (mstembera)
+Michael Chaly (Vizvezdenec)
+Michel Van den Bergh (vdbergh)
+Miguel Lahoz (miguel-l)
+Mikael Bäckman (mbootsector)
+Mike Whiteley (protonspring)
+Miroslav Fontán (Hexik)
+Moez Jellouli (MJZ1977)
+Mohammed Li (tthsqe12)
+Nathan Rugg (nmrugg)
+Nicklas Persson (NicklasPersson)
+Niklas Fiekas (niklasf)
+Ondrej Mosnáček (WOnder93)
+Oskar Werkelin Ahlin
+Pablo Vazquez
+Pascal Romaret
+Pasquale Pigazzini (ppigazzini)
+Patrick Jansen (mibere)
 pellanda
+Peter Zsifkovits (CoffeeOne)
+Ralph Stößer (Ralph Stoesser)
+Raminder Singh
 renouve
+Reuven Peleg
+Richard Lloyd
+Rodrigo Exterckötter Tjäder
+Ron Britvich (Britvich)
+Ronald de Man (syzygy1)
+Ryan Schmitt
+Ryan Takker
+Sebastian Buchwald (UniQP)
+Sergei Antonov (saproj)
+sf-x
 shane31
+Steinar Gunderson (sesse)
+Stefan Geschwentner (locutus2)
+Stefano Cardanobile (Stefano80)
+Stéphane Nicolet (snicolet)
+Thanar2
 thaspel
+Tom Vijlbrief (tomtor)
+Torsten Franz (torfranz)
+Uri Blass (uriblass)
+Vince Negri

Readme.md

@@ -1,5 +1,8 @@
 ### Overview
 
+[![Build Status](https://travis-ci.org/official-stockfish/Stockfish.svg?branch=master)](https://travis-ci.org/official-stockfish/Stockfish)
+[![Build Status](https://ci.appveyor.com/api/projects/status/github/official-stockfish/Stockfish?svg=true)](https://ci.appveyor.com/project/mcostalba/stockfish)
+
 Stockfish is a free UCI chess engine derived from Glaurung 2.1. It is
 not a complete chess program and requires some UCI-compatible GUI
 (e.g. XBoard with PolyGlot, eboard, Arena, Sigma Chess, Shredder, Chess
@@ -7,7 +10,7 @@ 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.
 
-This version of Stockfish supports up to 128 cores. The engine defaults
+This version of Stockfish supports up to 512 cores. The engine defaults
 to one search thread, so it is therefore recommended to inspect the value of
 the *Threads* UCI parameter, and to make sure it equals the number of CPU
 cores on your computer.
@@ -54,9 +57,9 @@ for correspondence games (because of tablebase adjudication).
 
 The "SyzygyProbeLimit" option should normally be left at its default value.
 
-**What to expect**  
+**What to expect**
 If the engine is searching a position that is not in the tablebases (e.g.
-a position with 7 pieces), it will access the tablebases during the search.
+a position with 8 pieces), it will access the tablebases during the search.
 If the engine reports a very large score (typically 123.xx), this means
 that it has found a winning line into a tablebase position.
 
@@ -93,6 +96,18 @@ compile (for instance with Microsoft MSVC) you need to manually
 set/unset some switches in the compiler command line; see file *types.h*
 for a quick reference.
 
+### Resource For Understanding the Code Base
+
+* [Chess Programming Wiki](https://www.chessprogramming.org/Main_Page) 
+has good overall chess engines explanations 
+(techniques used here are well explained like hash maps etc), it was 
+also recommended by the [support team at stockfish.](http://support.stockfishchess.org/discussions/questions/1132-how-to-understand-stockfish-sources)
+
+* [Here](https://www.chessprogramming.org/Stockfish) you can find a set 
+of features and techniques used by Stockfish and each of them is explained 
+at the wiki, however, it's a generic way rather than focusing on Stockfish's 
+own implementation, but it will still help you.
+
 
 ### Terms of use
 
@@ -109,4 +124,4 @@ to where the source code can be found. If you make any changes to the
 source code, these changes must also be made available under the GPL.
 
 For full details, read the copy of the GPL found in the file named
-*Copying.txt*
+*Copying.txt*.

Top CPU Contributors.txt

@@ -0,0 +1,146 @@
+Contributors with >10,000 CPU hours as of November 4, 2018
+Thank you!
+
+Username               CPU Hours   Games played
+noobpwnftw             3730975     292309380   
+mibere                 535242      43333774    
+crunchy                375564      29121434    
+cw                     371664      28748719    
+fastgm                 318178      22283584    
+JojoM                  295354      20958931    
+dew                    215476      17079219    
+ctoks                  214031      17312035    
+glinscott              204517      13932027    
+bking_US               187568      12233168    
+velislav               168404      13336219    
+CSU_Dynasty            168069      14417712    
+Thanar                 162373      13842179    
+spams                  149531      10940322    
+Fisherman              141137      12099359    
+drabel                 134441      11180178    
+leszek                 133658      9812120     
+marrco                 133566      10115202    
+sqrt2                  128420      10022279    
+vdbergh                123230      9200516     
+tvijlbrief             123007      9498831     
+vdv                    120381      8555423     
+malala                 117291      8126488     
+dsmith                 114010      7622414     
+BrunoBanani            104938      7448565     
+CoffeeOne              100042      4593596     
+Data                   94621       8433010     
+mgrabiak               92248       7787406     
+bcross                 89440       8506568     
+brabos                 81868       6647613     
+BRAVONE                80811       5341681     
+psk                    77195       6156031     
+nordlandia             74833       6231930     
+robal                  72818       5969856     
+TueRens                72523       6383294     
+sterni1971             71049       5647590     
+sunu                   65855       5360884     
+mhoram                 65034       5192880     
+davar                  64794       5457564     
+nssy                   64607       5371952     
+Pking_cda              64499       5704075     
+biffhero               63557       5480444     
+teddybaer              62147       5585620     
+solarlight             61278       5402642     
+ElbertoOne             60156       5504304     
+jromang                58854       4704502     
+dv8silencer            57421       3961325     
+tinker                 56039       4204914     
+Freja                  50331       3808121     
+renouve                50318       3544864     
+robnjr                 47504       4131742     
+grandphish2            47377       4110003     
+eva42                  46857       4075716     
+ttruscott              46802       3811534     
+finfish                46244       3481661     
+rap                    46201       3219490     
+ronaldjerum            45641       3964331     
+xoto                   44998       4170431     
+gvreuls                44359       3902234     
+bigpen0r               41780       3448224     
+Bobo1239               40767       3657490     
+Antihistamine          39218       2792761     
+mhunt                  38991       2697512     
+racerschmacer          38929       3756111     
+VoyagerOne             35896       3378887     
+homyur                 35561       3012398     
+rkl                    33217       2978536     
+pb00067                33034       2803485     
+speedycpu              32043       2531964     
+SC                     31954       2848432     
+EthanOConnor           31638       2143255     
+oryx                   30962       2899534     
+gri                    30108       2429137     
+csnodgrass             29396       2808611     
+Garf                   28887       2873564     
+Pyafue                 28885       1986098     
+jkiiski                28014       1923255     
+slakovv                27017       2031279     
+Prcuvu                 26300       2307154     
+hyperbolic.tom         26248       2200777     
+jbwiebe                25663       2129063     
+anst                   25525       2279159     
+Patrick_G              24222       1835674     
+nabildanial            23524       1586321     
+achambord              23495       1942546     
+Sharaf_DG              22975       1790697     
+chriswk                22876       1947731     
+ncfish1                22689       1830009     
+cuistot                22201       1383031     
+Zirie                  21171       1493227     
+Isidor                 20634       1736219     
+JanErik                20596       1791991     
+xor12                  20535       1819280     
+team-oh                20364       1653708     
+nesoneg                20264       1493435     
+dex                    20110       1682756     
+rstoesser              19802       1335177     
+Vizvezdenec            19750       1695579     
+eastorwest             19531       1841839     
+sg4032                 18913       1720157     
+horst.prack            18425       1708197     
+cisco2015              18408       1793774     
+ianh2105               18133       1668562     
+MazeOfGalious          18022       1644593     
+ville                  17900       1539130     
+j3corre                17607       975954      
+eudhan                 17502       1424648     
+jmdana                 17351       1287546     
+iisiraider             17175       1118788     
+jundery                17172       1115855     
+wei                    16852       1822582     
+SFTUser                16635       1363975     
+purplefishies          16621       1106850     
+DragonLord             16599       1252348     
+chris                  15274       1575333     
+IgorLeMasson           15201       1364148     
+dju                    15074       914278      
+Flopzee                14700       1331632     
+OssumOpossum           14149       1029265     
+enedene                13762       935618      
+ako027ako              13442       1250249     
+AdrianSA               13324       924980      
+bpfliegel              13318       886523      
+Nikolay.IT             13260       1155612     
+jpulman                12776       854815      
+joster                 12438       988413      
+fatmurphy              12015       901134      
+Nesa92                 11711       1132245     
+Adrian.Schmidt123      11542       898699      
+modolief               11228       926456      
+Dark_wizzie            11214       1017910     
+mschmidt               10973       818594      
+Andrew Grant           10780       947859      
+infinity               10762       746397      
+SapphireBrand          10692       1024604     
+Thomas A. Anderson     10553       736094      
+basepi                 10434       935168      
+lantonov               10325       972610      
+pgontarz               10294       878746      
+Spprtr                 10189       823246      
+crocogoat              10115       1017325     
+stocky                 10083       718114      

appveyor.yml

@@ -0,0 +1,71 @@
+version: 1.0.{build}
+clone_depth: 50
+
+branches:
+  only:
+    - master
+    - appveyor
+
+# Operating system (build VM template)
+os: Visual Studio 2015
+
+# 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 3.8)',
+           'project(Stockfish)',
+           '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
+      $g = "Visual Studio 14 2015"
+      If (${env:PLATFORM} -eq 'x64') { $g = $g + ' Win64' }
+      cmake -G "${g}" .
+      Write-Host "Generated files for: " $g
+
+build_script:
+  - cmake --build . --config %CONFIGURATION% -- /verbosity:minimal
+
+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

@@ -1,6 +1,7 @@
 # Stockfish, a UCI chess playing engine derived from Glaurung 2.1
 # Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
 # Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+# Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 #
 # Stockfish is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -20,24 +21,31 @@
 ### Section 1. General Configuration
 ### ==========================================================================
 
-### Establish the operating system name
-UNAME = $(shell uname)
-
 ### Executable name
+ifeq ($(COMP),mingw)
+EXE = stockfish.exe
+else
 EXE = stockfish
+endif
 
 ### Installation dir definitions
 PREFIX = /usr/local
 BINDIR = $(PREFIX)/bin
 
 ### Built-in benchmark for pgo-builds
-PGOBENCH = ./$(EXE) bench 16 1 1000 default time
+PGOBENCH = ./$(EXE) bench
 
 ### Object files
 OBJS = benchmark.o bitbase.o bitboard.o endgame.o evaluate.o main.o \
-	material.o misc.o movegen.o movepick.o pawns.o position.o \
+	material.o misc.o movegen.o movepick.o pawns.o position.o psqt.o \
 	search.o thread.o timeman.o tt.o uci.o ucioption.o syzygy/tbprobe.o
 
+### Establish the operating system name
+KERNEL = $(shell uname -s)
+ifeq ($(KERNEL),Linux)
+	OS = $(shell uname -o)
+endif
+
 ### ==========================================================================
 ### Section 2. High-level Configuration
 ### ==========================================================================
@@ -46,13 +54,14 @@ OBJS = benchmark.o bitbase.o bitboard.o endgame.o evaluate.o main.o \
 # ----------------------------------------------------------------------------
 #
 # debug = yes/no      --- -DNDEBUG         --- Enable/Disable debug mode
+# sanitize = undefined/thread/no (-fsanitize )
+#                     --- ( undefined )    --- enable undefined behavior checks
+#                     --- ( thread    )    --- enable threading error  checks
 # optimize = yes/no   --- (-O3/-fast etc.) --- Enable/Disable optimizations
 # arch = (name)       --- (-arch)          --- Target architecture
 # bits = 64/32        --- -DIS_64BIT       --- 64-/32-bit operating system
-# prefetch = yes/no   --- -DUSE_PREFETCH   --- Use prefetch x86 asm-instruction
-# bsfq = yes/no       --- -DUSE_BSFQ       --- Use bsfq x86_64 asm-instruction (only
-#                                              with GCC and ICC 64-bit)
-# popcnt = yes/no     --- -DUSE_POPCNT     --- Use popcnt x86_64 asm-instruction
+# prefetch = yes/no   --- -DUSE_PREFETCH   --- Use prefetch asm-instruction
+# popcnt = yes/no     --- -DUSE_POPCNT     --- Use popcnt asm-instruction
 # sse = yes/no        --- -msse            --- Use Intel Streaming SIMD Extensions
 # pext = yes/no       --- -DUSE_PEXT       --- Use pext x86_64 asm-instruction
 #
@@ -63,9 +72,9 @@ OBJS = benchmark.o bitbase.o bitboard.o endgame.o evaluate.o main.o \
 ### 2.1. General and architecture defaults
 optimize = yes
 debug = no
+sanitize = no
 bits = 32
 prefetch = no
-bsfq = no
 popcnt = no
 sse = no
 pext = no
@@ -95,7 +104,6 @@ ifeq ($(ARCH),x86-64)
 	arch = x86_64
 	bits = 64
 	prefetch = yes
-	bsfq = yes
 	sse = yes
 endif
 
@@ -103,7 +111,6 @@ ifeq ($(ARCH),x86-64-modern)
 	arch = x86_64
 	bits = 64
 	prefetch = yes
-	bsfq = yes
 	popcnt = yes
 	sse = yes
 endif
@@ -112,7 +119,6 @@ ifeq ($(ARCH),x86-64-bmi2)
 	arch = x86_64
 	bits = 64
 	prefetch = yes
-	bsfq = yes
 	popcnt = yes
 	sse = yes
 	pext = yes
@@ -121,7 +127,6 @@ endif
 ifeq ($(ARCH),armv7)
 	arch = armv7
 	prefetch = yes
-	bsfq = yes
 endif
 
 ifeq ($(ARCH),ppc-32)
@@ -140,7 +145,8 @@ endif
 
 ### 3.1 Selecting compiler (default = gcc)
 
-CXXFLAGS += -Wall -Wcast-qual -fno-exceptions -fno-rtti $(EXTRACXXFLAGS)
+CXXFLAGS += -Wall -Wcast-qual -fno-exceptions -std=c++11 $(EXTRACXXFLAGS)
+DEPENDFLAGS += -std=c++11
 LDFLAGS += $(EXTRALDFLAGS)
 
 ifeq ($(COMP),)
@@ -150,14 +156,46 @@ endif
 ifeq ($(COMP),gcc)
 	comp=gcc
 	CXX=g++
-	CXXFLAGS += -ansi -pedantic -Wno-long-long -Wextra -Wshadow
+	CXXFLAGS += -pedantic -Wextra -Wshadow
+
+	ifeq ($(ARCH),armv7)
+		ifeq ($(OS),Android)
+			CXXFLAGS += -m$(bits)
+			LDFLAGS += -m$(bits)
+		endif
+	else
+		CXXFLAGS += -m$(bits)
+		LDFLAGS += -m$(bits)
+	endif
+
+	ifneq ($(KERNEL),Darwin)
+	   LDFLAGS += -Wl,--no-as-needed
+	endif
 endif
 
 ifeq ($(COMP),mingw)
 	comp=mingw
-	CXX=g++
+
+	ifeq ($(KERNEL),Linux)
+		ifeq ($(bits),64)
+			ifeq ($(shell which x86_64-w64-mingw32-c++-posix),)
+				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=i686-w64-mingw32-c++
+			else
+				CXX=i686-w64-mingw32-c++-posix
+			endif
+		endif
+	else
+		CXX=g++
+	endif
+
 	CXXFLAGS += -Wextra -Wshadow
-	LDFLAGS += -static-libstdc++ -static-libgcc
+	LDFLAGS += -static
 endif
 
 ifeq ($(COMP),icc)
@@ -169,100 +207,101 @@ endif
 ifeq ($(COMP),clang)
 	comp=clang
 	CXX=clang++
-	CXXFLAGS += -pedantic -Wno-long-long -Wextra -Wshadow
+	CXXFLAGS += -pedantic -Wextra -Wshadow
+
+	ifneq ($(KERNEL),Darwin)
+	ifneq ($(KERNEL),OpenBSD)
+		LDFLAGS += -latomic
+	endif
+	endif
+
+	ifeq ($(ARCH),armv7)
+		ifeq ($(OS),Android)
+			CXXFLAGS += -m$(bits)
+			LDFLAGS += -m$(bits)
+		endif
+	else
+		CXXFLAGS += -m$(bits)
+		LDFLAGS += -m$(bits)
+	endif
 endif
 
 ifeq ($(comp),icc)
-	profile_prepare = icc-profile-prepare
 	profile_make = icc-profile-make
 	profile_use = icc-profile-use
-	profile_clean = icc-profile-clean
 else
-	profile_prepare = gcc-profile-prepare
+ifeq ($(comp),clang)
+	profile_make = clang-profile-make
+	profile_use = clang-profile-use
+else
 	profile_make = gcc-profile-make
 	profile_use = gcc-profile-use
-	profile_clean = gcc-profile-clean
+endif
 endif
 
-ifeq ($(UNAME),Darwin)
-	CXXFLAGS += -arch $(arch) -mmacosx-version-min=10.6
-	LDFLAGS += -arch $(arch) -mmacosx-version-min=10.6
+ifeq ($(KERNEL),Darwin)
+	CXXFLAGS += -arch $(arch) -mmacosx-version-min=10.9
+	LDFLAGS += -arch $(arch) -mmacosx-version-min=10.9
+endif
+
+### Travis CI script uses COMPILER to overwrite CXX
+ifdef COMPILER
+	COMPCXX=$(COMPILER)
+endif
+
+### Allow overwriting CXX from command line
+ifdef COMPCXX
+	CXX=$(COMPCXX)
 endif
 
 ### On mingw use Windows threads, otherwise POSIX
 ifneq ($(comp),mingw)
 	# On Android Bionic's C library comes with its own pthread implementation bundled in
-	ifneq ($(arch),armv7)
+	ifneq ($(OS),Android)
 		# Haiku has pthreads in its libroot, so only link it in on other platforms
-		ifneq ($(UNAME),Haiku)
+		ifneq ($(KERNEL),Haiku)
 			LDFLAGS += -lpthread
 		endif
 	endif
 endif
 
-### 3.4 Debugging
+### 3.2.1 Debugging
 ifeq ($(debug),no)
 	CXXFLAGS += -DNDEBUG
 else
 	CXXFLAGS += -g
 endif
 
-### 3.5 Optimization
+### 3.2.2 Debugging with undefined behavior sanitizers
+ifneq ($(sanitize),no)
+        CXXFLAGS += -g3 -fsanitize=$(sanitize) -fuse-ld=gold
+        LDFLAGS += -fsanitize=$(sanitize) -fuse-ld=gold
+endif
+
+### 3.3 Optimization
 ifeq ($(optimize),yes)
 
+	CXXFLAGS += -O3
+
 	ifeq ($(comp),gcc)
-		CXXFLAGS += -O3
-
-		ifeq ($(UNAME),Darwin)
-			ifeq ($(arch),i386)
-				CXXFLAGS += -mdynamic-no-pic
-			endif
-			ifeq ($(arch),x86_64)
-				CXXFLAGS += -mdynamic-no-pic
-			endif
-		endif
-
-		ifeq ($(arch),armv7)
+		ifeq ($(OS), Android)
 			CXXFLAGS += -fno-gcse -mthumb -march=armv7-a -mfloat-abi=softfp
 		endif
 	endif
-
-	ifeq ($(comp),mingw)
-		CXXFLAGS += -O3
-	endif
-
-	ifeq ($(comp),icc)
-		ifeq ($(UNAME),Darwin)
-			CXXFLAGS += -fast -mdynamic-no-pic
-		else
-			CXXFLAGS += -fast
-		endif
-	endif
-
-	ifeq ($(comp),clang)
-		CXXFLAGS += -O3
-
-		ifeq ($(UNAME),Darwin)
-			ifeq ($(pext),no)
-				CXXFLAGS += -flto
-				LDFLAGS += $(CXXFLAGS)
-			endif
-			ifeq ($(arch),i386)
-				CXXFLAGS += -mdynamic-no-pic
-			endif
-			ifeq ($(arch),x86_64)
-				CXXFLAGS += -mdynamic-no-pic
-			endif
+	
+	ifeq ($(comp),$(filter $(comp),gcc clang icc))
+		ifeq ($(KERNEL),Darwin)
+			CXXFLAGS += -mdynamic-no-pic
 		endif
 	endif
 endif
 
-### 3.6. Bits
+### 3.4 Bits
 ifeq ($(bits),64)
 	CXXFLAGS += -DIS_64BIT
 endif
 
-### 3.7 prefetch
+### 3.5 prefetch
 ifeq ($(prefetch),yes)
 	ifeq ($(sse),yes)
 		CXXFLAGS += -msse
@@ -272,12 +311,7 @@ else
 	CXXFLAGS += -DNO_PREFETCH
 endif
 
-### 3.8 bsfq
-ifeq ($(bsfq),yes)
-	CXXFLAGS += -DUSE_BSFQ
-endif
-
-### 3.9 popcnt
+### 3.6 popcnt
 ifeq ($(popcnt),yes)
 	ifeq ($(comp),icc)
 		CXXFLAGS += -msse3 -DUSE_POPCNT
@@ -286,33 +320,36 @@ ifeq ($(popcnt),yes)
 	endif
 endif
 
-### 3.10 pext
+### 3.7 pext
 ifeq ($(pext),yes)
 	CXXFLAGS += -DUSE_PEXT
 	ifeq ($(comp),$(filter $(comp),gcc clang mingw))
-		CXXFLAGS += -mbmi -mbmi2
+		CXXFLAGS += -mbmi2
 	endif
 endif
 
-### 3.11 Link Time Optimization, it works since gcc 4.5 but not on mingw.
+### 3.8 Link Time Optimization, it works since gcc 4.5 but not on mingw under Windows.
 ### This is a mix of compile and link time options because the lto link phase
 ### needs access to the optimization flags.
-ifeq ($(comp),gcc)
-	ifeq ($(optimize),yes)
-	ifeq ($(debug),no)
-		GCC_MAJOR := `$(CXX) -dumpversion | cut -f1 -d.`
-		GCC_MINOR := `$(CXX) -dumpversion | cut -f2 -d.`
-		ifeq (1,$(shell expr \( $(GCC_MAJOR) \> 4 \) \| \( $(GCC_MAJOR) \= 4 \& $(GCC_MINOR) \>= 5 \)))
-			CXXFLAGS += -flto
-			LDFLAGS += $(CXXFLAGS)
-		endif
+ifeq ($(optimize),yes)
+ifeq ($(debug), no)
+	ifeq ($(comp),$(filter $(comp),gcc clang))
+		CXXFLAGS += -flto
+		LDFLAGS += $(CXXFLAGS)
+	endif
+
+	ifeq ($(comp),mingw)
+	ifeq ($(KERNEL),Linux)
+		CXXFLAGS += -flto
+		LDFLAGS += $(CXXFLAGS)
 	endif
 	endif
 endif
+endif
 
-### 3.12 Android 5 can only run position independent executables. Note that this
+### 3.9 Android 5 can only run position independent executables. Note that this
 ### breaks Android 4.0 and earlier.
-ifeq ($(arch),armv7)
+ifeq ($(OS), Android)
 	CXXFLAGS += -fPIE
 	LDFLAGS += -fPIE -pie
 endif
@@ -326,7 +363,7 @@ help:
 	@echo ""
 	@echo "To compile stockfish, type: "
 	@echo ""
-	@echo "make target ARCH=arch [COMP=comp]"
+	@echo "make target ARCH=arch [COMP=compiler] [COMPCXX=cxx]"
 	@echo ""
 	@echo "Supported targets:"
 	@echo ""
@@ -356,36 +393,39 @@ help:
 	@echo "clang                   > LLVM Clang compiler"
 	@echo "icc                     > Intel compiler"
 	@echo ""
-	@echo "Examples. If you don't know what to do, you likely want to run: "
+	@echo "Simple examples. If you don't know what to do, you likely want to run: "
 	@echo ""
 	@echo "make build ARCH=x86-64    (This is for 64-bit systems)"
 	@echo "make build ARCH=x86-32    (This is for 32-bit systems)"
 	@echo ""
+	@echo "Advanced examples, for experienced users: "
+	@echo ""
+	@echo "make build ARCH=x86-64 COMP=clang"
+	@echo "make profile-build ARCH=x86-64-modern COMP=gcc COMPCXX=g++-4.8"
+	@echo ""
 
-.PHONY: build profile-build
-build:
-	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) config-sanity
+
+.PHONY: help build profile-build strip install clean objclean profileclean help \
+        config-sanity icc-profile-use icc-profile-make gcc-profile-use gcc-profile-make \
+        clang-profile-use clang-profile-make
+
+build: config-sanity
 	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) all
 
-profile-build:
-	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) config-sanity
+profile-build: config-sanity objclean profileclean
 	@echo ""
-	@echo "Step 0/4. Preparing for profile build."
-	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) $(profile_prepare)
-	@echo ""
-	@echo "Step 1/4. Building executable for benchmark ..."
-	@touch *.cpp *.h syzygy/*.cpp syzygy/*.h
+	@echo "Step 1/4. Building instrumented executable ..."
 	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) $(profile_make)
 	@echo ""
 	@echo "Step 2/4. Running benchmark for pgo-build ..."
-	@$(PGOBENCH) > /dev/null
+	$(PGOBENCH) > /dev/null
 	@echo ""
-	@echo "Step 3/4. Building final executable ..."
-	@touch *.cpp *.h syzygy/*.cpp syzygy/*.h
+	@echo "Step 3/4. Building optimized executable ..."
+	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) objclean
 	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) $(profile_use)
 	@echo ""
 	@echo "Step 4/4. Deleting profile data ..."
-	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) $(profile_clean)
+	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) profileclean
 
 strip:
 	strip $(EXE)
@@ -395,8 +435,19 @@ install:
 	-cp $(EXE) $(BINDIR)
 	-strip $(BINDIR)/$(EXE)
 
-clean:
-	$(RM) $(EXE) $(EXE).exe *.o .depend *~ core bench.txt *.gcda ./syzygy/*.o ./syzygy/*.gcda
+#clean all
+clean: objclean profileclean
+	@rm -f .depend *~ core
+
+# clean binaries and objects
+objclean:
+	@rm -f $(EXE) *.o ./syzygy/*.o
+
+# clean auxiliary profiling files
+profileclean:
+	@rm -rf profdir
+	@rm -f bench.txt *.gcda ./syzygy/*.gcda *.gcno ./syzygy/*.gcno
+	@rm -f stockfish.profdata *.profraw
 
 default:
 	help
@@ -411,11 +462,13 @@ config-sanity:
 	@echo ""
 	@echo "Config:"
 	@echo "debug: '$(debug)'"
+	@echo "sanitize: '$(sanitize)'"
 	@echo "optimize: '$(optimize)'"
 	@echo "arch: '$(arch)'"
 	@echo "bits: '$(bits)'"
+	@echo "kernel: '$(KERNEL)'"
+	@echo "os: '$(OS)'"
 	@echo "prefetch: '$(prefetch)'"
-	@echo "bsfq: '$(bsfq)'"
 	@echo "popcnt: '$(popcnt)'"
 	@echo "sse: '$(sse)'"
 	@echo "pext: '$(pext)'"
@@ -428,12 +481,12 @@ config-sanity:
 	@echo "Testing config sanity. If this fails, try 'make help' ..."
 	@echo ""
 	@test "$(debug)" = "yes" || test "$(debug)" = "no"
+	@test "$(sanitize)" = "undefined" || test "$(sanitize)" = "thread" || test "$(sanitize)" = "no"
 	@test "$(optimize)" = "yes" || test "$(optimize)" = "no"
 	@test "$(arch)" = "any" || test "$(arch)" = "x86_64" || test "$(arch)" = "i386" || \
 	 test "$(arch)" = "ppc64" || test "$(arch)" = "ppc" || test "$(arch)" = "armv7"
 	@test "$(bits)" = "32" || test "$(bits)" = "64"
 	@test "$(prefetch)" = "yes" || test "$(prefetch)" = "no"
-	@test "$(bsfq)" = "yes" || test "$(bsfq)" = "no"
 	@test "$(popcnt)" = "yes" || test "$(popcnt)" = "no"
 	@test "$(sse)" = "yes" || test "$(sse)" = "no"
 	@test "$(pext)" = "yes" || test "$(pext)" = "no"
@@ -442,32 +495,33 @@ config-sanity:
 $(EXE): $(OBJS)
 	$(CXX) -o $@ $(OBJS) $(LDFLAGS)
 
-gcc-profile-prepare:
-	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) gcc-profile-clean
+clang-profile-make:
+	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) \
+	EXTRACXXFLAGS='-fprofile-instr-generate ' \
+	EXTRALDFLAGS=' -fprofile-instr-generate' \
+	all
+
+clang-profile-use:
+	llvm-profdata merge -output=stockfish.profdata *.profraw
+	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) \
+	EXTRACXXFLAGS='-fprofile-instr-use=stockfish.profdata' \
+	EXTRALDFLAGS='-fprofile-use ' \
+	all
 
 gcc-profile-make:
 	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) \
-	EXTRACXXFLAGS='-fprofile-arcs' \
+	EXTRACXXFLAGS='-fprofile-generate' \
 	EXTRALDFLAGS='-lgcov' \
 	all
 
 gcc-profile-use:
-# Deleting corrupt ucioption.gc* profile files is necessary to avoid an 
-# "internal compiler error" for gcc versions 4.7.x
-	@rm -f ucioption.gc*
 	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) \
-	EXTRACXXFLAGS='-fbranch-probabilities' \
+	EXTRACXXFLAGS='-fprofile-use -fno-peel-loops -fno-tracer' \
 	EXTRALDFLAGS='-lgcov' \
 	all
 
-gcc-profile-clean:
-	@rm -rf *.gcda *.gcno syzygy/*.gcda syzygy/*.gcno bench.txt
-
-icc-profile-prepare:
-	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) icc-profile-clean
-	@mkdir profdir
-
 icc-profile-make:
+	@mkdir -p profdir
 	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) \
 	EXTRACXXFLAGS='-prof-gen=srcpos -prof_dir ./profdir' \
 	all
@@ -477,9 +531,6 @@ icc-profile-use:
 	EXTRACXXFLAGS='-prof_use -prof_dir ./profdir' \
 	all
 
-icc-profile-clean:
-	@rm -rf profdir bench.txt
-
 .depend:
 	-@$(CXX) $(DEPENDFLAGS) -MM $(OBJS:.o=.cpp) > $@ 2> /dev/null
 

src/benchmark.cpp

@@ -2,6 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -17,30 +18,25 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <algorithm>
 #include <fstream>
 #include <iostream>
 #include <istream>
 #include <vector>
 
-#include "misc.h"
 #include "position.h"
-#include "search.h"
-#include "thread.h"
-#include "tt.h"
-#include "uci.h"
 
 using namespace std;
 
 namespace {
 
-const char* Defaults[] = {
+const vector<string> Defaults = {
+  "setoption name UCI_Chess960 value false",
   "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1",
   "r3k2r/p1ppqpb1/bn2pnp1/3PN3/1p2P3/2N2Q1p/PPPBBPPP/R3K2R w KQkq - 0 10",
   "8/2p5/3p4/KP5r/1R3p1k/8/4P1P1/8 w - - 0 11",
   "4rrk1/pp1n3p/3q2pQ/2p1pb2/2PP4/2P3N1/P2B2PP/4RRK1 b - - 7 19",
-  "rq3rk1/ppp2ppp/1bnpb3/3N2B1/3NP3/7P/PPPQ1PP1/2KR3R w - - 7 14",
-  "r1bq1r1k/1pp1n1pp/1p1p4/4p2Q/4Pp2/1BNP4/PPP2PPP/3R1RK1 w - - 2 14",
+  "rq3rk1/ppp2ppp/1bnpb3/3N2B1/3NP3/7P/PPPQ1PP1/2KR3R w - - 7 14 moves d4e6",
+  "r1bq1r1k/1pp1n1pp/1p1p4/4p2Q/4Pp2/1BNP4/PPP2PPP/3R1RK1 w - - 2 14 moves g2g4",
   "r3r1k1/2p2ppp/p1p1bn2/8/1q2P3/2NPQN2/PPP3PP/R4RK1 b - - 2 15",
   "r1bbk1nr/pp3p1p/2n5/1N4p1/2Np1B2/8/PPP2PPP/2KR1B1R w kq - 0 13",
   "r1bq1rk1/ppp1nppp/4n3/3p3Q/3P4/1BP1B3/PP1N2PP/R4RK1 w - - 1 16",
@@ -53,7 +49,7 @@ const char* Defaults[] = {
   "3q2k1/pb3p1p/4pbp1/2r5/PpN2N2/1P2P2P/5PP1/Q2R2K1 b - - 4 26",
   "6k1/6p1/6Pp/ppp5/3pn2P/1P3K2/1PP2P2/3N4 b - - 0 1",
   "3b4/5kp1/1p1p1p1p/pP1PpP1P/P1P1P3/3KN3/8/8 w - - 0 1",
-  "2K5/p7/7P/5pR1/8/5k2/r7/8 w - - 0 1",
+  "2K5/p7/7P/5pR1/8/5k2/r7/8 w - - 0 1 moves g5g6 f3e3 g6g5 e3f3",
   "8/6pk/1p6/8/PP3p1p/5P2/4KP1q/3Q4 w - - 0 1",
   "7k/3p2pp/4q3/8/4Q3/5Kp1/P6b/8 w - - 0 1",
   "8/2p5/8/2kPKp1p/2p4P/2P5/3P4/8 w - - 0 1",
@@ -78,23 +74,37 @@ const char* Defaults[] = {
 
   // 7-man positions
   "8/R7/2q5/8/6k1/8/1P5p/K6R w - - 0 124", // Draw
+
+  // Mate and stalemate positions
+  "6k1/3b3r/1p1p4/p1n2p2/1PPNpP1q/P3Q1p1/1R1RB1P1/5K2 b - - 0 1",
+  "r2r1n2/pp2bk2/2p1p2p/3q4/3PN1QP/2P3R1/P4PP1/5RK1 w - - 0 1",
+  "8/8/8/8/8/6k1/6p1/6K1 w - -",
+  "7k/7P/6K1/8/3B4/8/8/8 b - -",
+
+  // Chess 960
+  "setoption name UCI_Chess960 value true",
+  "bbqnnrkr/pppppppp/8/8/8/8/PPPPPPPP/BBQNNRKR w KQkq - 0 1 moves g2g3 d7d5 d2d4 c8h3 c1g5 e8d6 g5e7 f7f6",
+  "setoption name UCI_Chess960 value false"
 };
 
 } // namespace
 
-/// benchmark() runs a simple benchmark by letting Stockfish analyze a set
-/// of positions for a given limit each. There are five parameters: the
-/// transposition table size, the number of search threads that should
-/// be used, the limit value spent for each position (optional, default is
-/// depth 13), an optional file name where to look for positions in FEN
-/// format (defaults are the positions defined above) and the type of the
-/// limit value: depth (default), time in millisecs or number of nodes.
+/// setup_bench() builds a list of UCI commands to be run by bench. There
+/// are five parameters: TT size in MB, number of search threads that
+/// should be used, the limit value spent for each position, a file name
+/// where to look for positions in FEN format and the type of the limit:
+/// depth, perft, nodes and movetime (in millisecs).
+///
+/// bench -> search default positions up to depth 13
+/// bench 64 1 15 -> search default positions up to depth 15 (TT = 64MB)
+/// bench 64 4 5000 current movetime -> search current position with 4 threads for 5 sec
+/// bench 64 1 100000 default nodes -> search default positions for 100K nodes each
+/// bench 16 1 5 default perft -> run a perft 5 on default positions
 
-void benchmark(const Position& current, istream& is) {
+vector<string> setup_bench(const Position& current, istream& is) {
 
-  string token;
-  Search::LimitsType limits;
-  vector<string> fens;
+  vector<string> fens, list;
+  string go, token;
 
   // Assign default values to missing arguments
   string ttSize    = (is >> token) ? token : "16";
@@ -103,24 +113,10 @@ void benchmark(const Position& current, istream& is) {
   string fenFile   = (is >> token) ? token : "default";
   string limitType = (is >> token) ? token : "depth";
 
-  Options["Hash"]    = ttSize;
-  Options["Threads"] = threads;
-  TT.clear();
-
-  if (limitType == "time")
-      limits.movetime = atoi(limit.c_str()); // movetime is in ms
-
-  else if (limitType == "nodes")
-      limits.nodes = atoi(limit.c_str());
-
-  else if (limitType == "mate")
-      limits.mate = atoi(limit.c_str());
-
-  else
-      limits.depth = atoi(limit.c_str());
+  go = "go " + limitType + " " + limit;
 
   if (fenFile == "default")
-      fens.assign(Defaults, Defaults + 37);
+      fens = Defaults;
 
   else if (fenFile == "current")
       fens.push_back(current.fen());
@@ -128,12 +124,12 @@ void benchmark(const Position& current, istream& is) {
   else
   {
       string fen;
-      ifstream file(fenFile.c_str());
+      ifstream file(fenFile);
 
       if (!file.is_open())
       {
           cerr << "Unable to open file " << fenFile << endl;
-          return;
+          exit(EXIT_FAILURE);
       }
 
       while (getline(file, fen))
@@ -143,33 +139,18 @@ void benchmark(const Position& current, istream& is) {
       file.close();
   }
 
-  uint64_t nodes = 0;
-  Search::StateStackPtr st;
-  Time::point elapsed = Time::now();
-
-  for (size_t i = 0; i < fens.size(); ++i)
-  {
-      Position pos(fens[i], Options["UCI_Chess960"], Threads.main());
-
-      cerr << "\nPosition: " << i + 1 << '/' << fens.size() << endl;
-
-      if (limitType == "perft")
-          nodes += Search::perft<true>(pos, limits.depth * ONE_PLY);
+  list.emplace_back("ucinewgame");
+  list.emplace_back("setoption name Threads value " + threads);
+  list.emplace_back("setoption name Hash value " + ttSize);
 
+  for (const string& fen : fens)
+      if (fen.find("setoption") != string::npos)
+          list.emplace_back(fen);
       else
       {
-          Threads.start_thinking(pos, limits, st);
-          Threads.wait_for_think_finished();
-          nodes += Search::RootPos.nodes_searched();
+          list.emplace_back("position fen " + fen);
+          list.emplace_back(go);
       }
-  }
 
-  elapsed = std::max(Time::now() - elapsed, Time::point(1)); // Avoid a 'divide by zero'
-
-  dbg_print(); // Just before to exit
-
-  cerr << "\n==========================="
-       << "\nTotal time (ms) : " << elapsed
-       << "\nNodes searched  : " << nodes
-       << "\nNodes/second    : " << 1000 * nodes / elapsed << endl;
+  return list;
 }

src/bitbase.cpp

@@ -2,6 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -17,7 +18,9 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include <algorithm>
 #include <cassert>
+#include <numeric>
 #include <vector>
 
 #include "bitboard.h"
@@ -26,7 +29,7 @@
 namespace {
 
   // There are 24 possible pawn squares: the first 4 files and ranks from 2 to 7
-  const unsigned MAX_INDEX = 2*24*64*64; // stm * psq * wksq * bksq = 196608
+  constexpr unsigned MAX_INDEX = 2*24*64*64; // stm * psq * wksq * bksq = 196608
 
   // Each uint32_t stores results of 32 positions, one per bit
   uint32_t KPKBitbase[MAX_INDEX / 32];
@@ -51,20 +54,19 @@ namespace {
     WIN     = 4
   };
 
-  inline Result& operator|=(Result& r, Result v) { return r = Result(r | v); }
+  Result& operator|=(Result& r, Result v) { return r = Result(r | v); }
 
   struct KPKPosition {
-
-    KPKPosition(unsigned idx);
+    KPKPosition() = default;
+    explicit KPKPosition(unsigned idx);
     operator Result() const { return result; }
     Result classify(const std::vector<KPKPosition>& db)
     { return us == WHITE ? classify<WHITE>(db) : classify<BLACK>(db); }
 
-  private:
     template<Color Us> Result classify(const std::vector<KPKPosition>& db);
 
     Color us;
-    Square bksq, wksq, psq;
+    Square ksq[COLOR_NB], psq;
     Result result;
   };
 
@@ -82,13 +84,12 @@ bool Bitbases::probe(Square wksq, Square wpsq, Square bksq, Color us) {
 
 void Bitbases::init() {
 
+  std::vector<KPKPosition> db(MAX_INDEX);
   unsigned idx, repeat = 1;
-  std::vector<KPKPosition> db;
-  db.reserve(MAX_INDEX);
 
   // Initialize db with known win / draw positions
   for (idx = 0; idx < MAX_INDEX; ++idx)
-      db.push_back(KPKPosition(idx));
+      db[idx] = KPKPosition(idx);
 
   // Iterate through the positions until none of the unknown positions can be
   // changed to either wins or draws (15 cycles needed).
@@ -107,69 +108,73 @@ namespace {
 
   KPKPosition::KPKPosition(unsigned idx) {
 
-    wksq   = Square((idx >>  0) & 0x3F);
-    bksq   = Square((idx >>  6) & 0x3F);
-    us     = Color ((idx >> 12) & 0x01);
-    psq    = make_square(File((idx >> 13) & 0x3), RANK_7 - Rank((idx >> 15) & 0x7));
-    result = UNKNOWN;
+    ksq[WHITE] = Square((idx >>  0) & 0x3F);
+    ksq[BLACK] = Square((idx >>  6) & 0x3F);
+    us         = Color ((idx >> 12) & 0x01);
+    psq        = make_square(File((idx >> 13) & 0x3), Rank(RANK_7 - ((idx >> 15) & 0x7)));
 
     // Check if two pieces are on the same square or if a king can be captured
-    if (   distance(wksq, bksq) <= 1
-        || wksq == psq
-        || bksq == psq
-        || (us == WHITE && (StepAttacksBB[PAWN][psq] & bksq)))
+    if (   distance(ksq[WHITE], ksq[BLACK]) <= 1
+        || ksq[WHITE] == psq
+        || ksq[BLACK] == psq
+        || (us == WHITE && (PawnAttacks[WHITE][psq] & ksq[BLACK])))
         result = INVALID;
 
-    else if (us == WHITE)
-    {
-        // Immediate win if a pawn can be promoted without getting captured
-        if (   rank_of(psq) == RANK_7
-            && wksq != psq + DELTA_N
-            && (   distance(bksq, psq + DELTA_N) > 1
-                ||(StepAttacksBB[KING][wksq] & (psq + DELTA_N))))
-            result = WIN;
-    }
+    // Immediate win if a pawn can be promoted without getting captured
+    else if (   us == WHITE
+             && rank_of(psq) == RANK_7
+             && ksq[us] != psq + NORTH
+             && (    distance(ksq[~us], psq + NORTH) > 1
+                 || (PseudoAttacks[KING][ksq[us]] & (psq + NORTH))))
+        result = WIN;
+
     // Immediate draw if it is a stalemate or a king captures undefended pawn
-    else if (  !(StepAttacksBB[KING][bksq] & ~(StepAttacksBB[KING][wksq] | StepAttacksBB[PAWN][psq]))
-             || (StepAttacksBB[KING][bksq] & psq & ~StepAttacksBB[KING][wksq]))
+    else if (   us == BLACK
+             && (  !(PseudoAttacks[KING][ksq[us]] & ~(PseudoAttacks[KING][ksq[~us]] | PawnAttacks[~us][psq]))
+                 || (PseudoAttacks[KING][ksq[us]] & psq & ~PseudoAttacks[KING][ksq[~us]])))
         result = DRAW;
+
+    // Position will be classified later
+    else
+        result = UNKNOWN;
   }
 
   template<Color Us>
   Result KPKPosition::classify(const std::vector<KPKPosition>& db) {
 
-    // White to Move: If one move leads to a position classified as WIN, the result
+    // White to move: If one move leads to a position classified as WIN, the result
     // of the current position is WIN. If all moves lead to positions classified
     // as DRAW, the current position is classified as DRAW, otherwise the current
     // position is classified as UNKNOWN.
     //
-    // Black to Move: If one move leads to a position classified as DRAW, the result
+    // Black to move: If one move leads to a position classified as DRAW, the result
     // of the current position is DRAW. If all moves lead to positions classified
     // as WIN, the position is classified as WIN, otherwise the current position is
     // classified as UNKNOWN.
 
-    const Color Them = (Us == WHITE ? BLACK : WHITE);
+    constexpr Color  Them = (Us == WHITE ? BLACK : WHITE);
+    constexpr Result Good = (Us == WHITE ? WIN   : DRAW);
+    constexpr Result Bad  = (Us == WHITE ? DRAW  : WIN);
 
     Result r = INVALID;
-    Bitboard b = StepAttacksBB[KING][Us == WHITE ? wksq : bksq];
+    Bitboard b = PseudoAttacks[KING][ksq[Us]];
 
     while (b)
-        r |= Us == WHITE ? db[index(Them, bksq, pop_lsb(&b), psq)]
-                         : db[index(Them, pop_lsb(&b), wksq, psq)];
-
-    if (Us == WHITE && rank_of(psq) < RANK_7)
-    {
-        Square s = psq + DELTA_N;
-        r |= db[index(BLACK, bksq, wksq, s)]; // Single push
-
-        if (rank_of(psq) == RANK_2 && s != wksq && s != bksq)
-            r |= db[index(BLACK, bksq, wksq, s + DELTA_N)]; // Double push
-    }
+        r |= Us == WHITE ? db[index(Them, ksq[Them]  , pop_lsb(&b), psq)]
+                         : db[index(Them, pop_lsb(&b), ksq[Them]  , psq)];
 
     if (Us == WHITE)
-        return result = r & WIN  ? WIN  : r & UNKNOWN ? UNKNOWN : DRAW;
-    else
-        return result = r & DRAW ? DRAW : r & UNKNOWN ? UNKNOWN : WIN;
+    {
+        if (rank_of(psq) < RANK_7)      // Single push
+            r |= db[index(Them, ksq[Them], ksq[Us], psq + NORTH)];
+
+        if (   rank_of(psq) == RANK_2   // Double push
+            && psq + NORTH != ksq[Us]
+            && psq + NORTH != ksq[Them])
+            r |= db[index(Them, ksq[Them], ksq[Us], psq + NORTH + NORTH)];
+    }
+
+    return result = r & Good  ? Good  : r & UNKNOWN ? UNKNOWN : Bad;
   }
 
 } // namespace

src/bitboard.cpp

@@ -2,6 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -18,102 +19,47 @@
 */
 
 #include <algorithm>
-#include <cstring>   // For std::memset
 
 #include "bitboard.h"
-#include "bitcount.h"
 #include "misc.h"
 
+uint8_t PopCnt16[1 << 16];
 int SquareDistance[SQUARE_NB][SQUARE_NB];
 
-Bitboard  RookMasks  [SQUARE_NB];
-Bitboard  RookMagics [SQUARE_NB];
-Bitboard* RookAttacks[SQUARE_NB];
-unsigned  RookShifts [SQUARE_NB];
-
-Bitboard  BishopMasks  [SQUARE_NB];
-Bitboard  BishopMagics [SQUARE_NB];
-Bitboard* BishopAttacks[SQUARE_NB];
-unsigned  BishopShifts [SQUARE_NB];
-
 Bitboard SquareBB[SQUARE_NB];
 Bitboard FileBB[FILE_NB];
 Bitboard RankBB[RANK_NB];
 Bitboard AdjacentFilesBB[FILE_NB];
-Bitboard InFrontBB[COLOR_NB][RANK_NB];
-Bitboard StepAttacksBB[PIECE_NB][SQUARE_NB];
+Bitboard ForwardRanksBB[COLOR_NB][RANK_NB];
 Bitboard BetweenBB[SQUARE_NB][SQUARE_NB];
 Bitboard LineBB[SQUARE_NB][SQUARE_NB];
 Bitboard DistanceRingBB[SQUARE_NB][8];
-Bitboard ForwardBB[COLOR_NB][SQUARE_NB];
+Bitboard ForwardFileBB[COLOR_NB][SQUARE_NB];
 Bitboard PassedPawnMask[COLOR_NB][SQUARE_NB];
 Bitboard PawnAttackSpan[COLOR_NB][SQUARE_NB];
 Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB];
+Bitboard PawnAttacks[COLOR_NB][SQUARE_NB];
+
+Magic RookMagics[SQUARE_NB];
+Magic BishopMagics[SQUARE_NB];
 
 namespace {
 
-  // De Bruijn sequences. See chessprogramming.wikispaces.com/BitScan
-  const uint64_t DeBruijn64 = 0x3F79D71B4CB0A89ULL;
-  const uint32_t DeBruijn32 = 0x783A9B23;
-
-  int MS1BTable[256];           // To implement software msb()
-  Square BSFTable[SQUARE_NB];   // To implement software bitscan
   Bitboard RookTable[0x19000];  // To store rook attacks
   Bitboard BishopTable[0x1480]; // To store bishop attacks
 
-  typedef unsigned (Fn)(Square, Bitboard);
+  void init_magics(Bitboard table[], Magic magics[], Direction directions[]);
 
-  void init_magics(Bitboard table[], Bitboard* attacks[], Bitboard magics[],
-                   Bitboard masks[], unsigned shifts[], Square deltas[], Fn index);
+  // popcount16() counts the non-zero bits using SWAR-Popcount algorithm
 
-  // bsf_index() returns the index into BSFTable[] to look up the bitscan. Uses
-  // Matt Taylor's folding for 32 bit case, extended to 64 bit by Kim Walisch.
-
-  FORCE_INLINE unsigned bsf_index(Bitboard b) {
-    b ^= b - 1;
-    return Is64Bit ? (b * DeBruijn64) >> 58
-                   : ((unsigned(b) ^ unsigned(b >> 32)) * DeBruijn32) >> 26;
+  unsigned popcount16(unsigned u) {
+    u -= (u >> 1) & 0x5555U;
+    u = ((u >> 2) & 0x3333U) + (u & 0x3333U);
+    u = ((u >> 4) + u) & 0x0F0FU;
+    return (u * 0x0101U) >> 8;
   }
 }
 
-#ifndef USE_BSFQ
-
-/// Software fall-back of lsb() and msb() for CPU lacking hardware support
-
-Square lsb(Bitboard b) {
-  return BSFTable[bsf_index(b)];
-}
-
-Square msb(Bitboard b) {
-
-  unsigned b32;
-  int result = 0;
-
-  if (b > 0xFFFFFFFF)
-  {
-      b >>= 32;
-      result = 32;
-  }
-
-  b32 = unsigned(b);
-
-  if (b32 > 0xFFFF)
-  {
-      b32 >>= 16;
-      result += 16;
-  }
-
-  if (b32 > 0xFF)
-  {
-      b32 >>= 8;
-      result += 8;
-  }
-
-  return Square(result + MS1BTable[b32]);
-}
-
-#endif // ifndef USE_BSFQ
-
 
 /// Bitboards::pretty() returns an ASCII representation of a bitboard suitable
 /// to be printed to standard output. Useful for debugging.
@@ -125,9 +71,9 @@ const std::string Bitboards::pretty(Bitboard b) {
   for (Rank r = RANK_8; r >= RANK_1; --r)
   {
       for (File f = FILE_A; f <= FILE_H; ++f)
-          s.append(b & make_square(f, r) ? "| X " : "|   ");
+          s += b & make_square(f, r) ? "| X " : "|   ";
 
-      s.append("|\n+---+---+---+---+---+---+---+---+\n");
+      s += "|\n+---+---+---+---+---+---+---+---+\n";
   }
 
   return s;
@@ -139,14 +85,11 @@ const std::string Bitboards::pretty(Bitboard b) {
 
 void Bitboards::init() {
 
-  for (Square s = SQ_A1; s <= SQ_H8; ++s)
-  {
-      SquareBB[s] = 1ULL << s;
-      BSFTable[bsf_index(SquareBB[s])] = s;
-  }
+  for (unsigned i = 0; i < (1 << 16); ++i)
+      PopCnt16[i] = (uint8_t) popcount16(i);
 
-  for (Bitboard b = 1; b < 256; ++b)
-      MS1BTable[b] = more_than_one(b) ? MS1BTable[b - 1] : lsb(b);
+  for (Square s = SQ_A1; s <= SQ_H8; ++s)
+      SquareBB[s] = (1ULL << s);
 
   for (File f = FILE_A; f <= FILE_H; ++f)
       FileBB[f] = f > FILE_A ? FileBB[f - 1] << 1 : FileABB;
@@ -158,14 +101,14 @@ void Bitboards::init() {
       AdjacentFilesBB[f] = (f > FILE_A ? FileBB[f - 1] : 0) | (f < FILE_H ? FileBB[f + 1] : 0);
 
   for (Rank r = RANK_1; r < RANK_8; ++r)
-      InFrontBB[WHITE][r] = ~(InFrontBB[BLACK][r + 1] = InFrontBB[BLACK][r] | RankBB[r]);
+      ForwardRanksBB[WHITE][r] = ~(ForwardRanksBB[BLACK][r + 1] = ForwardRanksBB[BLACK][r] | RankBB[r]);
 
   for (Color c = WHITE; c <= BLACK; ++c)
       for (Square s = SQ_A1; s <= SQ_H8; ++s)
       {
-          ForwardBB[c][s]      = InFrontBB[c][rank_of(s)] & FileBB[file_of(s)];
-          PawnAttackSpan[c][s] = InFrontBB[c][rank_of(s)] & AdjacentFilesBB[file_of(s)];
-          PassedPawnMask[c][s] = ForwardBB[c][s] | PawnAttackSpan[c][s];
+          ForwardFileBB [c][s] = ForwardRanksBB[c][rank_of(s)] & FileBB[file_of(s)];
+          PawnAttackSpan[c][s] = ForwardRanksBB[c][rank_of(s)] & AdjacentFilesBB[file_of(s)];
+          PassedPawnMask[c][s] = ForwardFileBB [c][s] | PawnAttackSpan[c][s];
       }
 
   for (Square s1 = SQ_A1; s1 <= SQ_H8; ++s1)
@@ -173,59 +116,61 @@ void Bitboards::init() {
           if (s1 != s2)
           {
               SquareDistance[s1][s2] = std::max(distance<File>(s1, s2), distance<Rank>(s1, s2));
-              DistanceRingBB[s1][SquareDistance[s1][s2] - 1] |= s2;
+              DistanceRingBB[s1][SquareDistance[s1][s2]] |= s2;
           }
 
-  int steps[][9] = { {}, { 7, 9 }, { 17, 15, 10, 6, -6, -10, -15, -17 },
-                     {}, {}, {}, { 9, 7, -7, -9, 8, 1, -1, -8 } };
+  int steps[][5] = { {}, { 7, 9 }, { 6, 10, 15, 17 }, {}, {}, {}, { 1, 7, 8, 9 } };
 
   for (Color c = WHITE; c <= BLACK; ++c)
-      for (PieceType pt = PAWN; pt <= KING; ++pt)
+      for (PieceType pt : { PAWN, KNIGHT, KING })
           for (Square s = SQ_A1; s <= SQ_H8; ++s)
               for (int i = 0; steps[pt][i]; ++i)
               {
-                  Square to = s + Square(c == WHITE ? steps[pt][i] : -steps[pt][i]);
+                  Square to = s + Direction(c == WHITE ? steps[pt][i] : -steps[pt][i]);
 
                   if (is_ok(to) && distance(s, to) < 3)
-                      StepAttacksBB[make_piece(c, pt)][s] |= to;
+                  {
+                      if (pt == PAWN)
+                          PawnAttacks[c][s] |= to;
+                      else
+                          PseudoAttacks[pt][s] |= to;
+                  }
               }
 
-  Square RookDeltas[] = { DELTA_N,  DELTA_E,  DELTA_S,  DELTA_W  };
-  Square BishopDeltas[] = { DELTA_NE, DELTA_SE, DELTA_SW, DELTA_NW };
+  Direction RookDirections[] = { NORTH, EAST, SOUTH, WEST };
+  Direction BishopDirections[] = { NORTH_EAST, SOUTH_EAST, SOUTH_WEST, NORTH_WEST };
 
-  init_magics(RookTable, RookAttacks, RookMagics, RookMasks, RookShifts, RookDeltas, magic_index<ROOK>);
-  init_magics(BishopTable, BishopAttacks, BishopMagics, BishopMasks, BishopShifts, BishopDeltas, magic_index<BISHOP>);
+  init_magics(RookTable, RookMagics, RookDirections);
+  init_magics(BishopTable, BishopMagics, BishopDirections);
 
   for (Square s1 = SQ_A1; s1 <= SQ_H8; ++s1)
   {
       PseudoAttacks[QUEEN][s1]  = PseudoAttacks[BISHOP][s1] = attacks_bb<BISHOP>(s1, 0);
       PseudoAttacks[QUEEN][s1] |= PseudoAttacks[  ROOK][s1] = attacks_bb<  ROOK>(s1, 0);
 
-      for (Square s2 = SQ_A1; s2 <= SQ_H8; ++s2)
-      {
-          Piece pc = (PseudoAttacks[BISHOP][s1] & s2) ? W_BISHOP :
-                     (PseudoAttacks[ROOK][s1]   & s2) ? W_ROOK   : NO_PIECE;
+      for (PieceType pt : { BISHOP, ROOK })
+          for (Square s2 = SQ_A1; s2 <= SQ_H8; ++s2)
+          {
+              if (!(PseudoAttacks[pt][s1] & s2))
+                  continue;
 
-          if (pc == NO_PIECE)
-              continue;
-
-          LineBB[s1][s2] = (attacks_bb(pc, s1, 0) & attacks_bb(pc, s2, 0)) | s1 | s2;
-          BetweenBB[s1][s2] = attacks_bb(pc, s1, SquareBB[s2]) & attacks_bb(pc, s2, SquareBB[s1]);
-      }
+              LineBB[s1][s2] = (attacks_bb(pt, s1, 0) & attacks_bb(pt, s2, 0)) | s1 | s2;
+              BetweenBB[s1][s2] = attacks_bb(pt, s1, SquareBB[s2]) & attacks_bb(pt, s2, SquareBB[s1]);
+          }
   }
 }
 
 
 namespace {
 
-  Bitboard sliding_attack(Square deltas[], Square sq, Bitboard occupied) {
+  Bitboard sliding_attack(Direction directions[], Square sq, Bitboard occupied) {
 
     Bitboard attack = 0;
 
     for (int i = 0; i < 4; ++i)
-        for (Square s = sq + deltas[i];
-             is_ok(s) && distance(s, s - deltas[i]) == 1;
-             s += deltas[i])
+        for (Square s = sq + directions[i];
+             is_ok(s) && distance(s, s - directions[i]) == 1;
+             s += directions[i])
         {
             attack |= s;
 
@@ -242,17 +187,14 @@ namespace {
   // chessprogramming.wikispaces.com/Magic+Bitboards. In particular, here we
   // use the so called "fancy" approach.
 
-  void init_magics(Bitboard table[], Bitboard* attacks[], Bitboard magics[],
-                   Bitboard masks[], unsigned shifts[], Square deltas[], Fn index) {
+  void init_magics(Bitboard table[], Magic magics[], Direction directions[]) {
 
+    // Optimal PRNG seeds to pick the correct magics in the shortest time
     int seeds[][RANK_NB] = { { 8977, 44560, 54343, 38998,  5731, 95205, 104912, 17020 },
                              {  728, 10316, 55013, 32803, 12281, 15100,  16645,   255 } };
 
     Bitboard occupancy[4096], reference[4096], edges, b;
-    int i, size;
-
-    // attacks[s] is a pointer to the beginning of the attacks table for square 's'
-    attacks[SQ_A1] = table;
+    int epoch[4096] = {}, cnt = 0, size = 0;
 
     for (Square s = SQ_A1; s <= SQ_H8; ++s)
     {
@@ -264,28 +206,28 @@ namespace {
         // all the attacks for each possible subset of the mask and so is 2 power
         // the number of 1s of the mask. Hence we deduce the size of the shift to
         // apply to the 64 or 32 bits word to get the index.
-        masks[s]  = sliding_attack(deltas, s, 0) & ~edges;
-        shifts[s] = (Is64Bit ? 64 : 32) - popcount<Max15>(masks[s]);
+        Magic& m = magics[s];
+        m.mask  = sliding_attack(directions, s, 0) & ~edges;
+        m.shift = (Is64Bit ? 64 : 32) - popcount(m.mask);
+
+        // Set the offset for the attacks table of the square. We have individual
+        // table sizes for each square with "Fancy Magic Bitboards".
+        m.attacks = s == SQ_A1 ? table : magics[s - 1].attacks + size;
 
         // Use Carry-Rippler trick to enumerate all subsets of masks[s] and
         // store the corresponding sliding attack bitboard in reference[].
         b = size = 0;
         do {
             occupancy[size] = b;
-            reference[size] = sliding_attack(deltas, s, b);
+            reference[size] = sliding_attack(directions, s, b);
 
             if (HasPext)
-                attacks[s][pext(b, masks[s])] = reference[size];
+                m.attacks[pext(b, m.mask)] = reference[size];
 
             size++;
-            b = (b - masks[s]) & masks[s];
+            b = (b - m.mask) & m.mask;
         } while (b);
 
-        // Set the offset for the table of the next square. We have individual
-        // table sizes for each square with "Fancy Magic Bitboards".
-        if (s < SQ_H8)
-            attacks[s + 1] = attacks[s] + size;
-
         if (HasPext)
             continue;
 
@@ -293,29 +235,30 @@ namespace {
 
         // Find a magic for square 's' picking up an (almost) random number
         // until we find the one that passes the verification test.
-        do {
-            do
-                magics[s] = rng.sparse_rand<Bitboard>();
-            while (popcount<Max15>((magics[s] * masks[s]) >> 56) < 6);
-
-            std::memset(attacks[s], 0, size * sizeof(Bitboard));
+        for (int i = 0; i < size; )
+        {
+            for (m.magic = 0; popcount((m.magic * m.mask) >> 56) < 6; )
+                m.magic = rng.sparse_rand<Bitboard>();
 
             // A good magic must map every possible occupancy to an index that
             // looks up the correct sliding attack in the attacks[s] database.
             // Note that we build up the database for square 's' as a side
-            // effect of verifying the magic.
-            for (i = 0; i < size; ++i)
+            // effect of verifying the magic. Keep track of the attempt count
+            // and save it in epoch[], little speed-up trick to avoid resetting
+            // m.attacks[] after every failed attempt.
+            for (++cnt, i = 0; i < size; ++i)
             {
-                Bitboard& attack = attacks[s][index(s, occupancy[i])];
+                unsigned idx = m.index(occupancy[i]);
 
-                if (attack && attack != reference[i])
+                if (epoch[idx] < cnt)
+                {
+                    epoch[idx] = cnt;
+                    m.attacks[idx] = reference[i];
+                }
+                else if (m.attacks[idx] != reference[i])
                     break;
-
-                assert(reference[i]);
-
-                attack = reference[i];
             }
-        } while (i < size);
+        }
     }
   }
 }

src/bitboard.h

@@ -2,13 +2,13 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   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
@@ -39,81 +39,102 @@ const std::string pretty(Bitboard b);
 
 }
 
-const Bitboard DarkSquares = 0xAA55AA55AA55AA55ULL;
+constexpr Bitboard AllSquares = ~Bitboard(0);
+constexpr Bitboard DarkSquares = 0xAA55AA55AA55AA55ULL;
 
-const Bitboard FileABB = 0x0101010101010101ULL;
-const Bitboard FileBBB = FileABB << 1;
-const Bitboard FileCBB = FileABB << 2;
-const Bitboard FileDBB = FileABB << 3;
-const Bitboard FileEBB = FileABB << 4;
-const Bitboard FileFBB = FileABB << 5;
-const Bitboard FileGBB = FileABB << 6;
-const Bitboard FileHBB = FileABB << 7;
+constexpr Bitboard FileABB = 0x0101010101010101ULL;
+constexpr Bitboard FileBBB = FileABB << 1;
+constexpr Bitboard FileCBB = FileABB << 2;
+constexpr Bitboard FileDBB = FileABB << 3;
+constexpr Bitboard FileEBB = FileABB << 4;
+constexpr Bitboard FileFBB = FileABB << 5;
+constexpr Bitboard FileGBB = FileABB << 6;
+constexpr Bitboard FileHBB = FileABB << 7;
 
-const Bitboard Rank1BB = 0xFF;
-const Bitboard Rank2BB = Rank1BB << (8 * 1);
-const Bitboard Rank3BB = Rank1BB << (8 * 2);
-const Bitboard Rank4BB = Rank1BB << (8 * 3);
-const Bitboard Rank5BB = Rank1BB << (8 * 4);
-const Bitboard Rank6BB = Rank1BB << (8 * 5);
-const Bitboard Rank7BB = Rank1BB << (8 * 6);
-const Bitboard Rank8BB = Rank1BB << (8 * 7);
+constexpr Bitboard Rank1BB = 0xFF;
+constexpr Bitboard Rank2BB = Rank1BB << (8 * 1);
+constexpr Bitboard Rank3BB = Rank1BB << (8 * 2);
+constexpr Bitboard Rank4BB = Rank1BB << (8 * 3);
+constexpr Bitboard Rank5BB = Rank1BB << (8 * 4);
+constexpr Bitboard Rank6BB = Rank1BB << (8 * 5);
+constexpr Bitboard Rank7BB = Rank1BB << (8 * 6);
+constexpr Bitboard Rank8BB = Rank1BB << (8 * 7);
 
 extern int SquareDistance[SQUARE_NB][SQUARE_NB];
 
-extern Bitboard  RookMasks  [SQUARE_NB];
-extern Bitboard  RookMagics [SQUARE_NB];
-extern Bitboard* RookAttacks[SQUARE_NB];
-extern unsigned  RookShifts [SQUARE_NB];
-
-extern Bitboard  BishopMasks  [SQUARE_NB];
-extern Bitboard  BishopMagics [SQUARE_NB];
-extern Bitboard* BishopAttacks[SQUARE_NB];
-extern unsigned  BishopShifts [SQUARE_NB];
-
 extern Bitboard SquareBB[SQUARE_NB];
 extern Bitboard FileBB[FILE_NB];
 extern Bitboard RankBB[RANK_NB];
 extern Bitboard AdjacentFilesBB[FILE_NB];
-extern Bitboard InFrontBB[COLOR_NB][RANK_NB];
-extern Bitboard StepAttacksBB[PIECE_NB][SQUARE_NB];
+extern Bitboard ForwardRanksBB[COLOR_NB][RANK_NB];
 extern Bitboard BetweenBB[SQUARE_NB][SQUARE_NB];
 extern Bitboard LineBB[SQUARE_NB][SQUARE_NB];
 extern Bitboard DistanceRingBB[SQUARE_NB][8];
-extern Bitboard ForwardBB[COLOR_NB][SQUARE_NB];
+extern Bitboard ForwardFileBB[COLOR_NB][SQUARE_NB];
 extern Bitboard PassedPawnMask[COLOR_NB][SQUARE_NB];
 extern Bitboard PawnAttackSpan[COLOR_NB][SQUARE_NB];
 extern Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB];
+extern Bitboard PawnAttacks[COLOR_NB][SQUARE_NB];
+
+
+/// Magic holds all magic bitboards relevant data for a single square
+struct Magic {
+  Bitboard  mask;
+  Bitboard  magic;
+  Bitboard* attacks;
+  unsigned  shift;
+
+  // Compute the attack's index using the 'magic bitboards' approach
+  unsigned index(Bitboard occupied) const {
+
+    if (HasPext)
+        return unsigned(pext(occupied, mask));
+
+    if (Is64Bit)
+        return unsigned(((occupied & mask) * magic) >> shift);
+
+    unsigned lo = unsigned(occupied) & unsigned(mask);
+    unsigned hi = unsigned(occupied >> 32) & unsigned(mask >> 32);
+    return (lo * unsigned(magic) ^ hi * unsigned(magic >> 32)) >> shift;
+  }
+};
+
+extern Magic RookMagics[SQUARE_NB];
+extern Magic BishopMagics[SQUARE_NB];
 
 
 /// Overloads of bitwise operators between a Bitboard and a Square for testing
 /// whether a given bit is set in a bitboard, and for setting and clearing bits.
 
 inline Bitboard operator&(Bitboard b, Square s) {
+  assert(s >= SQ_A1 && s <= SQ_H8);
   return b & SquareBB[s];
 }
 
 inline Bitboard operator|(Bitboard b, Square s) {
+  assert(s >= SQ_A1 && s <= SQ_H8);
   return b | SquareBB[s];
 }
 
 inline Bitboard operator^(Bitboard b, Square s) {
+  assert(s >= SQ_A1 && s <= SQ_H8);
   return b ^ SquareBB[s];
 }
 
 inline Bitboard& operator|=(Bitboard& b, Square s) {
+  assert(s >= SQ_A1 && s <= SQ_H8);
   return b |= SquareBB[s];
 }
 
 inline Bitboard& operator^=(Bitboard& b, Square s) {
+  assert(s >= SQ_A1 && s <= SQ_H8);
   return b ^= SquareBB[s];
 }
 
-inline bool more_than_one(Bitboard b) {
+constexpr bool more_than_one(Bitboard b) {
   return b & (b - 1);
 }
 
-
 /// rank_bb() and file_bb() return a bitboard representing all the squares on
 /// the given file or rank.
 
@@ -134,17 +155,28 @@ inline Bitboard file_bb(Square s) {
 }
 
 
-/// shift_bb() moves a bitboard one step along direction Delta. Mainly for pawns
+/// shift() moves a bitboard one step along direction D (mainly for pawns)
 
-template<Square Delta>
-inline Bitboard shift_bb(Bitboard b) {
-  return  Delta == DELTA_N  ?  b             << 8 : Delta == DELTA_S  ?  b             >> 8
-        : Delta == DELTA_NE ? (b & ~FileHBB) << 9 : Delta == DELTA_SE ? (b & ~FileHBB) >> 7
-        : Delta == DELTA_NW ? (b & ~FileABB) << 7 : Delta == DELTA_SW ? (b & ~FileABB) >> 9
+template<Direction D>
+constexpr Bitboard shift(Bitboard b) {
+  return  D == NORTH      ?  b             << 8 : D == SOUTH      ?  b             >> 8
+        : D == EAST       ? (b & ~FileHBB) << 1 : D == WEST       ? (b & ~FileABB) >> 1
+        : D == NORTH_EAST ? (b & ~FileHBB) << 9 : D == NORTH_WEST ? (b & ~FileABB) << 7
+        : D == SOUTH_EAST ? (b & ~FileHBB) >> 7 : D == SOUTH_WEST ? (b & ~FileABB) >> 9
         : 0;
 }
 
 
+/// pawn_attacks_bb() returns the pawn attacks for the given color from the
+/// squares in the given bitboard.
+
+template<Color C>
+constexpr Bitboard pawn_attacks_bb(Bitboard b) {
+  return C == WHITE ? shift<NORTH_WEST>(b) | shift<NORTH_EAST>(b)
+                    : shift<SOUTH_WEST>(b) | shift<SOUTH_EAST>(b);
+}
+
+
 /// adjacent_files_bb() returns a bitboard representing all the squares on the
 /// adjacent files of the given one.
 
@@ -163,28 +195,28 @@ inline Bitboard between_bb(Square s1, Square s2) {
 }
 
 
-/// in_front_bb() returns a bitboard representing all the squares on all the ranks
-/// in front of the given one, from the point of view of the given color. For
-/// instance, in_front_bb(BLACK, RANK_3) will return the squares on ranks 1 and 2.
+/// forward_ranks_bb() returns a bitboard representing the squares on all the ranks
+/// in front of the given one, from the point of view of the given color. For instance,
+/// forward_ranks_bb(BLACK, SQ_D3) will return the 16 squares on ranks 1 and 2.
 
-inline Bitboard in_front_bb(Color c, Rank r) {
-  return InFrontBB[c][r];
+inline Bitboard forward_ranks_bb(Color c, Square s) {
+  return ForwardRanksBB[c][rank_of(s)];
 }
 
 
-/// forward_bb() returns a bitboard representing all the squares along the line
+/// forward_file_bb() returns a bitboard representing all the squares along the line
 /// in front of the given one, from the point of view of the given color:
-///        ForwardBB[c][s] = in_front_bb(c, s) & file_bb(s)
+///      ForwardFileBB[c][s] = forward_ranks_bb(c, s) & file_bb(s)
 
-inline Bitboard forward_bb(Color c, Square s) {
-  return ForwardBB[c][s];
+inline Bitboard forward_file_bb(Color c, Square s) {
+  return ForwardFileBB[c][s];
 }
 
 
 /// pawn_attack_span() returns a bitboard representing all the squares that can be
 /// attacked by a pawn of the given color when it moves along its file, starting
 /// from the given square:
-///       PawnAttackSpan[c][s] = in_front_bb(c, s) & adjacent_files_bb(s);
+///      PawnAttackSpan[c][s] = forward_ranks_bb(c, s) & adjacent_files_bb(file_of(s));
 
 inline Bitboard pawn_attack_span(Color c, Square s) {
   return PawnAttackSpan[c][s];
@@ -193,21 +225,13 @@ inline Bitboard pawn_attack_span(Color c, Square s) {
 
 /// passed_pawn_mask() returns a bitboard mask which can be used to test if a
 /// pawn of the given color and on the given square is a passed pawn:
-///       PassedPawnMask[c][s] = pawn_attack_span(c, s) | forward_bb(c, s)
+///      PassedPawnMask[c][s] = pawn_attack_span(c, s) | forward_file_bb(c, s)
 
 inline Bitboard passed_pawn_mask(Color c, Square s) {
   return PassedPawnMask[c][s];
 }
 
 
-/// squares_of_color() returns a bitboard representing all the squares of the
-/// same color of the given one.
-
-inline Bitboard squares_of_color(Square s) {
-  return DarkSquares & s ? DarkSquares : ~DarkSquares;
-}
-
-
 /// aligned() returns true if the squares s1, s2 and s3 are aligned either on a
 /// straight or on a diagonal line.
 
@@ -228,103 +252,123 @@ template<> inline int distance<Rank>(Square x, Square y) { return distance(rank_
 
 
 /// attacks_bb() returns a bitboard representing all the squares attacked by a
-/// piece of type Pt (bishop or rook) placed on 's'. The helper magic_index()
-/// looks up the index using the 'magic bitboards' approach.
-template<PieceType Pt>
-FORCE_INLINE unsigned magic_index(Square s, Bitboard occupied) {
-
-  Bitboard* const Masks  = Pt == ROOK ? RookMasks  : BishopMasks;
-  Bitboard* const Magics = Pt == ROOK ? RookMagics : BishopMagics;
-  unsigned* const Shifts = Pt == ROOK ? RookShifts : BishopShifts;
-
-  if (HasPext)
-      return unsigned(pext(occupied, Masks[s]));
-
-  if (Is64Bit)
-      return unsigned(((occupied & Masks[s]) * Magics[s]) >> Shifts[s]);
-
-  unsigned lo = unsigned(occupied) & unsigned(Masks[s]);
-  unsigned hi = unsigned(occupied >> 32) & unsigned(Masks[s] >> 32);
-  return (lo * unsigned(Magics[s]) ^ hi * unsigned(Magics[s] >> 32)) >> Shifts[s];
-}
+/// piece of type Pt (bishop or rook) placed on 's'.
 
 template<PieceType Pt>
 inline Bitboard attacks_bb(Square s, Bitboard occupied) {
-  return (Pt == ROOK ? RookAttacks : BishopAttacks)[s][magic_index<Pt>(s, occupied)];
+
+  const Magic& m = Pt == ROOK ? RookMagics[s] : BishopMagics[s];
+  return m.attacks[m.index(occupied)];
 }
 
-inline Bitboard attacks_bb(Piece pc, Square s, Bitboard occupied) {
+inline Bitboard attacks_bb(PieceType pt, Square s, Bitboard occupied) {
 
-  switch (type_of(pc))
+  assert(pt != PAWN);
+
+  switch (pt)
   {
   case BISHOP: return attacks_bb<BISHOP>(s, occupied);
-  case ROOK  : return attacks_bb<ROOK>(s, occupied);
+  case ROOK  : return attacks_bb<  ROOK>(s, occupied);
   case QUEEN : return attacks_bb<BISHOP>(s, occupied) | attacks_bb<ROOK>(s, occupied);
-  default    : return StepAttacksBB[pc][s];
+  default    : return PseudoAttacks[pt][s];
   }
 }
 
 
+/// popcount() counts the number of non-zero bits in a bitboard
+
+inline int popcount(Bitboard b) {
+
+#ifndef USE_POPCNT
+
+  extern uint8_t PopCnt16[1 << 16];
+  union { Bitboard bb; uint16_t u[4]; } v = { b };
+  return PopCnt16[v.u[0]] + PopCnt16[v.u[1]] + PopCnt16[v.u[2]] + PopCnt16[v.u[3]];
+
+#elif defined(_MSC_VER) || defined(__INTEL_COMPILER)
+
+  return (int)_mm_popcnt_u64(b);
+
+#else // Assumed gcc or compatible compiler
+
+  return __builtin_popcountll(b);
+
+#endif
+}
+
+
 /// lsb() and msb() return the least/most significant bit in a non-zero bitboard
 
-#ifdef USE_BSFQ
+#if defined(__GNUC__)  // GCC, Clang, ICC
 
-#  if defined(_MSC_VER) && !defined(__INTEL_COMPILER)
+inline Square lsb(Bitboard b) {
+  assert(b);
+  return Square(__builtin_ctzll(b));
+}
 
-FORCE_INLINE Square lsb(Bitboard b) {
+inline Square msb(Bitboard b) {
+  assert(b);
+  return Square(63 ^ __builtin_clzll(b));
+}
+
+#elif defined(_MSC_VER)  // MSVC
+
+#ifdef _WIN64  // MSVC, WIN64
+
+inline Square lsb(Bitboard b) {
+  assert(b);
   unsigned long idx;
   _BitScanForward64(&idx, b);
   return (Square) idx;
 }
 
-FORCE_INLINE Square msb(Bitboard b) {
+inline Square msb(Bitboard b) {
+  assert(b);
   unsigned long idx;
   _BitScanReverse64(&idx, b);
   return (Square) idx;
 }
 
-#  elif defined(__arm__)
+#else  // MSVC, WIN32
 
-FORCE_INLINE int lsb32(uint32_t v) {
-  __asm__("rbit %0, %1" : "=r"(v) : "r"(v));
-  return __builtin_clz(v);
+inline Square lsb(Bitboard b) {
+  assert(b);
+  unsigned long idx;
+
+  if (b & 0xffffffff) {
+      _BitScanForward(&idx, int32_t(b));
+      return Square(idx);
+  } else {
+      _BitScanForward(&idx, int32_t(b >> 32));
+      return Square(idx + 32);
+  }
 }
 
-FORCE_INLINE Square msb(Bitboard b) {
-  return (Square) (63 - __builtin_clzll(b));
+inline Square msb(Bitboard b) {
+  assert(b);
+  unsigned long idx;
+
+  if (b >> 32) {
+      _BitScanReverse(&idx, int32_t(b >> 32));
+      return Square(idx + 32);
+  } else {
+      _BitScanReverse(&idx, int32_t(b));
+      return Square(idx);
+  }
 }
 
-FORCE_INLINE Square lsb(Bitboard b) {
-  return (Square) (uint32_t(b) ? lsb32(uint32_t(b)) : 32 + lsb32(uint32_t(b >> 32)));
-}
+#endif
 
-#  else // Assumed gcc or compatible compiler
+#else  // Compiler is neither GCC nor MSVC compatible
 
-FORCE_INLINE Square lsb(Bitboard b) { // Assembly code by Heinz van Saanen
-  Bitboard idx;
-  __asm__("bsfq %1, %0": "=r"(idx): "rm"(b) );
-  return (Square) idx;
-}
-
-FORCE_INLINE Square msb(Bitboard b) {
-  Bitboard idx;
-  __asm__("bsrq %1, %0": "=r"(idx): "rm"(b) );
-  return (Square) idx;
-}
-
-#  endif
-
-#else // ifdef(USE_BSFQ)
-
-Square lsb(Bitboard b);
-Square msb(Bitboard b);
+#error "Compiler not supported."
 
 #endif
 
 
 /// pop_lsb() finds and clears the least significant bit in a non-zero bitboard
 
-FORCE_INLINE Square pop_lsb(Bitboard* b) {
+inline Square pop_lsb(Bitboard* b) {
   const Square s = lsb(*b);
   *b &= *b - 1;
   return s;

src/bitcount.h

@@ -1,105 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
-
-  Stockfish is free software: you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation, either version 3 of the License, or
-  (at your option) any later version.
-
-
-  Stockfish is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-#ifndef BITCOUNT_H_INCLUDED
-#define BITCOUNT_H_INCLUDED
-
-#include <cassert>
-
-#include "types.h"
-
-enum BitCountType {
-  CNT_64,
-  CNT_64_MAX15,
-  CNT_32,
-  CNT_32_MAX15,
-  CNT_HW_POPCNT
-};
-
-/// Determine at compile time the best popcount<> specialization according to
-/// whether the platform is 32 or 64 bit, the maximum number of non-zero
-/// bits to count and if the hardware popcnt instruction is available.
-const BitCountType Full  = HasPopCnt ? CNT_HW_POPCNT : Is64Bit ? CNT_64       : CNT_32;
-const BitCountType Max15 = HasPopCnt ? CNT_HW_POPCNT : Is64Bit ? CNT_64_MAX15 : CNT_32_MAX15;
-
-
-/// popcount() counts the number of non-zero bits in a bitboard
-template<BitCountType> inline int popcount(Bitboard);
-
-template<>
-inline int popcount<CNT_64>(Bitboard b) {
-  b -=  (b >> 1) & 0x5555555555555555ULL;
-  b  = ((b >> 2) & 0x3333333333333333ULL) + (b & 0x3333333333333333ULL);
-  b  = ((b >> 4) + b) & 0x0F0F0F0F0F0F0F0FULL;
-  return (b * 0x0101010101010101ULL) >> 56;
-}
-
-template<>
-inline int popcount<CNT_64_MAX15>(Bitboard b) {
-  b -=  (b >> 1) & 0x5555555555555555ULL;
-  b  = ((b >> 2) & 0x3333333333333333ULL) + (b & 0x3333333333333333ULL);
-  return (b * 0x1111111111111111ULL) >> 60;
-}
-
-template<>
-inline int popcount<CNT_32>(Bitboard b) {
-  unsigned w = unsigned(b >> 32), v = unsigned(b);
-  v -=  (v >> 1) & 0x55555555; // 0-2 in 2 bits
-  w -=  (w >> 1) & 0x55555555;
-  v  = ((v >> 2) & 0x33333333) + (v & 0x33333333); // 0-4 in 4 bits
-  w  = ((w >> 2) & 0x33333333) + (w & 0x33333333);
-  v  = ((v >> 4) + v + (w >> 4) + w) & 0x0F0F0F0F;
-  return (v * 0x01010101) >> 24;
-}
-
-template<>
-inline int popcount<CNT_32_MAX15>(Bitboard b) {
-  unsigned w = unsigned(b >> 32), v = unsigned(b);
-  v -=  (v >> 1) & 0x55555555; // 0-2 in 2 bits
-  w -=  (w >> 1) & 0x55555555;
-  v  = ((v >> 2) & 0x33333333) + (v & 0x33333333); // 0-4 in 4 bits
-  w  = ((w >> 2) & 0x33333333) + (w & 0x33333333);
-  return ((v + w) * 0x11111111) >> 28;
-}
-
-template<>
-inline int popcount<CNT_HW_POPCNT>(Bitboard b) {
-
-#ifndef USE_POPCNT
-
-  assert(false);
-  return b != 0; // Avoid 'b not used' warning
-
-#elif defined(_MSC_VER) && defined(__INTEL_COMPILER)
-
-  return _mm_popcnt_u64(b);
-
-#elif defined(_MSC_VER)
-
-  return (int)__popcnt64(b);
-
-#else // Assumed gcc or compatible compiler
-
-  return __builtin_popcountll(b);
-
-#endif
-}
-
-#endif // #ifndef BITCOUNT_H_INCLUDED

src/endgame.cpp

@@ -2,6 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -21,7 +22,6 @@
 #include <cassert>
 
 #include "bitboard.h"
-#include "bitcount.h"
 #include "endgame.h"
 #include "movegen.h"
 
@@ -31,7 +31,7 @@ namespace {
 
   // Table used to drive the king towards the edge of the board
   // in KX vs K and KQ vs KR endgames.
-  const int PushToEdges[SQUARE_NB] = {
+  constexpr int PushToEdges[SQUARE_NB] = {
     100, 90, 80, 70, 70, 80, 90, 100,
      90, 70, 60, 50, 50, 60, 70,  90,
      80, 60, 40, 30, 30, 40, 60,  80,
@@ -39,12 +39,12 @@ namespace {
      70, 50, 30, 20, 20, 30, 50,  70,
      80, 60, 40, 30, 30, 40, 60,  80,
      90, 70, 60, 50, 50, 60, 70,  90,
-    100, 90, 80, 70, 70, 80, 90, 100,
+    100, 90, 80, 70, 70, 80, 90, 100
   };
 
   // Table used to drive the king towards a corner square of the
   // right color in KBN vs K endgames.
-  const int PushToCorners[SQUARE_NB] = {
+  constexpr int PushToCorners[SQUARE_NB] = {
     200, 190, 180, 170, 160, 150, 140, 130,
     190, 180, 170, 160, 150, 140, 130, 140,
     180, 170, 155, 140, 140, 125, 140, 150,
@@ -56,8 +56,11 @@ namespace {
   };
 
   // Tables used to drive a piece towards or away from another piece
-  const int PushClose[8] = { 0, 0, 100, 80, 60, 40, 20, 10 };
-  const int PushAway [8] = { 0, 5, 20, 40, 60, 80, 90, 100 };
+  constexpr int PushClose[8] = { 0, 0, 100, 80, 60, 40, 20, 10 };
+  constexpr int PushAway [8] = { 0, 5, 20, 40, 60, 80, 90, 100 };
+
+  // Pawn Rank based scaling factors used in KRPPKRP endgame
+  constexpr int KRPPKRPScaleFactors[RANK_NB] = { 0, 9, 10, 14, 21, 44, 0, 0 };
 
 #ifndef NDEBUG
   bool verify_material(const Position& pos, Color c, Value npm, int pawnsCnt) {
@@ -71,7 +74,7 @@ namespace {
 
     assert(pos.count<PAWN>(strongSide) == 1);
 
-    if (file_of(pos.list<PAWN>(strongSide)[0]) >= FILE_E)
+    if (file_of(pos.square<PAWN>(strongSide)) >= FILE_E)
         sq = Square(sq ^ 7); // Mirror SQ_H1 -> SQ_A1
 
     if (strongSide == BLACK)
@@ -80,68 +83,9 @@ namespace {
     return sq;
   }
 
-  // Get the material key of Position out of the given endgame key code
-  // like "KBPKN". The trick here is to first forge an ad-hoc FEN string
-  // and then let a Position object do the work for us.
-  Key key(const string& code, Color c) {
-
-    assert(code.length() > 0 && code.length() < 8);
-    assert(code[0] == 'K');
-
-    string sides[] = { code.substr(code.find('K', 1)),      // Weak
-                       code.substr(0, code.find('K', 1)) }; // Strong
-
-    std::transform(sides[c].begin(), sides[c].end(), sides[c].begin(), tolower);
-
-    string fen =  sides[0] + char(8 - sides[0].length() + '0') + "/8/8/8/8/8/8/"
-                + sides[1] + char(8 - sides[1].length() + '0') + " w - - 0 10";
-
-    return Position(fen, false, NULL).material_key();
-  }
-
-  template<typename M>
-  void delete_endgame(const typename M::value_type& p) { delete p.second; }
-
 } // namespace
 
 
-/// Endgames members definitions
-
-Endgames::Endgames() {
-
-  add<KPK>("KPK");
-  add<KNNK>("KNNK");
-  add<KBNK>("KBNK");
-  add<KRKP>("KRKP");
-  add<KRKB>("KRKB");
-  add<KRKN>("KRKN");
-  add<KQKP>("KQKP");
-  add<KQKR>("KQKR");
-
-  add<KNPK>("KNPK");
-  add<KNPKB>("KNPKB");
-  add<KRPKR>("KRPKR");
-  add<KRPKB>("KRPKB");
-  add<KBPKB>("KBPKB");
-  add<KBPKN>("KBPKN");
-  add<KBPPKB>("KBPPKB");
-  add<KRPPKRP>("KRPPKRP");
-}
-
-Endgames::~Endgames() {
-
-  for_each(m1.begin(), m1.end(), delete_endgame<M1>);
-  for_each(m2.begin(), m2.end(), delete_endgame<M2>);
-}
-
-template<EndgameType E>
-void Endgames::add(const string& code) {
-
-  map((Endgame<E>*)0)[key(code, WHITE)] = new Endgame<E>(WHITE);
-  map((Endgame<E>*)0)[key(code, BLACK)] = new Endgame<E>(BLACK);
-}
-
-
 /// Mate with KX vs K. This function is used to evaluate positions with
 /// king and plenty of material vs a lone king. It simply gives the
 /// attacking side a bonus for driving the defending king towards the edge
@@ -156,8 +100,8 @@ Value Endgame<KXK>::operator()(const Position& pos) const {
   if (pos.side_to_move() == weakSide && !MoveList<LEGAL>(pos).size())
       return VALUE_DRAW;
 
-  Square winnerKSq = pos.king_square(strongSide);
-  Square loserKSq = pos.king_square(weakSide);
+  Square winnerKSq = pos.square<KING>(strongSide);
+  Square loserKSq = pos.square<KING>(weakSide);
 
   Value result =  pos.non_pawn_material(strongSide)
                 + pos.count<PAWN>(strongSide) * PawnValueEg
@@ -167,9 +111,9 @@ Value Endgame<KXK>::operator()(const Position& pos) const {
   if (   pos.count<QUEEN>(strongSide)
       || pos.count<ROOK>(strongSide)
       ||(pos.count<BISHOP>(strongSide) && pos.count<KNIGHT>(strongSide))
-      ||(pos.count<BISHOP>(strongSide) > 1 && opposite_colors(pos.list<BISHOP>(strongSide)[0],
-                                                              pos.list<BISHOP>(strongSide)[1])))
-      result += VALUE_KNOWN_WIN;
+      || (   (pos.pieces(strongSide, BISHOP) & ~DarkSquares)
+          && (pos.pieces(strongSide, BISHOP) &  DarkSquares)))
+      result = std::min(result + VALUE_KNOWN_WIN, VALUE_MATE_IN_MAX_PLY - 1);
 
   return strongSide == pos.side_to_move() ? result : -result;
 }
@@ -183,9 +127,9 @@ Value Endgame<KBNK>::operator()(const Position& pos) const {
   assert(verify_material(pos, strongSide, KnightValueMg + BishopValueMg, 0));
   assert(verify_material(pos, weakSide, VALUE_ZERO, 0));
 
-  Square winnerKSq = pos.king_square(strongSide);
-  Square loserKSq = pos.king_square(weakSide);
-  Square bishopSq = pos.list<BISHOP>(strongSide)[0];
+  Square winnerKSq = pos.square<KING>(strongSide);
+  Square loserKSq = pos.square<KING>(weakSide);
+  Square bishopSq = pos.square<BISHOP>(strongSide);
 
   // kbnk_mate_table() tries to drive toward corners A1 or H8. If we have a
   // bishop that cannot reach the above squares, we flip the kings in order
@@ -212,9 +156,9 @@ Value Endgame<KPK>::operator()(const Position& pos) const {
   assert(verify_material(pos, weakSide, VALUE_ZERO, 0));
 
   // Assume strongSide is white and the pawn is on files A-D
-  Square wksq = normalize(pos, strongSide, pos.king_square(strongSide));
-  Square bksq = normalize(pos, strongSide, pos.king_square(weakSide));
-  Square psq  = normalize(pos, strongSide, pos.list<PAWN>(strongSide)[0]);
+  Square wksq = normalize(pos, strongSide, pos.square<KING>(strongSide));
+  Square bksq = normalize(pos, strongSide, pos.square<KING>(weakSide));
+  Square psq  = normalize(pos, strongSide, pos.square<PAWN>(strongSide));
 
   Color us = strongSide == pos.side_to_move() ? WHITE : BLACK;
 
@@ -237,16 +181,16 @@ Value Endgame<KRKP>::operator()(const Position& pos) const {
   assert(verify_material(pos, strongSide, RookValueMg, 0));
   assert(verify_material(pos, weakSide, VALUE_ZERO, 1));
 
-  Square wksq = relative_square(strongSide, pos.king_square(strongSide));
-  Square bksq = relative_square(strongSide, pos.king_square(weakSide));
-  Square rsq  = relative_square(strongSide, pos.list<ROOK>(strongSide)[0]);
-  Square psq  = relative_square(strongSide, pos.list<PAWN>(weakSide)[0]);
+  Square wksq = relative_square(strongSide, pos.square<KING>(strongSide));
+  Square bksq = relative_square(strongSide, pos.square<KING>(weakSide));
+  Square rsq  = relative_square(strongSide, pos.square<ROOK>(strongSide));
+  Square psq  = relative_square(strongSide, pos.square<PAWN>(weakSide));
 
   Square queeningSq = make_square(file_of(psq), RANK_1);
   Value result;
 
   // If the stronger side's king is in front of the pawn, it's a win
-  if (wksq < psq && file_of(wksq) == file_of(psq))
+  if (forward_file_bb(WHITE, wksq) & psq)
       result = RookValueEg - distance(wksq, psq);
 
   // If the weaker side's king is too far from the pawn and the rook,
@@ -264,15 +208,15 @@ Value Endgame<KRKP>::operator()(const Position& pos) const {
       result = Value(80) - 8 * distance(wksq, psq);
 
   else
-      result =  Value(200) - 8 * (  distance(wksq, psq + DELTA_S)
-                                  - distance(bksq, psq + DELTA_S)
+      result =  Value(200) - 8 * (  distance(wksq, psq + SOUTH)
+                                  - distance(bksq, psq + SOUTH)
                                   - distance(psq, queeningSq));
 
   return strongSide == pos.side_to_move() ? result : -result;
 }
 
 
-/// KR vs KB. This is very simple, and always returns drawish scores.  The
+/// KR vs KB. This is very simple, and always returns drawish scores. The
 /// score is slightly bigger when the defending king is close to the edge.
 template<>
 Value Endgame<KRKB>::operator()(const Position& pos) const {
@@ -280,7 +224,7 @@ Value Endgame<KRKB>::operator()(const Position& pos) const {
   assert(verify_material(pos, strongSide, RookValueMg, 0));
   assert(verify_material(pos, weakSide, BishopValueMg, 0));
 
-  Value result = Value(PushToEdges[pos.king_square(weakSide)]);
+  Value result = Value(PushToEdges[pos.square<KING>(weakSide)]);
   return strongSide == pos.side_to_move() ? result : -result;
 }
 
@@ -293,8 +237,8 @@ Value Endgame<KRKN>::operator()(const Position& pos) const {
   assert(verify_material(pos, strongSide, RookValueMg, 0));
   assert(verify_material(pos, weakSide, KnightValueMg, 0));
 
-  Square bksq = pos.king_square(weakSide);
-  Square bnsq = pos.list<KNIGHT>(weakSide)[0];
+  Square bksq = pos.square<KING>(weakSide);
+  Square bnsq = pos.square<KNIGHT>(weakSide);
   Value result = Value(PushToEdges[bksq] + PushAway[distance(bksq, bnsq)]);
   return strongSide == pos.side_to_move() ? result : -result;
 }
@@ -310,9 +254,9 @@ Value Endgame<KQKP>::operator()(const Position& pos) const {
   assert(verify_material(pos, strongSide, QueenValueMg, 0));
   assert(verify_material(pos, weakSide, VALUE_ZERO, 1));
 
-  Square winnerKSq = pos.king_square(strongSide);
-  Square loserKSq = pos.king_square(weakSide);
-  Square pawnSq = pos.list<PAWN>(weakSide)[0];
+  Square winnerKSq = pos.square<KING>(strongSide);
+  Square loserKSq = pos.square<KING>(weakSide);
+  Square pawnSq = pos.square<PAWN>(weakSide);
 
   Value result = Value(PushClose[distance(winnerKSq, loserKSq)]);
 
@@ -335,8 +279,8 @@ Value Endgame<KQKR>::operator()(const Position& pos) const {
   assert(verify_material(pos, strongSide, QueenValueMg, 0));
   assert(verify_material(pos, weakSide, RookValueMg, 0));
 
-  Square winnerKSq = pos.king_square(strongSide);
-  Square loserKSq = pos.king_square(weakSide);
+  Square winnerKSq = pos.square<KING>(strongSide);
+  Square loserKSq = pos.square<KING>(weakSide);
 
   Value result =  QueenValueEg
                 - RookValueEg
@@ -365,15 +309,15 @@ ScaleFactor Endgame<KBPsK>::operator()(const Position& pos) const {
   // be detected even when the weaker side has some pawns.
 
   Bitboard pawns = pos.pieces(strongSide, PAWN);
-  File pawnFile = file_of(pos.list<PAWN>(strongSide)[0]);
+  File pawnsFile = file_of(lsb(pawns));
 
-  // All pawns are on a single rook file ?
-  if (    (pawnFile == FILE_A || pawnFile == FILE_H)
-      && !(pawns & ~file_bb(pawnFile)))
+  // All pawns are on a single rook file?
+  if (    (pawnsFile == FILE_A || pawnsFile == FILE_H)
+      && !(pawns & ~file_bb(pawnsFile)))
   {
-      Square bishopSq = pos.list<BISHOP>(strongSide)[0];
-      Square queeningSq = relative_square(strongSide, make_square(pawnFile, RANK_8));
-      Square kingSq = pos.king_square(weakSide);
+      Square bishopSq = pos.square<BISHOP>(strongSide);
+      Square queeningSq = relative_square(strongSide, make_square(pawnsFile, RANK_8));
+      Square kingSq = pos.square<KING>(weakSide);
 
       if (   opposite_colors(queeningSq, bishopSq)
           && distance(queeningSq, kingSq) <= 1)
@@ -381,17 +325,17 @@ ScaleFactor Endgame<KBPsK>::operator()(const Position& pos) const {
   }
 
   // If all the pawns are on the same B or G file, then it's potentially a draw
-  if (    (pawnFile == FILE_B || pawnFile == FILE_G)
-      && !(pos.pieces(PAWN) & ~file_bb(pawnFile))
+  if (    (pawnsFile == FILE_B || pawnsFile == FILE_G)
+      && !(pos.pieces(PAWN) & ~file_bb(pawnsFile))
       && pos.non_pawn_material(weakSide) == 0
       && pos.count<PAWN>(weakSide) >= 1)
   {
       // Get weakSide pawn that is closest to the home rank
       Square weakPawnSq = backmost_sq(weakSide, pos.pieces(weakSide, PAWN));
 
-      Square strongKingSq = pos.king_square(strongSide);
-      Square weakKingSq = pos.king_square(weakSide);
-      Square bishopSq = pos.list<BISHOP>(strongSide)[0];
+      Square strongKingSq = pos.square<KING>(strongSide);
+      Square weakKingSq = pos.square<KING>(weakSide);
+      Square bishopSq = pos.square<BISHOP>(strongSide);
 
       // There's potential for a draw if our pawn is blocked on the 7th rank,
       // the bishop cannot attack it or they only have one pawn left
@@ -428,11 +372,11 @@ ScaleFactor Endgame<KQKRPs>::operator()(const Position& pos) const {
   assert(pos.count<ROOK>(weakSide) == 1);
   assert(pos.count<PAWN>(weakSide) >= 1);
 
-  Square kingSq = pos.king_square(weakSide);
-  Square rsq = pos.list<ROOK>(weakSide)[0];
+  Square kingSq = pos.square<KING>(weakSide);
+  Square rsq = pos.square<ROOK>(weakSide);
 
   if (    relative_rank(weakSide, kingSq) <= RANK_2
-      &&  relative_rank(weakSide, pos.king_square(strongSide)) >= RANK_4
+      &&  relative_rank(weakSide, pos.square<KING>(strongSide)) >= RANK_4
       &&  relative_rank(weakSide, rsq) == RANK_3
       && (  pos.pieces(weakSide, PAWN)
           & pos.attacks_from<KING>(kingSq)
@@ -456,11 +400,11 @@ ScaleFactor Endgame<KRPKR>::operator()(const Position& pos) const {
   assert(verify_material(pos, weakSide,   RookValueMg, 0));
 
   // Assume strongSide is white and the pawn is on files A-D
-  Square wksq = normalize(pos, strongSide, pos.king_square(strongSide));
-  Square bksq = normalize(pos, strongSide, pos.king_square(weakSide));
-  Square wrsq = normalize(pos, strongSide, pos.list<ROOK>(strongSide)[0]);
-  Square wpsq = normalize(pos, strongSide, pos.list<PAWN>(strongSide)[0]);
-  Square brsq = normalize(pos, strongSide, pos.list<ROOK>(weakSide)[0]);
+  Square wksq = normalize(pos, strongSide, pos.square<KING>(strongSide));
+  Square bksq = normalize(pos, strongSide, pos.square<KING>(weakSide));
+  Square wrsq = normalize(pos, strongSide, pos.square<ROOK>(strongSide));
+  Square wpsq = normalize(pos, strongSide, pos.square<PAWN>(strongSide));
+  Square brsq = normalize(pos, strongSide, pos.square<ROOK>(weakSide));
 
   File f = file_of(wpsq);
   Rank r = rank_of(wpsq);
@@ -480,7 +424,7 @@ ScaleFactor Endgame<KRPKR>::operator()(const Position& pos) const {
   if (   r == RANK_6
       && distance(bksq, queeningSq) <= 1
       && rank_of(wksq) + tempo <= RANK_6
-      && (rank_of(brsq) == RANK_1 || (!tempo && distance(file_of(brsq), f) >= 3)))
+      && (rank_of(brsq) == RANK_1 || (!tempo && distance<File>(brsq, wpsq) >= 3)))
       return SCALE_FACTOR_DRAW;
 
   if (   r >= RANK_6
@@ -501,7 +445,7 @@ ScaleFactor Endgame<KRPKR>::operator()(const Position& pos) const {
   // If the defending king blocks the pawn and the attacking king is too far
   // away, it's a draw.
   if (   r <= RANK_5
-      && bksq == wpsq + DELTA_N
+      && bksq == wpsq + NORTH
       && distance(wksq, wpsq) - tempo >= 2
       && distance(wksq, brsq) - tempo >= 2)
       return SCALE_FACTOR_DRAW;
@@ -522,10 +466,10 @@ ScaleFactor Endgame<KRPKR>::operator()(const Position& pos) const {
       && file_of(wrsq) == f
       && wrsq < wpsq
       && (distance(wksq, queeningSq) < distance(bksq, queeningSq) - 2 + tempo)
-      && (distance(wksq, wpsq + DELTA_N) < distance(bksq, wpsq + DELTA_N) - 2 + tempo)
+      && (distance(wksq, wpsq + NORTH) < distance(bksq, wpsq + NORTH) - 2 + tempo)
       && (  distance(bksq, wrsq) + tempo >= 3
           || (    distance(wksq, queeningSq) < distance(bksq, wrsq) + tempo
-              && (distance(wksq, wpsq + DELTA_N) < distance(bksq, wrsq) + tempo))))
+              && (distance(wksq, wpsq + NORTH) < distance(bksq, wrsq) + tempo))))
       return ScaleFactor(  SCALE_FACTOR_MAX
                          - 8 * distance(wpsq, queeningSq)
                          - 2 * distance(wksq, queeningSq));
@@ -552,11 +496,11 @@ ScaleFactor Endgame<KRPKB>::operator()(const Position& pos) const {
   // Test for a rook pawn
   if (pos.pieces(PAWN) & (FileABB | FileHBB))
   {
-      Square ksq = pos.king_square(weakSide);
-      Square bsq = pos.list<BISHOP>(weakSide)[0];
-      Square psq = pos.list<PAWN>(strongSide)[0];
+      Square ksq = pos.square<KING>(weakSide);
+      Square bsq = pos.square<BISHOP>(weakSide);
+      Square psq = pos.square<PAWN>(strongSide);
       Rank rk = relative_rank(strongSide, psq);
-      Square push = pawn_push(strongSide);
+      Direction push = pawn_push(strongSide);
 
       // If the pawn is on the 5th rank and the pawn (currently) is on
       // the same color square as the bishop then there is a chance of
@@ -567,7 +511,7 @@ ScaleFactor Endgame<KRPKB>::operator()(const Position& pos) const {
       {
           int d = distance(psq + 3 * push, ksq);
 
-          if (d <= 2 && !(d == 0 && ksq == pos.king_square(strongSide) + 2 * push))
+          if (d <= 2 && !(d == 0 && ksq == pos.square<KING>(strongSide) + 2 * push))
               return ScaleFactor(24);
           else
               return ScaleFactor(48);
@@ -595,9 +539,9 @@ ScaleFactor Endgame<KRPPKRP>::operator()(const Position& pos) const {
   assert(verify_material(pos, strongSide, RookValueMg, 2));
   assert(verify_material(pos, weakSide,   RookValueMg, 1));
 
-  Square wpsq1 = pos.list<PAWN>(strongSide)[0];
-  Square wpsq2 = pos.list<PAWN>(strongSide)[1];
-  Square bksq = pos.king_square(weakSide);
+  Square wpsq1 = pos.squares<PAWN>(strongSide)[0];
+  Square wpsq2 = pos.squares<PAWN>(strongSide)[1];
+  Square bksq = pos.square<KING>(weakSide);
 
   // Does the stronger side have a passed pawn?
   if (pos.pawn_passed(strongSide, wpsq1) || pos.pawn_passed(strongSide, wpsq2))
@@ -609,14 +553,8 @@ ScaleFactor Endgame<KRPPKRP>::operator()(const Position& pos) const {
       && distance<File>(bksq, wpsq2) <= 1
       && relative_rank(strongSide, bksq) > r)
   {
-      switch (r) {
-      case RANK_2: return ScaleFactor(10);
-      case RANK_3: return ScaleFactor(10);
-      case RANK_4: return ScaleFactor(15);
-      case RANK_5: return ScaleFactor(20);
-      case RANK_6: return ScaleFactor(40);
-      default: assert(false);
-      }
+      assert(r > RANK_1 && r < RANK_7);
+      return ScaleFactor(KRPPKRPScaleFactors[r]);
   }
   return SCALE_FACTOR_NONE;
 }
@@ -631,15 +569,14 @@ ScaleFactor Endgame<KPsK>::operator()(const Position& pos) const {
   assert(pos.count<PAWN>(strongSide) >= 2);
   assert(verify_material(pos, weakSide, VALUE_ZERO, 0));
 
-  Square ksq = pos.king_square(weakSide);
+  Square ksq = pos.square<KING>(weakSide);
   Bitboard pawns = pos.pieces(strongSide, PAWN);
-  Square psq = pos.list<PAWN>(strongSide)[0];
 
   // If all pawns are ahead of the king, on a single rook file and
   // the king is within one file of the pawns, it's a draw.
-  if (   !(pawns & ~in_front_bb(weakSide, rank_of(ksq)))
+  if (   !(pawns & ~forward_ranks_bb(weakSide, ksq))
       && !((pawns & ~FileABB) && (pawns & ~FileHBB))
-      &&  distance<File>(ksq, psq) <= 1)
+      &&  distance<File>(ksq, lsb(pawns)) <= 1)
       return SCALE_FACTOR_DRAW;
 
   return SCALE_FACTOR_NONE;
@@ -656,10 +593,10 @@ ScaleFactor Endgame<KBPKB>::operator()(const Position& pos) const {
   assert(verify_material(pos, strongSide, BishopValueMg, 1));
   assert(verify_material(pos, weakSide,   BishopValueMg, 0));
 
-  Square pawnSq = pos.list<PAWN>(strongSide)[0];
-  Square strongBishopSq = pos.list<BISHOP>(strongSide)[0];
-  Square weakBishopSq = pos.list<BISHOP>(weakSide)[0];
-  Square weakKingSq = pos.king_square(weakSide);
+  Square pawnSq = pos.square<PAWN>(strongSide);
+  Square strongBishopSq = pos.square<BISHOP>(strongSide);
+  Square weakBishopSq = pos.square<BISHOP>(weakSide);
+  Square weakKingSq = pos.square<KING>(weakSide);
 
   // Case 1: Defending king blocks the pawn, and cannot be driven away
   if (   file_of(weakKingSq) == file_of(pawnSq)
@@ -670,31 +607,8 @@ ScaleFactor Endgame<KBPKB>::operator()(const Position& pos) const {
 
   // Case 2: Opposite colored bishops
   if (opposite_colors(strongBishopSq, weakBishopSq))
-  {
-      // We assume that the position is drawn in the following three situations:
-      //
-      //   a. The pawn is on rank 5 or further back.
-      //   b. The defending king is somewhere in the pawn's path.
-      //   c. The defending bishop attacks some square along the pawn's path,
-      //      and is at least three squares away from the pawn.
-      //
-      // These rules are probably not perfect, but in practice they work
-      // reasonably well.
+      return SCALE_FACTOR_DRAW;
 
-      if (relative_rank(strongSide, pawnSq) <= RANK_5)
-          return SCALE_FACTOR_DRAW;
-      else
-      {
-          Bitboard path = forward_bb(strongSide, pawnSq);
-
-          if (path & pos.pieces(weakSide, KING))
-              return SCALE_FACTOR_DRAW;
-
-          if (  (pos.attacks_from<BISHOP>(weakBishopSq) & path)
-              && distance(weakBishopSq, pawnSq) >= 3)
-              return SCALE_FACTOR_DRAW;
-      }
-  }
   return SCALE_FACTOR_NONE;
 }
 
@@ -706,15 +620,15 @@ ScaleFactor Endgame<KBPPKB>::operator()(const Position& pos) const {
   assert(verify_material(pos, strongSide, BishopValueMg, 2));
   assert(verify_material(pos, weakSide,   BishopValueMg, 0));
 
-  Square wbsq = pos.list<BISHOP>(strongSide)[0];
-  Square bbsq = pos.list<BISHOP>(weakSide)[0];
+  Square wbsq = pos.square<BISHOP>(strongSide);
+  Square bbsq = pos.square<BISHOP>(weakSide);
 
   if (!opposite_colors(wbsq, bbsq))
       return SCALE_FACTOR_NONE;
 
-  Square ksq = pos.king_square(weakSide);
-  Square psq1 = pos.list<PAWN>(strongSide)[0];
-  Square psq2 = pos.list<PAWN>(strongSide)[1];
+  Square ksq = pos.square<KING>(weakSide);
+  Square psq1 = pos.squares<PAWN>(strongSide)[0];
+  Square psq2 = pos.squares<PAWN>(strongSide)[1];
   Rank r1 = rank_of(psq1);
   Rank r2 = rank_of(psq2);
   Square blockSq1, blockSq2;
@@ -777,9 +691,9 @@ ScaleFactor Endgame<KBPKN>::operator()(const Position& pos) const {
   assert(verify_material(pos, strongSide, BishopValueMg, 1));
   assert(verify_material(pos, weakSide, KnightValueMg, 0));
 
-  Square pawnSq = pos.list<PAWN>(strongSide)[0];
-  Square strongBishopSq = pos.list<BISHOP>(strongSide)[0];
-  Square weakKingSq = pos.king_square(weakSide);
+  Square pawnSq = pos.square<PAWN>(strongSide);
+  Square strongBishopSq = pos.square<BISHOP>(strongSide);
+  Square weakKingSq = pos.square<KING>(weakSide);
 
   if (   file_of(weakKingSq) == file_of(pawnSq)
       && relative_rank(strongSide, pawnSq) < relative_rank(strongSide, weakKingSq)
@@ -800,8 +714,8 @@ ScaleFactor Endgame<KNPK>::operator()(const Position& pos) const {
   assert(verify_material(pos, weakSide, VALUE_ZERO, 0));
 
   // Assume strongSide is white and the pawn is on files A-D
-  Square pawnSq     = normalize(pos, strongSide, pos.list<PAWN>(strongSide)[0]);
-  Square weakKingSq = normalize(pos, strongSide, pos.king_square(weakSide));
+  Square pawnSq     = normalize(pos, strongSide, pos.square<PAWN>(strongSide));
+  Square weakKingSq = normalize(pos, strongSide, pos.square<KING>(weakSide));
 
   if (pawnSq == SQ_A7 && distance(SQ_A8, weakKingSq) <= 1)
       return SCALE_FACTOR_DRAW;
@@ -815,13 +729,13 @@ ScaleFactor Endgame<KNPK>::operator()(const Position& pos) const {
 template<>
 ScaleFactor Endgame<KNPKB>::operator()(const Position& pos) const {
 
-  Square pawnSq = pos.list<PAWN>(strongSide)[0];
-  Square bishopSq = pos.list<BISHOP>(weakSide)[0];
-  Square weakKingSq = pos.king_square(weakSide);
+  Square pawnSq = pos.square<PAWN>(strongSide);
+  Square bishopSq = pos.square<BISHOP>(weakSide);
+  Square weakKingSq = pos.square<KING>(weakSide);
 
   // King needs to get close to promoting pawn to prevent knight from blocking.
   // Rules for this are very tricky, so just approximate.
-  if (forward_bb(strongSide, pawnSq) & pos.attacks_from<BISHOP>(bishopSq))
+  if (forward_file_bb(strongSide, pawnSq) & pos.attacks_from<BISHOP>(bishopSq))
       return ScaleFactor(distance(weakKingSq, pawnSq));
 
   return SCALE_FACTOR_NONE;
@@ -840,9 +754,9 @@ ScaleFactor Endgame<KPKP>::operator()(const Position& pos) const {
   assert(verify_material(pos, weakSide,   VALUE_ZERO, 1));
 
   // Assume strongSide is white and the pawn is on files A-D
-  Square wksq = normalize(pos, strongSide, pos.king_square(strongSide));
-  Square bksq = normalize(pos, strongSide, pos.king_square(weakSide));
-  Square psq  = normalize(pos, strongSide, pos.list<PAWN>(strongSide)[0]);
+  Square wksq = normalize(pos, strongSide, pos.square<KING>(strongSide));
+  Square bksq = normalize(pos, strongSide, pos.square<KING>(weakSide));
+  Square psq  = normalize(pos, strongSide, pos.square<PAWN>(strongSide));
 
   Color us = strongSide == pos.side_to_move() ? WHITE : BLACK;
 

src/endgame.h

@@ -2,6 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -21,18 +22,20 @@
 #define ENDGAME_H_INCLUDED
 
 #include <map>
+#include <memory>
 #include <string>
+#include <type_traits>
+#include <utility>
 
 #include "position.h"
 #include "types.h"
 
 
-/// EndgameType lists all supported endgames
+/// EndgameCode lists all supported endgame functions by corresponding codes
 
-enum EndgameType {
-
-  // Evaluation functions
+enum EndgameCode {
 
+  EVALUATION_FUNCTIONS,
   KNNK,  // KNN vs K
   KXK,   // Generic "mate lone king" eval
   KBNK,  // KBN vs K
@@ -43,10 +46,7 @@ enum EndgameType {
   KQKP,  // KQ vs KP
   KQKR,  // KQ vs KR
 
-
-  // Scaling functions
   SCALING_FUNCTIONS,
-
   KBPsK,   // KB and pawns vs K
   KQKRPs,  // KQ vs KR and pawns
   KRPKR,   // KRP vs KR
@@ -63,33 +63,30 @@ enum EndgameType {
 
 
 /// Endgame functions can be of two types depending on whether they return a
-/// Value or a ScaleFactor. Type eg_fun<int>::type returns either ScaleFactor
-/// or Value depending on whether the template parameter is 0 or 1.
+/// Value or a ScaleFactor.
 
-template<int> struct eg_fun { typedef Value type; };
-template<> struct eg_fun<1> { typedef ScaleFactor type; };
+template<EndgameCode E> using
+eg_type = typename std::conditional<(E < SCALING_FUNCTIONS), Value, ScaleFactor>::type;
 
 
-/// Base and derived templates for endgame evaluation and scaling functions
+/// Base and derived functors for endgame evaluation and scaling functions
 
 template<typename T>
 struct EndgameBase {
 
-  virtual ~EndgameBase() {}
-  virtual Color strong_side() const = 0;
+  explicit EndgameBase(Color c) : strongSide(c), weakSide(~c) {}
+  virtual ~EndgameBase() = default;
   virtual T operator()(const Position&) const = 0;
+
+  const Color strongSide, weakSide;
 };
 
 
-template<EndgameType E, typename T = typename eg_fun<(E > SCALING_FUNCTIONS)>::type>
+template<EndgameCode E, typename T = eg_type<E>>
 struct Endgame : public EndgameBase<T> {
 
-  explicit Endgame(Color c) : strongSide(c), weakSide(~c) {}
-  Color strong_side() const { return strongSide; }
-  T operator()(const Position&) const;
-
-private:
-  Color strongSide, weakSide;
+  explicit Endgame(Color c) : EndgameBase<T>(c) {}
+  T operator()(const Position&) const override;
 };
 
 
@@ -99,23 +96,49 @@ private:
 
 class Endgames {
 
-  typedef std::map<Key, EndgameBase<eg_fun<0>::type>*> M1;
-  typedef std::map<Key, EndgameBase<eg_fun<1>::type>*> M2;
+  template<typename T> using Ptr = std::unique_ptr<EndgameBase<T>>;
+  template<typename T> using Map = std::map<Key, Ptr<T>>;
 
-  M1 m1;
-  M2 m2;
+  template<typename T>
+  Map<T>& map() {
+    return std::get<std::is_same<T, ScaleFactor>::value>(maps);
+  }
 
-  M1& map(M1::mapped_type) { return m1; }
-  M2& map(M2::mapped_type) { return m2; }
+  template<EndgameCode E, typename T = eg_type<E>>
+  void add(const std::string& code) {
 
-  template<EndgameType E> void add(const std::string& code);
+    StateInfo st;
+    map<T>()[Position().set(code, WHITE, &st).material_key()] = Ptr<T>(new Endgame<E>(WHITE));
+    map<T>()[Position().set(code, BLACK, &st).material_key()] = Ptr<T>(new Endgame<E>(BLACK));
+  }
+
+  std::pair<Map<Value>, Map<ScaleFactor>> maps;
 
 public:
-  Endgames();
- ~Endgames();
+  Endgames() {
 
-  template<typename T> T probe(Key key, T& eg) {
-    return eg = map(eg).count(key) ? map(eg)[key] : NULL;
+    add<KPK>("KPK");
+    add<KNNK>("KNNK");
+    add<KBNK>("KBNK");
+    add<KRKP>("KRKP");
+    add<KRKB>("KRKB");
+    add<KRKN>("KRKN");
+    add<KQKP>("KQKP");
+    add<KQKR>("KQKR");
+
+    add<KNPK>("KNPK");
+    add<KNPKB>("KNPKB");
+    add<KRPKR>("KRPKR");
+    add<KRPKB>("KRPKB");
+    add<KBPKB>("KBPKB");
+    add<KBPKN>("KBPKN");
+    add<KBPPKB>("KBPPKB");
+    add<KRPPKRP>("KRPPKRP");
+  }
+
+  template<typename T>
+  const EndgameBase<T>* probe(Key key) {
+    return map<T>().count(key) ? map<T>()[key].get() : nullptr;
   }
 };
 

src/evaluate.h

@@ -2,6 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -28,12 +29,11 @@ class Position;
 
 namespace Eval {
 
-const Value Tempo = Value(17); // Must be visible to search
+constexpr Value Tempo = Value(20); // Must be visible to search
 
-void init();
-Value evaluate(const Position& pos);
 std::string trace(const Position& pos);
 
+Value evaluate(const Position& pos);
 }
 
 #endif // #ifndef EVALUATE_H_INCLUDED

src/main.cpp

@@ -2,6 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -20,7 +21,6 @@
 #include <iostream>
 
 #include "bitboard.h"
-#include "evaluate.h"
 #include "position.h"
 #include "search.h"
 #include "thread.h"
@@ -28,22 +28,26 @@
 #include "uci.h"
 #include "syzygy/tbprobe.h"
 
+namespace PSQT {
+  void init();
+}
+
 int main(int argc, char* argv[]) {
 
   std::cout << engine_info() << std::endl;
 
   UCI::init(Options);
+  PSQT::init();
   Bitboards::init();
   Position::init();
   Bitbases::init();
   Search::init();
-  Eval::init();
   Pawns::init();
-  Threads.init();
-  Tablebases::init(Options["SyzygyPath"]);
-  TT.resize(Options["Hash"]);
+  Threads.set(Options["Threads"]);
+  Search::clear(); // After threads are up
 
   UCI::loop(argc, argv);
 
-  Threads.exit();
+  Threads.set(0);
+  return 0;
 }

src/material.cpp

@@ -2,6 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -30,29 +31,26 @@ namespace {
 
   // Polynomial material imbalance parameters
 
-  //                      pair  pawn knight bishop rook queen
-  const int Linear[6] = { 1852, -162, -1122, -183,  249, -154 };
-
-  const int QuadraticOurs[][PIECE_TYPE_NB] = {
+  constexpr int QuadraticOurs[][PIECE_TYPE_NB] = {
     //            OUR PIECES
     // pair pawn knight bishop rook queen
-    {   0                               }, // Bishop pair
-    {  39,    2                         }, // Pawn
-    {  35,  271,  -4                    }, // Knight      OUR PIECES
-    {   0,  105,   4,    0              }, // Bishop
-    { -27,   -2,  46,   100,  -141      }, // Rook
-    {-177,   25, 129,   142,  -137,   0 }  // Queen
+    {1438                               }, // Bishop pair
+    {  40,   38                         }, // Pawn
+    {  32,  255, -62                    }, // Knight      OUR PIECES
+    {   0,  104,   4,    0              }, // Bishop
+    { -26,   -2,  47,   105,  -208      }, // Rook
+    {-189,   24, 117,   133,  -134, -6  }  // Queen
   };
 
-  const int QuadraticTheirs[][PIECE_TYPE_NB] = {
+  constexpr int QuadraticTheirs[][PIECE_TYPE_NB] = {
     //           THEIR PIECES
     // pair pawn knight bishop rook queen
     {   0                               }, // Bishop pair
-    {  37,    0                         }, // Pawn
-    {  10,   62,   0                    }, // Knight      OUR PIECES
-    {  57,   64,  39,     0             }, // Bishop
-    {  50,   40,  23,   -22,    0       }, // Rook
-    {  98,  105, -39,   141,  274,    0 }  // Queen
+    {  36,    0                         }, // Pawn
+    {   9,   63,   0                    }, // Knight      OUR PIECES
+    {  59,   65,  42,     0             }, // Bishop
+    {  46,   39,  24,   -24,    0       }, // Rook
+    {  97,  100, -42,   137,  268,    0 }  // Queen
   };
 
   // Endgame evaluation and scaling functions are accessed directly and not through
@@ -64,45 +62,42 @@ namespace {
   Endgame<KPsK>   ScaleKPsK[]   = { Endgame<KPsK>(WHITE),   Endgame<KPsK>(BLACK) };
   Endgame<KPKP>   ScaleKPKP[]   = { Endgame<KPKP>(WHITE),   Endgame<KPKP>(BLACK) };
 
-  // Helper templates used to detect a given material distribution
-  template<Color Us> bool is_KXK(const Position& pos) {
-    const Color Them = (Us == WHITE ? BLACK : WHITE);
-    return  !more_than_one(pos.pieces(Them))
-          && pos.non_pawn_material(Us) >= RookValueMg;
+  // Helper used to detect a given material distribution
+  bool is_KXK(const Position& pos, Color us) {
+    return  !more_than_one(pos.pieces(~us))
+          && pos.non_pawn_material(us) >= RookValueMg;
   }
 
-  template<Color Us> bool is_KBPsKs(const Position& pos) {
-    return   pos.non_pawn_material(Us) == BishopValueMg
-          && pos.count<BISHOP>(Us) == 1
-          && pos.count<PAWN  >(Us) >= 1;
+  bool is_KBPsK(const Position& pos, Color us) {
+    return   pos.non_pawn_material(us) == BishopValueMg
+          && pos.count<BISHOP>(us) == 1
+          && pos.count<PAWN  >(us) >= 1;
   }
 
-  template<Color Us> bool is_KQKRPs(const Position& pos) {
-    const Color Them = (Us == WHITE ? BLACK : WHITE);
-    return  !pos.count<PAWN>(Us)
-          && pos.non_pawn_material(Us) == QueenValueMg
-          && pos.count<QUEEN>(Us)  == 1
-          && pos.count<ROOK>(Them) == 1
-          && pos.count<PAWN>(Them) >= 1;
+  bool is_KQKRPs(const Position& pos, Color us) {
+    return  !pos.count<PAWN>(us)
+          && pos.non_pawn_material(us) == QueenValueMg
+          && pos.count<QUEEN>(us) == 1
+          && pos.count<ROOK>(~us) == 1
+          && pos.count<PAWN>(~us) >= 1;
   }
 
   /// imbalance() calculates the imbalance by comparing the piece count of each
   /// piece type for both colors.
-
   template<Color Us>
   int imbalance(const int pieceCount[][PIECE_TYPE_NB]) {
 
-    const Color Them = (Us == WHITE ? BLACK : WHITE);
+    constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
 
     int bonus = 0;
 
-    // Second-degree polynomial material imbalance by Tord Romstad
+    // Second-degree polynomial material imbalance, by Tord Romstad
     for (int pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; ++pt1)
     {
         if (!pieceCount[Us][pt1])
             continue;
 
-        int v = Linear[pt1];
+        int v = 0;
 
         for (int pt2 = NO_PIECE_TYPE; pt2 <= pt1; ++pt2)
             v +=  QuadraticOurs[pt1][pt2] * pieceCount[Us][pt2]
@@ -134,53 +129,48 @@ Entry* probe(const Position& pos) {
   std::memset(e, 0, sizeof(Entry));
   e->key = key;
   e->factor[WHITE] = e->factor[BLACK] = (uint8_t)SCALE_FACTOR_NORMAL;
-  e->gamePhase = pos.game_phase();
+
+  Value npm_w = pos.non_pawn_material(WHITE);
+  Value npm_b = pos.non_pawn_material(BLACK);
+  Value npm = std::max(EndgameLimit, std::min(npm_w + npm_b, MidgameLimit));
+
+  // Map total non-pawn material into [PHASE_ENDGAME, PHASE_MIDGAME]
+  e->gamePhase = Phase(((npm - EndgameLimit) * PHASE_MIDGAME) / (MidgameLimit - EndgameLimit));
 
   // Let's look if we have a specialized evaluation function for this particular
   // material configuration. Firstly we look for a fixed configuration one, then
   // for a generic one if the previous search failed.
-  if (pos.this_thread()->endgames.probe(key, e->evaluationFunction))
+  if ((e->evaluationFunction = pos.this_thread()->endgames.probe<Value>(key)) != nullptr)
       return e;
 
-  if (is_KXK<WHITE>(pos))
-  {
-      e->evaluationFunction = &EvaluateKXK[WHITE];
-      return e;
-  }
-
-  if (is_KXK<BLACK>(pos))
-  {
-      e->evaluationFunction = &EvaluateKXK[BLACK];
-      return e;
-  }
+  for (Color c = WHITE; c <= BLACK; ++c)
+      if (is_KXK(pos, c))
+      {
+          e->evaluationFunction = &EvaluateKXK[c];
+          return e;
+      }
 
   // OK, we didn't find any special evaluation function for the current material
   // configuration. Is there a suitable specialized scaling function?
-  EndgameBase<ScaleFactor>* sf;
+  const EndgameBase<ScaleFactor>* sf;
 
-  if (pos.this_thread()->endgames.probe(key, sf))
+  if ((sf = pos.this_thread()->endgames.probe<ScaleFactor>(key)) != nullptr)
   {
-      e->scalingFunction[sf->strong_side()] = sf; // Only strong color assigned
+      e->scalingFunction[sf->strongSide] = sf; // Only strong color assigned
       return e;
   }
 
   // We didn't find any specialized scaling function, so fall back on generic
   // ones that refer to more than one material distribution. Note that in this
   // case we don't return after setting the function.
-  if (is_KBPsKs<WHITE>(pos))
-      e->scalingFunction[WHITE] = &ScaleKBPsK[WHITE];
+  for (Color c = WHITE; c <= BLACK; ++c)
+  {
+    if (is_KBPsK(pos, c))
+        e->scalingFunction[c] = &ScaleKBPsK[c];
 
-  if (is_KBPsKs<BLACK>(pos))
-      e->scalingFunction[BLACK] = &ScaleKBPsK[BLACK];
-
-  if (is_KQKRPs<WHITE>(pos))
-      e->scalingFunction[WHITE] = &ScaleKQKRPs[WHITE];
-
-  else if (is_KQKRPs<BLACK>(pos))
-      e->scalingFunction[BLACK] = &ScaleKQKRPs[BLACK];
-
-  Value npm_w = pos.non_pawn_material(WHITE);
-  Value npm_b = pos.non_pawn_material(BLACK);
+    else if (is_KQKRPs(pos, c))
+        e->scalingFunction[c] = &ScaleKQKRPs[c];
+  }
 
   if (npm_w + npm_b == VALUE_ZERO && pos.pieces(PAWN)) // Only pawns on the board
   {
@@ -210,28 +200,22 @@ Entry* probe(const Position& pos) {
   // drawish scale factor for cases such as KRKBP and KmmKm (except for KBBKN).
   if (!pos.count<PAWN>(WHITE) && npm_w - npm_b <= BishopValueMg)
       e->factor[WHITE] = uint8_t(npm_w <  RookValueMg   ? SCALE_FACTOR_DRAW :
-                                 npm_b <= BishopValueMg ? 4 : 12);
+                                 npm_b <= BishopValueMg ? 4 : 14);
 
   if (!pos.count<PAWN>(BLACK) && npm_b - npm_w <= BishopValueMg)
       e->factor[BLACK] = uint8_t(npm_b <  RookValueMg   ? SCALE_FACTOR_DRAW :
-                                 npm_w <= BishopValueMg ? 4 : 12);
-
-  if (pos.count<PAWN>(WHITE) == 1 && npm_w - npm_b <= BishopValueMg)
-      e->factor[WHITE] = (uint8_t) SCALE_FACTOR_ONEPAWN;
-
-  if (pos.count<PAWN>(BLACK) == 1 && npm_b - npm_w <= BishopValueMg)
-      e->factor[BLACK] = (uint8_t) SCALE_FACTOR_ONEPAWN;
+                                 npm_w <= BishopValueMg ? 4 : 14);
 
   // Evaluate the material imbalance. We use PIECE_TYPE_NONE as a place holder
   // for the bishop pair "extended piece", which allows us to be more flexible
   // in defining bishop pair bonuses.
-  const int PieceCount[COLOR_NB][PIECE_TYPE_NB] = {
+  const int pieceCount[COLOR_NB][PIECE_TYPE_NB] = {
   { pos.count<BISHOP>(WHITE) > 1, pos.count<PAWN>(WHITE), pos.count<KNIGHT>(WHITE),
     pos.count<BISHOP>(WHITE)    , pos.count<ROOK>(WHITE), pos.count<QUEEN >(WHITE) },
   { pos.count<BISHOP>(BLACK) > 1, pos.count<PAWN>(BLACK), pos.count<KNIGHT>(BLACK),
     pos.count<BISHOP>(BLACK)    , pos.count<ROOK>(BLACK), pos.count<QUEEN >(BLACK) } };
 
-  e->value = int16_t((imbalance<WHITE>(PieceCount) - imbalance<BLACK>(PieceCount)) / 16);
+  e->value = int16_t((imbalance<WHITE>(pieceCount) - imbalance<BLACK>(pieceCount)) / 16);
   return e;
 }
 

src/material.h

@@ -2,6 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -40,7 +41,7 @@ struct Entry {
 
   Score imbalance() const { return make_score(value, value); }
   Phase game_phase() const { return gamePhase; }
-  bool specialized_eval_exists() const { return evaluationFunction != NULL; }
+  bool specialized_eval_exists() const { return evaluationFunction != nullptr; }
   Value evaluate(const Position& pos) const { return (*evaluationFunction)(pos); }
 
   // scale_factor takes a position and a color as input and returns a scale factor
@@ -49,17 +50,17 @@ struct Entry {
   // the position. For instance, in KBP vs K endgames, the scaling function looks
   // for rook pawns and wrong-colored bishops.
   ScaleFactor scale_factor(const Position& pos, Color c) const {
-    return   !scalingFunction[c]
-          || (*scalingFunction[c])(pos) == SCALE_FACTOR_NONE ? ScaleFactor(factor[c])
-                                                             : (*scalingFunction[c])(pos);
+    ScaleFactor sf = scalingFunction[c] ? (*scalingFunction[c])(pos)
+                                        :  SCALE_FACTOR_NONE;
+    return sf != SCALE_FACTOR_NONE ? sf : ScaleFactor(factor[c]);
   }
 
   Key key;
+  const EndgameBase<Value>* evaluationFunction;
+  const EndgameBase<ScaleFactor>* scalingFunction[COLOR_NB]; // Could be one for each
+                                                             // side (e.g. KPKP, KBPsKs)
   int16_t value;
   uint8_t factor[COLOR_NB];
-  EndgameBase<Value>* evaluationFunction;
-  EndgameBase<ScaleFactor>* scalingFunction[COLOR_NB]; // Could be one for each
-                                                       // side (e.g. KPKP, KBPsKs)
   Phase gamePhase;
 };
 

src/misc.cpp

@@ -2,6 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -17,10 +18,34 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#ifdef _WIN32
+#if _WIN32_WINNT < 0x0601
+#undef  _WIN32_WINNT
+#define _WIN32_WINNT 0x0601 // Force to include needed API prototypes
+#endif
+
+#ifndef NOMINMAX
+#define NOMINMAX
+#endif
+
+#include <windows.h>
+// The needed Windows API for processor groups could be missed from old Windows
+// versions, so instead of calling them directly (forcing the linker to resolve
+// the calls at compile time), try to load them at runtime. To do this we need
+// first to define the corresponding function pointers.
+extern "C" {
+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);
+}
+#endif
+
 #include <fstream>
 #include <iomanip>
 #include <iostream>
 #include <sstream>
+#include <vector>
 
 #include "misc.h"
 #include "thread.h"
@@ -31,60 +56,56 @@ namespace {
 
 /// Version number. If Version is left empty, then compile date in the format
 /// DD-MM-YY and show in engine_info.
-const string Version = "6";
-
-/// Debug counters
-int64_t hits[2], means[2];
+const string Version = "10";
 
 /// 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
 /// can toggle the logging of std::cout and std:cin at runtime whilst preserving
-/// usual i/o functionality, all without changing a single line of code!
+/// usual I/O functionality, all without changing a single line of code!
 /// Idea from http://groups.google.com/group/comp.lang.c++/msg/1d941c0f26ea0d81
 
-struct Tie: public streambuf { // MSVC requires splitted streambuf for cin and cout
+struct Tie: public streambuf { // MSVC requires split streambuf for cin and cout
 
-  Tie(streambuf* b, ofstream* f) : buf(b), file(f) {}
+  Tie(streambuf* b, streambuf* l) : buf(b), logBuf(l) {}
 
-  int sync() { return file->rdbuf()->pubsync(), buf->pubsync(); }
-  int overflow(int c) { return log(buf->sputc((char)c), "<< "); }
-  int underflow() { return buf->sgetc(); }
-  int uflow() { return log(buf->sbumpc(), ">> "); }
+  int sync() override { return logBuf->pubsync(), buf->pubsync(); }
+  int overflow(int c) override { return log(buf->sputc((char)c), "<< "); }
+  int underflow() override { return buf->sgetc(); }
+  int uflow() override { return log(buf->sbumpc(), ">> "); }
 
-  streambuf* buf;
-  ofstream* file;
+  streambuf *buf, *logBuf;
 
   int log(int c, const char* prefix) {
 
-    static int last = '\n';
+    static int last = '\n'; // Single log file
 
     if (last == '\n')
-        file->rdbuf()->sputn(prefix, 3);
+        logBuf->sputn(prefix, 3);
 
-    return last = file->rdbuf()->sputc((char)c);
+    return last = logBuf->sputc((char)c);
   }
 };
 
 class Logger {
 
-  Logger() : in(cin.rdbuf(), &file), out(cout.rdbuf(), &file) {}
- ~Logger() { start(false); }
+  Logger() : in(cin.rdbuf(), file.rdbuf()), out(cout.rdbuf(), file.rdbuf()) {}
+ ~Logger() { start(""); }
 
   ofstream file;
   Tie in, out;
 
 public:
-  static void start(bool b) {
+  static void start(const std::string& fname) {
 
     static Logger l;
 
-    if (b && !l.file.is_open())
+    if (!fname.empty() && !l.file.is_open())
     {
-        l.file.open("io_log.txt", ifstream::out | ifstream::app);
+        l.file.open(fname, ifstream::out);
         cin.rdbuf(&l.in);
         cout.rdbuf(&l.out);
     }
-    else if (!b && l.file.is_open())
+    else if (fname.empty() && l.file.is_open())
     {
         cout.rdbuf(l.out.buf);
         cin.rdbuf(l.in.buf);
@@ -117,16 +138,17 @@ const string engine_info(bool to_uci) {
   ss << (Is64Bit ? " 64" : "")
      << (HasPext ? " BMI2" : (HasPopCnt ? " POPCNT" : ""))
      << (to_uci  ? "\nid author ": " by ")
-     << "Tord Romstad, Marco Costalba and Joona Kiiski";
+     << "T. Romstad, M. Costalba, J. Kiiski, G. Linscott";
 
   return ss.str();
 }
 
 
 /// Debug functions used mainly to collect run-time statistics
+static int64_t hits[2], means[2];
 
 void dbg_hit_on(bool b) { ++hits[0]; if (b) ++hits[1]; }
-void dbg_hit_on_c(bool c, bool b) { if (c) dbg_hit_on(b); }
+void dbg_hit_on(bool c, bool b) { if (c) dbg_hit_on(b); }
 void dbg_mean_of(int v) { ++means[0]; means[1] += v; }
 
 void dbg_print() {
@@ -159,26 +181,7 @@ std::ostream& operator<<(std::ostream& os, SyncCout sc) {
 
 
 /// Trampoline helper to avoid moving Logger to misc.h
-void start_logger(bool b) { Logger::start(b); }
-
-
-/// timed_wait() waits for msec milliseconds. It is mainly a helper to wrap
-/// the conversion from milliseconds to struct timespec, as used by pthreads.
-
-void timed_wait(WaitCondition& sleepCond, Lock& sleepLock, int msec) {
-
-#ifdef _WIN32
-  int tm = msec;
-#else
-  timespec ts, *tm = &ts;
-  uint64_t ms = Time::now() + msec;
-
-  ts.tv_sec = ms / 1000;
-  ts.tv_nsec = (ms % 1000) * 1000000LL;
-#endif
-
-  cond_timedwait(sleepCond, sleepLock, tm);
-}
+void start_logger(const std::string& fname) { Logger::start(fname); }
 
 
 /// prefetch() preloads the given address in L1/L2 cache. This is a non-blocking
@@ -186,11 +189,11 @@ void timed_wait(WaitCondition& sleepCond, Lock& sleepLock, int msec) {
 /// which can be quite slow.
 #ifdef NO_PREFETCH
 
-void prefetch(char*) {}
+void prefetch(void*) {}
 
 #else
 
-void prefetch(char* addr) {
+void prefetch(void* addr) {
 
 #  if defined(__INTEL_COMPILER)
    // This hack prevents prefetches from being optimized away by
@@ -199,10 +202,121 @@ void prefetch(char* addr) {
 #  endif
 
 #  if defined(__INTEL_COMPILER) || defined(_MSC_VER)
-  _mm_prefetch(addr, _MM_HINT_T0);
+  _mm_prefetch((char*)addr, _MM_HINT_T0);
 #  else
   __builtin_prefetch(addr);
 #  endif
 }
 
 #endif
+
+void prefetch2(void* addr) {
+
+  prefetch(addr);
+  prefetch((uint8_t*)addr + 64);
+}
+
+namespace WinProcGroup {
+
+#ifndef _WIN32
+
+void bindThisThread(size_t) {}
+
+#else
+
+/// best_group() retrieves logical processor information using Windows specific
+/// API and returns the best group id for the thread with index idx. Original
+/// code from Texel by Peter Österlund.
+
+int best_group(size_t idx) {
+
+  int threads = 0;
+  int nodes = 0;
+  int cores = 0;
+  DWORD returnLength = 0;
+  DWORD byteOffset = 0;
+
+  // Early exit if the needed API is not available at runtime
+  HMODULE k32 = GetModuleHandle("Kernel32.dll");
+  auto fun1 = (fun1_t)(void(*)())GetProcAddress(k32, "GetLogicalProcessorInformationEx");
+  if (!fun1)
+      return -1;
+
+  // First call to get returnLength. We expect it to fail due to null buffer
+  if (fun1(RelationAll, nullptr, &returnLength))
+      return -1;
+
+  // Once we know returnLength, allocate the buffer
+  SYSTEM_LOGICAL_PROCESSOR_INFORMATION_EX *buffer, *ptr;
+  ptr = buffer = (SYSTEM_LOGICAL_PROCESSOR_INFORMATION_EX*)malloc(returnLength);
+
+  // Second call, now we expect to succeed
+  if (!fun1(RelationAll, buffer, &returnLength))
+  {
+      free(buffer);
+      return -1;
+  }
+
+  while (ptr->Size > 0 && byteOffset + ptr->Size <= returnLength)
+  {
+      if (ptr->Relationship == RelationNumaNode)
+          nodes++;
+
+      else if (ptr->Relationship == RelationProcessorCore)
+      {
+          cores++;
+          threads += (ptr->Processor.Flags == LTP_PC_SMT) ? 2 : 1;
+      }
+
+      byteOffset += ptr->Size;
+      ptr = (SYSTEM_LOGICAL_PROCESSOR_INFORMATION_EX*)(((char*)ptr) + ptr->Size);
+  }
+
+  free(buffer);
+
+  std::vector<int> groups;
+
+  // Run as many threads as possible on the same node until core limit is
+  // reached, then move on filling the next node.
+  for (int n = 0; n < nodes; n++)
+      for (int i = 0; i < cores / nodes; i++)
+          groups.push_back(n);
+
+  // In case a core has more than one logical processor (we assume 2) and we
+  // have still threads to allocate, then spread them evenly across available
+  // nodes.
+  for (int t = 0; t < threads - cores; t++)
+      groups.push_back(t % nodes);
+
+  // If we still have more threads than the total number of logical processors
+  // then return -1 and let the OS to decide what to do.
+  return idx < groups.size() ? groups[idx] : -1;
+}
+
+
+/// bindThisThread() set the group affinity of the current thread
+
+void bindThisThread(size_t idx) {
+
+  // Use only local variables to be thread-safe
+  int group = best_group(idx);
+
+  if (group == -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");
+
+  if (!fun2 || !fun3)
+      return;
+
+  GROUP_AFFINITY affinity;
+  if (fun2(group, &affinity))
+      fun3(GetCurrentThread(), &affinity, nullptr);
+}
+
+#endif
+
+} // namespace WinProcGroup

src/misc.h

@@ -2,6 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -21,6 +22,7 @@
 #define MISC_H_INCLUDED
 
 #include <cassert>
+#include <chrono>
 #include <ostream>
 #include <string>
 #include <vector>
@@ -28,29 +30,30 @@
 #include "types.h"
 
 const std::string engine_info(bool to_uci = false);
-void timed_wait(WaitCondition&, Lock&, int);
-void prefetch(char* addr);
-void start_logger(bool b);
+void prefetch(void* addr);
+void prefetch2(void* addr);
+void start_logger(const std::string& fname);
 
 void dbg_hit_on(bool b);
-void dbg_hit_on_c(bool c, bool b);
+void dbg_hit_on(bool c, bool b);
 void dbg_mean_of(int v);
 void dbg_print();
 
+typedef std::chrono::milliseconds::rep TimePoint; // A value in milliseconds
 
-namespace Time {
-  typedef int64_t point;
-  inline point now() { return system_time_to_msec(); }
+static_assert(sizeof(TimePoint) == sizeof(int64_t), "TimePoint should be 64 bits");
+
+inline TimePoint now() {
+  return std::chrono::duration_cast<std::chrono::milliseconds>
+        (std::chrono::steady_clock::now().time_since_epoch()).count();
 }
 
-
 template<class Entry, int Size>
 struct HashTable {
-  HashTable() : table(Size, Entry()) {}
   Entry* operator[](Key key) { return &table[(uint32_t)key & (Size - 1)]; }
 
 private:
-  std::vector<Entry> table;
+  std::vector<Entry> table = std::vector<Entry>(Size);
 };
 
 
@@ -97,4 +100,15 @@ public:
   { return T(rand64() & rand64() & rand64()); }
 };
 
+
+/// Under Windows it is not possible for a process to run on more than one
+/// logical processor group. This usually means to be limited to use max 64
+/// cores. To overcome this, some special platform specific API should be
+/// called to set group affinity for each thread. Original code from Texel by
+/// Peter Österlund.
+
+namespace WinProcGroup {
+  void bindThisThread(size_t idx);
+}
+
 #endif // #ifndef MISC_H_INCLUDED

src/movegen.cpp

@@ -2,6 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -24,84 +25,83 @@
 
 namespace {
 
-  template<CastlingRight Cr, bool Checks, bool Chess960>
-  ExtMove* generate_castling(const Position& pos, ExtMove* moveList, Color us, const CheckInfo* ci) {
+  template<Color Us, CastlingSide Cs, bool Checks, bool Chess960>
+  ExtMove* generate_castling(const Position& pos, ExtMove* moveList) {
 
-    static const bool KingSide = (Cr == WHITE_OO || Cr == BLACK_OO);
+    constexpr CastlingRight Cr = Us | Cs;
+    constexpr bool KingSide = (Cr == WHITE_OO || Cr == BLACK_OO);
 
     if (pos.castling_impeded(Cr) || !pos.can_castle(Cr))
         return moveList;
 
     // After castling, the rook and king final positions are the same in Chess960
     // as they would be in standard chess.
-    Square kfrom = pos.king_square(us);
+    Square kfrom = pos.square<KING>(Us);
     Square rfrom = pos.castling_rook_square(Cr);
-    Square kto = relative_square(us, KingSide ? SQ_G1 : SQ_C1);
-    Bitboard enemies = pos.pieces(~us);
+    Square kto = relative_square(Us, KingSide ? SQ_G1 : SQ_C1);
+    Bitboard enemies = pos.pieces(~Us);
 
     assert(!pos.checkers());
 
-    const Square K = Chess960 ? kto > kfrom ? DELTA_W : DELTA_E
-                              : KingSide    ? DELTA_W : DELTA_E;
+    const Direction step = Chess960 ? kto > kfrom ? WEST : EAST
+                                    : KingSide    ? WEST : EAST;
 
-    for (Square s = kto; s != kfrom; s += K)
+    for (Square s = kto; s != kfrom; s += step)
         if (pos.attackers_to(s) & enemies)
             return moveList;
 
     // Because we generate only legal castling moves we need to verify that
     // when moving the castling rook we do not discover some hidden checker.
     // For instance an enemy queen in SQ_A1 when castling rook is in SQ_B1.
-    if (Chess960 && (attacks_bb<ROOK>(kto, pos.pieces() ^ rfrom) & pos.pieces(~us, ROOK, QUEEN)))
+    if (Chess960 && (attacks_bb<ROOK>(kto, pos.pieces() ^ rfrom) & pos.pieces(~Us, ROOK, QUEEN)))
         return moveList;
 
     Move m = make<CASTLING>(kfrom, rfrom);
 
-    if (Checks && !pos.gives_check(m, *ci))
+    if (Checks && !pos.gives_check(m))
         return moveList;
 
-    (moveList++)->move = m;
-
+    *moveList++ = m;
     return moveList;
   }
 
 
-  template<GenType Type, Square Delta>
-  inline ExtMove* make_promotions(ExtMove* moveList, Square to, const CheckInfo* ci) {
+  template<GenType Type, Direction D>
+  ExtMove* make_promotions(ExtMove* moveList, Square to, Square ksq) {
 
     if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS)
-        (moveList++)->move = make<PROMOTION>(to - Delta, to, QUEEN);
+        *moveList++ = make<PROMOTION>(to - D, to, QUEEN);
 
     if (Type == QUIETS || Type == EVASIONS || Type == NON_EVASIONS)
     {
-        (moveList++)->move = make<PROMOTION>(to - Delta, to, ROOK);
-        (moveList++)->move = make<PROMOTION>(to - Delta, to, BISHOP);
-        (moveList++)->move = make<PROMOTION>(to - Delta, to, KNIGHT);
+        *moveList++ = make<PROMOTION>(to - D, to, ROOK);
+        *moveList++ = make<PROMOTION>(to - D, to, BISHOP);
+        *moveList++ = make<PROMOTION>(to - D, to, KNIGHT);
     }
 
     // Knight promotion is the only promotion that can give a direct check
     // that's not already included in the queen promotion.
-    if (Type == QUIET_CHECKS && (StepAttacksBB[W_KNIGHT][to] & ci->ksq))
-        (moveList++)->move = make<PROMOTION>(to - Delta, to, KNIGHT);
+    if (Type == QUIET_CHECKS && (PseudoAttacks[KNIGHT][to] & ksq))
+        *moveList++ = make<PROMOTION>(to - D, to, KNIGHT);
     else
-        (void)ci; // Silence a warning under MSVC
+        (void)ksq; // Silence a warning under MSVC
 
     return moveList;
   }
 
 
   template<Color Us, GenType Type>
-  ExtMove* generate_pawn_moves(const Position& pos, ExtMove* moveList,
-                               Bitboard target, const CheckInfo* ci) {
+  ExtMove* generate_pawn_moves(const Position& pos, ExtMove* moveList, Bitboard target) {
 
     // Compute our parametrized parameters at compile time, named according to
     // the point of view of white side.
-    const Color    Them     = (Us == WHITE ? BLACK    : WHITE);
-    const Bitboard TRank8BB = (Us == WHITE ? Rank8BB  : Rank1BB);
-    const Bitboard TRank7BB = (Us == WHITE ? Rank7BB  : Rank2BB);
-    const Bitboard TRank3BB = (Us == WHITE ? Rank3BB  : Rank6BB);
-    const Square   Up       = (Us == WHITE ? DELTA_N  : DELTA_S);
-    const Square   Right    = (Us == WHITE ? DELTA_NE : DELTA_SW);
-    const Square   Left     = (Us == WHITE ? DELTA_NW : DELTA_SE);
+    constexpr Color     Them     = (Us == WHITE ? BLACK      : WHITE);
+    constexpr Bitboard  TRank8BB = (Us == WHITE ? Rank8BB    : Rank1BB);
+    constexpr Bitboard  TRank7BB = (Us == WHITE ? Rank7BB    : Rank2BB);
+    constexpr Bitboard  TRank3BB = (Us == WHITE ? Rank3BB    : Rank6BB);
+    constexpr Direction Up       = (Us == WHITE ? NORTH      : SOUTH);
+    constexpr Direction UpRight  = (Us == WHITE ? NORTH_EAST : SOUTH_WEST);
+    constexpr Direction UpLeft   = (Us == WHITE ? NORTH_WEST : SOUTH_EAST);
 
     Bitboard emptySquares;
 
@@ -116,8 +116,8 @@ namespace {
     {
         emptySquares = (Type == QUIETS || Type == QUIET_CHECKS ? target : ~pos.pieces());
 
-        Bitboard b1 = shift_bb<Up>(pawnsNotOn7)   & emptySquares;
-        Bitboard b2 = shift_bb<Up>(b1 & TRank3BB) & emptySquares;
+        Bitboard b1 = shift<Up>(pawnsNotOn7)   & emptySquares;
+        Bitboard b2 = shift<Up>(b1 & TRank3BB) & emptySquares;
 
         if (Type == EVASIONS) // Consider only blocking squares
         {
@@ -127,17 +127,20 @@ namespace {
 
         if (Type == QUIET_CHECKS)
         {
-            b1 &= pos.attacks_from<PAWN>(ci->ksq, Them);
-            b2 &= pos.attacks_from<PAWN>(ci->ksq, Them);
+            Square ksq = pos.square<KING>(Them);
+
+            b1 &= pos.attacks_from<PAWN>(ksq, Them);
+            b2 &= pos.attacks_from<PAWN>(ksq, Them);
 
             // Add pawn pushes which give discovered check. This is possible only
             // if the pawn is not on the same file as the enemy king, because we
             // don't generate captures. Note that a possible discovery check
             // promotion has been already generated amongst the captures.
-            if (pawnsNotOn7 & ci->dcCandidates)
+            Bitboard dcCandidates = pos.blockers_for_king(Them);
+            if (pawnsNotOn7 & dcCandidates)
             {
-                Bitboard dc1 = shift_bb<Up>(pawnsNotOn7 & ci->dcCandidates) & emptySquares & ~file_bb(ci->ksq);
-                Bitboard dc2 = shift_bb<Up>(dc1 & TRank3BB) & emptySquares;
+                Bitboard dc1 = shift<Up>(pawnsNotOn7 & dcCandidates) & emptySquares & ~file_bb(ksq);
+                Bitboard dc2 = shift<Up>(dc1 & TRank3BB) & emptySquares;
 
                 b1 |= dc1;
                 b2 |= dc2;
@@ -147,13 +150,13 @@ namespace {
         while (b1)
         {
             Square to = pop_lsb(&b1);
-            (moveList++)->move = make_move(to - Up, to);
+            *moveList++ = make_move(to - Up, to);
         }
 
         while (b2)
         {
             Square to = pop_lsb(&b2);
-            (moveList++)->move = make_move(to - Up - Up, to);
+            *moveList++ = make_move(to - Up - Up, to);
         }
     }
 
@@ -166,36 +169,38 @@ namespace {
         if (Type == EVASIONS)
             emptySquares &= target;
 
-        Bitboard b1 = shift_bb<Right>(pawnsOn7) & enemies;
-        Bitboard b2 = shift_bb<Left >(pawnsOn7) & enemies;
-        Bitboard b3 = shift_bb<Up   >(pawnsOn7) & emptySquares;
+        Bitboard b1 = shift<UpRight>(pawnsOn7) & enemies;
+        Bitboard b2 = shift<UpLeft >(pawnsOn7) & enemies;
+        Bitboard b3 = shift<Up     >(pawnsOn7) & emptySquares;
+
+        Square ksq = pos.square<KING>(Them);
 
         while (b1)
-            moveList = make_promotions<Type, Right>(moveList, pop_lsb(&b1), ci);
+            moveList = make_promotions<Type, UpRight>(moveList, pop_lsb(&b1), ksq);
 
         while (b2)
-            moveList = make_promotions<Type, Left >(moveList, pop_lsb(&b2), ci);
+            moveList = make_promotions<Type, UpLeft >(moveList, pop_lsb(&b2), ksq);
 
         while (b3)
-            moveList = make_promotions<Type, Up   >(moveList, pop_lsb(&b3), ci);
+            moveList = make_promotions<Type, Up     >(moveList, pop_lsb(&b3), ksq);
     }
 
     // Standard and en-passant captures
     if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS)
     {
-        Bitboard b1 = shift_bb<Right>(pawnsNotOn7) & enemies;
-        Bitboard b2 = shift_bb<Left >(pawnsNotOn7) & enemies;
+        Bitboard b1 = shift<UpRight>(pawnsNotOn7) & enemies;
+        Bitboard b2 = shift<UpLeft >(pawnsNotOn7) & enemies;
 
         while (b1)
         {
             Square to = pop_lsb(&b1);
-            (moveList++)->move = make_move(to - Right, to);
+            *moveList++ = make_move(to - UpRight, to);
         }
 
         while (b2)
         {
             Square to = pop_lsb(&b2);
-            (moveList++)->move = make_move(to - Left, to);
+            *moveList++ = make_move(to - UpLeft, to);
         }
 
         if (pos.ep_square() != SQ_NONE)
@@ -213,7 +218,7 @@ namespace {
             assert(b1);
 
             while (b1)
-                (moveList++)->move = make<ENPASSANT>(pop_lsb(&b1), pos.ep_square());
+                *moveList++ = make<ENPASSANT>(pop_lsb(&b1), pos.ep_square());
         }
     }
 
@@ -221,70 +226,69 @@ namespace {
   }
 
 
-  template<PieceType Pt, bool Checks> FORCE_INLINE
+  template<PieceType Pt, bool Checks>
   ExtMove* generate_moves(const Position& pos, ExtMove* moveList, Color us,
-                          Bitboard target, const CheckInfo* ci) {
+                          Bitboard target) {
 
     assert(Pt != KING && Pt != PAWN);
 
-    const Square* pl = pos.list<Pt>(us);
+    const Square* pl = pos.squares<Pt>(us);
 
     for (Square from = *pl; from != SQ_NONE; from = *++pl)
     {
         if (Checks)
         {
             if (    (Pt == BISHOP || Pt == ROOK || Pt == QUEEN)
-                && !(PseudoAttacks[Pt][from] & target & ci->checkSq[Pt]))
+                && !(PseudoAttacks[Pt][from] & target & pos.check_squares(Pt)))
                 continue;
 
-            if (ci->dcCandidates && (ci->dcCandidates & from))
+            if (pos.blockers_for_king(~us) & from)
                 continue;
         }
 
         Bitboard b = pos.attacks_from<Pt>(from) & target;
 
         if (Checks)
-            b &= ci->checkSq[Pt];
+            b &= pos.check_squares(Pt);
 
         while (b)
-            (moveList++)->move = make_move(from, pop_lsb(&b));
+            *moveList++ = make_move(from, pop_lsb(&b));
     }
 
     return moveList;
   }
 
 
-  template<Color Us, GenType Type> FORCE_INLINE
-  ExtMove* generate_all(const Position& pos, ExtMove* moveList, Bitboard target,
-                        const CheckInfo* ci = NULL) {
+  template<Color Us, GenType Type>
+  ExtMove* generate_all(const Position& pos, ExtMove* moveList, Bitboard target) {
 
-    const bool Checks = Type == QUIET_CHECKS;
+    constexpr bool Checks = Type == QUIET_CHECKS;
 
-    moveList = generate_pawn_moves<Us, Type>(pos, moveList, target, ci);
-    moveList = generate_moves<KNIGHT, Checks>(pos, moveList, Us, target, ci);
-    moveList = generate_moves<BISHOP, Checks>(pos, moveList, Us, target, ci);
-    moveList = generate_moves<  ROOK, Checks>(pos, moveList, Us, target, ci);
-    moveList = generate_moves< QUEEN, Checks>(pos, moveList, Us, target, ci);
+    moveList = generate_pawn_moves<Us, Type>(pos, moveList, target);
+    moveList = generate_moves<KNIGHT, Checks>(pos, moveList, Us, target);
+    moveList = generate_moves<BISHOP, Checks>(pos, moveList, Us, target);
+    moveList = generate_moves<  ROOK, Checks>(pos, moveList, Us, target);
+    moveList = generate_moves< QUEEN, Checks>(pos, moveList, Us, target);
 
     if (Type != QUIET_CHECKS && Type != EVASIONS)
     {
-        Square ksq = pos.king_square(Us);
+        Square ksq = pos.square<KING>(Us);
         Bitboard b = pos.attacks_from<KING>(ksq) & target;
         while (b)
-            (moveList++)->move = make_move(ksq, pop_lsb(&b));
+            *moveList++ = make_move(ksq, pop_lsb(&b));
     }
 
     if (Type != CAPTURES && Type != EVASIONS && pos.can_castle(Us))
     {
         if (pos.is_chess960())
         {
-            moveList = generate_castling<MakeCastling<Us,  KING_SIDE>::right, Checks, true>(pos, moveList, Us, ci);
-            moveList = generate_castling<MakeCastling<Us, QUEEN_SIDE>::right, Checks, true>(pos, moveList, Us, ci);
+            moveList = generate_castling<Us, KING_SIDE, Checks, true>(pos, moveList);
+            moveList = generate_castling<Us, QUEEN_SIDE, Checks, true>(pos, moveList);
         }
         else
         {
-            moveList = generate_castling<MakeCastling<Us,  KING_SIDE>::right, Checks, false>(pos, moveList, Us, ci);
-            moveList = generate_castling<MakeCastling<Us, QUEEN_SIDE>::right, Checks, false>(pos, moveList, Us, ci);
+            moveList = generate_castling<Us, KING_SIDE, Checks, false>(pos, moveList);
+            moveList = generate_castling<Us, QUEEN_SIDE, Checks, false>(pos, moveList);
         }
     }
 
@@ -333,8 +337,7 @@ ExtMove* generate<QUIET_CHECKS>(const Position& pos, ExtMove* moveList) {
   assert(!pos.checkers());
 
   Color us = pos.side_to_move();
-  CheckInfo ci(pos);
-  Bitboard dc = ci.dcCandidates;
+  Bitboard dc = pos.blockers_for_king(~us) & pos.pieces(us);
 
   while (dc)
   {
@@ -344,17 +347,17 @@ ExtMove* generate<QUIET_CHECKS>(const Position& pos, ExtMove* moveList) {
      if (pt == PAWN)
          continue; // Will be generated together with direct checks
 
-     Bitboard b = pos.attacks_from(Piece(pt), from) & ~pos.pieces();
+     Bitboard b = pos.attacks_from(pt, from) & ~pos.pieces();
 
      if (pt == KING)
-         b &= ~PseudoAttacks[QUEEN][ci.ksq];
+         b &= ~PseudoAttacks[QUEEN][pos.square<KING>(~us)];
 
      while (b)
-         (moveList++)->move = make_move(from, pop_lsb(&b));
+         *moveList++ = make_move(from, pop_lsb(&b));
   }
 
-  return us == WHITE ? generate_all<WHITE, QUIET_CHECKS>(pos, moveList, ~pos.pieces(), &ci)
-                     : generate_all<BLACK, QUIET_CHECKS>(pos, moveList, ~pos.pieces(), &ci);
+  return us == WHITE ? generate_all<WHITE, QUIET_CHECKS>(pos, moveList, ~pos.pieces())
+                     : generate_all<BLACK, QUIET_CHECKS>(pos, moveList, ~pos.pieces());
 }
 
 
@@ -366,7 +369,7 @@ ExtMove* generate<EVASIONS>(const Position& pos, ExtMove* moveList) {
   assert(pos.checkers());
 
   Color us = pos.side_to_move();
-  Square ksq = pos.king_square(us);
+  Square ksq = pos.square<KING>(us);
   Bitboard sliderAttacks = 0;
   Bitboard sliders = pos.checkers() & ~pos.pieces(KNIGHT, PAWN);
 
@@ -382,7 +385,7 @@ ExtMove* generate<EVASIONS>(const Position& pos, ExtMove* moveList) {
   // Generate evasions for king, capture and non capture moves
   Bitboard b = pos.attacks_from<KING>(ksq) & ~pos.pieces(us) & ~sliderAttacks;
   while (b)
-      (moveList++)->move = make_move(ksq, pop_lsb(&b));
+      *moveList++ = make_move(ksq, pop_lsb(&b));
 
   if (more_than_one(pos.checkers()))
       return moveList; // Double check, only a king move can save the day
@@ -401,16 +404,17 @@ ExtMove* generate<EVASIONS>(const Position& pos, ExtMove* moveList) {
 template<>
 ExtMove* generate<LEGAL>(const Position& pos, ExtMove* moveList) {
 
-  Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
-  Square ksq = pos.king_square(pos.side_to_move());
+  Color us = pos.side_to_move();
+  Bitboard pinned = pos.blockers_for_king(us) & pos.pieces(us);
+  Square ksq = pos.square<KING>(us);
   ExtMove* cur = moveList;
 
   moveList = pos.checkers() ? generate<EVASIONS    >(pos, moveList)
                             : generate<NON_EVASIONS>(pos, moveList);
   while (cur != moveList)
-      if (   (pinned || from_sq(cur->move) == ksq || type_of(cur->move) == ENPASSANT)
-          && !pos.legal(cur->move, pinned))
-          cur->move = (--moveList)->move;
+      if (   (pinned || from_sq(*cur) == ksq || type_of(*cur) == ENPASSANT)
+          && !pos.legal(*cur))
+          *cur = (--moveList)->move;
       else
           ++cur;
 

src/movegen.h

@@ -2,6 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -20,6 +21,8 @@
 #ifndef MOVEGEN_H_INCLUDED
 #define MOVEGEN_H_INCLUDED
 
+#include <algorithm>
+
 #include "types.h"
 
 class Position;
@@ -35,7 +38,14 @@ enum GenType {
 
 struct ExtMove {
   Move move;
-  Value value;
+  int value;
+
+  operator Move() const { return move; }
+  void operator=(Move m) { move = m; }
+
+  // Inhibit unwanted implicit conversions to Move
+  // with an ambiguity that yields to a compile error.
+  operator float() const = delete;
 };
 
 inline bool operator<(const ExtMove& f, const ExtMove& s) {
@@ -50,18 +60,16 @@ ExtMove* generate(const Position& pos, ExtMove* moveList);
 template<GenType T>
 struct MoveList {
 
-  explicit MoveList(const Position& pos) : cur(moveList), last(generate<T>(pos, moveList)) { last->move = MOVE_NONE; }
-  void operator++() { ++cur; }
-  Move operator*() const { return cur->move; }
+  explicit MoveList(const Position& pos) : last(generate<T>(pos, moveList)) {}
+  const ExtMove* begin() const { return moveList; }
+  const ExtMove* end() const { return last; }
   size_t size() const { return last - moveList; }
-  bool contains(Move m) const {
-    for (const ExtMove* it(moveList); it != last; ++it) if (it->move == m) return true;
-    return false;
+  bool contains(Move move) const {
+    return std::find(begin(), end(), move) != end();
   }
 
 private:
-  ExtMove moveList[MAX_MOVES];
-  ExtMove *cur, *last;
+  ExtMove moveList[MAX_MOVES], *last;
 };
 
 #endif // #ifndef MOVEGEN_H_INCLUDED

src/movepick.cpp

@@ -2,13 +2,13 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   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
@@ -21,365 +21,249 @@
 #include <cassert>
 
 #include "movepick.h"
-#include "thread.h"
 
 namespace {
 
   enum Stages {
-    MAIN_SEARCH, CAPTURES_S1, KILLERS_S1, QUIETS_1_S1, QUIETS_2_S1, BAD_CAPTURES_S1,
-    EVASION,     EVASIONS_S2,
-    QSEARCH_0,   CAPTURES_S3, QUIET_CHECKS_S3,
-    QSEARCH_1,   CAPTURES_S4,
-    PROBCUT,     CAPTURES_S5,
-    RECAPTURE,   CAPTURES_S6,
-    STOP
+    MAIN_TT, CAPTURE_INIT, GOOD_CAPTURE, REFUTATION, QUIET_INIT, QUIET, BAD_CAPTURE,
+    EVASION_TT, EVASION_INIT, EVASION,
+    PROBCUT_TT, PROBCUT_INIT, PROBCUT,
+    QSEARCH_TT, QCAPTURE_INIT, QCAPTURE, QCHECK_INIT, QCHECK
   };
 
-  // Our insertion sort, which is guaranteed (and also needed) to be stable
-  void insertion_sort(ExtMove* begin, ExtMove* end)
-  {
-    ExtMove tmp, *p, *q;
+  // Helper filter used with select()
+  const auto Any = [](){ return true; };
 
-    for (p = begin + 1; p < end; ++p)
-    {
-        tmp = *p;
-        for (q = p; q != begin && *(q-1) < tmp; --q)
-            *q = *(q-1);
-        *q = tmp;
-    }
+  // partial_insertion_sort() sorts moves in descending order up to and including
+  // a given limit. The order of moves smaller than the limit is left unspecified.
+  void partial_insertion_sort(ExtMove* begin, ExtMove* end, int limit) {
+
+    for (ExtMove *sortedEnd = begin, *p = begin + 1; p < end; ++p)
+        if (p->value >= limit)
+        {
+            ExtMove tmp = *p, *q;
+            *p = *++sortedEnd;
+            for (q = sortedEnd; q != begin && *(q - 1) < tmp; --q)
+                *q = *(q - 1);
+            *q = tmp;
+        }
   }
 
-  // Unary predicate used by std::partition to split positive values from remaining
-  // ones so as to sort the two sets separately, with the second sort delayed.
-  inline bool has_positive_value(const ExtMove& move) { return move.value > VALUE_ZERO; }
-
-  // Picks the best move in the range (begin, end) and moves it to the front.
-  // It's faster than sorting all the moves in advance when there are few
-  // moves e.g. possible captures.
-  inline ExtMove* pick_best(ExtMove* begin, ExtMove* end)
-  {
-      std::swap(*begin, *std::max_element(begin, end));
-      return begin;
-  }
 } // namespace
 
 
 /// Constructors of the MovePicker class. As arguments we pass information
 /// to help it to return the (presumably) good moves first, to decide which
 /// moves to return (in the quiescence search, for instance, we only want to
-/// search captures, promotions and some checks) and how important good move
+/// search captures, promotions, and some checks) and how important good move
 /// ordering is at the current node.
 
-MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const HistoryStats& h,
-                       Move* cm, Move* fm, Search::Stack* s) : pos(p), history(h), depth(d) {
+/// MovePicker constructor for the main search
+MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh,
+                       const CapturePieceToHistory* cph, const PieceToHistory** ch, Move cm, Move* killers)
+           : pos(p), mainHistory(mh), captureHistory(cph), continuationHistory(ch),
+             refutations{{killers[0], 0}, {killers[1], 0}, {cm, 0}}, depth(d) {
 
   assert(d > DEPTH_ZERO);
 
-  cur = end = moves;
-  endBadCaptures = moves + MAX_MOVES - 1;
-  countermoves = cm;
-  followupmoves = fm;
-  ss = s;
-
-  if (pos.checkers())
-      stage = EVASION;
-
-  else
-      stage = MAIN_SEARCH;
-
-  ttMove = (ttm && pos.pseudo_legal(ttm) ? ttm : MOVE_NONE);
-  end += (ttMove != MOVE_NONE);
+  stage = pos.checkers() ? EVASION_TT : MAIN_TT;
+  ttMove = ttm && pos.pseudo_legal(ttm) ? ttm : MOVE_NONE;
+  stage += (ttMove == MOVE_NONE);
 }
 
-MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const HistoryStats& h,
-                       Square s) : pos(p), history(h), cur(moves), end(moves) {
+/// MovePicker constructor for quiescence search
+MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh,
+                       const CapturePieceToHistory* cph, const PieceToHistory** ch, Square rs)
+           : pos(p), mainHistory(mh), captureHistory(cph), continuationHistory(ch), recaptureSquare(rs), depth(d) {
 
   assert(d <= DEPTH_ZERO);
 
-  if (pos.checkers())
-      stage = EVASION;
-
-  else if (d > DEPTH_QS_NO_CHECKS)
-      stage = QSEARCH_0;
-
-  else if (d > DEPTH_QS_RECAPTURES)
-      stage = QSEARCH_1;
-
-  else
-  {
-      stage = RECAPTURE;
-      recaptureSquare = s;
-      ttm = MOVE_NONE;
-  }
-
-  ttMove = (ttm && pos.pseudo_legal(ttm) ? ttm : MOVE_NONE);
-  end += (ttMove != MOVE_NONE);
+  stage = pos.checkers() ? EVASION_TT : QSEARCH_TT;
+  ttMove =    ttm
+           && pos.pseudo_legal(ttm)
+           && (depth > DEPTH_QS_RECAPTURES || to_sq(ttm) == recaptureSquare) ? ttm : MOVE_NONE;
+  stage += (ttMove == MOVE_NONE);
 }
 
-MovePicker::MovePicker(const Position& p, Move ttm, const HistoryStats& h, PieceType pt)
-                       : pos(p), history(h), cur(moves), end(moves) {
+/// 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), threshold(th) {
 
   assert(!pos.checkers());
 
-  stage = PROBCUT;
-
-  // In ProbCut we generate only captures that are better than the parent's
-  // captured piece.
-  captureThreshold = PieceValue[MG][pt];
-  ttMove = (ttm && pos.pseudo_legal(ttm) ? ttm : MOVE_NONE);
-
-  if (ttMove && (!pos.capture(ttMove) || pos.see(ttMove) <= captureThreshold))
-      ttMove = MOVE_NONE;
-
-  end += (ttMove != MOVE_NONE);
+  stage = PROBCUT_TT;
+  ttMove =   ttm
+          && pos.pseudo_legal(ttm)
+          && pos.capture(ttm)
+          && pos.see_ge(ttm, threshold) ? ttm : MOVE_NONE;
+  stage += (ttMove == MOVE_NONE);
 }
 
+/// MovePicker::score() assigns a numerical value to each move in a list, used
+/// for sorting. Captures are ordered by Most Valuable Victim (MVV), preferring
+/// captures with a good history. Quiets moves are ordered using the histories.
+template<GenType Type>
+void MovePicker::score() {
 
-/// score() assign a numerical value to each move in a move list. The moves with
-/// highest values will be picked first.
-template<>
-void MovePicker::score<CAPTURES>() {
-  // Winning and equal captures in the main search are ordered by MVV/LVA.
-  // Suprisingly, this appears to perform slightly better than SEE based
-  // move ordering. The reason is probably that in a position with a winning
-  // capture, capturing a more valuable (but sufficiently defended) piece
-  // first usually doesn't hurt. The opponent will have to recapture, and
-  // the hanging piece will still be hanging (except in the unusual cases
-  // where it is possible to recapture with the hanging piece). Exchanging
-  // big pieces before capturing a hanging piece probably helps to reduce
-  // the subtree size.
-  // In main search we want to push captures with negative SEE values to the
-  // badCaptures[] array, but instead of doing it now we delay until the move
-  // has been picked up in pick_move_from_list(). This way we save some SEE
-  // calls in case we get a cutoff.
-  Move m;
+  static_assert(Type == CAPTURES || Type == QUIETS || Type == EVASIONS, "Wrong type");
 
-  for (ExtMove* it = moves; it != end; ++it)
+  for (auto& m : *this)
+      if (Type == CAPTURES)
+          m.value =  PieceValue[MG][pos.piece_on(to_sq(m))]
+                   + (*captureHistory)[pos.moved_piece(m)][to_sq(m)][type_of(pos.piece_on(to_sq(m)))] / 8;
+
+      else if (Type == QUIETS)
+          m.value =  (*mainHistory)[pos.side_to_move()][from_to(m)]
+                   + (*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)];
+
+      else // Type == EVASIONS
+      {
+          if (pos.capture(m))
+              m.value =  PieceValue[MG][pos.piece_on(to_sq(m))]
+                       - Value(type_of(pos.moved_piece(m)));
+          else
+              m.value =  (*mainHistory)[pos.side_to_move()][from_to(m)]
+                       + (*continuationHistory[0])[pos.moved_piece(m)][to_sq(m)]
+                       - (1 << 28);
+      }
+}
+
+/// MovePicker::select() returns the next move satisfying a predicate function.
+/// It never returns the TT move.
+template<MovePicker::PickType T, typename Pred>
+Move MovePicker::select(Pred filter) {
+
+  while (cur < endMoves)
   {
-      m = it->move;
-      it->value =  PieceValue[MG][pos.piece_on(to_sq(m))]
-                 - Value(type_of(pos.moved_piece(m)));
+      if (T == Best)
+          std::swap(*cur, *std::max_element(cur, endMoves));
 
-      if (type_of(m) == ENPASSANT)
-          it->value += PieceValue[MG][PAWN];
+      move = *cur++;
 
-      else if (type_of(m) == PROMOTION)
-          it->value += PieceValue[MG][promotion_type(m)] - PieceValue[MG][PAWN];
+      if (move != ttMove && filter())
+          return move;
   }
+  return move = MOVE_NONE;
 }
 
-template<>
-void MovePicker::score<QUIETS>() {
+/// MovePicker::next_move() is the most important method of the MovePicker class. It
+/// returns a new pseudo legal move every time it is called until there are no more
+/// moves left, picking the move with the highest score from a list of generated moves.
+Move MovePicker::next_move(bool skipQuiets) {
 
-  Move m;
+top:
+  switch (stage) {
 
-  for (ExtMove* it = moves; it != end; ++it)
-  {
-      m = it->move;
-      it->value = history[pos.moved_piece(m)][to_sq(m)];
-  }
-}
+  case MAIN_TT:
+  case EVASION_TT:
+  case QSEARCH_TT:
+  case PROBCUT_TT:
+      ++stage;
+      return ttMove;
 
-template<>
-void MovePicker::score<EVASIONS>() {
-  // Try good captures ordered by MVV/LVA, then non-captures if destination square
-  // is not under attack, ordered by history value, then bad-captures and quiet
-  // moves with a negative SEE. This last group is ordered by the SEE value.
-  Move m;
-  Value see;
+  case CAPTURE_INIT:
+  case PROBCUT_INIT:
+  case QCAPTURE_INIT:
+      cur = endBadCaptures = moves;
+      endMoves = generate<CAPTURES>(pos, cur);
 
-  for (ExtMove* it = moves; it != end; ++it)
-  {
-      m = it->move;
-      if ((see = pos.see_sign(m)) < VALUE_ZERO)
-          it->value = see - HistoryStats::Max; // At the bottom
-
-      else if (pos.capture(m))
-          it->value =  PieceValue[MG][pos.piece_on(to_sq(m))]
-                     - Value(type_of(pos.moved_piece(m))) + HistoryStats::Max;
-      else
-          it->value = history[pos.moved_piece(m)][to_sq(m)];
-  }
-}
-
-
-/// generate_next_stage() generates, scores and sorts the next bunch of moves,
-/// when there are no more moves to try for the current stage.
-
-void MovePicker::generate_next_stage() {
-
-  cur = moves;
-
-  switch (++stage) {
-
-  case CAPTURES_S1: case CAPTURES_S3: case CAPTURES_S4: case CAPTURES_S5: case CAPTURES_S6:
-      end = generate<CAPTURES>(pos, moves);
       score<CAPTURES>();
-      return;
+      ++stage;
+      goto top;
 
-  case KILLERS_S1:
-      cur = killers;
-      end = cur + 2;
+  case GOOD_CAPTURE:
+      if (select<Best>([&](){
+                       return pos.see_ge(move, Value(-55 * (cur-1)->value / 1024)) ?
+                              // Move losing capture to endBadCaptures to be tried later
+                              true : (*endBadCaptures++ = move, false); }))
+          return move;
 
-      killers[0].move = ss->killers[0];
-      killers[1].move = ss->killers[1];
-      killers[2].move = killers[3].move = MOVE_NONE;
-      killers[4].move = killers[5].move = MOVE_NONE;
+      // Prepare the pointers to loop over the refutations array
+      cur = std::begin(refutations);
+      endMoves = std::end(refutations);
 
-      // Please note that following code is racy and could yield to rare (less
-      // than 1 out of a million) duplicated entries in SMP case. This is harmless.
+      // If the countermove is the same as a killer, skip it
+      if (   refutations[0].move == refutations[2].move
+          || refutations[1].move == refutations[2].move)
+          --endMoves;
 
-      // Be sure countermoves are different from killers
-      for (int i = 0; i < 2; ++i)
-          if (   countermoves[i] != (cur+0)->move
-              && countermoves[i] != (cur+1)->move)
-              (end++)->move = countermoves[i];
+      ++stage;
+      /* fallthrough */
 
-      // Be sure followupmoves are different from killers and countermoves
-      for (int i = 0; i < 2; ++i)
-          if (   followupmoves[i] != (cur+0)->move
-              && followupmoves[i] != (cur+1)->move
-              && followupmoves[i] != (cur+2)->move
-              && followupmoves[i] != (cur+3)->move)
-              (end++)->move = followupmoves[i];
-      return;
+  case REFUTATION:
+      if (select<Next>([&](){ return    move != MOVE_NONE
+                                    && !pos.capture(move)
+                                    &&  pos.pseudo_legal(move); }))
+          return move;
+      ++stage;
+      /* fallthrough */
+
+  case QUIET_INIT:
+      cur = endBadCaptures;
+      endMoves = generate<QUIETS>(pos, cur);
 
-  case QUIETS_1_S1:
-      endQuiets = end = generate<QUIETS>(pos, moves);
       score<QUIETS>();
-      end = std::partition(cur, end, has_positive_value);
-      insertion_sort(cur, end);
-      return;
+      partial_insertion_sort(cur, endMoves, -4000 * depth / ONE_PLY);
+      ++stage;
+      /* fallthrough */
 
-  case QUIETS_2_S1:
-      cur = end;
-      end = endQuiets;
-      if (depth >= 3 * ONE_PLY)
-          insertion_sort(cur, end);
-      return;
+  case QUIET:
+      if (   !skipQuiets
+          && select<Next>([&](){return   move != refutations[0]
+                                      && move != refutations[1]
+                                      && move != refutations[2];}))
+          return move;
 
-  case BAD_CAPTURES_S1:
-      // Just pick them in reverse order to get MVV/LVA ordering
-      cur = moves + MAX_MOVES - 1;
-      end = endBadCaptures;
-      return;
+      // Prepare the pointers to loop over the bad captures
+      cur = moves;
+      endMoves = endBadCaptures;
 
-  case EVASIONS_S2:
-      end = generate<EVASIONS>(pos, moves);
-      if (end > moves + 1)
-          score<EVASIONS>();
-      return;
+      ++stage;
+      /* fallthrough */
 
-  case QUIET_CHECKS_S3:
-      end = generate<QUIET_CHECKS>(pos, moves);
-      return;
+  case BAD_CAPTURE:
+      return select<Next>(Any);
 
-  case EVASION: case QSEARCH_0: case QSEARCH_1: case PROBCUT: case RECAPTURE:
-      stage = STOP;
-      /* Fall through */
+  case EVASION_INIT:
+      cur = moves;
+      endMoves = generate<EVASIONS>(pos, cur);
 
-  case STOP:
-      end = cur + 1; // Avoid another next_phase() call
-      return;
+      score<EVASIONS>();
+      ++stage;
+      /* fallthrough */
 
-  default:
-      assert(false);
-  }
-}
+  case EVASION:
+      return select<Best>(Any);
 
+  case PROBCUT:
+      return select<Best>([&](){ return pos.see_ge(move, threshold); });
 
-/// next_move() is the most important method of the MovePicker class. It returns
-/// a new pseudo legal move every time it is called, until there are no more moves
-/// left. It picks the move with the biggest value from a list of generated moves
-/// taking care not to return the ttMove if it has already been searched.
-template<>
-Move MovePicker::next_move<false>() {
+  case QCAPTURE:
+      if (select<Best>([&](){ return   depth > DEPTH_QS_RECAPTURES
+                                    || to_sq(move) == recaptureSquare; }))
+          return move;
 
-  Move move;
-
-  while (true)
-  {
-      while (cur == end)
-          generate_next_stage();
-
-      switch (stage) {
-
-      case MAIN_SEARCH: case EVASION: case QSEARCH_0: case QSEARCH_1: case PROBCUT:
-          ++cur;
-          return ttMove;
-
-      case CAPTURES_S1:
-          move = pick_best(cur++, end)->move;
-          if (move != ttMove)
-          {
-              if (pos.see_sign(move) >= VALUE_ZERO)
-                  return move;
-
-              // Losing capture, move it to the tail of the array
-              (endBadCaptures--)->move = move;
-          }
-          break;
-
-      case KILLERS_S1:
-          move = (cur++)->move;
-          if (    move != MOVE_NONE
-              &&  move != ttMove
-              &&  pos.pseudo_legal(move)
-              && !pos.capture(move))
-              return move;
-          break;
-
-      case QUIETS_1_S1: case QUIETS_2_S1:
-          move = (cur++)->move;
-          if (   move != ttMove
-              && move != killers[0].move
-              && move != killers[1].move
-              && move != killers[2].move
-              && move != killers[3].move
-              && move != killers[4].move
-              && move != killers[5].move)
-              return move;
-          break;
-
-      case BAD_CAPTURES_S1:
-          return (cur--)->move;
-
-      case EVASIONS_S2: case CAPTURES_S3: case CAPTURES_S4:
-          move = pick_best(cur++, end)->move;
-          if (move != ttMove)
-              return move;
-          break;
-
-      case CAPTURES_S5:
-           move = pick_best(cur++, end)->move;
-           if (move != ttMove && pos.see(move) > captureThreshold)
-               return move;
-           break;
-
-      case CAPTURES_S6:
-          move = pick_best(cur++, end)->move;
-          if (to_sq(move) == recaptureSquare)
-              return move;
-          break;
-
-      case QUIET_CHECKS_S3:
-          move = (cur++)->move;
-          if (move != ttMove)
-              return move;
-          break;
-
-      case STOP:
+      // If we did not find any move and we do not try checks, we have finished
+      if (depth != DEPTH_QS_CHECKS)
           return MOVE_NONE;
 
-      default:
-          assert(false);
-      }
+      ++stage;
+      /* fallthrough */
+
+  case QCHECK_INIT:
+      cur = moves;
+      endMoves = generate<QUIET_CHECKS>(pos, cur);
+
+      ++stage;
+      /* fallthrough */
+
+  case QCHECK:
+      return select<Next>(Any);
   }
+
+  assert(false);
+  return MOVE_NONE; // Silence warning
 }
-
-
-/// Version of next_move() to use at split point nodes where the move is grabbed
-/// from the split point's shared MovePicker object. This function is not thread
-/// safe so must be lock protected by the caller.
-template<>
-Move MovePicker::next_move<true>() { return ss->splitPoint->movePicker->next_move<false>(); }

src/movepick.h

@@ -2,6 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -20,56 +21,87 @@
 #ifndef MOVEPICK_H_INCLUDED
 #define MOVEPICK_H_INCLUDED
 
-#include <algorithm> // For std::max
-#include <cstring>   // For std::memset
+#include <array>
+#include <limits>
+#include <type_traits>
 
 #include "movegen.h"
 #include "position.h"
-#include "search.h"
 #include "types.h"
 
+/// StatsEntry stores the stat table value. It is usually a number but could
+/// be a move or even a nested history. We use a class instead of naked value
+/// to directly call history update operator<<() on the entry so to use stats
+/// tables at caller sites as simple multi-dim arrays.
+template<typename T, int D>
+class StatsEntry {
 
-/// The Stats struct stores moves statistics. According to the template parameter
-/// the class can store History, Gains and Countermoves. History records how often
-/// different moves have been successful or unsuccessful during the current search
-/// and is used for reduction and move ordering decisions. Gains records the move's
-/// best evaluation gain from one ply to the next and is used for pruning decisions.
-/// Countermoves store the move that refute a previous one. Entries are stored
-/// using only the moving piece and destination square, hence two moves with
-/// different origin but same destination and piece will be considered identical.
-template<bool Gain, typename T>
-struct Stats {
+  T entry;
 
-  static const Value Max = Value(250);
+public:
+  void operator=(const T& v) { entry = v; }
+  T* operator&() { return &entry; }
+  T* operator->() { return &entry; }
+  operator const T&() const { return entry; }
 
-  const T* operator[](Piece pc) const { return table[pc]; }
-  void clear() { std::memset(table, 0, sizeof(table)); }
+  void operator<<(int bonus) {
+    assert(abs(bonus) <= D); // Ensure range is [-D, D]
+    static_assert(D <= std::numeric_limits<T>::max(), "D overflows T");
 
-  void update(Piece pc, Square to, Move m) {
+    entry += bonus - entry * abs(bonus) / D;
 
-    if (m == table[pc][to].first)
-        return;
-
-    table[pc][to].second = table[pc][to].first;
-    table[pc][to].first = m;
+    assert(abs(entry) <= D);
   }
-
-  void update(Piece pc, Square to, Value v) {
-
-    if (Gain)
-        table[pc][to] = std::max(v, table[pc][to] - 1);
-
-    else if (abs(table[pc][to] + v) < Max)
-        table[pc][to] +=  v;
-  }
-
-private:
-  T table[PIECE_NB][SQUARE_NB];
 };
 
-typedef Stats< true, Value> GainsStats;
-typedef Stats<false, Value> HistoryStats;
-typedef Stats<false, std::pair<Move, Move> > MovesStats;
+/// Stats is a generic N-dimensional array used to store various statistics.
+/// The first template parameter T is the base type of the array, the second
+/// template parameter D limits the range of updates in [-D, D] when we update
+/// values with the << operator, while the last parameters (Size and Sizes)
+/// encode the dimensions of the array.
+template <typename T, int D, int Size, int... Sizes>
+struct Stats : public std::array<Stats<T, D, Sizes...>, Size>
+{
+  typedef Stats<T, D, Size, Sizes...> stats;
+
+  void fill(const T& v) {
+
+    // For standard-layout 'this' points to first struct member
+    assert(std::is_standard_layout<stats>::value);
+
+    typedef StatsEntry<T, D> entry;
+    entry* p = reinterpret_cast<entry*>(this);
+    std::fill(p, p + sizeof(*this) / sizeof(entry), v);
+  }
+};
+
+template <typename T, int D, int Size>
+struct Stats<T, D, Size> : public std::array<StatsEntry<T, D>, Size> {};
+
+/// In stats table, D=0 means that the template parameter is not used
+enum StatsParams { NOT_USED = 0 };
+
+
+/// ButterflyHistory records how often quiet moves have been successful or
+/// unsuccessful during the current search, and is used for reduction and move
+/// ordering decisions. It uses 2 tables (one for each color) indexed by
+/// the move's from and to squares, see chessprogramming.wikispaces.com/Butterfly+Boards
+typedef Stats<int16_t, 10692, COLOR_NB, int(SQUARE_NB) * int(SQUARE_NB)> ButterflyHistory;
+
+/// CounterMoveHistory stores counter moves indexed by [piece][to] of the previous
+/// move, see chessprogramming.wikispaces.com/Countermove+Heuristic
+typedef Stats<Move, NOT_USED, PIECE_NB, SQUARE_NB> CounterMoveHistory;
+
+/// CapturePieceToHistory is addressed by a move's [piece][to][captured piece type]
+typedef Stats<int16_t, 10692, PIECE_NB, SQUARE_NB, PIECE_TYPE_NB> CapturePieceToHistory;
+
+/// PieceToHistory is like ButterflyHistory but is addressed by a move's [piece][to]
+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.
+typedef Stats<PieceToHistory, NOT_USED, PIECE_NB, SQUARE_NB> ContinuationHistory;
 
 
 /// MovePicker class is used to pick one pseudo legal move at a time from the
@@ -78,34 +110,42 @@ typedef Stats<false, std::pair<Move, Move> > MovesStats;
 /// when MOVE_NONE is returned. In order to improve the efficiency of the alpha
 /// beta algorithm, MovePicker attempts to return the moves which are most likely
 /// to get a cut-off first.
-
 class MovePicker {
 
-  MovePicker& operator=(const MovePicker&); // Silence a warning under MSVC
+  enum PickType { Next, Best };
 
 public:
-  MovePicker(const Position&, Move, Depth, const HistoryStats&, Square);
-  MovePicker(const Position&, Move, const HistoryStats&, PieceType);
-  MovePicker(const Position&, Move, Depth, const HistoryStats&, Move*, Move*, Search::Stack*);
-
-  template<bool SpNode> Move next_move();
+  MovePicker(const MovePicker&) = delete;
+  MovePicker& operator=(const MovePicker&) = delete;
+  MovePicker(const Position&, Move, Value, const CapturePieceToHistory*);
+  MovePicker(const Position&, Move, Depth, const ButterflyHistory*,
+                                           const CapturePieceToHistory*,
+                                           const PieceToHistory**,
+                                           Square);
+  MovePicker(const Position&, Move, Depth, const ButterflyHistory*,
+                                           const CapturePieceToHistory*,
+                                           const PieceToHistory**,
+                                           Move,
+                                           Move*);
+  Move next_move(bool skipQuiets = false);
 
 private:
+  template<PickType T, typename Pred> Move select(Pred);
   template<GenType> void score();
-  void generate_next_stage();
+  ExtMove* begin() { return cur; }
+  ExtMove* end() { return endMoves; }
 
   const Position& pos;
-  const HistoryStats& history;
-  Search::Stack* ss;
-  Move* countermoves;
-  Move* followupmoves;
-  Depth depth;
+  const ButterflyHistory* mainHistory;
+  const CapturePieceToHistory* captureHistory;
+  const PieceToHistory** continuationHistory;
   Move ttMove;
-  ExtMove killers[6];
-  Square recaptureSquare;
-  Value captureThreshold;
+  ExtMove refutations[3], *cur, *endMoves, *endBadCaptures;
   int stage;
-  ExtMove *cur, *end, *endQuiets, *endBadCaptures;
+  Move move;
+  Square recaptureSquare;
+  Value threshold;
+  Depth depth;
   ExtMove moves[MAX_MOVES];
 };
 

src/pawns.cpp

@@ -2,6 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -21,7 +22,6 @@
 #include <cassert>
 
 #include "bitboard.h"
-#include "bitcount.h"
 #include "pawns.h"
 #include "position.h"
 #include "thread.h"
@@ -31,65 +31,32 @@ namespace {
   #define V Value
   #define S(mg, eg) make_score(mg, eg)
 
-  // Doubled pawn penalty by file
-  const Score Doubled[FILE_NB] = {
-    S(13, 43), S(20, 48), S(23, 48), S(23, 48),
-    S(23, 48), S(23, 48), S(20, 48), S(13, 43) };
+  // Pawn penalties
+  constexpr Score Backward = S( 9, 24);
+  constexpr Score Doubled  = S(11, 56);
+  constexpr Score Isolated = S( 5, 15);
 
-  // Isolated pawn penalty by opposed flag and file
-  const Score Isolated[2][FILE_NB] = {
-  { S(37, 45), S(54, 52), S(60, 52), S(60, 52),
-    S(60, 52), S(60, 52), S(54, 52), S(37, 45) },
-  { S(25, 30), S(36, 35), S(40, 35), S(40, 35),
-    S(40, 35), S(40, 35), S(36, 35), S(25, 30) } };
+  // Connected pawn bonus by opposed, phalanx, #support and rank
+  Score Connected[2][2][3][RANK_NB];
 
-  // Backward pawn penalty by opposed flag and file
-  const Score Backward[2][FILE_NB] = {
-  { S(30, 42), S(43, 46), S(49, 46), S(49, 46),
-    S(49, 46), S(49, 46), S(43, 46), S(30, 42) },
-  { S(20, 28), S(29, 31), S(33, 31), S(33, 31),
-    S(33, 31), S(33, 31), S(29, 31), S(20, 28) } };
+  // 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( -6), V( 81), V( 93), V( 58), V( 39), V( 18), V(  25) },
+    { V(-43), V( 61), V( 35), V(-49), V(-29), V(-11), V( -63) },
+    { V(-10), V( 75), V( 23), V( -2), V( 32), V(  3), V( -45) },
+    { V(-39), V(-13), V(-29), V(-52), V(-48), V(-67), V(-166) }
+  };
 
-  // Connected pawn bonus by opposed, phalanx flags and rank
-  Score Connected[2][2][RANK_NB];
-
-  // Levers bonus by rank
-  const Score Lever[RANK_NB] = {
-    S( 0, 0), S( 0, 0), S(0, 0), S(0, 0),
-    S(20,20), S(40,40), S(0, 0), S(0, 0) };
-
-  // Unsupported pawn penalty
-  const Score UnsupportedPawnPenalty = S(20, 10);
-
-  // Weakness of our pawn shelter in front of the king by [distance from edge][rank]
-  const Value ShelterWeakness[][RANK_NB] = {
-  { V(100), V(13), V(24), V(64), V(89), V( 93), V(104) },
-  { V(110), V( 1), V(29), V(75), V(96), V(102), V(107) },
-  { V(102), V( 0), V(39), V(74), V(88), V(101), V( 98) },
-  { V( 88), V( 4), V(33), V(67), V(92), V( 94), V(107) } };
-
-  // Danger of enemy pawns moving toward our king by [type][distance from edge][rank]
-  const Value StormDanger[][4][RANK_NB] = {
-  { { V( 0),  V(  63), V( 128), V(43), V(27) },
-    { V( 0),  V(  62), V( 131), V(44), V(26) },
-    { V( 0),  V(  59), V( 121), V(50), V(28) },
-    { V( 0),  V(  62), V( 127), V(54), V(28) } },
-  { { V(24),  V(  40), V(  93), V(42), V(22) },
-    { V(24),  V(  28), V( 101), V(38), V(20) },
-    { V(24),  V(  32), V(  95), V(36), V(23) },
-    { V(27),  V(  24), V(  99), V(36), V(24) } },
-  { { V( 0),  V(   0), V(  81), V(16), V( 6) },
-    { V( 0),  V(   0), V( 165), V(29), V( 9) },
-    { V( 0),  V(   0), V( 163), V(23), V(12) },
-    { V( 0),  V(   0), V( 161), V(28), V(13) } },
-  { { V( 0),  V(-296), V(-299), V(55), V(25) },
-    { V( 0),  V(  67), V( 131), V(46), V(21) },
-    { V( 0),  V(  65), V( 135), V(50), V(31) },
-    { V( 0),  V(  62), V( 128), V(51), V(24) } } };
-
-  // Max bonus for king safety. Corresponds to start position with all the pawns
-  // in front of the king and no enemy pawn on the horizon.
-  const Value MaxSafetyBonus = V(257);
+  // Danger of enemy pawns moving toward our king by [distance from edge][rank].
+  // RANK_1 = 0 is used for files where the enemy has no pawn, or their pawn
+  // is behind our king.
+  constexpr Value UnblockedStorm[int(FILE_NB) / 2][RANK_NB] = {
+    { V( 89), V(107), V(123), V(93), V(57), V( 45), V( 51) },
+    { V( 44), V(-18), V(123), V(46), V(39), V( -7), V( 23) },
+    { V(  4), V( 52), V(162), V(37), V( 7), V(-14), V( -2) },
+    { V(-10), V(-14), V( 90), V(15), V( 2), V( -7), V(-16) }
+  };
 
   #undef S
   #undef V
@@ -97,26 +64,24 @@ namespace {
   template<Color Us>
   Score evaluate(const Position& pos, Pawns::Entry* e) {
 
-    const Color  Them  = (Us == WHITE ? BLACK    : WHITE);
-    const Square Up    = (Us == WHITE ? DELTA_N  : DELTA_S);
-    const Square Right = (Us == WHITE ? DELTA_NE : DELTA_SW);
-    const Square Left  = (Us == WHITE ? DELTA_NW : DELTA_SE);
+    constexpr Color     Them = (Us == WHITE ? BLACK : WHITE);
+    constexpr Direction Up   = (Us == WHITE ? NORTH : SOUTH);
 
-    Bitboard b, p, doubled, connected;
+    Bitboard b, neighbours, stoppers, doubled, supported, phalanx;
+    Bitboard lever, leverPush;
     Square s;
-    bool passed, isolated, opposed, phalanx, backward, unsupported, lever;
+    bool opposed, backward;
     Score score = SCORE_ZERO;
-    const Square* pl = pos.list<PAWN>(Us);
-    const Bitboard* pawnAttacksBB = StepAttacksBB[make_piece(Us, PAWN)];
+    const Square* pl = pos.squares<PAWN>(Us);
 
-    Bitboard ourPawns   = pos.pieces(Us  , PAWN);
+    Bitboard ourPawns   = pos.pieces(  Us, PAWN);
     Bitboard theirPawns = pos.pieces(Them, PAWN);
 
-    e->passedPawns[Us] = 0;
-    e->kingSquares[Us] = SQ_NONE;
+    e->passedPawns[Us] = e->pawnAttacksSpan[Us] = e->weakUnopposed[Us] = 0;
     e->semiopenFiles[Us] = 0xFF;
-    e->pawnAttacks[Us] = shift_bb<Right>(ourPawns) | shift_bb<Left>(ourPawns);
-    e->pawnsOnSquares[Us][BLACK] = popcount<Max15>(ourPawns & DarkSquares);
+    e->kingSquares[Us]   = SQ_NONE;
+    e->pawnAttacks[Us]   = pawn_attacks_bb<Us>(ourPawns);
+    e->pawnsOnSquares[Us][BLACK] = popcount(ourPawns & DarkSquares);
     e->pawnsOnSquares[Us][WHITE] = pos.count<PAWN>(Us) - e->pawnsOnSquares[Us][BLACK];
 
     // Loop through all pawns of the current color and score each pawn
@@ -126,76 +91,56 @@ namespace {
 
         File f = file_of(s);
 
-        // This file cannot be semi-open
-        e->semiopenFiles[Us] &= ~(1 << f);
+        e->semiopenFiles[Us]   &= ~(1 << f);
+        e->pawnAttacksSpan[Us] |= pawn_attack_span(Us, s);
 
-        // Previous rank
-        p = rank_bb(s - pawn_push(Us));
+        // Flag the pawn
+        opposed    = theirPawns & forward_file_bb(Us, s);
+        stoppers   = theirPawns & passed_pawn_mask(Us, s);
+        lever      = theirPawns & PawnAttacks[Us][s];
+        leverPush  = theirPawns & PawnAttacks[Us][s + Up];
+        doubled    = ourPawns   & (s - Up);
+        neighbours = ourPawns   & adjacent_files_bb(f);
+        phalanx    = neighbours & rank_bb(s);
+        supported  = neighbours & rank_bb(s - Up);
 
-        // Flag the pawn as passed, isolated, doubled,
-        // unsupported or connected (but not the backward one).
-        connected   =   ourPawns   & adjacent_files_bb(f) & (rank_bb(s) | p);
-        phalanx     =   connected  & rank_bb(s);
-        unsupported = !(ourPawns   & adjacent_files_bb(f) & p);
-        isolated    = !(ourPawns   & adjacent_files_bb(f));
-        doubled     =   ourPawns   & forward_bb(Us, s);
-        opposed     =   theirPawns & forward_bb(Us, s);
-        passed      = !(theirPawns & passed_pawn_mask(Us, s));
-        lever       =   theirPawns & pawnAttacksBB[s];
-
-        // Test for backward pawn.
-        // If the pawn is passed, isolated, or connected it cannot be
-        // backward. If there are friendly pawns behind on adjacent files
-        // or if it can capture an enemy pawn it cannot be backward either.
-        if (   (passed | isolated | connected)
-            || (ourPawns & pawn_attack_span(Them, s))
-            || (pos.attacks_from<PAWN>(s, Us) & theirPawns))
-            backward = false;
-        else
-        {
-            // We now know that there are no friendly pawns beside or behind this
-            // pawn on adjacent files. We now check whether the pawn is
-            // backward by looking in the forward direction on the adjacent
-            // files, and picking the closest pawn there.
-            b = pawn_attack_span(Us, s) & (ourPawns | theirPawns);
-            b = pawn_attack_span(Us, s) & rank_bb(backmost_sq(Us, b));
-
-            // If we have an enemy pawn in the same or next rank, the pawn is
-            // backward because it cannot advance without being captured.
-            backward = (b | shift_bb<Up>(b)) & theirPawns;
-        }
-
-        assert(opposed | passed | (pawn_attack_span(Us, s) & theirPawns));
+        // A pawn is backward when it is behind all pawns of the same color
+        // on the adjacent files and cannot be safely advanced.
+        backward =  !(ourPawns & pawn_attack_span(Them, s + Up))
+                  && (stoppers & (leverPush | (s + Up)));
 
         // Passed pawns will be properly scored in evaluation because we need
-        // full attack info to evaluate passed pawns. Only the frontmost passed
-        // pawn on each file is considered a true passed pawn.
-        if (passed && !doubled)
+        // full attack info to evaluate them. Include also not passed pawns
+        // which could become passed after one or two pawn pushes when are
+        // not attacked more times than defended.
+        if (   !(stoppers ^ lever ^ leverPush)
+            && popcount(supported) >= popcount(lever) - 1
+            && popcount(phalanx)   >= popcount(leverPush))
             e->passedPawns[Us] |= s;
 
+        else if (   stoppers == SquareBB[s + Up]
+                 && relative_rank(Us, s) >= RANK_5)
+        {
+            b = shift<Up>(supported) & ~theirPawns;
+            while (b)
+                if (!more_than_one(theirPawns & PawnAttacks[Us][pop_lsb(&b)]))
+                    e->passedPawns[Us] |= s;
+        }
+
         // Score this pawn
-        if (isolated)
-            score -= Isolated[opposed][f];
+        if (supported | phalanx)
+            score += Connected[opposed][bool(phalanx)][popcount(supported)][relative_rank(Us, s)];
 
-        if (unsupported && !isolated)
-            score -= UnsupportedPawnPenalty;
+        else if (!neighbours)
+            score -= Isolated, e->weakUnopposed[Us] += !opposed;
 
-        if (doubled)
-            score -= Doubled[f] / distance<Rank>(s, frontmost_sq(Us, doubled));
+        else if (backward)
+            score -= Backward, e->weakUnopposed[Us] += !opposed;
 
-        if (backward)
-            score -= Backward[opposed][f];
-
-        if (connected)
-            score += Connected[opposed][phalanx][relative_rank(Us, s)];
-
-        if (lever)
-            score += Lever[relative_rank(Us, s)];
+        if (doubled && !supported)
+            score -= Doubled;
     }
 
-    b = e->semiopenFiles[Us] ^ 0xFF;
-    e->pawnSpan[Us] = b ? int(msb(b) - lsb(b)) : 0;
-
     return score;
   }
 
@@ -207,17 +152,20 @@ namespace Pawns {
 /// hard-coded tables, when makes sense, we prefer to calculate them with a formula
 /// to reduce independent parameters and to allow easier tuning and better insight.
 
-void init()
-{
-  static const int Seed[RANK_NB] = { 0, 6, 15, 10, 57, 75, 135, 258 };
+void init() {
+
+  static constexpr int Seed[RANK_NB] = { 0, 13, 24, 18, 65, 100, 175, 330 };
 
   for (int opposed = 0; opposed <= 1; ++opposed)
       for (int phalanx = 0; phalanx <= 1; ++phalanx)
-          for (Rank r = RANK_2; r < RANK_8; ++r)
-          {
-              int bonus = Seed[r] + (phalanx ? (Seed[r + 1] - Seed[r]) / 2 : 0);
-              Connected[opposed][phalanx][r] = make_score(bonus / 2, bonus >> opposed);
-          }
+          for (int support = 0; support <= 2; ++support)
+              for (Rank r = RANK_2; r < RANK_8; ++r)
+  {
+      int v = 17 * support;
+      v += (Seed[r] + (phalanx ? (Seed[r + 1] - Seed[r]) / 2 : 0)) >> opposed;
+
+      Connected[opposed][phalanx][support][r] = make_score(v, v * (r - 2) / 4);
+  }
 }
 
 
@@ -235,41 +183,46 @@ Entry* probe(const Position& pos) {
       return e;
 
   e->key = key;
-  e->score = evaluate<WHITE>(pos, e) - evaluate<BLACK>(pos, e);
+  e->scores[WHITE] = evaluate<WHITE>(pos, e);
+  e->scores[BLACK] = evaluate<BLACK>(pos, e);
+  e->openFiles = popcount(e->semiopenFiles[WHITE] & e->semiopenFiles[BLACK]);
+  e->asymmetry = popcount(  (e->passedPawns[WHITE]   | e->passedPawns[BLACK])
+                          | (e->semiopenFiles[WHITE] ^ e->semiopenFiles[BLACK]));
+
   return e;
 }
 
 
-/// Entry::shelter_storm() calculates shelter and storm penalties for the file
-/// the king is on, as well as the two adjacent files.
+/// Entry::evaluate_shelter() calculates the shelter bonus and the storm
+/// penalty for a king, looking at the king file and the two closest files.
 
 template<Color Us>
-Value Entry::shelter_storm(const Position& pos, Square ksq) {
+Value Entry::evaluate_shelter(const Position& pos, Square ksq) {
 
-  const Color Them = (Us == WHITE ? BLACK : WHITE);
+  constexpr Color     Them = (Us == WHITE ? BLACK : WHITE);
+  constexpr Direction Down = (Us == WHITE ? SOUTH : NORTH);
+  constexpr Bitboard  BlockRanks = (Us == WHITE ? Rank1BB | Rank2BB : Rank8BB | Rank7BB);
 
-  enum { NoFriendlyPawn, Unblocked, BlockedByPawn, BlockedByKing };
-
-  Bitboard b = pos.pieces(PAWN) & (in_front_bb(Us, rank_of(ksq)) | rank_bb(ksq));
+  Bitboard b = pos.pieces(PAWN) & ~forward_ranks_bb(Them, ksq);
   Bitboard ourPawns = b & pos.pieces(Us);
   Bitboard theirPawns = b & pos.pieces(Them);
-  Value safety = MaxSafetyBonus;
-  File center = std::max(FILE_B, std::min(FILE_G, file_of(ksq)));
 
-  for (File f = center - File(1); f <= center + File(1); ++f)
+  Value safety = (shift<Down>(theirPawns) & (FileABB | FileHBB) & BlockRanks & ksq) ?
+                 Value(374) : Value(5);
+
+  File center = std::max(FILE_B, std::min(FILE_G, file_of(ksq)));
+  for (File f = File(center - 1); f <= File(center + 1); ++f)
   {
       b = ourPawns & file_bb(f);
-      Rank rkUs = b ? relative_rank(Us, backmost_sq(Us, b)) : RANK_1;
+      int ourRank = b ? relative_rank(Us, backmost_sq(Us, b)) : 0;
 
-      b  = theirPawns & file_bb(f);
-      Rank rkThem = b ? relative_rank(Us, frontmost_sq(Them, b)) : RANK_1;
+      b = theirPawns & file_bb(f);
+      int theirRank = b ? relative_rank(Us, frontmost_sq(Them, b)) : 0;
 
-      safety -=  ShelterWeakness[std::min(f, FILE_H - f)][rkUs]
-               + StormDanger
-                 [f == file_of(ksq) && rkThem == relative_rank(Us, ksq) + 1 ? BlockedByKing  :
-                  rkUs   == RANK_1                                          ? NoFriendlyPawn :
-                  rkThem == rkUs + 1                                        ? BlockedByPawn  : Unblocked]
-                 [std::min(f, FILE_H - f)][rkThem];
+      int d = std::min(f, ~f);
+      safety += ShelterStrength[d][ourRank];
+      safety -= (ourRank && (ourRank == theirRank - 1)) ? 66 * (theirRank == RANK_3)
+                                                        : UnblockedStorm[d][theirRank];
   }
 
   return safety;
@@ -280,33 +233,31 @@ Value Entry::shelter_storm(const Position& pos, Square ksq) {
 /// when king square changes, which is about 20% of total king_safety() calls.
 
 template<Color Us>
-Score Entry::do_king_safety(const Position& pos, Square ksq) {
+Score Entry::do_king_safety(const Position& pos) {
 
+  Square ksq = pos.square<KING>(Us);
   kingSquares[Us] = ksq;
   castlingRights[Us] = pos.can_castle(Us);
-  minKingPawnDistance[Us] = 0;
+  int minKingPawnDistance = 0;
 
   Bitboard pawns = pos.pieces(Us, PAWN);
   if (pawns)
-      while (!(DistanceRingBB[ksq][minKingPawnDistance[Us]++] & pawns)) {}
+      while (!(DistanceRingBB[ksq][++minKingPawnDistance] & pawns)) {}
 
-  if (relative_rank(Us, ksq) > RANK_4)
-      return make_score(0, -16 * minKingPawnDistance[Us]);
-
-  Value bonus = shelter_storm<Us>(pos, ksq);
+  Value bonus = evaluate_shelter<Us>(pos, ksq);
 
   // If we can castle use the bonus after the castling if it is bigger
-  if (pos.can_castle(MakeCastling<Us, KING_SIDE>::right))
-      bonus = std::max(bonus, shelter_storm<Us>(pos, relative_square(Us, SQ_G1)));
+  if (pos.can_castle(Us | KING_SIDE))
+      bonus = std::max(bonus, evaluate_shelter<Us>(pos, relative_square(Us, SQ_G1)));
 
-  if (pos.can_castle(MakeCastling<Us, QUEEN_SIDE>::right))
-      bonus = std::max(bonus, shelter_storm<Us>(pos, relative_square(Us, SQ_C1)));
+  if (pos.can_castle(Us | QUEEN_SIDE))
+      bonus = std::max(bonus, evaluate_shelter<Us>(pos, relative_square(Us, SQ_C1)));
 
-  return make_score(bonus, -16 * minKingPawnDistance[Us]);
+  return make_score(bonus, -16 * minKingPawnDistance);
 }
 
 // Explicit template instantiation
-template Score Entry::do_king_safety<WHITE>(const Position& pos, Square ksq);
-template Score Entry::do_king_safety<BLACK>(const Position& pos, Square ksq);
+template Score Entry::do_king_safety<WHITE>(const Position& pos);
+template Score Entry::do_king_safety<BLACK>(const Position& pos);
 
 } // namespace Pawns

src/pawns.h

@@ -2,6 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -32,46 +33,47 @@ namespace Pawns {
 
 struct Entry {
 
-  Score pawns_score() const { return score; }
+  Score pawn_score(Color c) const { return scores[c]; }
   Bitboard pawn_attacks(Color c) const { return pawnAttacks[c]; }
   Bitboard passed_pawns(Color c) const { return passedPawns[c]; }
-  int pawn_span(Color c) const { return pawnSpan[c]; }
+  Bitboard pawn_attacks_span(Color c) const { return pawnAttacksSpan[c]; }
+  int weak_unopposed(Color c) const { return weakUnopposed[c]; }
+  int pawn_asymmetry() const { return asymmetry; }
+  int open_files() const { return openFiles; }
 
   int semiopen_file(Color c, File f) const {
     return semiopenFiles[c] & (1 << f);
   }
 
-  int semiopen_side(Color c, File f, bool leftSide) const {
-    return semiopenFiles[c] & (leftSide ? (1 << f) - 1 : ~((1 << (f + 1)) - 1));
-  }
-
   int pawns_on_same_color_squares(Color c, Square s) const {
-    return pawnsOnSquares[c][!!(DarkSquares & s)];
+    return pawnsOnSquares[c][bool(DarkSquares & s)];
   }
 
   template<Color Us>
-  Score king_safety(const Position& pos, Square ksq)  {
-    return  kingSquares[Us] == ksq && castlingRights[Us] == pos.can_castle(Us)
-          ? kingSafety[Us] : (kingSafety[Us] = do_king_safety<Us>(pos, ksq));
+  Score king_safety(const Position& pos) {
+    return  kingSquares[Us] == pos.square<KING>(Us) && castlingRights[Us] == pos.can_castle(Us)
+          ? kingSafety[Us] : (kingSafety[Us] = do_king_safety<Us>(pos));
   }
 
   template<Color Us>
-  Score do_king_safety(const Position& pos, Square ksq);
+  Score do_king_safety(const Position& pos);
 
   template<Color Us>
-  Value shelter_storm(const Position& pos, Square ksq);
+  Value evaluate_shelter(const Position& pos, Square ksq);
 
   Key key;
-  Score score;
+  Score scores[COLOR_NB];
   Bitboard passedPawns[COLOR_NB];
   Bitboard pawnAttacks[COLOR_NB];
+  Bitboard pawnAttacksSpan[COLOR_NB];
   Square kingSquares[COLOR_NB];
   Score kingSafety[COLOR_NB];
-  int minKingPawnDistance[COLOR_NB];
+  int weakUnopposed[COLOR_NB];
   int castlingRights[COLOR_NB];
   int semiopenFiles[COLOR_NB];
-  int pawnSpan[COLOR_NB];
   int pawnsOnSquares[COLOR_NB][COLOR_NB]; // [color][light/dark squares]
+  int asymmetry;
+  int openFiles;
 };
 
 typedef HashTable<Entry, 16384> Table;

src/platform.h

@@ -1,116 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
-
-  Stockfish is free software: you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation, either version 3 of the License, or
-  (at your option) any later version.
-
-  Stockfish is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-#ifndef PLATFORM_H_INCLUDED
-#define PLATFORM_H_INCLUDED
-
-#ifdef _MSC_VER
-
-// Disable some silly and noisy warnings from MSVC compiler
-#pragma warning(disable: 4127) // Conditional expression is constant
-#pragma warning(disable: 4146) // Unary minus operator applied to unsigned type
-#pragma warning(disable: 4800) // Forcing value to bool 'true' or 'false'
-#pragma warning(disable: 4996) // Function _ftime() may be unsafe
-
-// MSVC does not support <inttypes.h>
-typedef   signed __int8    int8_t;
-typedef unsigned __int8   uint8_t;
-typedef   signed __int16  int16_t;
-typedef unsigned __int16 uint16_t;
-typedef   signed __int32  int32_t;
-typedef unsigned __int32 uint32_t;
-typedef   signed __int64  int64_t;
-typedef unsigned __int64 uint64_t;
-
-#else
-#  include <inttypes.h>
-#endif
-
-#ifndef _WIN32 // Linux - Unix
-
-#  include <sys/time.h>
-
-inline int64_t system_time_to_msec() {
-  timeval t;
-  gettimeofday(&t, NULL);
-  return t.tv_sec * 1000LL + t.tv_usec / 1000;
-}
-
-#  include <pthread.h>
-typedef pthread_mutex_t Lock;
-typedef pthread_cond_t WaitCondition;
-typedef pthread_t NativeHandle;
-typedef void*(*pt_start_fn)(void*);
-
-#  define lock_init(x) pthread_mutex_init(&(x), NULL)
-#  define lock_grab(x) pthread_mutex_lock(&(x))
-#  define lock_release(x) pthread_mutex_unlock(&(x))
-#  define lock_destroy(x) pthread_mutex_destroy(&(x))
-#  define cond_destroy(x) pthread_cond_destroy(&(x))
-#  define cond_init(x) pthread_cond_init(&(x), NULL)
-#  define cond_signal(x) pthread_cond_signal(&(x))
-#  define cond_wait(x,y) pthread_cond_wait(&(x),&(y))
-#  define cond_timedwait(x,y,z) pthread_cond_timedwait(&(x),&(y),z)
-#  define thread_create(x,f,t) pthread_create(&(x),NULL,(pt_start_fn)f,t)
-#  define thread_join(x) pthread_join(x, NULL)
-
-#else // Windows and MinGW
-
-#  include <sys/timeb.h>
-
-inline int64_t system_time_to_msec() {
-  _timeb t;
-  _ftime(&t);
-  return t.time * 1000LL + t.millitm;
-}
-
-#ifndef NOMINMAX
-#  define NOMINMAX // disable macros min() and max()
-#endif
-
-#define WIN32_LEAN_AND_MEAN
-#include <windows.h>
-#undef WIN32_LEAN_AND_MEAN
-#undef NOMINMAX
-
-// We use critical sections on Windows to support Windows XP and older versions.
-// Unfortunately, cond_wait() is racy between lock_release() and WaitForSingleObject()
-// but apart from this they have the same speed performance of SRW locks.
-typedef CRITICAL_SECTION Lock;
-typedef HANDLE WaitCondition;
-typedef HANDLE NativeHandle;
-
-// On Windows 95 and 98 parameter lpThreadId may not be null
-inline DWORD* dwWin9xKludge() { static DWORD dw; return &dw; }
-
-#  define lock_init(x) InitializeCriticalSection(&(x))
-#  define lock_grab(x) EnterCriticalSection(&(x))
-#  define lock_release(x) LeaveCriticalSection(&(x))
-#  define lock_destroy(x) DeleteCriticalSection(&(x))
-#  define cond_init(x) { x = CreateEvent(0, FALSE, FALSE, 0); }
-#  define cond_destroy(x) CloseHandle(x)
-#  define cond_signal(x) SetEvent(x)
-#  define cond_wait(x,y) { lock_release(y); WaitForSingleObject(x, INFINITE); lock_grab(y); }
-#  define cond_timedwait(x,y,z) { lock_release(y); WaitForSingleObject(x,z); lock_grab(y); }
-#  define thread_create(x,f,t) (x = CreateThread(NULL,0,(LPTHREAD_START_ROUTINE)f,t,0,dwWin9xKludge()))
-#  define thread_join(x) { WaitForSingleObject(x, INFINITE); CloseHandle(x); }
-
-#endif
-
-#endif // #ifndef PLATFORM_H_INCLUDED

src/position.h

@@ -2,6 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -21,28 +22,13 @@
 #define POSITION_H_INCLUDED
 
 #include <cassert>
-#include <cstddef>  // For offsetof()
+#include <deque>
+#include <memory> // For std::unique_ptr
 #include <string>
 
 #include "bitboard.h"
 #include "types.h"
 
-class Position;
-struct Thread;
-
-/// CheckInfo struct is initialized at c'tor time and keeps info used to detect
-/// if a move gives check.
-
-struct CheckInfo {
-
-  explicit CheckInfo(const Position&);
-
-  Bitboard dcCandidates;
-  Bitboard pinned;
-  Bitboard checkSq[PIECE_TYPE_NB];
-  Square   ksq;
-};
-
 
 /// StateInfo struct stores information needed to restore a Position object to
 /// its previous state when we retract a move. Whenever a move is made on the
@@ -57,43 +43,42 @@ struct StateInfo {
   int    castlingRights;
   int    rule50;
   int    pliesFromNull;
-  Score  psq;
   Square epSquare;
 
-  // Not copied when making a move
+  // Not copied when making a move (will be recomputed anyhow)
   Key        key;
   Bitboard   checkersBB;
-  PieceType  capturedType;
+  Piece      capturedPiece;
   StateInfo* previous;
+  Bitboard   blockersForKing[COLOR_NB];
+  Bitboard   pinners[COLOR_NB];
+  Bitboard   checkSquares[PIECE_TYPE_NB];
 };
 
-
-/// When making a move the current StateInfo up to 'key' excluded is copied to
-/// the new one. Here we calculate the quad words (64 bit) needed to be copied.
-const size_t StateCopySize64 = offsetof(StateInfo, key) / sizeof(uint64_t) + 1;
+/// A list to keep track of the position states along the setup moves (from the
+/// start position to the position just before the search starts). Needed by
+/// 'draw by repetition' detection. Use a std::deque because pointers to
+/// elements are not invalidated upon list resizing.
+typedef std::unique_ptr<std::deque<StateInfo>> StateListPtr;
 
 
 /// Position class stores information regarding the board representation as
 /// pieces, side to move, hash keys, castling info, etc. Important methods are
 /// do_move() and undo_move(), used by the search to update node info when
 /// traversing the search tree.
+class Thread;
 
 class Position {
-
-  friend std::ostream& operator<<(std::ostream&, const Position&);
-
-  Position(const Position&); // Disable the default copy constructor
-
 public:
   static void init();
 
-  Position() {} // To define the global object RootPos
-  Position(const Position& pos, Thread* th) { *this = pos; thisThread = th; }
-  Position(const std::string& f, bool c960, Thread* th) { set(f, c960, th); }
-  Position& operator=(const Position&); // To assign RootPos from UCI
+  Position() = default;
+  Position(const Position&) = delete;
+  Position& operator=(const Position&) = delete;
 
   // FEN string input/output
-  void set(const std::string& fenStr, bool isChess960, Thread* th);
+  Position& set(const std::string& fenStr, bool isChess960, StateInfo* si, Thread* th);
+  Position& set(const std::string& code, Color c, StateInfo* si);
   const std::string fen() const;
 
   // Position representation
@@ -104,11 +89,12 @@ public:
   Bitboard pieces(Color c, PieceType pt) const;
   Bitboard pieces(Color c, PieceType pt1, PieceType pt2) const;
   Piece piece_on(Square s) const;
-  Square king_square(Color c) const;
   Square ep_square() const;
   bool empty(Square s) const;
   template<PieceType Pt> int count(Color c) const;
-  template<PieceType Pt> const Square* list(Color c) const;
+  template<PieceType Pt> int count() const;
+  template<PieceType Pt> const Square* squares(Color c) const;
+  template<PieceType Pt> Square square(Color c) const;
 
   // Castling
   int can_castle(Color c) const;
@@ -118,99 +104,101 @@ public:
 
   // Checking
   Bitboard checkers() const;
-  Bitboard discovered_check_candidates() const;
-  Bitboard pinned_pieces(Color c) const;
+  Bitboard blockers_for_king(Color c) const;
+  Bitboard check_squares(PieceType pt) const;
 
   // Attacks to/from a given square
   Bitboard attackers_to(Square s) const;
   Bitboard attackers_to(Square s, Bitboard occupied) const;
-  Bitboard attacks_from(Piece pc, Square s) const;
+  Bitboard attacks_from(PieceType pt, Square s) const;
   template<PieceType> Bitboard attacks_from(Square s) const;
   template<PieceType> Bitboard attacks_from(Square s, Color c) const;
+  Bitboard slider_blockers(Bitboard sliders, Square s, Bitboard& pinners) const;
 
   // Properties of moves
-  bool legal(Move m, Bitboard pinned) const;
+  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 CheckInfo& ci) const;
+  bool gives_check(Move m) const;
   bool advanced_pawn_push(Move m) const;
   Piece moved_piece(Move m) const;
-  PieceType captured_piece_type() const;
+  Piece captured_piece() const;
 
   // Piece specific
   bool pawn_passed(Color c, Square s) const;
-  bool pawn_on_7th(Color c) const;
   bool opposite_bishops() const;
 
   // Doing and undoing moves
-  void do_move(Move m, StateInfo& st);
-  void do_move(Move m, StateInfo& st, const CheckInfo& ci, bool moveIsCheck);
+  void do_move(Move m, StateInfo& newSt);
+  void do_move(Move m, StateInfo& newSt, bool givesCheck);
   void undo_move(Move m);
-  void do_null_move(StateInfo& st);
+  void do_null_move(StateInfo& newSt);
   void undo_null_move();
 
-  // Static exchange evaluation
-  Value see(Move m) const;
-  Value see_sign(Move m) const;
+  // Static Exchange Evaluation
+  bool see_ge(Move m, Value threshold = VALUE_ZERO) const;
 
   // Accessing hash keys
   Key key() const;
   Key key_after(Move m) const;
-  Key exclusion_key() const;
   Key material_key() const;
   Key pawn_key() const;
 
   // Other properties of the position
   Color side_to_move() const;
-  Phase game_phase() const;
   int game_ply() const;
   bool is_chess960() const;
   Thread* this_thread() const;
-  uint64_t nodes_searched() const;
-  void set_nodes_searched(uint64_t n);
-  bool is_draw() const;
+  bool is_draw(int ply) const;
+  bool has_game_cycle(int ply) const;
+  bool has_repeated() const;
   int rule50_count() const;
   Score psq_score() const;
   Value non_pawn_material(Color c) const;
+  Value non_pawn_material() const;
 
   // Position consistency check, for debugging
-  bool pos_is_ok(int* step = NULL) const;
+  bool pos_is_ok() const;
   void flip();
 
 private:
   // Initialization helpers (used while setting up a position)
-  void clear();
   void set_castling_right(Color c, Square rfrom);
   void set_state(StateInfo* si) const;
+  void set_check_info(StateInfo* si) const;
 
   // Other helpers
-  Bitboard check_blockers(Color c, Color kingColor) const;
-  void put_piece(Square s, Color c, PieceType pt);
-  void remove_piece(Square s, Color c, PieceType pt);
-  void move_piece(Square from, Square to, Color c, PieceType pt);
+  void put_piece(Piece pc, Square s);
+  void remove_piece(Piece pc, Square s);
+  void move_piece(Piece pc, Square from, Square to);
   template<bool Do>
-  void do_castling(Square from, Square& to, Square& rfrom, Square& rto);
+  void do_castling(Color us, Square from, Square& to, Square& rfrom, Square& rto);
 
   // Data members
   Piece board[SQUARE_NB];
   Bitboard byTypeBB[PIECE_TYPE_NB];
   Bitboard byColorBB[COLOR_NB];
-  int pieceCount[COLOR_NB][PIECE_TYPE_NB];
-  Square pieceList[COLOR_NB][PIECE_TYPE_NB][16];
+  int pieceCount[PIECE_NB];
+  Square pieceList[PIECE_NB][16];
   int index[SQUARE_NB];
   int castlingRightsMask[SQUARE_NB];
   Square castlingRookSquare[CASTLING_RIGHT_NB];
   Bitboard castlingPath[CASTLING_RIGHT_NB];
-  StateInfo startState;
-  uint64_t nodes;
   int gamePly;
   Color sideToMove;
+  Score psq;
   Thread* thisThread;
   StateInfo* st;
   bool chess960;
 };
 
+namespace PSQT {
+  extern Score psq[PIECE_NB][SQUARE_NB];
+}
+
+extern std::ostream& operator<<(std::ostream& os, const Position& pos);
+
 inline Color Position::side_to_move() const {
   return sideToMove;
 }
@@ -252,15 +240,20 @@ inline Bitboard Position::pieces(Color c, PieceType pt1, PieceType pt2) const {
 }
 
 template<PieceType Pt> inline int Position::count(Color c) const {
-  return pieceCount[c][Pt];
+  return pieceCount[make_piece(c, Pt)];
 }
 
-template<PieceType Pt> inline const Square* Position::list(Color c) const {
-  return pieceList[c][Pt];
+template<PieceType Pt> inline int Position::count() const {
+  return pieceCount[make_piece(WHITE, Pt)] + pieceCount[make_piece(BLACK, Pt)];
 }
 
-inline Square Position::king_square(Color c) const {
-  return pieceList[c][KING][0];
+template<PieceType Pt> inline const Square* Position::squares(Color c) const {
+  return pieceList[make_piece(c, Pt)];
+}
+
+template<PieceType Pt> inline Square Position::square(Color c) const {
+  assert(pieceCount[make_piece(c, Pt)] == 1);
+  return pieceList[make_piece(c, Pt)][0];
 }
 
 inline Square Position::ep_square() const {
@@ -285,18 +278,19 @@ inline Square Position::castling_rook_square(CastlingRight cr) const {
 
 template<PieceType Pt>
 inline Bitboard Position::attacks_from(Square s) const {
+  assert(Pt != PAWN);
   return  Pt == BISHOP || Pt == ROOK ? attacks_bb<Pt>(s, byTypeBB[ALL_PIECES])
         : Pt == QUEEN  ? attacks_from<ROOK>(s) | attacks_from<BISHOP>(s)
-        : StepAttacksBB[Pt][s];
+        : PseudoAttacks[Pt][s];
 }
 
 template<>
 inline Bitboard Position::attacks_from<PAWN>(Square s, Color c) const {
-  return StepAttacksBB[make_piece(c, PAWN)][s];
+  return PawnAttacks[c][s];
 }
 
-inline Bitboard Position::attacks_from(Piece pc, Square s) const {
-  return attacks_bb(pc, s, byTypeBB[ALL_PIECES]);
+inline Bitboard Position::attacks_from(PieceType pt, Square s) const {
+  return attacks_bb(pt, s, byTypeBB[ALL_PIECES]);
 }
 
 inline Bitboard Position::attackers_to(Square s) const {
@@ -307,12 +301,12 @@ inline Bitboard Position::checkers() const {
   return st->checkersBB;
 }
 
-inline Bitboard Position::discovered_check_candidates() const {
-  return check_blockers(sideToMove, ~sideToMove);
+inline Bitboard Position::blockers_for_king(Color c) const {
+  return st->blockersForKing[c];
 }
 
-inline Bitboard Position::pinned_pieces(Color c) const {
-  return check_blockers(c, c);
+inline Bitboard Position::check_squares(PieceType pt) const {
+  return st->checkSquares[pt];
 }
 
 inline bool Position::pawn_passed(Color c, Square s) const {
@@ -337,13 +331,17 @@ inline Key Position::material_key() const {
 }
 
 inline Score Position::psq_score() const {
-  return st->psq;
+  return psq;
 }
 
 inline Value Position::non_pawn_material(Color c) const {
   return st->nonPawnMaterial[c];
 }
 
+inline Value Position::non_pawn_material() const {
+  return st->nonPawnMaterial[WHITE] + st->nonPawnMaterial[BLACK];
+}
+
 inline int Position::game_ply() const {
   return gamePly;
 }
@@ -352,22 +350,10 @@ inline int Position::rule50_count() const {
   return st->rule50;
 }
 
-inline uint64_t Position::nodes_searched() const {
-  return nodes;
-}
-
-inline void Position::set_nodes_searched(uint64_t n) {
-  nodes = n;
-}
-
 inline bool Position::opposite_bishops() const {
-  return   pieceCount[WHITE][BISHOP] == 1
-        && pieceCount[BLACK][BISHOP] == 1
-        && opposite_colors(pieceList[WHITE][BISHOP][0], pieceList[BLACK][BISHOP][0]);
-}
-
-inline bool Position::pawn_on_7th(Color c) const {
-  return pieces(c, PAWN) & rank_bb(relative_rank(c, RANK_7));
+  return   pieceCount[W_BISHOP] == 1
+        && pieceCount[B_BISHOP] == 1
+        && opposite_colors(square<BISHOP>(WHITE), square<BISHOP>(BLACK));
 }
 
 inline bool Position::is_chess960() const {
@@ -375,66 +361,71 @@ inline bool Position::is_chess960() const {
 }
 
 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 {
-
-  // Castling is encoded as "king captures the rook"
   assert(is_ok(m));
+  // Castling is encoded as "king captures rook"
   return (!empty(to_sq(m)) && type_of(m) != CASTLING) || type_of(m) == ENPASSANT;
 }
 
-inline PieceType Position::captured_piece_type() const {
-  return st->capturedType;
+inline Piece Position::captured_piece() const {
+  return st->capturedPiece;
 }
 
 inline Thread* Position::this_thread() const {
   return thisThread;
 }
 
-inline void Position::put_piece(Square s, Color c, PieceType pt) {
+inline void Position::put_piece(Piece pc, Square s) {
 
-  board[s] = make_piece(c, pt);
+  board[s] = pc;
   byTypeBB[ALL_PIECES] |= s;
-  byTypeBB[pt] |= s;
-  byColorBB[c] |= s;
-  index[s] = pieceCount[c][pt]++;
-  pieceList[c][pt][index[s]] = s;
-  pieceCount[c][ALL_PIECES]++;
+  byTypeBB[type_of(pc)] |= s;
+  byColorBB[color_of(pc)] |= s;
+  index[s] = pieceCount[pc]++;
+  pieceList[pc][index[s]] = s;
+  pieceCount[make_piece(color_of(pc), ALL_PIECES)]++;
+  psq += PSQT::psq[pc][s];
 }
 
-inline void Position::move_piece(Square from, Square to, Color c, PieceType pt) {
-
-  // index[from] is not updated and becomes stale. This works as long as index[]
-  // is accessed just by known occupied squares.
-  Bitboard from_to_bb = SquareBB[from] ^ SquareBB[to];
-  byTypeBB[ALL_PIECES] ^= from_to_bb;
-  byTypeBB[pt] ^= from_to_bb;
-  byColorBB[c] ^= from_to_bb;
-  board[from] = NO_PIECE;
-  board[to] = make_piece(c, pt);
-  index[to] = index[from];
-  pieceList[c][pt][index[to]] = to;
-}
-
-inline void Position::remove_piece(Square s, Color c, PieceType pt) {
+inline void Position::remove_piece(Piece pc, Square s) {
 
   // WARNING: This is not a reversible operation. If we remove a piece in
   // do_move() and then replace it in undo_move() we will put it at the end of
   // the list and not in its original place, it means index[] and pieceList[]
-  // are not guaranteed to be invariant to a do_move() + undo_move() sequence.
+  // are not invariant to a do_move() + undo_move() sequence.
   byTypeBB[ALL_PIECES] ^= s;
-  byTypeBB[pt] ^= s;
-  byColorBB[c] ^= s;
+  byTypeBB[type_of(pc)] ^= s;
+  byColorBB[color_of(pc)] ^= s;
   /* board[s] = NO_PIECE;  Not needed, overwritten by the capturing one */
-  Square lastSquare = pieceList[c][pt][--pieceCount[c][pt]];
+  Square lastSquare = pieceList[pc][--pieceCount[pc]];
   index[lastSquare] = index[s];
-  pieceList[c][pt][index[lastSquare]] = lastSquare;
-  pieceList[c][pt][pieceCount[c][pt]] = SQ_NONE;
-  pieceCount[c][ALL_PIECES]--;
+  pieceList[pc][index[lastSquare]] = lastSquare;
+  pieceList[pc][pieceCount[pc]] = SQ_NONE;
+  pieceCount[make_piece(color_of(pc), ALL_PIECES)]--;
+  psq -= PSQT::psq[pc][s];
+}
+
+inline void Position::move_piece(Piece pc, Square from, Square to) {
+
+  // index[from] is not updated and becomes stale. This works as long as index[]
+  // is accessed just by known occupied squares.
+  Bitboard fromTo = SquareBB[from] ^ SquareBB[to];
+  byTypeBB[ALL_PIECES] ^= fromTo;
+  byTypeBB[type_of(pc)] ^= fromTo;
+  byColorBB[color_of(pc)] ^= fromTo;
+  board[from] = NO_PIECE;
+  board[to] = pc;
+  index[to] = index[from];
+  pieceList[pc][index[to]] = to;
+  psq += PSQT::psq[pc][to] - PSQT::psq[pc][from];
+}
+
+inline void Position::do_move(Move m, StateInfo& newSt) {
+  do_move(m, newSt, gives_check(m));
 }
 
 #endif // #ifndef POSITION_H_INCLUDED

src/psqt.cpp

@@ -0,0 +1,126 @@
+/*
+  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+  Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
+  Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+
+  Stockfish is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  Stockfish is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <algorithm>
+
+#include "types.h"
+
+Value PieceValue[PHASE_NB][PIECE_NB] = {
+  { VALUE_ZERO, PawnValueMg, KnightValueMg, BishopValueMg, RookValueMg, QueenValueMg },
+  { VALUE_ZERO, PawnValueEg, KnightValueEg, BishopValueEg, RookValueEg, QueenValueEg }
+};
+
+namespace PSQT {
+
+#define S(mg, eg) make_score(mg, eg)
+
+// Bonus[PieceType][Square / 2] contains Piece-Square scores. For each piece
+// type on a given square a (middlegame, endgame) score pair is assigned. Table
+// is defined for files A..D and white side: it is symmetric for black side and
+// second half of the files.
+constexpr Score Bonus[][RANK_NB][int(FILE_NB) / 2] = {
+  { },
+  { // Pawn
+   { S(  0, 0), S(  0,  0), S(  0, 0), S( 0, 0) },
+   { S(-11,-3), S(  7, -1), S(  7, 7), S(17, 2) },
+   { S(-16,-2), S( -3,  2), S( 23, 6), S(23,-1) },
+   { S(-14, 7), S( -7, -4), S( 20,-8), S(24, 2) },
+   { S( -5,13), S( -2, 10), S( -1,-1), S(12,-8) },
+   { S(-11,16), S(-12,  6), S( -2, 1), S( 4,16) },
+   { S( -2, 1), S( 20,-12), S(-10, 6), S(-2,25) }
+  },
+  { // Knight
+   { S(-169,-105), S(-96,-74), S(-80,-46), S(-79,-18) },
+   { S( -79, -70), S(-39,-56), S(-24,-15), S( -9,  6) },
+   { S( -64, -38), S(-20,-33), S(  4, -5), S( 19, 27) },
+   { S( -28, -36), S(  5,  0), S( 41, 13), S( 47, 34) },
+   { S( -29, -41), S( 13,-20), S( 42,  4), S( 52, 35) },
+   { S( -11, -51), S( 28,-38), S( 63,-17), S( 55, 19) },
+   { S( -67, -64), S(-21,-45), S(  6,-37), S( 37, 16) },
+   { S(-200, -98), S(-80,-89), S(-53,-53), S(-32,-16) }
+  },
+  { // Bishop
+   { S(-49,-58), S(- 7,-31), S(-10,-37), S(-34,-19) },
+   { S(-24,-34), S(  9, -9), S( 15,-14), S(  1,  4) },
+   { S( -9,-23), S( 22,  0), S( -3, -3), S( 12, 16) },
+   { S(  4,-26), S(  9, -3), S( 18, -5), S( 40, 16) },
+   { S( -8,-26), S( 27, -4), S( 13, -7), S( 30, 14) },
+   { S(-17,-24), S( 14, -2), S( -6,  0), S(  6, 13) },
+   { S(-19,-34), S(-13,-10), S(  7,-12), S(-11,  6) },
+   { S(-47,-55), S( -7,-32), S(-17,-36), S(-29,-17) }
+  },
+  { // Rook
+   { S(-24, 0), S(-15, 3), S( -8, 0), S( 0, 3) },
+   { S(-18,-7), S( -5,-5), S( -1,-5), S( 1,-1) },
+   { S(-19, 6), S(-10,-7), S(  1, 3), S( 0, 3) },
+   { S(-21, 0), S( -7, 4), S( -4,-2), S(-4, 1) },
+   { S(-21,-7), S(-12, 5), S( -1,-5), S( 4,-7) },
+   { S(-23, 3), S(-10, 2), S(  1,-1), S( 6, 3) },
+   { S(-11,-1), S(  8, 7), S(  9,11), S(12,-1) },
+   { S(-25, 6), S(-18, 4), S(-11, 6), S( 2, 2) }
+  },
+  { // Queen
+   { S(  3,-69), S(-5,-57), S(-5,-47), S( 4,-26) },
+   { S( -3,-55), S( 5,-31), S( 8,-22), S(12, -4) },
+   { S( -3,-39), S( 6,-18), S(13, -9), S( 7,  3) },
+   { S(  4,-23), S( 5, -3), S( 9, 13), S( 8, 24) },
+   { S(  0,-29), S(14, -6), S(12,  9), S( 5, 21) },
+   { S( -4,-38), S(10,-18), S( 6,-12), S( 8,  1) },
+   { S( -5,-50), S( 6,-27), S(10,-24), S( 8, -8) },
+   { S( -2,-75), S(-2,-52), S( 1,-43), S(-2,-36) }
+  },
+  { // King
+   { S(272,  0), S(325, 41), S(273, 80), S(190, 93) },
+   { S(277, 57), S(305, 98), S(241,138), S(183,131) },
+   { S(198, 86), S(253,138), S(168,165), S(120,173) },
+   { S(169,103), S(191,152), S(136,168), S(108,169) },
+   { S(145, 98), S(176,166), S(112,197), S(69, 194) },
+   { S(122, 87), S(159,164), S(85, 174), S(36, 189) },
+   { S(87,  40), S(120, 99), S(64, 128), S(25, 141) },
+   { S(64,   5), S(87,  60), S(49,  75), S(0,   75) }
+  }
+};
+
+#undef S
+
+Score psq[PIECE_NB][SQUARE_NB];
+
+// init() initializes piece-square tables: the white halves of the tables are
+// copied from Bonus[] adding the piece value, then the black halves of the
+// tables are initialized by flipping and changing the sign of the white scores.
+void init() {
+
+  for (Piece pc = W_PAWN; pc <= W_KING; ++pc)
+  {
+      PieceValue[MG][~pc] = PieceValue[MG][pc];
+      PieceValue[EG][~pc] = PieceValue[EG][pc];
+
+      Score score = make_score(PieceValue[MG][pc], PieceValue[EG][pc]);
+
+      for (Square s = SQ_A1; s <= SQ_H8; ++s)
+      {
+          File f = std::min(file_of(s), ~file_of(s));
+          psq[ pc][ s] = score + Bonus[pc][rank_of(s)][f];
+          psq[~pc][~s] = -psq[pc][s];
+      }
+  }
+}
+
+} // namespace PSQT

src/psqtab.h

@@ -1,98 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
-
-  Stockfish is free software: you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation, either version 3 of the License, or
-  (at your option) any later version.
-
-  Stockfish is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-#ifndef PSQTAB_H_INCLUDED
-#define PSQTAB_H_INCLUDED
-
-#include "types.h"
-
-#define S(mg, eg) make_score(mg, eg)
-
-
-/// PSQT[PieceType][Square] contains Piece-Square scores. For each piece type on
-/// a given square a (middlegame, endgame) score pair is assigned. PSQT is defined
-/// for the white side and the tables are symmetric for the black side.
-
-static const Score PSQT[][SQUARE_NB] = {
-  { },
-  { // Pawn
-   S(  0, 0), S( 0, 0), S( 0, 0), S( 0, 0), S(0,  0), S( 0, 0), S( 0, 0), S(  0, 0),
-   S(-20, 0), S( 0, 0), S( 0, 0), S( 0, 0), S(0,  0), S( 0, 0), S( 0, 0), S(-20, 0),
-   S(-20, 0), S( 0, 0), S(10, 0), S(20, 0), S(20, 0), S(10, 0), S( 0, 0), S(-20, 0),
-   S(-20, 0), S( 0, 0), S(20, 0), S(40, 0), S(40, 0), S(20, 0), S( 0, 0), S(-20, 0),
-   S(-20, 0), S( 0, 0), S(10, 0), S(20, 0), S(20, 0), S(10, 0), S( 0, 0), S(-20, 0),
-   S(-20, 0), S( 0, 0), S( 0, 0), S( 0, 0), S(0,  0), S( 0, 0), S( 0, 0), S(-20, 0),
-   S(-20, 0), S( 0, 0), S( 0, 0), S( 0, 0), S(0,  0), S( 0, 0), S( 0, 0), S(-20, 0),
-   S(  0, 0), S( 0, 0), S( 0, 0), S( 0, 0), S(0,  0), S( 0, 0), S( 0, 0), S(  0, 0)
-  },
-  { // Knight
-   S(-144,-98), S(-109,-83), S(-85,-51), S(-73,-16), S(-73,-16), S(-85,-51), S(-109,-83), S(-144,-98),
-   S( -88,-68), S( -43,-53), S(-19,-21), S( -7, 14), S( -7, 14), S(-19,-21), S( -43,-53), S( -88,-68),
-   S( -69,-53), S( -24,-38), S(  0, -6), S( 12, 29), S( 12, 29), S(  0, -6), S( -24,-38), S( -69,-53),
-   S( -28,-42), S(  17,-27), S( 41,  5), S( 53, 40), S( 53, 40), S( 41,  5), S(  17,-27), S( -28,-42),
-   S( -30,-42), S(  15,-27), S( 39,  5), S( 51, 40), S( 51, 40), S( 39,  5), S(  15,-27), S( -30,-42),
-   S( -10,-53), S(  35,-38), S( 59, -6), S( 71, 29), S( 71, 29), S( 59, -6), S(  35,-38), S( -10,-53),
-   S( -64,-68), S( -19,-53), S(  5,-21), S( 17, 14), S( 17, 14), S(  5,-21), S( -19,-53), S( -64,-68),
-   S(-200,-98), S( -65,-83), S(-41,-51), S(-29,-16), S(-29,-16), S(-41,-51), S( -65,-83), S(-200,-98)
-  },
-  { // Bishop
-   S(-54,-65), S(-27,-42), S(-34,-44), S(-43,-26), S(-43,-26), S(-34,-44), S(-27,-42), S(-54,-65),
-   S(-29,-43), S(  8,-20), S(  1,-22), S( -8, -4), S( -8, -4), S(  1,-22), S(  8,-20), S(-29,-43),
-   S(-20,-33), S( 17,-10), S( 10,-12), S(  1,  6), S(  1,  6), S( 10,-12), S( 17,-10), S(-20,-33),
-   S(-19,-35), S( 18,-12), S( 11,-14), S(  2,  4), S(  2,  4), S( 11,-14), S( 18,-12), S(-19,-35),
-   S(-22,-35), S( 15,-12), S(  8,-14), S( -1,  4), S( -1,  4), S(  8,-14), S( 15,-12), S(-22,-35),
-   S(-28,-33), S(  9,-10), S(  2,-12), S( -7,  6), S( -7,  6), S(  2,-12), S(  9,-10), S(-28,-33),
-   S(-32,-43), S(  5,-20), S( -2,-22), S(-11, -4), S(-11, -4), S( -2,-22), S(  5,-20), S(-32,-43),
-   S(-49,-65), S(-22,-42), S(-29,-44), S(-38,-26), S(-38,-26), S(-29,-44), S(-22,-42), S(-49,-65)
-  },
-  { // Rook
-   S(-22, 3), S(-17, 3), S(-12, 3), S(-8, 3), S(-8, 3), S(-12, 3), S(-17, 3), S(-22, 3),
-   S(-22, 3), S( -7, 3), S( -2, 3), S( 2, 3), S( 2, 3), S( -2, 3), S( -7, 3), S(-22, 3),
-   S(-22, 3), S( -7, 3), S( -2, 3), S( 2, 3), S( 2, 3), S( -2, 3), S( -7, 3), S(-22, 3),
-   S(-22, 3), S( -7, 3), S( -2, 3), S( 2, 3), S( 2, 3), S( -2, 3), S( -7, 3), S(-22, 3),
-   S(-22, 3), S( -7, 3), S( -2, 3), S( 2, 3), S( 2, 3), S( -2, 3), S( -7, 3), S(-22, 3),
-   S(-22, 3), S( -7, 3), S( -2, 3), S( 2, 3), S( 2, 3), S( -2, 3), S( -7, 3), S(-22, 3),
-   S(-11, 3), S(  4, 3), S(  9, 3), S(13, 3), S(13, 3), S(  9, 3), S(  4, 3), S(-11, 3),
-   S(-22, 3), S(-17, 3), S(-12, 3), S(-8, 3), S(-8, 3), S(-12, 3), S(-17, 3), S(-22, 3)
-  },
-  { // Queen
-   S(-2,-80), S(-2,-54), S(-2,-42), S(-2,-30), S(-2,-30), S(-2,-42), S(-2,-54), S(-2,-80),
-   S(-2,-54), S( 8,-30), S( 8,-18), S( 8, -6), S( 8, -6), S( 8,-18), S( 8,-30), S(-2,-54),
-   S(-2,-42), S( 8,-18), S( 8, -6), S( 8,  6), S( 8,  6), S( 8, -6), S( 8,-18), S(-2,-42),
-   S(-2,-30), S( 8, -6), S( 8,  6), S( 8, 18), S( 8, 18), S( 8,  6), S( 8, -6), S(-2,-30),
-   S(-2,-30), S( 8, -6), S( 8,  6), S( 8, 18), S( 8, 18), S( 8,  6), S( 8, -6), S(-2,-30),
-   S(-2,-42), S( 8,-18), S( 8, -6), S( 8,  6), S( 8,  6), S( 8, -6), S( 8,-18), S(-2,-42),
-   S(-2,-54), S( 8,-30), S( 8,-18), S( 8, -6), S( 8, -6), S( 8,-18), S( 8,-30), S(-2,-54),
-   S(-2,-80), S(-2,-54), S(-2,-42), S(-2,-30), S(-2,-30), S(-2,-42), S(-2,-54), S(-2,-80)
-  },
-  { // King
-   S(298, 27), S(332, 81), S(273,108), S(225,116), S(225,116), S(273,108), S(332, 81), S(298, 27),
-   S(287, 74), S(321,128), S(262,155), S(214,163), S(214,163), S(262,155), S(321,128), S(287, 74),
-   S(224,111), S(258,165), S(199,192), S(151,200), S(151,200), S(199,192), S(258,165), S(224,111),
-   S(196,135), S(230,189), S(171,216), S(123,224), S(123,224), S(171,216), S(230,189), S(196,135),
-   S(173,135), S(207,189), S(148,216), S(100,224), S(100,224), S(148,216), S(207,189), S(173,135),
-   S(146,111), S(180,165), S(121,192), S( 73,200), S( 73,200), S(121,192), S(180,165), S(146,111),
-   S(119, 74), S(153,128), S( 94,155), S( 46,163), S( 46,163), S( 94,155), S(153,128), S(119, 74),
-   S( 98, 27), S(132, 81), S( 73,108), S( 25,116), S( 25,116), S( 73,108), S(132, 81), S( 98, 27)
-  }
-};
-
-#undef S
-
-#endif // #ifndef PSQTAB_H_INCLUDED

src/search.h

@@ -2,6 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -20,94 +21,87 @@
 #ifndef SEARCH_H_INCLUDED
 #define SEARCH_H_INCLUDED
 
-#include <memory>  // For std::auto_ptr
-#include <stack>
 #include <vector>
 
 #include "misc.h"
-#include "position.h"
+#include "movepick.h"
 #include "types.h"
 
-struct SplitPoint;
+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
 /// its own array of Stack objects, indexed by the current ply.
 
 struct Stack {
-  SplitPoint* splitPoint;
   Move* pv;
+  PieceToHistory* continuationHistory;
   int ply;
   Move currentMove;
-  Move ttMove;
   Move excludedMove;
   Move killers[2];
-  Depth reduction;
   Value staticEval;
-  bool skipEarlyPruning;
+  int statScore;
+  int moveCount;
 };
 
+
 /// RootMove struct is used for moves at the root of the tree. For each root move
 /// we store a score and a PV (really a refutation in the case of moves which
 /// fail low). Score is normally set at -VALUE_INFINITE for all non-pv moves.
 
 struct RootMove {
 
-  RootMove(Move m) : score(-VALUE_INFINITE), previousScore(-VALUE_INFINITE), pv(1, m) {}
-
-  bool operator<(const RootMove& m) const { return score > m.score; } // Ascending sort
+  explicit RootMove(Move m) : pv(1, m) {}
+  bool extract_ponder_from_tt(Position& pos);
   bool operator==(const Move& m) const { return pv[0] == m; }
-  void insert_pv_in_tt(Position& pos);
-  Move extract_ponder_from_tt(Position& pos);
+  bool operator<(const RootMove& m) const { // Sort in descending order
+    return m.score != score ? m.score < score
+                            : m.previousScore < previousScore;
+  }
 
-  Value score;
-  Value previousScore;
+  Value score = -VALUE_INFINITE;
+  Value previousScore = -VALUE_INFINITE;
+  int selDepth = 0;
+  int tbRank;
+  Value tbScore;
   std::vector<Move> pv;
 };
 
-typedef std::vector<RootMove> RootMoveVector;
+typedef std::vector<RootMove> RootMoves;
+
 
 /// LimitsType struct stores information sent by GUI about available time to
-/// search the current move, maximum depth/time, if we are in analysis mode or
-/// if we have to ponder while it's our opponent's turn to move.
+/// search the current move, maximum depth/time, or if we are in analysis mode.
 
 struct LimitsType {
 
   LimitsType() { // Init explicitly due to broken value-initialization of non POD in MSVC
-    nodes = time[WHITE] = time[BLACK] = inc[WHITE] = inc[BLACK] = movestogo =
-    depth = movetime = mate = infinite = ponder = 0;
+    time[WHITE] = time[BLACK] = inc[WHITE] = inc[BLACK] = npmsec = movetime = TimePoint(0);
+    movestogo = depth = mate = perft = infinite = 0;
+    nodes = 0;
   }
 
   bool use_time_management() const {
-    return !(mate | movetime | depth | nodes | infinite);
+    return !(mate | movetime | depth | nodes | perft | infinite);
   }
 
   std::vector<Move> searchmoves;
-  int time[COLOR_NB], inc[COLOR_NB], movestogo, depth, movetime, mate, infinite, ponder;
+  TimePoint time[COLOR_NB], inc[COLOR_NB], npmsec, movetime, startTime;
+  int movestogo, depth, mate, perft, infinite;
   int64_t nodes;
 };
 
-/// The SignalsType struct stores volatile flags updated during the search
-/// typically in an async fashion e.g. to stop the search by the GUI.
-
-struct SignalsType {
-  bool stop, stopOnPonderhit, firstRootMove, failedLowAtRoot;
-};
-
-typedef std::auto_ptr<std::stack<StateInfo> > StateStackPtr;
-
-extern volatile SignalsType Signals;
 extern LimitsType Limits;
-extern RootMoveVector RootMoves;
-extern Position RootPos;
-extern Time::point SearchTime;
-extern StateStackPtr SetupStates;
 
 void init();
-void think();
-template<bool Root> uint64_t perft(Position& pos, Depth depth);
+void clear();
 
 } // namespace Search
 

src/syzygy/tbcore.h

@@ -1,169 +0,0 @@
-/*
-  Copyright (c) 2011-2013 Ronald de Man
-*/
-
-#ifndef TBCORE_H
-#define TBCORE_H
-
-#ifndef _WIN32
-#include <pthread.h>
-#define SEP_CHAR ':'
-#define FD int
-#define FD_ERR -1
-#else
-#include <windows.h>
-#define SEP_CHAR ';'
-#define FD HANDLE
-#define FD_ERR INVALID_HANDLE_VALUE
-#endif
-
-#ifndef _WIN32
-#define LOCK_T pthread_mutex_t
-#define LOCK_INIT(x) pthread_mutex_init(&(x), NULL)
-#define LOCK(x) pthread_mutex_lock(&(x))
-#define UNLOCK(x) pthread_mutex_unlock(&(x))
-#else
-#define LOCK_T HANDLE
-#define LOCK_INIT(x) do { x = CreateMutex(NULL, FALSE, NULL); } while (0)
-#define LOCK(x) WaitForSingleObject(x, INFINITE)
-#define UNLOCK(x) ReleaseMutex(x)
-#endif
-
-#ifndef _MSC_VER
-#define BSWAP32(v) __builtin_bswap32(v)
-#define BSWAP64(v) __builtin_bswap64(v)
-#else
-#define BSWAP32(v) _byteswap_ulong(v)
-#define BSWAP64(v) _byteswap_uint64(v)
-#endif
-
-#define WDLSUFFIX ".rtbw"
-#define DTZSUFFIX ".rtbz"
-#define WDLDIR "RTBWDIR"
-#define DTZDIR "RTBZDIR"
-#define TBPIECES 6
-
-typedef unsigned long long uint64;
-typedef unsigned int uint32;
-typedef unsigned char ubyte;
-typedef unsigned short ushort;
-
-const ubyte WDL_MAGIC[4] = { 0x71, 0xe8, 0x23, 0x5d };
-const ubyte DTZ_MAGIC[4] = { 0xd7, 0x66, 0x0c, 0xa5 };
-
-#define TBHASHBITS 10
-
-struct TBHashEntry;
-
-typedef uint64 base_t;
-
-struct PairsData {
-  char *indextable;
-  ushort *sizetable;
-  ubyte *data;
-  ushort *offset;
-  ubyte *symlen;
-  ubyte *sympat;
-  int blocksize;
-  int idxbits;
-  int min_len;
-  base_t base[1]; // C++ complains about base[]...
-};
-
-struct TBEntry {
-  char *data;
-  uint64 key;
-  uint64 mapping;
-  ubyte ready;
-  ubyte num;
-  ubyte symmetric;
-  ubyte has_pawns;
-}
-#ifndef _WIN32
-__attribute__((__may_alias__))
-#endif
-;
-
-struct TBEntry_piece {
-  char *data;
-  uint64 key;
-  uint64 mapping;
-  ubyte ready;
-  ubyte num;
-  ubyte symmetric;
-  ubyte has_pawns;
-  ubyte enc_type;
-  struct PairsData *precomp[2];
-  int factor[2][TBPIECES];
-  ubyte pieces[2][TBPIECES];
-  ubyte norm[2][TBPIECES];
-};
-
-struct TBEntry_pawn {
-  char *data;
-  uint64 key;
-  uint64 mapping;
-  ubyte ready;
-  ubyte num;
-  ubyte symmetric;
-  ubyte has_pawns;
-  ubyte pawns[2];
-  struct {
-    struct PairsData *precomp[2];
-    int factor[2][TBPIECES];
-    ubyte pieces[2][TBPIECES];
-    ubyte norm[2][TBPIECES];
-  } file[4];
-};
-
-struct DTZEntry_piece {
-  char *data;
-  uint64 key;
-  uint64 mapping;
-  ubyte ready;
-  ubyte num;
-  ubyte symmetric;
-  ubyte has_pawns;
-  ubyte enc_type;
-  struct PairsData *precomp;
-  int factor[TBPIECES];
-  ubyte pieces[TBPIECES];
-  ubyte norm[TBPIECES];
-  ubyte flags; // accurate, mapped, side
-  ushort map_idx[4];
-  ubyte *map;
-};
-
-struct DTZEntry_pawn {
-  char *data;
-  uint64 key;
-  uint64 mapping;
-  ubyte ready;
-  ubyte num;
-  ubyte symmetric;
-  ubyte has_pawns;
-  ubyte pawns[2];
-  struct {
-    struct PairsData *precomp;
-    int factor[TBPIECES];
-    ubyte pieces[TBPIECES];
-    ubyte norm[TBPIECES];
-  } file[4];
-  ubyte flags[4];
-  ushort map_idx[4][4];
-  ubyte *map;
-};
-
-struct TBHashEntry {
-  uint64 key;
-  struct TBEntry *ptr;
-};
-
-struct DTZTableEntry {
-  uint64 key1;
-  uint64 key2;
-  struct TBEntry *entry;
-};
-
-#endif
-

src/syzygy/tbprobe.h

@@ -1,17 +1,78 @@
+/*
+  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+  Copyright (c) 2013 Ronald de Man
+  Copyright (C) 2016-2018 Marco Costalba, Lucas Braesch
+
+  Stockfish is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  Stockfish is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
 #ifndef TBPROBE_H
 #define TBPROBE_H
 
+#include <ostream>
+
 #include "../search.h"
 
 namespace Tablebases {
 
+enum WDLScore {
+    WDLLoss        = -2, // Loss
+    WDLBlessedLoss = -1, // Loss, but draw under 50-move rule
+    WDLDraw        =  0, // Draw
+    WDLCursedWin   =  1, // Win, but draw under 50-move rule
+    WDLWin         =  2, // Win
+
+    WDLScoreNone  = -1000
+};
+
+// Possible states after a probing operation
+enum ProbeState {
+    FAIL              =  0, // Probe failed (missing file table)
+    OK                =  1, // Probe succesful
+    CHANGE_STM        = -1, // DTZ should check the other side
+    ZEROING_BEST_MOVE =  2  // Best move zeroes DTZ (capture or pawn move)
+};
+
 extern int MaxCardinality;
 
-void init(const std::string& path);
-int probe_wdl(Position& pos, int *success);
-int probe_dtz(Position& pos, int *success);
-bool root_probe(Position& pos, Search::RootMoveVector& rootMoves, Value& score);
-bool root_probe_wdl(Position& pos, Search::RootMoveVector& rootMoves, Value& score);
+void init(const std::string& paths);
+WDLScore probe_wdl(Position& pos, ProbeState* result);
+int probe_dtz(Position& pos, ProbeState* result);
+bool root_probe(Position& pos, Search::RootMoves& rootMoves);
+bool root_probe_wdl(Position& pos, Search::RootMoves& rootMoves);
+void rank_root_moves(Position& pos, Search::RootMoves& rootMoves);
+
+inline std::ostream& operator<<(std::ostream& os, const WDLScore v) {
+
+    os << (v == WDLLoss        ? "Loss" :
+           v == WDLBlessedLoss ? "Blessed loss" :
+           v == WDLDraw        ? "Draw" :
+           v == WDLCursedWin   ? "Cursed win" :
+           v == WDLWin         ? "Win" : "None");
+
+    return os;
+}
+
+inline std::ostream& operator<<(std::ostream& os, const ProbeState v) {
+
+    os << (v == FAIL              ? "Failed" :
+           v == OK                ? "Success" :
+           v == CHANGE_STM        ? "Probed opponent side" :
+           v == ZEROING_BEST_MOVE ? "Best move zeroes DTZ" : "None");
+
+    return os;
+}
 
 }
 

src/thread.cpp

@@ -2,6 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -24,362 +25,179 @@
 #include "search.h"
 #include "thread.h"
 #include "uci.h"
-
-using namespace Search;
+#include "syzygy/tbprobe.h"
+#include "tt.h"
 
 ThreadPool Threads; // Global object
 
-extern void check_time();
 
-namespace {
+/// Thread constructor launches the thread and waits until it goes to sleep
+/// in idle_loop(). Note that 'searching' and 'exit' should be alredy set.
 
- // start_routine() is the C function which is called when a new thread
- // is launched. It is a wrapper to the virtual function idle_loop().
-
- extern "C" { long start_routine(ThreadBase* th) { th->idle_loop(); return 0; } }
-
-
- // Helpers to launch a thread after creation and joining before delete. Must be
- // outside Thread c'tor and d'tor because the object must be fully initialized
- // when start_routine (and hence virtual idle_loop) is called and when joining.
-
- template<typename T> T* new_thread() {
-   T* th = new T();
-   thread_create(th->handle, start_routine, th); // Will go to sleep
-   return th;
- }
-
- void delete_thread(ThreadBase* th) {
-
-   th->mutex.lock();
-   th->exit = true; // Search must be already finished
-   th->mutex.unlock();
-
-   th->notify_one();
-   thread_join(th->handle); // Wait for thread termination
-   delete th;
- }
+Thread::Thread(size_t n) : idx(n), stdThread(&Thread::idle_loop, this) {
 
+  wait_for_search_finished();
 }
 
 
-// ThreadBase::notify_one() wakes up the thread when there is some work to do
+/// Thread destructor wakes up the thread in idle_loop() and waits
+/// for its termination. Thread should be already waiting.
 
-void ThreadBase::notify_one() {
+Thread::~Thread() {
 
-  mutex.lock();
-  sleepCondition.notify_one();
-  mutex.unlock();
-}
-
-
-// ThreadBase::wait_for() set the thread to sleep until 'condition' turns true
-
-void ThreadBase::wait_for(volatile const bool& condition) {
-
-  mutex.lock();
-  while (!condition) sleepCondition.wait(mutex);
-  mutex.unlock();
-}
-
-
-// Thread c'tor makes some init but does not launch any execution thread that
-// will be started only when c'tor returns.
-
-Thread::Thread() /* : splitPoints() */ { // Initialization of non POD broken in MSVC
-
-  searching = false;
-  maxPly = splitPointsSize = 0;
-  activeSplitPoint = NULL;
-  activePosition = NULL;
-  idx = Threads.size(); // Starts from 0
-}
-
-
-// Thread::cutoff_occurred() checks whether a beta cutoff has occurred in the
-// current active split point, or in some ancestor of the split point.
-
-bool Thread::cutoff_occurred() const {
-
-  for (SplitPoint* sp = activeSplitPoint; sp; sp = sp->parentSplitPoint)
-      if (sp->cutoff)
-          return true;
-
-  return false;
-}
-
-
-// Thread::available_to() checks whether the thread is available to help the
-// thread 'master' at a split point. An obvious requirement is that thread must
-// be idle. With more than two threads, this is not sufficient: If the thread is
-// the master of some split point, it is only available as a slave to the slaves
-// which are busy searching the split point at the top of slave's split point
-// stack (the "helpful master concept" in YBWC terminology).
-
-bool Thread::available_to(const Thread* master) const {
-
-  if (searching)
-      return false;
-
-  // Make a local copy to be sure it doesn't become zero under our feet while
-  // testing next condition and so leading to an out of bounds access.
-  const int size = splitPointsSize;
-
-  // No split points means that the thread is available as a slave for any
-  // other thread otherwise apply the "helpful master" concept if possible.
-  return !size || splitPoints[size - 1].slavesMask.test(master->idx);
-}
-
-
-// Thread::split() does the actual work of distributing the work at a node between
-// several available threads. If it does not succeed in splitting the node
-// (because no idle threads are available), the function immediately returns.
-// If splitting is possible, a SplitPoint object is initialized with all the
-// data that must be copied to the helper threads and then helper threads are
-// informed that they have been assigned work. This will cause them to instantly
-// leave their idle loops and call search(). When all threads have returned from
-// search() then split() returns.
-
-void Thread::split(Position& pos, Stack* ss, Value alpha, Value beta, Value* bestValue,
-                   Move* bestMove, Depth depth, int moveCount,
-                   MovePicker* movePicker, int nodeType, bool cutNode) {
-
-  assert(searching);
-  assert(-VALUE_INFINITE < *bestValue && *bestValue <= alpha && alpha < beta && beta <= VALUE_INFINITE);
-  assert(depth >= Threads.minimumSplitDepth);
-  assert(splitPointsSize < MAX_SPLITPOINTS_PER_THREAD);
-
-  // Pick and init the next available split point
-  SplitPoint& sp = splitPoints[splitPointsSize];
-
-  sp.masterThread = this;
-  sp.parentSplitPoint = activeSplitPoint;
-  sp.slavesMask = 0, sp.slavesMask.set(idx);
-  sp.depth = depth;
-  sp.bestValue = *bestValue;
-  sp.bestMove = *bestMove;
-  sp.alpha = alpha;
-  sp.beta = beta;
-  sp.nodeType = nodeType;
-  sp.cutNode = cutNode;
-  sp.movePicker = movePicker;
-  sp.moveCount = moveCount;
-  sp.pos = &pos;
-  sp.nodes = 0;
-  sp.cutoff = false;
-  sp.ss = ss;
-
-  // Try to allocate available threads and ask them to start searching setting
-  // 'searching' flag. This must be done under lock protection to avoid concurrent
-  // allocation of the same slave by another master.
-  Threads.mutex.lock();
-  sp.mutex.lock();
-
-  sp.allSlavesSearching = true; // Must be set under lock protection
-  ++splitPointsSize;
-  activeSplitPoint = &sp;
-  activePosition = NULL;
-
-  Thread* slave;
-
-  while ((slave = Threads.available_slave(this)) != NULL)
-  {
-      sp.slavesMask.set(slave->idx);
-      slave->activeSplitPoint = &sp;
-      slave->searching = true; // Slave leaves idle_loop()
-      slave->notify_one(); // Could be sleeping
-  }
-
-  // Everything is set up. The master thread enters the idle loop, from which
-  // it will instantly launch a search, because its 'searching' flag is set.
-  // The thread will return from the idle loop when all slaves have finished
-  // their work at this split point.
-  sp.mutex.unlock();
-  Threads.mutex.unlock();
-
-  Thread::idle_loop(); // Force a call to base class idle_loop()
-
-  // In the helpful master concept, a master can help only a sub-tree of its
-  // split point and because everything is finished here, it's not possible
-  // for the master to be booked.
   assert(!searching);
-  assert(!activePosition);
 
-  // We have returned from the idle loop, which means that all threads are
-  // finished. Note that setting 'searching' and decreasing splitPointsSize must
-  // be done under lock protection to avoid a race with Thread::available_to().
-  Threads.mutex.lock();
-  sp.mutex.lock();
+  exit = true;
+  start_searching();
+  stdThread.join();
+}
 
+
+/// Thread::clear() reset histories, usually before a new game
+
+void Thread::clear() {
+
+  counterMoves.fill(MOVE_NONE);
+  mainHistory.fill(0);
+  captureHistory.fill(0);
+
+  for (auto& to : continuationHistory)
+      for (auto& h : to)
+          h->fill(0);
+
+  continuationHistory[NO_PIECE][0]->fill(Search::CounterMovePruneThreshold - 1);
+}
+
+/// Thread::start_searching() wakes up the thread that will start the search
+
+void Thread::start_searching() {
+
+  std::lock_guard<Mutex> lk(mutex);
   searching = true;
-  --splitPointsSize;
-  activeSplitPoint = sp.parentSplitPoint;
-  activePosition = &pos;
-  pos.set_nodes_searched(pos.nodes_searched() + sp.nodes);
-  *bestMove = sp.bestMove;
-  *bestValue = sp.bestValue;
-
-  sp.mutex.unlock();
-  Threads.mutex.unlock();
+  cv.notify_one(); // Wake up the thread in idle_loop()
 }
 
 
-// TimerThread::idle_loop() is where the timer thread waits Resolution milliseconds
-// and then calls check_time(). When not searching, thread sleeps until it's woken up.
+/// Thread::wait_for_search_finished() blocks on the condition variable
+/// until the thread has finished searching.
 
-void TimerThread::idle_loop() {
+void Thread::wait_for_search_finished() {
 
-  while (!exit)
+  std::unique_lock<Mutex> lk(mutex);
+  cv.wait(lk, [&]{ return !searching; });
+}
+
+
+/// Thread::idle_loop() is where the thread is parked, blocked on the
+/// condition variable, when it has no work to do.
+
+void Thread::idle_loop() {
+
+  // If OS already scheduled us on a different group than 0 then don't overwrite
+  // the choice, eventually we are one of many one-threaded processes running on
+  // some Windows NUMA hardware, for instance in fishtest. To make it simple,
+  // just check if running threads are below a threshold, in this case all this
+  // NUMA machinery is not needed.
+  if (Options["Threads"] > 8)
+      WinProcGroup::bindThisThread(idx);
+
+  while (true)
   {
-      mutex.lock();
+      std::unique_lock<Mutex> lk(mutex);
+      searching = false;
+      cv.notify_one(); // Wake up anyone waiting for search finished
+      cv.wait(lk, [&]{ return searching; });
 
-      if (!exit)
-          sleepCondition.wait_for(mutex, run ? Resolution : INT_MAX);
+      if (exit)
+          return;
 
-      mutex.unlock();
+      lk.unlock();
 
-      if (run)
-          check_time();
+      search();
   }
 }
 
+/// ThreadPool::set() creates/destroys threads to match the requested number.
+/// Created and launched threads will go immediately to sleep in idle_loop.
+/// Upon resizing, threads are recreated to allow for binding if necessary.
 
-// MainThread::idle_loop() is where the main thread is parked waiting to be started
-// when there is a new search. The main thread will launch all the slave threads.
+void ThreadPool::set(size_t requested) {
 
-void MainThread::idle_loop() {
+  if (size() > 0) { // destroy any existing thread(s)
+      main()->wait_for_search_finished();
 
-  while (!exit)
-  {
-      mutex.lock();
-
-      thinking = false;
-
-      while (!thinking && !exit)
-      {
-          Threads.sleepCondition.notify_one(); // Wake up the UI thread if needed
-          sleepCondition.wait(mutex);
-      }
-
-      mutex.unlock();
-
-      if (!exit)
-      {
-          searching = true;
-
-          Search::think();
-
-          assert(searching);
-
-          searching = false;
-      }
-  }
-}
-
-
-// ThreadPool::init() is called at startup to create and launch requested threads,
-// that will go immediately to sleep. We cannot use a c'tor because Threads is a
-// static object and we need a fully initialized engine at this point due to
-// allocation of Endgames in Thread c'tor.
-
-void ThreadPool::init() {
-
-  timer = new_thread<TimerThread>();
-  push_back(new_thread<MainThread>());
-  read_uci_options();
-}
-
-
-// ThreadPool::exit() terminates the threads before the program exits. Cannot be
-// done in d'tor because threads must be terminated before freeing us.
-
-void ThreadPool::exit() {
-
-  delete_thread(timer); // As first because check_time() accesses threads data
-
-  for (iterator it = begin(); it != end(); ++it)
-      delete_thread(*it);
-}
-
-
-// ThreadPool::read_uci_options() updates internal threads parameters from the
-// corresponding UCI options and creates/destroys threads to match the requested
-// number. Thread objects are dynamically allocated to avoid creating all possible
-// threads in advance (which include pawns and material tables), even if only a
-// few are to be used.
-
-void ThreadPool::read_uci_options() {
-
-  minimumSplitDepth = Options["Min Split Depth"] * ONE_PLY;
-  size_t requested  = Options["Threads"];
-
-  assert(requested > 0);
-
-  // If zero (default) then set best minimum split depth automatically
-  if (!minimumSplitDepth)
-      minimumSplitDepth = requested < 8 ? 4 * ONE_PLY : 7 * ONE_PLY;
-
-  while (size() < requested)
-      push_back(new_thread<Thread>());
-
-  while (size() > requested)
-  {
-      delete_thread(back());
-      pop_back();
-  }
-}
-
-
-// ThreadPool::available_slave() tries to find an idle thread which is available
-// as a slave for the thread 'master'.
-
-Thread* ThreadPool::available_slave(const Thread* master) const {
-
-  for (const_iterator it = begin(); it != end(); ++it)
-      if ((*it)->available_to(master))
-          return *it;
-
-  return NULL;
-}
-
-
-// ThreadPool::wait_for_think_finished() waits for main thread to finish the search
-
-void ThreadPool::wait_for_think_finished() {
-
-  MainThread* th = main();
-  th->mutex.lock();
-  while (th->thinking) sleepCondition.wait(th->mutex);
-  th->mutex.unlock();
-}
-
-
-// ThreadPool::start_thinking() wakes up the main thread sleeping in
-// MainThread::idle_loop() and starts a new search, then returns immediately.
-
-void ThreadPool::start_thinking(const Position& pos, const LimitsType& limits,
-                                StateStackPtr& states) {
-  wait_for_think_finished();
-
-  SearchTime = Time::now(); // As early as possible
-
-  Signals.stopOnPonderhit = Signals.firstRootMove = false;
-  Signals.stop = Signals.failedLowAtRoot = false;
-
-  RootMoves.clear();
-  RootPos = pos;
-  Limits = limits;
-  if (states.get()) // If we don't set a new position, preserve current state
-  {
-      SetupStates = states; // Ownership transfer here
-      assert(!states.get());
+      while (size() > 0)
+          delete back(), pop_back();
   }
 
-  for (MoveList<LEGAL> it(pos); *it; ++it)
+  if (requested > 0) { // create new thread(s)
+      push_back(new MainThread(0));
+
+      while (size() < requested)
+          push_back(new Thread(size()));
+      clear();
+  }
+
+  // Reallocate the hash with the new threadpool size
+  TT.resize(Options["Hash"]);
+}
+
+/// ThreadPool::clear() sets threadPool data to initial values.
+
+void ThreadPool::clear() {
+
+  for (Thread* th : *this)
+      th->clear();
+
+  main()->callsCnt = 0;
+  main()->previousScore = VALUE_INFINITE;
+  main()->previousTimeReduction = 1.0;
+}
+
+/// ThreadPool::start_thinking() wakes up main thread waiting in idle_loop() and
+/// returns immediately. Main thread will wake up other threads and start the search.
+
+void ThreadPool::start_thinking(Position& pos, StateListPtr& states,
+                                const Search::LimitsType& limits, bool ponderMode) {
+
+  main()->wait_for_search_finished();
+
+  stopOnPonderhit = stop = false;
+  ponder = ponderMode;
+  Search::Limits = limits;
+  Search::RootMoves rootMoves;
+
+  for (const auto& m : MoveList<LEGAL>(pos))
       if (   limits.searchmoves.empty()
-          || std::count(limits.searchmoves.begin(), limits.searchmoves.end(), *it))
-          RootMoves.push_back(RootMove(*it));
+          || std::count(limits.searchmoves.begin(), limits.searchmoves.end(), m))
+          rootMoves.emplace_back(m);
 
-  main()->thinking = true;
-  main()->notify_one(); // Starts main thread
+  if (!rootMoves.empty())
+      Tablebases::rank_root_moves(pos, rootMoves);
+
+  // After ownership transfer 'states' becomes empty, so if we stop the search
+  // and call 'go' again without setting a new position states.get() == NULL.
+  assert(states.get() || setupStates.get());
+
+  if (states.get())
+      setupStates = std::move(states); // Ownership transfer, states is now empty
+
+  // We use Position::set() to set root position across threads. But there are
+  // some StateInfo fields (previous, pliesFromNull, capturedPiece) that cannot
+  // be deduced from a fen string, so set() clears them and to not lose the info
+  // we need to backup and later restore setupStates->back(). Note that setupStates
+  // is shared by threads but is accessed in read-only mode.
+  StateInfo tmp = setupStates->back();
+
+  for (Thread* th : *this)
+  {
+      th->nodes = th->tbHits = th->nmpMinPly = 0;
+      th->rootDepth = th->completedDepth = DEPTH_ZERO;
+      th->rootMoves = rootMoves;
+      th->rootPos.set(pos.fen(), pos.is_chess960(), &setupStates->back(), th);
+  }
+
+  setupStates->back() = tmp;
+
+  main()->start_searching();
 }

src/thread.h

@@ -2,6 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -20,7 +21,10 @@
 #ifndef THREAD_H_INCLUDED
 #define THREAD_H_INCLUDED
 
-#include <bitset>
+#include <atomic>
+#include <condition_variable>
+#include <mutex>
+#include <thread>
 #include <vector>
 
 #include "material.h"
@@ -28,157 +32,91 @@
 #include "pawns.h"
 #include "position.h"
 #include "search.h"
-
-struct Thread;
-
-const int MAX_THREADS = 128;
-const int MAX_SPLITPOINTS_PER_THREAD = 8;
-
-/// Mutex and ConditionVariable struct are wrappers of the low level locking
-/// machinery and are modeled after the corresponding C++11 classes.
-
-struct Mutex {
-  Mutex() { lock_init(l); }
- ~Mutex() { lock_destroy(l); }
-
-  void lock() { lock_grab(l); }
-  void unlock() { lock_release(l); }
-
-private:
-  friend struct ConditionVariable;
-
-  Lock l;
-};
-
-struct ConditionVariable {
-  ConditionVariable() { cond_init(c); }
- ~ConditionVariable() { cond_destroy(c); }
-
-  void wait(Mutex& m) { cond_wait(c, m.l); }
-  void wait_for(Mutex& m, int ms) { timed_wait(c, m.l, ms); }
-  void notify_one() { cond_signal(c); }
-
-private:
-  WaitCondition c;
-};
+#include "thread_win32.h"
 
 
-/// SplitPoint struct stores information shared by the threads searching in
-/// parallel below the same split point. It is populated at splitting time.
+/// Thread class keeps together all the thread-related stuff. We use
+/// per-thread pawn and material hash tables so that once we get a
+/// pointer to an entry its life time is unlimited and we don't have
+/// to care about someone changing the entry under our feet.
 
-struct SplitPoint {
-
-  // Const data after split point has been setup
-  const Position* pos;
-  Search::Stack* ss;
-  Thread* masterThread;
-  Depth depth;
-  Value beta;
-  int nodeType;
-  bool cutNode;
-
-  // Const pointers to shared data
-  MovePicker* movePicker;
-  SplitPoint* parentSplitPoint;
-
-  // Shared variable data
-  Mutex mutex;
-  std::bitset<MAX_THREADS> slavesMask;
-  volatile bool allSlavesSearching;
-  volatile uint64_t nodes;
-  volatile Value alpha;
-  volatile Value bestValue;
-  volatile Move bestMove;
-  volatile int moveCount;
-  volatile bool cutoff;
-};
-
-
-/// ThreadBase struct is the base of the hierarchy from where we derive all the
-/// specialized thread classes.
-
-struct ThreadBase {
-
-  ThreadBase() : handle(NativeHandle()), exit(false) {}
-  virtual ~ThreadBase() {}
-  virtual void idle_loop() = 0;
-  void notify_one();
-  void wait_for(volatile const bool& b);
+class Thread {
 
   Mutex mutex;
-  ConditionVariable sleepCondition;
-  NativeHandle handle;
-  volatile bool exit;
-};
+  ConditionVariable cv;
+  size_t idx;
+  bool exit = false, searching = true; // Set before starting std::thread
+  std::thread stdThread;
 
+public:
+  explicit Thread(size_t);
+  virtual ~Thread();
+  virtual void search();
+  void clear();
+  void idle_loop();
+  void start_searching();
+  void wait_for_search_finished();
 
-/// Thread struct keeps together all the thread related stuff like locks, state
-/// and especially split points. We also use per-thread pawn and material hash
-/// tables so that once we get a pointer to an entry its life time is unlimited
-/// and we don't have to care about someone changing the entry under our feet.
-
-struct Thread : public ThreadBase {
-
-  Thread();
-  virtual void idle_loop();
-  bool cutoff_occurred() const;
-  bool available_to(const Thread* master) const;
-
-  void split(Position& pos, Search::Stack* ss, Value alpha, Value beta, Value* bestValue, Move* bestMove,
-             Depth depth, int moveCount, MovePicker* movePicker, int nodeType, bool cutNode);
-
-  SplitPoint splitPoints[MAX_SPLITPOINTS_PER_THREAD];
   Pawns::Table pawnsTable;
   Material::Table materialTable;
   Endgames endgames;
-  Position* activePosition;
-  size_t idx;
-  int maxPly;
-  SplitPoint* volatile activeSplitPoint;
-  volatile int splitPointsSize;
-  volatile bool searching;
+  size_t pvIdx, pvLast;
+  int selDepth, nmpMinPly;
+  Color nmpColor;
+  std::atomic<uint64_t> nodes, tbHits;
+
+  Position rootPos;
+  Search::RootMoves rootMoves;
+  Depth rootDepth, completedDepth;
+  CounterMoveHistory counterMoves;
+  ButterflyHistory mainHistory;
+  CapturePieceToHistory captureHistory;
+  ContinuationHistory continuationHistory;
+  Score contempt;
 };
 
 
-/// MainThread and TimerThread are derived classes used to characterize the two
-/// special threads: the main one and the recurring timer.
+/// MainThread is a derived class specific for main thread
 
 struct MainThread : public Thread {
-  MainThread() : thinking(true) {} // Avoid a race with start_thinking()
-  virtual void idle_loop();
-  volatile bool thinking;
-};
 
-struct TimerThread : public ThreadBase {
+  using Thread::Thread;
 
-  static const int Resolution = 5; // Millisec between two check_time() calls
+  void search() override;
+  void check_time();
 
-  TimerThread() : run(false) {}
-  virtual void idle_loop();
-
-  bool run;
+  double bestMoveChanges, previousTimeReduction;
+  Value previousScore;
+  int callsCnt;
 };
 
 
-/// ThreadPool struct handles all the threads related stuff like init, starting,
-/// parking and, most importantly, launching a slave thread at a split point.
-/// All the access to shared thread data is done through this class.
+/// ThreadPool struct handles all the threads-related stuff like init, starting,
+/// parking and, most importantly, launching a thread. All the access to threads
+/// is done through this class.
 
 struct ThreadPool : public std::vector<Thread*> {
 
-  void init(); // No c'tor and d'tor, threads rely on globals that should be
-  void exit(); // initialized and are valid during the whole thread lifetime.
+  void start_thinking(Position&, StateListPtr&, const Search::LimitsType&, bool = false);
+  void clear();
+  void set(size_t);
 
-  MainThread* main() { return static_cast<MainThread*>(at(0)); }
-  void read_uci_options();
-  Thread* available_slave(const Thread* master) const;
-  void wait_for_think_finished();
-  void start_thinking(const Position&, const Search::LimitsType&, Search::StateStackPtr&);
+  MainThread* main()        const { return static_cast<MainThread*>(front()); }
+  uint64_t nodes_searched() const { return accumulate(&Thread::nodes); }
+  uint64_t tb_hits()        const { return accumulate(&Thread::tbHits); }
 
-  Depth minimumSplitDepth;
-  Mutex mutex;
-  ConditionVariable sleepCondition;
-  TimerThread* timer;
+  std::atomic_bool stop, ponder, stopOnPonderhit;
+
+private:
+  StateListPtr setupStates;
+
+  uint64_t accumulate(std::atomic<uint64_t> Thread::* member) const {
+
+    uint64_t sum = 0;
+    for (Thread* th : *this)
+        sum += (th->*member).load(std::memory_order_relaxed);
+    return sum;
+  }
 };
 
 extern ThreadPool Threads;

src/thread_win32.h

@@ -0,0 +1,70 @@
+/*
+  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+  Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
+  Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+
+  Stockfish is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  Stockfish is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef THREAD_WIN32_H_INCLUDED
+#define THREAD_WIN32_H_INCLUDED
+
+/// STL thread library used by mingw and gcc when cross compiling for Windows
+/// relies on libwinpthread. Currently libwinpthread implements mutexes directly
+/// on top of Windows semaphores. Semaphores, being kernel objects, require kernel
+/// mode transition in order to lock or unlock, which is very slow compared to
+/// interlocked operations (about 30% slower on bench test). To work around this
+/// issue, we define our wrappers to the low level Win32 calls. We use critical
+/// sections to support Windows XP and older versions. Unfortunately, cond_wait()
+/// is racy between unlock() and WaitForSingleObject() but they have the same
+/// speed performance as the SRW locks.
+
+#include <condition_variable>
+#include <mutex>
+
+#if defined(_WIN32) && !defined(_MSC_VER)
+
+#ifndef NOMINMAX
+#  define NOMINMAX // Disable macros min() and max()
+#endif
+
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+#undef WIN32_LEAN_AND_MEAN
+#undef NOMINMAX
+
+/// Mutex and ConditionVariable struct are wrappers of the low level locking
+/// machinery and are modeled after the corresponding C++11 classes.
+
+struct Mutex {
+  Mutex() { InitializeCriticalSection(&cs); }
+ ~Mutex() { DeleteCriticalSection(&cs); }
+  void lock() { EnterCriticalSection(&cs); }
+  void unlock() { LeaveCriticalSection(&cs); }
+
+private:
+  CRITICAL_SECTION cs;
+};
+
+typedef std::condition_variable_any ConditionVariable;
+
+#else // Default case: use STL classes
+
+typedef std::mutex Mutex;
+typedef std::condition_variable ConditionVariable;
+
+#endif
+
+#endif // #ifndef THREAD_WIN32_H_INCLUDED

src/timeman.cpp

@@ -2,6 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -25,37 +26,39 @@
 #include "timeman.h"
 #include "uci.h"
 
+TimeManagement Time; // Our global time management object
+
 namespace {
 
   enum TimeType { OptimumTime, MaxTime };
 
-  const int MoveHorizon   = 50;   // Plan time management at most this many moves ahead
-  const double MaxRatio   = 7.0;  // When in trouble, we can step over reserved time with this ratio
-  const double StealRatio = 0.33; // However we must not steal time from remaining moves over this ratio
+  constexpr int MoveHorizon   = 50;   // Plan time management at most this many moves ahead
+  constexpr double MaxRatio   = 7.3;  // When in trouble, we can step over reserved time with this ratio
+  constexpr double StealRatio = 0.34; // However we must not steal time from remaining moves over this ratio
 
 
   // move_importance() is a skew-logistic function based on naive statistical
   // analysis of "how many games are still undecided after n half-moves". Game
   // is considered "undecided" as long as neither side has >275cp advantage.
-  // Data was extracted from CCRL game database with some simple filtering criteria.
+  // Data was extracted from the CCRL game database with some simple filtering criteria.
 
   double move_importance(int ply) {
 
-    const double XScale = 9.3;
-    const double XShift = 59.8;
-    const double Skew   = 0.172;
+    constexpr double XScale = 6.85;
+    constexpr double XShift = 64.5;
+    constexpr double Skew   = 0.171;
 
     return pow((1 + exp((ply - XShift) / XScale)), -Skew) + DBL_MIN; // Ensure non-zero
   }
 
   template<TimeType T>
-  int remaining(int myTime, int movesToGo, int ply, int slowMover)
-  {
-    const double TMaxRatio   = (T == OptimumTime ? 1 : MaxRatio);
-    const double TStealRatio = (T == OptimumTime ? 0 : StealRatio);
+  TimePoint remaining(TimePoint myTime, int movesToGo, int ply, TimePoint slowMover) {
 
-    double moveImportance = (move_importance(ply) * slowMover) / 100;
-    double otherMovesImportance = 0;
+    constexpr double TMaxRatio   = (T == OptimumTime ? 1.0 : MaxRatio);
+    constexpr double TStealRatio = (T == OptimumTime ? 0.0 : StealRatio);
+
+    double moveImportance = (move_importance(ply) * slowMover) / 100.0;
+    double otherMovesImportance = 0.0;
 
     for (int i = 1; i < movesToGo; ++i)
         otherMovesImportance += move_importance(ply + 2 * i);
@@ -63,7 +66,7 @@ namespace {
     double ratio1 = (TMaxRatio * moveImportance) / (TMaxRatio * moveImportance + otherMovesImportance);
     double ratio2 = (moveImportance + TStealRatio * otherMovesImportance) / (moveImportance + otherMovesImportance);
 
-    return int(myTime * std::min(ratio1, ratio2)); // Intel C++ asks an explicit cast
+    return TimePoint(myTime * std::min(ratio1, ratio2)); // Intel C++ asks for an explicit cast
   }
 
 } // namespace
@@ -78,39 +81,53 @@ namespace {
 ///  inc >  0 && movestogo == 0 means: x basetime + z increment
 ///  inc >  0 && movestogo != 0 means: x moves in y minutes + z increment
 
-void TimeManager::init(const Search::LimitsType& limits, Color us, int ply)
-{
-  int minThinkingTime = Options["Minimum Thinking Time"];
-  int moveOverhead    = Options["Move Overhead"];
-  int slowMover       = Options["Slow Mover"];
+void TimeManagement::init(Search::LimitsType& limits, Color us, int ply) {
 
-  // Initialize unstablePvFactor to 1 and search times to maximum values
-  unstablePvFactor = 1;
-  optimumSearchTime = maximumSearchTime = std::max(limits.time[us], minThinkingTime);
+  TimePoint minThinkingTime = Options["Minimum Thinking Time"];
+  TimePoint moveOverhead    = Options["Move Overhead"];
+  TimePoint slowMover       = Options["Slow Mover"];
+  TimePoint npmsec          = Options["nodestime"];
+  TimePoint hypMyTime;
 
-  const int MaxMTG = limits.movestogo ? std::min(limits.movestogo, MoveHorizon) : MoveHorizon;
+  // If we have to play in 'nodes as time' mode, then convert from time
+  // to nodes, and use resulting values in time management formulas.
+  // WARNING: to avoid time losses, the given npmsec (nodes per millisecond)
+  // must be much lower than the real engine speed.
+  if (npmsec)
+  {
+      if (!availableNodes) // Only once at game start
+          availableNodes = npmsec * limits.time[us]; // Time is in msec
 
-  // We calculate optimum time usage for different hypothetical "moves to go"-values
+      // Convert from milliseconds to nodes
+      limits.time[us] = TimePoint(availableNodes);
+      limits.inc[us] *= npmsec;
+      limits.npmsec = npmsec;
+  }
+
+  startTime = limits.startTime;
+  optimumTime = maximumTime = std::max(limits.time[us], minThinkingTime);
+
+  const int maxMTG = limits.movestogo ? std::min(limits.movestogo, MoveHorizon) : MoveHorizon;
+
+  // We calculate optimum time usage for different hypothetical "moves to go" values
   // and choose the minimum of calculated search time values. Usually the greatest
   // hypMTG gives the minimum values.
-  for (int hypMTG = 1; hypMTG <= MaxMTG; ++hypMTG)
+  for (int hypMTG = 1; hypMTG <= maxMTG; ++hypMTG)
   {
       // Calculate thinking time for hypothetical "moves to go"-value
-      int hypMyTime =  limits.time[us]
-                     + limits.inc[us] * (hypMTG - 1)
-                     - moveOverhead * (2 + std::min(hypMTG, 40));
+      hypMyTime =  limits.time[us]
+                 + limits.inc[us] * (hypMTG - 1)
+                 - moveOverhead * (2 + std::min(hypMTG, 40));
 
-      hypMyTime = std::max(hypMyTime, 0);
+      hypMyTime = std::max(hypMyTime, TimePoint(0));
 
-      int t1 = minThinkingTime + remaining<OptimumTime>(hypMyTime, hypMTG, ply, slowMover);
-      int t2 = minThinkingTime + remaining<MaxTime    >(hypMyTime, hypMTG, ply, slowMover);
+      TimePoint t1 = minThinkingTime + remaining<OptimumTime>(hypMyTime, hypMTG, ply, slowMover);
+      TimePoint t2 = minThinkingTime + remaining<MaxTime    >(hypMyTime, hypMTG, ply, slowMover);
 
-      optimumSearchTime = std::min(t1, optimumSearchTime);
-      maximumSearchTime = std::min(t2, maximumSearchTime);
+      optimumTime = std::min(t1, optimumTime);
+      maximumTime = std::min(t2, maximumTime);
   }
 
   if (Options["Ponder"])
-      optimumSearchTime += optimumSearchTime / 4;
-
-  optimumSearchTime = std::min(optimumSearchTime, maximumSearchTime);
+      optimumTime += optimumTime / 4;
 }

src/timeman.h

@@ -2,6 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -20,20 +21,29 @@
 #ifndef TIMEMAN_H_INCLUDED
 #define TIMEMAN_H_INCLUDED
 
-/// The TimeManager class computes the optimal time to think depending on the
-/// maximum available time, the game move number and other parameters.
+#include "misc.h"
+#include "search.h"
+#include "thread.h"
 
-class TimeManager {
+/// The TimeManagement class computes the optimal time to think depending on
+/// the maximum available time, the game move number and other parameters.
+
+class TimeManagement {
 public:
-  void init(const Search::LimitsType& limits, Color us, int ply);
-  void pv_instability(double bestMoveChanges) { unstablePvFactor = 1 + bestMoveChanges; }
-  int available_time() const { return int(optimumSearchTime * unstablePvFactor * 0.71); }
-  int maximum_time() const { return maximumSearchTime; }
+  void init(Search::LimitsType& limits, Color us, int ply);
+  TimePoint optimum() const { return optimumTime; }
+  TimePoint maximum() const { return maximumTime; }
+  TimePoint elapsed() const { return Search::Limits.npmsec ?
+                                     TimePoint(Threads.nodes_searched()) : now() - startTime; }
+
+  int64_t availableNodes; // When in 'nodes as time' mode
 
 private:
-  int optimumSearchTime;
-  int maximumSearchTime;
-  double unstablePvFactor;
+  TimePoint startTime;
+  TimePoint optimumTime;
+  TimePoint maximumTime;
 };
 
+extern TimeManagement Time;
+
 #endif // #ifndef TIMEMAN_H_INCLUDED

src/tt.cpp

@@ -2,6 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -19,12 +20,37 @@
 
 #include <cstring>   // For std::memset
 #include <iostream>
+#include <thread>
 
 #include "bitboard.h"
+#include "misc.h"
 #include "tt.h"
+#include "uci.h"
 
 TranspositionTable TT; // Our global transposition table
 
+/// TTEntry::save saves a TTEntry
+void TTEntry::save(Key k, Value v, Bound b, Depth d, Move m, Value ev) {
+
+  assert(d / ONE_PLY * ONE_PLY == d);
+
+  // Preserve any existing move for the same position
+  if (m || (k >> 48) != key16)
+      move16 = (uint16_t)m;
+
+  // Overwrite less valuable entries
+  if (  (k >> 48) != key16
+      || d / ONE_PLY > depth8 - 4
+      || b == BOUND_EXACT)
+  {
+      key16     = (uint16_t)(k >> 48);
+      value16   = (int16_t)v;
+      eval16    = (int16_t)ev;
+      genBound8 = (uint8_t)(TT.generation8 | b);
+      depth8    = (int8_t)(d / ONE_PLY);
+  }
+}
+
 
 /// TranspositionTable::resize() sets the size of the transposition table,
 /// measured in megabytes. Transposition table consists of a power of 2 number
@@ -32,17 +58,10 @@ TranspositionTable TT; // Our global transposition table
 
 void TranspositionTable::resize(size_t mbSize) {
 
-  assert(sizeof(Cluster) == CacheLineSize / 2);
-
-  size_t newClusterCount = size_t(1) << msb((mbSize * 1024 * 1024) / sizeof(Cluster));
-
-  if (newClusterCount == clusterCount)
-      return;
-
-  clusterCount = newClusterCount;
+  clusterCount = mbSize * 1024 * 1024 / sizeof(Cluster);
 
   free(mem);
-  mem = calloc(clusterCount * sizeof(Cluster) + CacheLineSize - 1, 1);
+  mem = malloc(clusterCount * sizeof(Cluster) + CacheLineSize - 1);
 
   if (!mem)
   {
@@ -52,25 +71,45 @@ void TranspositionTable::resize(size_t mbSize) {
   }
 
   table = (Cluster*)((uintptr_t(mem) + CacheLineSize - 1) & ~(CacheLineSize - 1));
+  clear();
 }
 
 
-/// TranspositionTable::clear() overwrites the entire transposition table
-/// with zeros. It is called whenever the table is resized, or when the
-/// user asks the program to clear the table (from the UCI interface).
+/// TranspositionTable::clear() initializes the entire transposition table to zero,
+//  in a multi-threaded way.
 
 void TranspositionTable::clear() {
 
-  std::memset(table, 0, clusterCount * sizeof(Cluster));
-}
+  std::vector<std::thread> threads;
 
+  for (size_t idx = 0; idx < Options["Threads"]; idx++)
+  {
+      threads.emplace_back([this, idx]() {
+
+          // Thread binding gives faster search on systems with a first-touch policy
+          if (Options["Threads"] > 8)
+              WinProcGroup::bindThisThread(idx);
+
+          // Each thread will zero its part of the hash table
+          const size_t stride = clusterCount / Options["Threads"],
+                       start  = stride * idx,
+                       len    = idx != Options["Threads"] - 1 ?
+                                stride : clusterCount - start;
+
+          std::memset(&table[start], 0, len * sizeof(Cluster));
+      });
+  }
+
+  for (std::thread& th: threads)
+      th.join();
+}
 
 /// TranspositionTable::probe() looks up the current position in the transposition
 /// table. It returns true and a pointer to the TTEntry if the position is found.
 /// Otherwise, it returns false and a pointer to an empty or least valuable TTEntry
-/// to be replaced later. A TTEntry t1 is considered to be more valuable than a
-/// TTEntry t2 if t1 is from the current search and t2 is from a previous search,
-/// or if the depth of t1 is bigger than the depth of t2.
+/// to be replaced later. The replace value of an entry is calculated as its depth
+/// minus 8 times its relative age. TTEntry t1 is considered more valuable than
+/// TTEntry t2 if its replace value is greater than that of t2.
 
 TTEntry* TranspositionTable::probe(const Key key, bool& found) const {
 
@@ -80,8 +119,7 @@ TTEntry* TranspositionTable::probe(const Key key, bool& found) const {
   for (int i = 0; i < ClusterSize; ++i)
       if (!tte[i].key16 || tte[i].key16 == key16)
       {
-          if (tte[i].key16)
-              tte[i].genBound8 = uint8_t(generation8 | tte[i].bound()); // Refresh
+          tte[i].genBound8 = uint8_t(generation8 | tte[i].bound()); // Refresh
 
           return found = (bool)tte[i].key16, &tte[i];
       }
@@ -89,10 +127,30 @@ TTEntry* TranspositionTable::probe(const Key key, bool& found) const {
   // Find an entry to be replaced according to the replacement strategy
   TTEntry* replace = tte;
   for (int i = 1; i < ClusterSize; ++i)
-      if (  ((  tte[i].genBound8 & 0xFC) == generation8 || tte[i].bound() == BOUND_EXACT)
-          - ((replace->genBound8 & 0xFC) == generation8)
-          - (tte[i].depth8 < replace->depth8) < 0)
+      // Due to our packed storage format for generation and its cyclic
+      // nature we add 259 (256 is the modulus plus 3 to keep the lowest
+      // two bound bits from affecting the result) to calculate the entry
+      // age correctly even after generation8 overflows into the next cycle.
+      if (  replace->depth8 - ((259 + generation8 - replace->genBound8) & 0xFC) * 2
+          >   tte[i].depth8 - ((259 + generation8 -   tte[i].genBound8) & 0xFC) * 2)
           replace = &tte[i];
 
   return found = false, replace;
 }
+
+
+/// TranspositionTable::hashfull() returns an approximation of the hashtable
+/// occupation during a search. The hash is x permill full, as per UCI protocol.
+
+int TranspositionTable::hashfull() const {
+
+  int cnt = 0;
+  for (int i = 0; i < 1000 / ClusterSize; i++)
+  {
+      const TTEntry* tte = &table[i].entry[0];
+      for (int j = 0; j < ClusterSize; j++)
+          if ((tte[j].genBound8 & 0xFC) == generation8)
+              cnt++;
+  }
+  return cnt;
+}

src/tt.h

@@ -2,6 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -38,20 +39,9 @@ struct TTEntry {
   Move  move()  const { return (Move )move16; }
   Value value() const { return (Value)value16; }
   Value eval()  const { return (Value)eval16; }
-  Depth depth() const { return (Depth)depth8; }
+  Depth depth() const { return (Depth)(depth8 * int(ONE_PLY)); }
   Bound bound() const { return (Bound)(genBound8 & 0x3); }
-
-  void save(Key k, Value v, Bound b, Depth d, Move m, Value ev, uint8_t g) {
-
-    if (m || (k >> 48) != key16) // Preserve any existing move for the same position
-        move16 = (uint16_t)m;
-
-    key16     = (uint16_t)(k >> 48);
-    value16   = (int16_t)v;
-    eval16    = (int16_t)ev;
-    genBound8 = (uint8_t)(g | b);
-    depth8    = (int8_t)d;
-  }
+  void save(Key k, Value v, Bound b, Depth d, Move m, Value ev);
 
 private:
   friend class TranspositionTable;
@@ -68,33 +58,38 @@ private:
 /// A TranspositionTable consists of a power of 2 number of clusters and each
 /// cluster consists of ClusterSize number of TTEntry. Each non-empty entry
 /// contains information of exactly one position. The size of a cluster should
-/// not be bigger than a cache line size. In case it is less, it should be padded
-/// to guarantee always aligned accesses.
+/// divide the size of a cache line size, to ensure that clusters never cross
+/// cache lines. This ensures best cache performance, as the cacheline is
+/// prefetched, as soon as possible.
 
 class TranspositionTable {
 
-  static const int CacheLineSize = 64;
-  static const int ClusterSize = 3;
+  static constexpr int CacheLineSize = 64;
+  static constexpr int ClusterSize = 3;
 
   struct Cluster {
     TTEntry entry[ClusterSize];
-    char padding[2]; // Align to the cache line size
+    char padding[2]; // Align to a divisor of the cache line size
   };
 
+  static_assert(CacheLineSize % sizeof(Cluster) == 0, "Cluster size incorrect");
+
 public:
  ~TranspositionTable() { free(mem); }
   void new_search() { generation8 += 4; } // Lower 2 bits are used by Bound
-  uint8_t generation() const { return generation8; }
   TTEntry* probe(const Key key, bool& found) const;
+  int hashfull() const;
   void resize(size_t mbSize);
   void clear();
 
-  // The lowest order bits of the key are used to get the index of the cluster
+  // The 32 lowest order bits of the key are used to get the index of the cluster
   TTEntry* first_entry(const Key key) const {
-    return &table[(size_t)key & (clusterCount - 1)].entry[0];
+    return &table[(uint32_t(key) * uint64_t(clusterCount)) >> 32].entry[0];
   }
 
 private:
+  friend struct TTEntry;
+
   size_t clusterCount;
   Cluster* table;
   void* mem;

src/types.h

@@ -2,6 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -33,13 +34,22 @@
 ///
 /// -DUSE_POPCNT  | Add runtime support for use of popcnt asm-instruction. Works
 ///               | only in 64-bit mode and requires hardware with popcnt support.
+///
+/// -DUSE_PEXT    | Add runtime support for use of pext asm-instruction. Works
+///               | only in 64-bit mode and requires hardware with pext support.
 
 #include <cassert>
 #include <cctype>
 #include <climits>
+#include <cstdint>
 #include <cstdlib>
 
-#include "platform.h"
+#if defined(_MSC_VER)
+// Disable some silly and noisy warning from MSVC compiler
+#pragma warning(disable: 4127) // Conditional expression is constant
+#pragma warning(disable: 4146) // Unary minus operator applied to unsigned type
+#pragma warning(disable: 4800) // Forcing value to bool 'true' or 'false'
+#endif
 
 /// Predefined macros hell:
 ///
@@ -49,14 +59,13 @@
 /// _WIN32             Building on Windows (any)
 /// _WIN64             Building on Windows 64 bit
 
-#if defined(_WIN64) && !defined(IS_64BIT) // Last condition means Makefile is not used
-#  include <intrin.h> // MSVC popcnt and bsfq instrinsics
+#if defined(_WIN64) && defined(_MSC_VER) // No Makefile used
+#  include <intrin.h> // Microsoft header for _BitScanForward64()
 #  define IS_64BIT
-#  define USE_BSFQ
 #endif
 
-#if defined(USE_POPCNT) && defined(__INTEL_COMPILER) && defined(_MSC_VER)
-#  include <nmmintrin.h> // Intel header for _mm_popcnt_u64() intrinsic
+#if defined(USE_POPCNT) && (defined(__INTEL_COMPILER) || defined(_MSC_VER))
+#  include <nmmintrin.h> // Intel and Microsoft header for _mm_popcnt_u64()
 #endif
 
 #if !defined(NO_PREFETCH) && (defined(__INTEL_COMPILER) || defined(_MSC_VER))
@@ -67,40 +76,32 @@
 #  include <immintrin.h> // Header for _pext_u64() intrinsic
 #  define pext(b, m) _pext_u64(b, m)
 #else
-#  define pext(b, m) (0)
-#endif
-
-#ifdef _MSC_VER
-#  define FORCE_INLINE  __forceinline
-#elif defined(__GNUC__)
-#  define FORCE_INLINE  inline __attribute__((always_inline))
-#else
-#  define FORCE_INLINE  inline
+#  define pext(b, m) 0
 #endif
 
 #ifdef USE_POPCNT
-const bool HasPopCnt = true;
+constexpr bool HasPopCnt = true;
 #else
-const bool HasPopCnt = false;
+constexpr bool HasPopCnt = false;
 #endif
 
 #ifdef USE_PEXT
-const bool HasPext = true;
+constexpr bool HasPext = true;
 #else
-const bool HasPext = false;
+constexpr bool HasPext = false;
 #endif
 
 #ifdef IS_64BIT
-const bool Is64Bit = true;
+constexpr bool Is64Bit = true;
 #else
-const bool Is64Bit = false;
+constexpr bool Is64Bit = false;
 #endif
 
 typedef uint64_t Key;
 typedef uint64_t Bitboard;
 
-const int MAX_MOVES = 256;
-const int MAX_PLY   = 128;
+constexpr int MAX_MOVES = 256;
+constexpr int MAX_PLY   = 128;
 
 /// A move needs 16 bits to be stored
 ///
@@ -114,7 +115,7 @@ const int MAX_PLY   = 128;
 /// any normal move destination square is always different from origin square
 /// while MOVE_NONE and MOVE_NULL have the same origin and destination square.
 
-enum Move {
+enum Move : int {
   MOVE_NONE,
   MOVE_NULL = 65
 };
@@ -127,7 +128,7 @@ enum MoveType {
 };
 
 enum Color {
-  WHITE, BLACK, NO_COLOR, COLOR_NB = 2
+  WHITE, BLACK, COLOR_NB = 2
 };
 
 enum CastlingSide {
@@ -144,12 +145,6 @@ enum CastlingRight {
   CASTLING_RIGHT_NB = 16
 };
 
-template<Color C, CastlingSide S> struct MakeCastling {
-  static const CastlingRight
-  right = C == WHITE ? S == QUEEN_SIDE ? WHITE_OOO : WHITE_OO
-                     : S == QUEEN_SIDE ? BLACK_OOO : BLACK_OO;
-};
-
 enum Phase {
   PHASE_ENDGAME,
   PHASE_MIDGAME = 128,
@@ -158,7 +153,6 @@ enum Phase {
 
 enum ScaleFactor {
   SCALE_FACTOR_DRAW    = 0,
-  SCALE_FACTOR_ONEPAWN = 48,
   SCALE_FACTOR_NORMAL  = 64,
   SCALE_FACTOR_MAX     = 128,
   SCALE_FACTOR_NONE    = 255
@@ -171,7 +165,7 @@ enum Bound {
   BOUND_EXACT = BOUND_UPPER | BOUND_LOWER
 };
 
-enum Value {
+enum Value : int {
   VALUE_ZERO      = 0,
   VALUE_DRAW      = 0,
   VALUE_KNOWN_WIN = 10000,
@@ -182,16 +176,13 @@ enum Value {
   VALUE_MATE_IN_MAX_PLY  =  VALUE_MATE - 2 * MAX_PLY,
   VALUE_MATED_IN_MAX_PLY = -VALUE_MATE + 2 * MAX_PLY,
 
-  VALUE_ENSURE_INTEGER_SIZE_P = INT_MAX,
-  VALUE_ENSURE_INTEGER_SIZE_N = INT_MIN,
+  PawnValueMg   = 136,   PawnValueEg   = 208,
+  KnightValueMg = 782,   KnightValueEg = 865,
+  BishopValueMg = 830,   BishopValueEg = 918,
+  RookValueMg   = 1289,  RookValueEg   = 1378,
+  QueenValueMg  = 2529,  QueenValueEg  = 2687,
 
-  PawnValueMg   = 198,   PawnValueEg   = 258,
-  KnightValueMg = 817,   KnightValueEg = 846,
-  BishopValueMg = 836,   BishopValueEg = 857,
-  RookValueMg   = 1270,  RookValueEg   = 1278,
-  QueenValueMg  = 2521,  QueenValueEg  = 2558,
-
-  MidgameLimit  = 15581, EndgameLimit  = 3998
+  MidgameLimit  = 15258, EndgameLimit  = 3915
 };
 
 enum PieceType {
@@ -207,20 +198,24 @@ enum Piece {
   PIECE_NB = 16
 };
 
-enum Depth {
+extern Value PieceValue[PHASE_NB][PIECE_NB];
+
+enum Depth : int {
 
   ONE_PLY = 1,
 
-  DEPTH_ZERO          =  0,
-  DEPTH_QS_CHECKS     =  0,
-  DEPTH_QS_NO_CHECKS  = -1,
-  DEPTH_QS_RECAPTURES = -5,
+  DEPTH_ZERO          =  0 * ONE_PLY,
+  DEPTH_QS_CHECKS     =  0 * ONE_PLY,
+  DEPTH_QS_NO_CHECKS  = -1 * ONE_PLY,
+  DEPTH_QS_RECAPTURES = -5 * ONE_PLY,
 
-  DEPTH_NONE = -6,
-  DEPTH_MAX  = MAX_PLY
+  DEPTH_NONE = -6 * ONE_PLY,
+  DEPTH_MAX  = MAX_PLY * ONE_PLY
 };
 
-enum Square {
+static_assert(!(ONE_PLY & (ONE_PLY - 1)), "ONE_PLY is not a power of 2");
+
+enum Square : int {
   SQ_A1, SQ_B1, SQ_C1, SQ_D1, SQ_E1, SQ_F1, SQ_G1, SQ_H1,
   SQ_A2, SQ_B2, SQ_C2, SQ_D2, SQ_E2, SQ_F2, SQ_G2, SQ_H2,
   SQ_A3, SQ_B3, SQ_C3, SQ_D3, SQ_E3, SQ_F3, SQ_G3, SQ_H3,
@@ -231,138 +226,161 @@ enum Square {
   SQ_A8, SQ_B8, SQ_C8, SQ_D8, SQ_E8, SQ_F8, SQ_G8, SQ_H8,
   SQ_NONE,
 
-  SQUARE_NB = 64,
-
-  DELTA_N =  8,
-  DELTA_E =  1,
-  DELTA_S = -8,
-  DELTA_W = -1,
-
-  DELTA_NN = DELTA_N + DELTA_N,
-  DELTA_NE = DELTA_N + DELTA_E,
-  DELTA_SE = DELTA_S + DELTA_E,
-  DELTA_SS = DELTA_S + DELTA_S,
-  DELTA_SW = DELTA_S + DELTA_W,
-  DELTA_NW = DELTA_N + DELTA_W
+  SQUARE_NB = 64
 };
 
-enum File {
+enum Direction : int {
+  NORTH =  8,
+  EAST  =  1,
+  SOUTH = -NORTH,
+  WEST  = -EAST,
+
+  NORTH_EAST = NORTH + EAST,
+  SOUTH_EAST = SOUTH + EAST,
+  SOUTH_WEST = SOUTH + WEST,
+  NORTH_WEST = NORTH + WEST
+};
+
+enum File : int {
   FILE_A, FILE_B, FILE_C, FILE_D, FILE_E, FILE_F, FILE_G, FILE_H, FILE_NB
 };
 
-enum Rank {
+enum Rank : int {
   RANK_1, RANK_2, RANK_3, RANK_4, RANK_5, RANK_6, RANK_7, RANK_8, RANK_NB
 };
 
 
-/// Score enum stores a middlegame and an endgame value in a single integer.
-/// The least significant 16 bits are used to store the endgame value and
-/// the upper 16 bits are used to store the middlegame value. The compiler
-/// is free to choose the enum type as long as it can store the data, so we
-/// ensure that Score is an integer type by assigning some big int values.
-enum Score {
-  SCORE_ZERO,
-  SCORE_ENSURE_INTEGER_SIZE_P = INT_MAX,
-  SCORE_ENSURE_INTEGER_SIZE_N = INT_MIN
-};
+/// Score enum stores a middlegame and an endgame value in a single integer (enum).
+/// The least significant 16 bits are used to store the middlegame value and the
+/// upper 16 bits are used to store the endgame value. We have to take care to
+/// avoid left-shifting a signed int to avoid undefined behavior.
+enum Score : int { SCORE_ZERO };
 
-inline Score make_score(int mg, int eg) {
-  return Score((mg << 16) + eg);
+constexpr Score make_score(int mg, int eg) {
+  return Score((int)((unsigned int)eg << 16) + mg);
 }
 
 /// Extracting the signed lower and upper 16 bits is not so trivial because
 /// according to the standard a simple cast to short is implementation defined
 /// and so is a right shift of a signed integer.
-inline Value mg_value(Score s) {
-
-  union { uint16_t u; int16_t s; } mg = { uint16_t(unsigned(s + 0x8000) >> 16) };
-  return Value(mg.s);
-}
-
 inline Value eg_value(Score s) {
-
-  union { uint16_t u; int16_t s; } eg = { uint16_t(unsigned(s)) };
+  union { uint16_t u; int16_t s; } eg = { uint16_t(unsigned(s + 0x8000) >> 16) };
   return Value(eg.s);
 }
 
-#define ENABLE_BASE_OPERATORS_ON(T)                             \
-inline T operator+(T d1, T d2) { return T(int(d1) + int(d2)); } \
-inline T operator-(T d1, T d2) { return T(int(d1) - int(d2)); } \
-inline T operator*(int i, T d) { return T(i * int(d)); }        \
-inline T operator*(T d, int i) { return T(int(d) * i); }        \
-inline T operator-(T d) { return T(-int(d)); }                  \
-inline T& operator+=(T& d1, T d2) { return d1 = d1 + d2; }      \
-inline T& operator-=(T& d1, T d2) { return d1 = d1 - d2; }      \
-inline T& operator*=(T& d, int i) { return d = T(int(d) * i); }
+inline Value mg_value(Score s) {
+  union { uint16_t u; int16_t s; } mg = { uint16_t(unsigned(s)) };
+  return Value(mg.s);
+}
 
-#define ENABLE_FULL_OPERATORS_ON(T)                             \
-ENABLE_BASE_OPERATORS_ON(T)                                     \
-inline T& operator++(T& d) { return d = T(int(d) + 1); }        \
-inline T& operator--(T& d) { return d = T(int(d) - 1); }        \
-inline T operator/(T d, int i) { return T(int(d) / i); }        \
-inline int operator/(T d1, T d2) { return int(d1) / int(d2); }  \
+#define ENABLE_BASE_OPERATORS_ON(T)                                \
+constexpr T operator+(T d1, T d2) { return T(int(d1) + int(d2)); } \
+constexpr T operator-(T d1, T d2) { return T(int(d1) - int(d2)); } \
+constexpr T operator-(T d) { return T(-int(d)); }                  \
+inline T& operator+=(T& d1, T d2) { return d1 = d1 + d2; }         \
+inline T& operator-=(T& d1, T d2) { return d1 = d1 - d2; }
+
+#define ENABLE_INCR_OPERATORS_ON(T)                                \
+inline T& operator++(T& d) { return d = T(int(d) + 1); }           \
+inline T& operator--(T& d) { return d = T(int(d) - 1); }
+
+#define ENABLE_FULL_OPERATORS_ON(T)                                \
+ENABLE_BASE_OPERATORS_ON(T)                                        \
+ENABLE_INCR_OPERATORS_ON(T)                                        \
+constexpr T operator*(int i, T d) { return T(i * int(d)); }        \
+constexpr T operator*(T d, int i) { return T(int(d) * i); }        \
+constexpr T operator/(T d, int i) { return T(int(d) / i); }        \
+constexpr int operator/(T d1, T d2) { return int(d1) / int(d2); }  \
+inline T& operator*=(T& d, int i) { return d = T(int(d) * i); }    \
 inline T& operator/=(T& d, int i) { return d = T(int(d) / i); }
 
 ENABLE_FULL_OPERATORS_ON(Value)
-ENABLE_FULL_OPERATORS_ON(PieceType)
-ENABLE_FULL_OPERATORS_ON(Piece)
-ENABLE_FULL_OPERATORS_ON(Color)
 ENABLE_FULL_OPERATORS_ON(Depth)
-ENABLE_FULL_OPERATORS_ON(Square)
-ENABLE_FULL_OPERATORS_ON(File)
-ENABLE_FULL_OPERATORS_ON(Rank)
+ENABLE_FULL_OPERATORS_ON(Direction)
+
+ENABLE_INCR_OPERATORS_ON(PieceType)
+ENABLE_INCR_OPERATORS_ON(Piece)
+ENABLE_INCR_OPERATORS_ON(Color)
+ENABLE_INCR_OPERATORS_ON(Square)
+ENABLE_INCR_OPERATORS_ON(File)
+ENABLE_INCR_OPERATORS_ON(Rank)
 
 ENABLE_BASE_OPERATORS_ON(Score)
 
 #undef ENABLE_FULL_OPERATORS_ON
+#undef ENABLE_INCR_OPERATORS_ON
 #undef ENABLE_BASE_OPERATORS_ON
 
 /// Additional operators to add integers to a Value
-inline Value operator+(Value v, int i) { return Value(int(v) + i); }
-inline Value operator-(Value v, int i) { return Value(int(v) - i); }
+constexpr Value operator+(Value v, int i) { return Value(int(v) + i); }
+constexpr Value operator-(Value v, int i) { return Value(int(v) - i); }
 inline Value& operator+=(Value& v, int i) { return v = v + i; }
 inline Value& operator-=(Value& v, int i) { return v = v - i; }
 
+/// Additional operators to add a Direction to a Square
+constexpr Square operator+(Square s, Direction d) { return Square(int(s) + int(d)); }
+constexpr Square operator-(Square s, Direction d) { return Square(int(s) - int(d)); }
+inline Square& operator+=(Square& s, Direction d) { return s = s + d; }
+inline Square& operator-=(Square& s, Direction d) { return s = s - d; }
+
 /// Only declared but not defined. We don't want to multiply two scores due to
 /// a very high risk of overflow. So user should explicitly convert to integer.
-inline Score operator*(Score s1, Score s2);
+Score operator*(Score, Score) = delete;
 
 /// Division of a Score must be handled separately for each term
 inline Score operator/(Score s, int i) {
   return make_score(mg_value(s) / i, eg_value(s) / i);
 }
 
-extern Value PieceValue[PHASE_NB][PIECE_NB];
+/// Multiplication of a Score by an integer. We check for overflow in debug mode.
+inline Score operator*(Score s, int i) {
 
-inline Color operator~(Color c) {
-  return Color(c ^ BLACK);
+  Score result = Score(int(s) * i);
+
+  assert(eg_value(result) == (i * eg_value(s)));
+  assert(mg_value(result) == (i * mg_value(s)));
+  assert((i == 0) || (result / i) == s);
+
+  return result;
 }
 
-inline Square operator~(Square s) {
+constexpr Color operator~(Color c) {
+  return Color(c ^ BLACK); // Toggle color
+}
+
+constexpr Square operator~(Square s) {
   return Square(s ^ SQ_A8); // Vertical flip SQ_A1 -> SQ_A8
 }
 
-inline CastlingRight operator|(Color c, CastlingSide s) {
+constexpr File operator~(File f) {
+  return File(f ^ FILE_H); // Horizontal flip FILE_A -> FILE_H
+}
+
+constexpr Piece operator~(Piece pc) {
+  return Piece(pc ^ 8); // Swap color of piece B_KNIGHT -> W_KNIGHT
+}
+
+constexpr CastlingRight operator|(Color c, CastlingSide s) {
   return CastlingRight(WHITE_OO << ((s == QUEEN_SIDE) + 2 * c));
 }
 
-inline Value mate_in(int ply) {
+constexpr Value mate_in(int ply) {
   return VALUE_MATE - ply;
 }
 
-inline Value mated_in(int ply) {
+constexpr Value mated_in(int ply) {
   return -VALUE_MATE + ply;
 }
 
-inline Square make_square(File f, Rank r) {
-  return Square((r << 3) | f);
+constexpr Square make_square(File f, Rank r) {
+  return Square((r << 3) + f);
 }
 
-inline Piece make_piece(Color c, PieceType pt) {
-  return Piece((c << 3) | pt);
+constexpr Piece make_piece(Color c, PieceType pt) {
+  return Piece((c << 3) + pt);
 }
 
-inline PieceType type_of(Piece pc)  {
+constexpr PieceType type_of(Piece pc) {
   return PieceType(pc & 7);
 }
 
@@ -371,27 +389,27 @@ inline Color color_of(Piece pc) {
   return Color(pc >> 3);
 }
 
-inline bool is_ok(Square s) {
+constexpr bool is_ok(Square s) {
   return s >= SQ_A1 && s <= SQ_H8;
 }
 
-inline File file_of(Square s) {
+constexpr File file_of(Square s) {
   return File(s & 7);
 }
 
-inline Rank rank_of(Square s) {
+constexpr Rank rank_of(Square s) {
   return Rank(s >> 3);
 }
 
-inline Square relative_square(Color c, Square s) {
+constexpr Square relative_square(Color c, Square s) {
   return Square(s ^ (c * 56));
 }
 
-inline Rank relative_rank(Color c, Rank r) {
+constexpr Rank relative_rank(Color c, Rank r) {
   return Rank(r ^ (c * 7));
 }
 
-inline Rank relative_rank(Color c, Square s) {
+constexpr Rank relative_rank(Color c, Square s) {
   return relative_rank(c, rank_of(s));
 }
 
@@ -400,36 +418,40 @@ inline bool opposite_colors(Square s1, Square s2) {
   return ((s >> 3) ^ s) & 1;
 }
 
-inline Square pawn_push(Color c) {
-  return c == WHITE ? DELTA_N : DELTA_S;
+constexpr Direction pawn_push(Color c) {
+  return c == WHITE ? NORTH : SOUTH;
 }
 
-inline Square from_sq(Move m) {
+constexpr Square from_sq(Move m) {
   return Square((m >> 6) & 0x3F);
 }
 
-inline Square to_sq(Move m) {
+constexpr Square to_sq(Move m) {
   return Square(m & 0x3F);
 }
 
-inline MoveType type_of(Move m) {
+constexpr int from_to(Move m) {
+ return m & 0xFFF;
+}
+
+constexpr MoveType type_of(Move m) {
   return MoveType(m & (3 << 14));
 }
 
-inline PieceType promotion_type(Move m) {
-  return PieceType(((m >> 12) & 3) + 2);
+constexpr PieceType promotion_type(Move m) {
+  return PieceType(((m >> 12) & 3) + KNIGHT);
 }
 
-inline Move make_move(Square from, Square to) {
-  return Move(to | (from << 6));
+constexpr Move make_move(Square from, Square to) {
+  return Move((from << 6) + to);
 }
 
 template<MoveType T>
-inline Move make(Square from, Square to, PieceType pt = KNIGHT) {
-  return Move(to | (from << 6) | T | ((pt - KNIGHT) << 12));
+constexpr Move make(Square from, Square to, PieceType pt = KNIGHT) {
+  return Move(T + ((pt - KNIGHT) << 12) + (from << 6) + to);
 }
 
-inline bool is_ok(Move m) {
+constexpr bool is_ok(Move m) {
   return from_sq(m) != to_sq(m); // Catch MOVE_NULL and MOVE_NONE
 }
 

src/uci.cpp

@@ -2,6 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -17,6 +18,7 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include <cassert>
 #include <iostream>
 #include <sstream>
 #include <string>
@@ -26,30 +28,27 @@
 #include "position.h"
 #include "search.h"
 #include "thread.h"
+#include "timeman.h"
 #include "tt.h"
 #include "uci.h"
+#include "syzygy/tbprobe.h"
 
 using namespace std;
 
-extern void benchmark(const Position& pos, istream& is);
+extern vector<string> setup_bench(const Position&, istream&);
 
 namespace {
 
   // FEN string of the initial position, normal chess
   const char* StartFEN = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
 
-  // Stack to keep track of the position states along the setup moves (from the
-  // start position to the position just before the search starts). Needed by
-  // 'draw by repetition' detection.
-  Search::StateStackPtr SetupStates;
-
 
   // position() is called when engine receives the "position" UCI command.
   // The function sets up the position described in the given FEN string ("fen")
   // or the starting position ("startpos") and then makes the moves given in the
   // following move list ("moves").
 
-  void position(Position& pos, istringstream& is) {
+  void position(Position& pos, istringstream& is, StateListPtr& states) {
 
     Move m;
     string token, fen;
@@ -67,14 +66,14 @@ namespace {
     else
         return;
 
-    pos.set(fen, Options["UCI_Chess960"], Threads.main());
-    SetupStates = Search::StateStackPtr(new std::stack<StateInfo>());
+    states = StateListPtr(new std::deque<StateInfo>(1)); // Drop old and create a new one
+    pos.set(fen, Options["UCI_Chess960"], &states->back(), Threads.main());
 
     // Parse move list (if any)
     while (is >> token && (m = UCI::to_move(pos, token)) != MOVE_NONE)
     {
-        SetupStates->push(StateInfo());
-        pos.do_move(m, SetupStates->top());
+        states->emplace_back();
+        pos.do_move(m, states->back());
     }
   }
 
@@ -90,11 +89,11 @@ namespace {
 
     // Read option name (can contain spaces)
     while (is >> token && token != "value")
-        name += string(" ", !name.empty()) + token;
+        name += (name.empty() ? "" : " ") + token;
 
     // Read option value (can contain spaces)
     while (is >> token)
-        value += string(" ", !value.empty()) + token;
+        value += (value.empty() ? "" : " ") + token;
 
     if (Options.count(name))
         Options[name] = value;
@@ -107,10 +106,13 @@ namespace {
   // the thinking time and other parameters from the input string, then starts
   // the search.
 
-  void go(const Position& pos, istringstream& is) {
+  void go(Position& pos, istringstream& is, StateListPtr& states) {
 
     Search::LimitsType limits;
     string token;
+    bool ponderMode = false;
+
+    limits.startTime = now(); // As early as possible!
 
     while (is >> token)
         if (token == "searchmoves")
@@ -126,10 +128,53 @@ namespace {
         else if (token == "nodes")     is >> limits.nodes;
         else if (token == "movetime")  is >> limits.movetime;
         else if (token == "mate")      is >> limits.mate;
-        else if (token == "infinite")  limits.infinite = true;
-        else if (token == "ponder")    limits.ponder = true;
+        else if (token == "perft")     is >> limits.perft;
+        else if (token == "infinite")  limits.infinite = 1;
+        else if (token == "ponder")    ponderMode = true;
 
-    Threads.start_thinking(pos, limits, SetupStates);
+    Threads.start_thinking(pos, states, limits, ponderMode);
+  }
+
+
+  // bench() is called when engine receives the "bench" command. Firstly
+  // a list of UCI commands is setup according to bench parameters, then
+  // it is run one by one printing a summary at the end.
+
+  void bench(Position& pos, istream& args, StateListPtr& states) {
+
+    string token;
+    uint64_t num, nodes = 0, cnt = 1;
+
+    vector<string> list = setup_bench(pos, args);
+    num = count_if(list.begin(), list.end(), [](string s) { return s.find("go ") == 0; });
+
+    TimePoint elapsed = now();
+
+    for (const auto& cmd : list)
+    {
+        istringstream is(cmd);
+        is >> skipws >> token;
+
+        if (token == "go")
+        {
+            cerr << "\nPosition: " << cnt++ << '/' << num << endl;
+            go(pos, is, states);
+            Threads.main()->wait_for_search_finished();
+            nodes += Threads.nodes_searched();
+        }
+        else if (token == "setoption")  setoption(is);
+        else if (token == "position")   position(pos, is, states);
+        else if (token == "ucinewgame") Search::clear();
+    }
+
+    elapsed = now() - elapsed + 1; // Ensure positivity to avoid a 'divide by zero'
+
+    dbg_print(); // Just before exiting
+
+    cerr << "\n==========================="
+         << "\nTotal time (ms) : " << elapsed
+         << "\nNodes searched  : " << nodes
+         << "\nNodes/second    : " << 1000 * nodes / elapsed << endl;
   }
 
 } // namespace
@@ -143,8 +188,12 @@ namespace {
 
 void UCI::loop(int argc, char* argv[]) {
 
-  Position pos(StartFEN, false, Threads.main()); // The root position
+  Position pos;
   string token, cmd;
+  StateListPtr states(new std::deque<StateInfo>(1));
+  auto uiThread = std::make_shared<Thread>(0);
+
+  pos.set(StartFEN, false, &states->back(), uiThread.get());
 
   for (int i = 1; i < argc; ++i)
       cmd += std::string(argv[i]) + " ";
@@ -155,57 +204,42 @@ void UCI::loop(int argc, char* argv[]) {
 
       istringstream is(cmd);
 
-      token.clear(); // getline() could return empty or blank line
+      token.clear(); // Avoid a stale if getline() returns empty or blank line
       is >> skipws >> token;
 
-      // The GUI sends 'ponderhit' to tell us to ponder on the same move the
-      // opponent has played. In case Signals.stopOnPonderhit is set we are
-      // waiting for 'ponderhit' to stop the search (for instance because we
-      // already ran out of time), otherwise we should continue searching but
-      // switching from pondering to normal search.
+      // The GUI sends 'ponderhit' to tell us the user has played the expected move.
+      // So 'ponderhit' will be sent if we were told to ponder on the same move the
+      // user has played. We should continue searching but switch from pondering to
+      // normal search. In case Threads.stopOnPonderhit is set we are waiting for
+      // 'ponderhit' to stop the search, for instance if max search depth is reached.
       if (    token == "quit"
           ||  token == "stop"
-          || (token == "ponderhit" && Search::Signals.stopOnPonderhit))
-      {
-          Search::Signals.stop = true;
-          Threads.main()->notify_one(); // Could be sleeping
-      }
+          || (token == "ponderhit" && Threads.stopOnPonderhit))
+          Threads.stop = true;
+
       else if (token == "ponderhit")
-          Search::Limits.ponder = false; // Switch to normal search
+          Threads.ponder = false; // Switch to normal search
 
       else if (token == "uci")
           sync_cout << "id name " << engine_info(true)
                     << "\n"       << Options
                     << "\nuciok"  << sync_endl;
 
-      else if (token == "isready")    sync_cout << "readyok" << sync_endl;
-      else if (token == "ucinewgame") TT.clear();
-      else if (token == "go")         go(pos, is);
-      else if (token == "position")   position(pos, is);
       else if (token == "setoption")  setoption(is);
+      else if (token == "go")         go(pos, is, states);
+      else if (token == "position")   position(pos, is, states);
+      else if (token == "ucinewgame") Search::clear();
+      else if (token == "isready")    sync_cout << "readyok" << sync_endl;
 
-      // Additional custom non-UCI commands, useful for debugging
-      else if (token == "flip")       pos.flip();
-      else if (token == "bench")      benchmark(pos, is);
-      else if (token == "d")          sync_cout << pos << sync_endl;
-      else if (token == "eval")       sync_cout << Eval::trace(pos) << sync_endl;
-      else if (token == "perft")
-      {
-          int depth;
-          stringstream ss;
-
-          is >> depth;
-          ss << Options["Hash"]    << " "
-             << Options["Threads"] << " " << depth << " current perft";
-
-          benchmark(pos, ss);
-      }
+      // Additional custom non-UCI commands, mainly for debugging
+      else if (token == "flip")  pos.flip();
+      else if (token == "bench") bench(pos, is, states);
+      else if (token == "d")     sync_cout << pos << sync_endl;
+      else if (token == "eval")  sync_cout << Eval::trace(pos) << sync_endl;
       else
           sync_cout << "Unknown command: " << cmd << sync_endl;
 
-  } while (token != "quit" && argc == 1); // Passed args have one-shot behaviour
-
-  Threads.wait_for_think_finished(); // Cannot quit whilst the search is running
+  } while (token != "quit" && argc == 1); // Command line args are one-shot
 }
 
 
@@ -218,6 +252,8 @@ void UCI::loop(int argc, char* argv[]) {
 
 string UCI::value(Value v) {
 
+  assert(-VALUE_INFINITE < v && v < VALUE_INFINITE);
+
   stringstream ss;
 
   if (abs(v) < VALUE_MATE - MAX_PLY)
@@ -232,9 +268,7 @@ string UCI::value(Value v) {
 /// UCI::square() converts a Square to a string in algebraic notation (g1, a7, etc.)
 
 std::string UCI::square(Square s) {
-
-  char sq[] = { char('a' + file_of(s)), char('1' + rank_of(s)), 0 }; // NULL terminated
-  return sq;
+  return std::string{ char('a' + file_of(s)), char('1' + rank_of(s)) };
 }
 
 
@@ -274,9 +308,9 @@ Move UCI::to_move(const Position& pos, string& str) {
   if (str.length() == 5) // Junior could send promotion piece in uppercase
       str[4] = char(tolower(str[4]));
 
-  for (MoveList<LEGAL> it(pos); *it; ++it)
-      if (str == UCI::move(*it, pos.is_chess960()))
-          return *it;
+  for (const auto& m : MoveList<LEGAL>(pos))
+      if (str == UCI::move(m, pos.is_chess960()))
+          return m;
 
   return MOVE_NONE;
 }

src/uci.h

@@ -2,6 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -17,8 +18,8 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#ifndef UCIOPTION_H_INCLUDED
-#define UCIOPTION_H_INCLUDED
+#ifndef UCI_H_INCLUDED
+#define UCI_H_INCLUDED
 
 #include <map>
 #include <string>
@@ -45,15 +46,17 @@ class Option {
   typedef void (*OnChange)(const Option&);
 
 public:
-  Option(OnChange = NULL);
-  Option(bool v, OnChange = NULL);
-  Option(const char* v, OnChange = NULL);
-  Option(int v, int min, int max, OnChange = NULL);
+  Option(OnChange = nullptr);
+  Option(bool v, OnChange = nullptr);
+  Option(const char* v, OnChange = nullptr);
+  Option(double v, int minv, int maxv, OnChange = nullptr);
+  Option(const char* v, const char* cur, OnChange = nullptr);
 
   Option& operator=(const std::string&);
   void operator<<(const Option&);
-  operator int() const;
+  operator double() const;
   operator std::string() const;
+  bool operator==(const char*) const;
 
 private:
   friend std::ostream& operator<<(std::ostream&, const OptionsMap&);
@@ -69,10 +72,11 @@ 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);
 Move to_move(const Position& pos, std::string& str);
 
 } // namespace UCI
 
 extern UCI::OptionsMap Options;
 
-#endif // #ifndef UCIOPTION_H_INCLUDED
+#endif // #ifndef UCI_H_INCLUDED

src/ucioption.cpp

@@ -2,6 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -19,10 +20,10 @@
 
 #include <algorithm>
 #include <cassert>
-#include <cstdlib>
-#include <sstream>
+#include <ostream>
 
 #include "misc.h"
+#include "search.h"
 #include "thread.h"
 #include "tt.h"
 #include "uci.h"
@@ -35,18 +36,18 @@ UCI::OptionsMap Options; // Global object
 namespace UCI {
 
 /// 'On change' actions, triggered by an option's value change
-void on_clear_hash(const Option&) { TT.clear(); }
+void on_clear_hash(const Option&) { Search::clear(); }
 void on_hash_size(const Option& o) { TT.resize(o); }
 void on_logger(const Option& o) { start_logger(o); }
-void on_threads(const Option&) { Threads.read_uci_options(); }
+void on_threads(const Option& o) { Threads.set(o); }
 void on_tb_path(const Option& o) { Tablebases::init(o); }
 
 
 /// Our case insensitive less() function as required by UCI protocol
-bool ci_less(char c1, char c2) { return tolower(c1) < tolower(c2); }
-
 bool CaseInsensitiveLess::operator() (const string& s1, const string& s2) const {
-  return std::lexicographical_compare(s1.begin(), s1.end(), s2.begin(), s2.end(), ci_less);
+
+  return std::lexicographical_compare(s1.begin(), s1.end(), s2.begin(), s2.end(),
+         [](char c1, char c2) { return tolower(c1) < tolower(c2); });
 }
 
 
@@ -54,25 +55,28 @@ bool CaseInsensitiveLess::operator() (const string& s1, const string& s2) const
 
 void init(OptionsMap& o) {
 
-  const int MaxHashMB = Is64Bit ? 1024 * 1024 : 2048;
+  // at most 2^32 clusters.
+  constexpr int MaxHashMB = Is64Bit ? 131072 : 2048;
 
-  o["Write Debug Log"]       << Option(false, on_logger);
-  o["Contempt"]              << Option(0, -100, 100);
-  o["Min Split Depth"]       << Option(0, 0, 12, on_threads);
-  o["Threads"]               << Option(1, 1, MAX_THREADS, on_threads);
+  o["Debug Log File"]        << Option("", on_logger);
+  o["Contempt"]              << Option(24, -100, 100);
+  o["Analysis Contempt"]     << Option("Both var Off var White var Black var Both", "Both");
+  o["Threads"]               << Option(1, 1, 512, on_threads);
   o["Hash"]                  << Option(16, 1, MaxHashMB, on_hash_size);
   o["Clear Hash"]            << Option(on_clear_hash);
-  o["Ponder"]                << Option(true);
+  o["Ponder"]                << Option(false);
   o["MultiPV"]               << Option(1, 1, 500);
   o["Skill Level"]           << Option(20, 0, 20);
   o["Move Overhead"]         << Option(30, 0, 5000);
   o["Minimum Thinking Time"] << Option(20, 0, 5000);
-  o["Slow Mover"]            << Option(80, 10, 1000);
+  o["Slow Mover"]            << Option(84, 10, 1000);
+  o["nodestime"]             << Option(0, 0, 10000);
   o["UCI_Chess960"]          << Option(false);
+  o["UCI_AnalyseMode"]       << Option(false);
   o["SyzygyPath"]            << Option("<empty>", on_tb_path);
   o["SyzygyProbeDepth"]      << Option(1, 1, 100);
   o["Syzygy50MoveRule"]      << Option(true);
-  o["SyzygyProbeLimit"]      << Option(6, 0, 6);
+  o["SyzygyProbeLimit"]      << Option(7, 0, 7);
 }
 
 
@@ -82,20 +86,23 @@ void init(OptionsMap& o) {
 std::ostream& operator<<(std::ostream& os, const OptionsMap& om) {
 
   for (size_t idx = 0; idx < om.size(); ++idx)
-      for (OptionsMap::const_iterator it = om.begin(); it != om.end(); ++it)
-          if (it->second.idx == idx)
+      for (const auto& it : om)
+          if (it.second.idx == idx)
           {
-              const Option& o = it->second;
-              os << "\noption name " << it->first << " type " << o.type;
+              const Option& o = it.second;
+              os << "\noption name " << it.first << " type " << o.type;
 
-              if (o.type != "button")
+              if (o.type == "string" || o.type == "check" || o.type == "combo")
                   os << " default " << o.defaultValue;
 
               if (o.type == "spin")
-                  os << " min " << o.min << " max " << o.max;
+                  os << " default " << int(stof(o.defaultValue))
+                     << " min "     << o.min
+                     << " max "     << o.max;
 
               break;
           }
+
   return os;
 }
 
@@ -111,13 +118,15 @@ Option::Option(bool v, OnChange f) : type("check"), min(0), max(0), on_change(f)
 Option::Option(OnChange f) : type("button"), min(0), max(0), on_change(f)
 {}
 
-Option::Option(int v, int minv, int maxv, OnChange f) : type("spin"), min(minv), max(maxv), on_change(f)
-{ std::ostringstream ss; ss << v; defaultValue = currentValue = ss.str(); }
+Option::Option(double v, int minv, int maxv, OnChange f) : type("spin"), min(minv), max(maxv), on_change(f)
+{ defaultValue = currentValue = std::to_string(v); }
 
+Option::Option(const char* v, const char* cur, OnChange f) : type("combo"), min(0), max(0), on_change(f)
+{ defaultValue = v; currentValue = cur; }
 
-Option::operator int() const {
+Option::operator double() const {
   assert(type == "check" || type == "spin");
-  return (type == "spin" ? atoi(currentValue.c_str()) : currentValue == "true");
+  return (type == "spin" ? stof(currentValue) : currentValue == "true");
 }
 
 Option::operator std::string() const {
@@ -125,6 +134,12 @@ Option::operator std::string() const {
   return currentValue;
 }
 
+bool Option::operator==(const char* s) const {
+  assert(type == "combo");
+  return    !CaseInsensitiveLess()(currentValue, s)
+         && !CaseInsensitiveLess()(s, currentValue);
+}
+
 
 /// operator<<() inits options and assigns idx in the correct printing order
 
@@ -147,7 +162,7 @@ Option& Option::operator=(const string& v) {
 
   if (   (type != "button" && v.empty())
       || (type == "check" && v != "true" && v != "false")
-      || (type == "spin" && (atoi(v.c_str()) < min || atoi(v.c_str()) > max)))
+      || (type == "spin" && (stof(v) < min || stof(v) > max)))
       return *this;
 
   if (type != "button")

tests/instrumented.sh

@@ -0,0 +1,144 @@
+#!/bin/bash
+# check for errors under valgrind or sanitizers.
+
+error()
+{
+  echo "instrumented testing failed on line $1"
+  exit 1
+}
+trap 'error ${LINENO}' ERR
+
+# define suitable post and prefixes for testing options
+case $1 in
+  --valgrind)
+    echo "valgrind testing started"
+    prefix=''
+    exeprefix='valgrind --error-exitcode=42'
+    postfix='1>/dev/null'
+    threads="1"
+  ;;
+  --valgrind-thread)
+    echo "valgrind-thread testing started"
+    prefix=''
+    exeprefix='valgrind --error-exitcode=42'
+    postfix='1>/dev/null'
+    threads="2"
+  ;;
+  --sanitizer-undefined)
+    echo "sanitizer-undefined testing started"
+    prefix='!'
+    exeprefix=''
+    postfix='2>&1 | grep "runtime error:"'
+    threads="1"
+  ;;
+  --sanitizer-thread)
+    echo "sanitizer-thread testing started"
+    prefix='!'
+    exeprefix=''
+    postfix='2>&1 | grep "WARNING: ThreadSanitizer:"'
+    threads="2"
+
+cat << EOF > tsan.supp
+race:TTEntry::move
+race:TTEntry::depth
+race:TTEntry::bound
+race:TTEntry::save
+race:TTEntry::value
+race:TTEntry::eval
+
+race:TranspositionTable::probe
+race:TranspositionTable::hashfull
+
+EOF
+
+    export TSAN_OPTIONS="suppressions=./tsan.supp"
+
+  ;;
+  *)
+    echo "unknown testing started"
+    prefix=''
+    exeprefix=''
+    postfix=''
+    threads="1"
+  ;;
+esac
+
+# simple command line testing
+for args in "eval" \
+            "go nodes 1000" \
+            "go depth 10" \
+            "go movetime 1000" \
+            "go wtime 8000 btime 8000 winc 500 binc 500" \
+            "bench 128 $threads 10 default depth"
+do
+
+   echo "$prefix $exeprefix ./stockfish $args $postfix"
+   eval "$prefix $exeprefix ./stockfish $args $postfix"
+
+done
+
+# more general testing, following an uci protocol exchange
+cat << EOF > game.exp
+ set timeout 10
+ spawn $exeprefix ./stockfish
+
+ send "uci\n"
+ expect "uciok"
+
+ send "setoption name Threads value $threads\n"
+
+ send "ucinewgame\n"
+ send "position startpos\n"
+ send "go nodes 1000\n"
+ expect "bestmove"
+
+ send "position startpos moves e2e4 e7e6\n"
+ send "go nodes 1000\n"
+ expect "bestmove"
+
+ send "position fen 5rk1/1K4p1/8/8/3B4/8/8/8 b - - 0 1\n"
+ send "go depth 30\n"
+ expect "bestmove"
+
+ send "quit\n"
+ expect eof
+
+ # return error code of the spawned program, useful for valgrind
+ lassign [wait] pid spawnid os_error_flag value
+ exit \$value
+EOF
+
+#download TB as needed
+if [ ! -d ../tests/syzygy ]; then
+   curl -sL https://api.github.com/repos/niklasf/python-chess/tarball/9b9aa13f9f36d08aadfabff872882f4ab1494e95 | tar -xzf -
+   mv niklasf-python-chess-9b9aa13 ../tests/syzygy
+fi
+
+cat << EOF > syzygy.exp
+ set timeout 240
+ spawn $exeprefix ./stockfish
+ send "uci\n"
+ send "setoption name SyzygyPath value ../tests/syzygy/\n"
+ expect "info string Found 35 tablebases" {} timeout {exit 1}
+ send "bench 128 1 10 default depth\n"
+ send "quit\n"
+ expect eof
+
+ # return error code of the spawned program, useful for valgrind
+ lassign [wait] pid spawnid os_error_flag value
+ exit \$value
+EOF
+
+for exp in game.exp syzygy.exp
+do
+
+  echo "$prefix expect $exp $postfix"
+  eval "$prefix expect $exp $postfix"
+
+  rm $exp
+
+done
+
+rm -f tsan.supp
+
+echo "instrumented testing OK"

tests/perft.sh

@@ -0,0 +1,32 @@
+#!/bin/bash
+# verify perft numbers (positions from https://chessprogramming.wikispaces.com/Perft+Results)
+
+error()
+{
+  echo "perft testing failed on line $1"
+  exit 1
+}
+trap 'error ${LINENO}' ERR
+
+echo "perft testing started"
+
+cat << EOF > perft.exp
+   set timeout 10
+   lassign \$argv pos depth result
+   spawn ./stockfish
+   send "position \$pos\\ngo perft \$depth\\n"
+   expect "Nodes searched? \$result" {} timeout {exit 1}
+   send "quit\\n"
+   expect eof
+EOF
+
+expect perft.exp startpos 5 4865609 > /dev/null
+expect perft.exp "fen r3k2r/p1ppqpb1/bn2pnp1/3PN3/1p2P3/2N2Q1p/PPPBBPPP/R3K2R w KQkq -" 5 193690690 > /dev/null
+expect perft.exp "fen 8/2p5/3p4/KP5r/1R3p1k/8/4P1P1/8 w - -" 6 11030083 > /dev/null
+expect perft.exp "fen r3k2r/Pppp1ppp/1b3nbN/nP6/BBP1P3/q4N2/Pp1P2PP/R2Q1RK1 w kq - 0 1" 5 15833292 > /dev/null
+expect perft.exp "fen rnbq1k1r/pp1Pbppp/2p5/8/2B5/8/PPP1NnPP/RNBQK2R w KQ - 1 8" 5 89941194 > /dev/null
+expect perft.exp "fen r4rk1/1pp1qppp/p1np1n2/2b1p1B1/2B1P1b1/P1NP1N2/1PP1QPPP/R4RK1 w - - 0 10" 5 164075551 > /dev/null
+
+rm perft.exp
+
+echo "perft testing OK"

tests/reprosearch.sh

@@ -0,0 +1,61 @@
+#!/bin/bash
+# verify reproducible search
+
+error()
+{
+  echo "reprosearch testing failed on line $1"
+  exit 1
+}
+trap 'error ${LINENO}' ERR
+
+echo "reprosearch testing started"
+
+# repeat two short games, separated by ucinewgame. 
+# with go nodes $nodes they should result in exactly
+# the same node count for each iteration.
+cat << EOF > repeat.exp
+ set timeout 10
+ spawn ./stockfish
+ lassign \$argv nodes
+
+ send "uci\n"
+ expect "uciok"
+
+ send "ucinewgame\n"
+ send "position startpos\n"
+ send "go nodes \$nodes\n"
+ expect "bestmove"
+
+ send "position startpos moves e2e4 e7e6\n"
+ send "go nodes \$nodes\n"
+ expect "bestmove"
+
+ send "ucinewgame\n"
+ send "position startpos\n"
+ send "go nodes \$nodes\n"
+ expect "bestmove"
+
+ send "position startpos moves e2e4 e7e6\n"
+ send "go nodes \$nodes\n"
+ expect "bestmove"
+
+ send "quit\n"
+ expect eof
+EOF
+
+# to increase the likelyhood of finding a non-reproducible case,
+# the allowed number of nodes are varied systematically
+for i in `seq 1 20`
+do
+
+  nodes=$((100*3**i/2**i))
+  echo "reprosearch testing with $nodes nodes"
+
+  # each line should appear exactly an even number of times
+  expect repeat.exp $nodes 2>&1 | grep -o "nodes [0-9]*" | sort | uniq -c | awk '{if ($1%2!=0) exit(1)}'
+
+done
+
+rm repeat.exp
+
+echo "reprosearch testing OK"

tests/signature.sh

@@ -0,0 +1,31 @@
+#!/bin/bash
+# obtain and optionally verify Bench / signature
+# if no reference is given, the output is deliberately limited to just the signature
+
+error()
+{
+  echo "running bench for signature failed on line $1"
+  exit 1
+}
+trap 'error ${LINENO}' ERR
+
+# obtain
+
+signature=`./stockfish bench 2>&1 | grep "Nodes searched  : " | awk '{print $4}'`
+
+if [ $# -gt 0 ]; then
+   # compare to given reference
+   if [ "$1" != "$signature" ]; then
+      if [ -z "$signature" ]; then
+         echo "No signature obtained from bench. Code crashed or assert triggered ?"
+      else
+         echo "signature mismatch: reference $1 obtained: $signature ."
+      fi
+      exit 1
+   else
+      echo "signature OK: $signature"
+   fi
+else
+   # just report signature
+   echo $signature
+fi