Stockfish 6

Stockfish bench signature is: 8918745

AUTHORS

@@ -0,0 +1,64 @@
+# Generated with git shortlog -sn | cut -c8-', which sorts by commits (manually moved Tord to top)
+
+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
+Alexander Kure
+Dan Schmidt
+H. Felix Wittmann
+Justin Blanchard
+Linus Arver
+RyanTaker
+ceebo
+Joseph H Ellis
+Stephane Nicolet
+Ajith
+Andy Duplain
+Auguste Pop
+Balint Pfliegel
+Chris Cain
+Dariusz Orzechowski
+Gregor Cramer
+Hiraoka Takuya
+Hongzhi Cheng
+Jonathan Calovski
+Joseph R. Prostko
+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
+kinderchocolate
+pellanda
+renouve
+shane31
+thaspel

Readme.md

@@ -0,0 +1,112 @@
+### Overview
+
+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
+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
+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.
+
+This version of Stockfish has support for Syzygybases.
+
+
+### Files
+
+This distribution of Stockfish consists of the following files:
+
+  * Readme.md, the file you are currently reading.
+
+  * Copying.txt, a text file containing the GNU General Public License.
+
+  * src, a subdirectory containing the full source code, including a Makefile
+    that can be used to compile Stockfish on Unix-like systems.
+
+
+### Syzygybases
+
+**Configuration**
+
+Syzygybases are configured using the UCI options "SyzygyPath",
+"SyzygyProbeDepth", "Syzygy50MoveRule" and "SyzygyProbeLimit".
+
+The option "SyzygyPath" should be set to the directory or directories that
+contain the .rtbw and .rtbz files. Multiple directories should be
+separated by ";" on Windows and by ":" on Unix-based operating systems.
+**Do not use spaces around the ";" or ":".**
+
+Example: `C:\tablebases\wdl345;C:\tablebases\wdl6;D:\tablebases\dtz345;D:\tablebases\dtz6`
+
+It is recommended to store .rtbw files on an SSD. There is no loss in
+storing the .rtbz files on a regular HD.
+
+Increasing the "SyzygyProbeDepth" option lets the engine probe less
+aggressively. Set this option to a higher value if you experience too much
+slowdown (in terms of nps) due to TB probing.
+
+Set the "Syzygy50MoveRule" option to false if you want tablebase positions
+that are drawn by the 50-move rule to count as win or loss. This may be useful
+for correspondence games (because of tablebase adjudication).
+
+The "SyzygyProbeLimit" option should normally be left at its default value.
+
+**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.
+If the engine reports a very large score (typically 123.xx), this means
+that it has found a winning line into a tablebase position.
+
+If the engine is given a position to search that is in the tablebases, it
+will use the tablebases at the beginning of the search to preselect all
+good moves, i.e. all moves that preserve the win or preserve the draw while
+taking into account the 50-move rule.
+It will then perform a search only on those moves. **The engine will not move
+immediately**, unless there is only a single good move. **The engine likely
+will not report a mate score even if the position is known to be won.**
+
+It is therefore clear that behaviour is not identical to what one might
+be used to with Nalimov tablebases. There are technical reasons for this
+difference, the main technical reason being that Nalimov tablebases use the
+DTM metric (distance-to-mate), while Syzygybases use a variation of the
+DTZ metric (distance-to-zero, zero meaning any move that resets the 50-move
+counter). This special metric is one of the reasons that Syzygybases are
+more compact than Nalimov tablebases, while still storing all information
+needed for optimal play and in addition being able to take into account
+the 50-move rule.
+
+
+### Compiling it yourself
+
+On Unix-like systems, it should be possible to compile Stockfish
+directly from the source code with the included Makefile.
+
+Stockfish has support for 32 or 64-bit CPUs, the hardware POPCNT
+instruction, big-endian machines such as Power PC, and other platforms.
+
+In general it is recommended to run `make help` to see a list of make
+targets with corresponding descriptions. When not using the Makefile to
+compile (for instance with Microsoft MSVC) you need to manually
+set/unset some switches in the compiler command line; see file *types.h*
+for a quick reference.
+
+
+### Terms of use
+
+Stockfish is free, and distributed under the **GNU General Public License**
+(GPL). Essentially, this means that you are free to do almost exactly
+what you want with the program, including distributing it among your
+friends, making it available for download from your web site, selling
+it (either by itself or as part of some bigger software package), or
+using it as the starting point for a software project of your own.
+
+The only real limitation is that whenever you distribute Stockfish in
+some way, you must always include the full source code, or a pointer
+to where the source code can be found. 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*

Readme.txt

@@ -1,81 +0,0 @@
-1. Introduction
----------------
-
-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
-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 32 CPUs, but has not been
-tested thoroughly with more than 4.  The program tries to detect the
-number of CPUs on your computer and sets the number of search threads
-accordingly, but please be aware that the detection is not always
-correct. 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. If you are using more than eight threads, it is
-recommended to raise the value of the "Min Split Depth" UCI parameter to
-7.
-
-
-2. Files
---------
-
-This distribution of Stockfish consists of the following files:
-
-  * Readme.txt, the file you are currently reading.
-
-  * Copying.txt, a text file containing the GNU General Public License.
-
-  * src/, a subdirectory containing the full source code, including a
-    Makefile that can be used to compile Stockfish on Unix-like systems.
-    For further information about how to compile Stockfish yourself read
-    section 4 below.
-
-  * polyglot.ini, for using Stockfish with Fabien Letouzey's PolyGlot
-    adapter.
-
-
-3. Opening books
-----------------
-
-This version of Stockfish has support for PolyGlot opening books. For
-information about how to create such books, consult the PolyGlot
-documentation. The book file can be selected by setting the "Book File"
-UCI parameter.
-
-
-4. Compiling it yourself
-------------------------
-
-On Unix-like systems, it should be possible to compile Stockfish
-directly from the source code with the included Makefile.
-
-Stockfish has support for 32 or 64-bit CPUs, the hardware POPCNT
-instruction, big-endian machines such as Power PC, and other platforms.
-
-In general it is recommended to run 'make help' to see a list of make
-targets with corresponding descriptions. When not using Makefile to
-compile (for instance with Microsoft MSVC) you need to manually
-set/unset some switches in the compiler command line; see file "types.h"
-for a quick reference.
-
-
-5. Terms of use
----------------
-
-Stockfish is free, and distributed under the GNU General Public License
-(GPL). Essentially, this means that you are free to do almost exactly
-what you want with the program, including distributing it among your
-friends, making it available for download from your web site, selling
-it (either by itself or as part of some bigger software package), or
-using it as the starting point for a software project of your own.
-
-The only real limitation is that whenever you distribute Stockfish in
-some way, you must always include the full source code, or a pointer
-to where the source code can be found. 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.

polyglot.ini

@@ -1,43 +0,0 @@
-
-[PolyGlot]
-
-EngineDir = .
-EngineCommand = ./stockfish
-
-Book = false
-BookFile = book.bin
-
-Log = false
-LogFile = stockfish.log
-
-Resign = true
-ResignScore = 600
-
-[Engine]
-
-Use Search Log = false
-Search Log Filename = SearchLog.txt
-Book File = book.bin
-Best Book Move = false
-Mobility (Middle Game) = 100
-Mobility (Endgame) = 100
-Passed Pawns (Middle Game) = 100
-Passed Pawns (Endgame) = 100
-Space = 100
-Aggressiveness = 100
-Cowardice = 100
-Min Split Depth = 4
-Max Threads per Split Point = 5
-Threads = 1
-Use Sleeping Threads = false
-Hash = 128
-Ponder = true
-OwnBook = false
-MultiPV = 1
-Skill Level = 20
-Emergency Move Horizon = 40
-Emergency Base Time = 200
-Emergency Move Time = 70
-Minimum Thinking Time = 20
-UCI_Chess960 = false
-UCI_AnalyseMode = false

src/Makefile

@@ -1,6 +1,6 @@
 # Stockfish, a UCI chess playing engine derived from Glaurung 2.1
 # Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-# Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+# 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
@@ -28,19 +28,15 @@ EXE = stockfish
 
 ### Installation dir definitions
 PREFIX = /usr/local
-# Haiku has a non-standard filesystem layout
-ifeq ($(UNAME),Haiku)
-	PREFIX=/boot/common
-endif
 BINDIR = $(PREFIX)/bin
 
 ### Built-in benchmark for pgo-builds
-PGOBENCH = ./$(EXE) bench 32 1 10 default depth
+PGOBENCH = ./$(EXE) bench 16 1 1000 default time
 
 ### Object files
-OBJS = benchmark.o bitbase.o bitboard.o book.o endgame.o evaluate.o main.o \
-	material.o misc.o movegen.o movepick.o notation.o pawns.o position.o \
-	search.o thread.o timeman.o tt.o uci.o ucioption.o
+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 \
+	search.o thread.o timeman.o tt.o uci.o ucioption.o syzygy/tbprobe.o
 
 ### ==========================================================================
 ### Section 2. High-level Configuration
@@ -52,114 +48,89 @@ OBJS = benchmark.o bitbase.o bitboard.o book.o endgame.o evaluate.o main.o \
 # debug = yes/no      --- -DNDEBUG         --- Enable/Disable debug mode
 # optimize = yes/no   --- (-O3/-fast etc.) --- Enable/Disable optimizations
 # arch = (name)       --- (-arch)          --- Target architecture
-# os = (name)         ---                  --- Target operating system
 # 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
+# sse = yes/no        --- -msse            --- Use Intel Streaming SIMD Extensions
+# pext = yes/no       --- -DUSE_PEXT       --- Use pext x86_64 asm-instruction
 #
 # Note that Makefile is space sensitive, so when adding new architectures
 # or modifying existing flags, you have to make sure there are no extra spaces
 # at the end of the line for flag values.
 
-### 2.1. General
-debug = no
+### 2.1. General and architecture defaults
 optimize = yes
+debug = no
+bits = 32
+prefetch = no
+bsfq = no
+popcnt = no
+sse = no
+pext = no
 
 ### 2.2 Architecture specific
 
-# General-section
-ifeq ($(ARCH),general-64)
-	arch = any
-	os = any
-	bits = 64
-	prefetch = no
-	bsfq = no
-	popcnt = no
-endif
-
 ifeq ($(ARCH),general-32)
 	arch = any
-	os = any
-	bits = 32
-	prefetch = no
-	bsfq = no
-	popcnt = no
-endif
-
-# x86-section
-ifeq ($(ARCH),x86-64)
-	arch = x86_64
-	os = any
-	bits = 64
-	prefetch = yes
-	bsfq = yes
-	popcnt = no
-endif
-
-ifeq ($(ARCH),x86-64-modern)
-	arch = x86_64
-	os = any
-	bits = 64
-	prefetch = yes
-	bsfq = yes
-	popcnt = yes
-endif
-
-ifeq ($(ARCH),x86-32)
-	arch = i386
-	os = any
-	bits = 32
-	prefetch = yes
-	bsfq = no
-	popcnt = no
 endif
 
 ifeq ($(ARCH),x86-32-old)
 	arch = i386
-	os = any
-	bits = 32
-	prefetch = no
-	bsfq = no
-	popcnt = no
 endif
 
-# osx-section
-ifeq ($(ARCH),osx-ppc-64)
-	arch = ppc64
-	os = osx
+ifeq ($(ARCH),x86-32)
+	arch = i386
+	prefetch = yes
+	sse = yes
+endif
+
+ifeq ($(ARCH),general-64)
+	arch = any
 	bits = 64
-	prefetch = no
-	bsfq = no
-	popcnt = no
 endif
 
-ifeq ($(ARCH),osx-ppc-32)
-	arch = ppc
-	os = osx
-	bits = 32
-	prefetch = no
-	bsfq = no
-	popcnt = no
-endif
-
-ifeq ($(ARCH),osx-x86-64)
+ifeq ($(ARCH),x86-64)
 	arch = x86_64
-	os = osx
 	bits = 64
 	prefetch = yes
 	bsfq = yes
-	popcnt = no
+	sse = yes
 endif
 
-ifeq ($(ARCH),osx-x86-32)
-	arch = i386
-	os = osx
-	bits = 32
+ifeq ($(ARCH),x86-64-modern)
+	arch = x86_64
+	bits = 64
 	prefetch = yes
-	bsfq = no
-	popcnt = no
+	bsfq = yes
+	popcnt = yes
+	sse = yes
+endif
+
+ifeq ($(ARCH),x86-64-bmi2)
+	arch = x86_64
+	bits = 64
+	prefetch = yes
+	bsfq = yes
+	popcnt = yes
+	sse = yes
+	pext = yes
+endif
+
+ifeq ($(ARCH),armv7)
+	arch = armv7
+	prefetch = yes
+	bsfq = yes
+endif
+
+ifeq ($(ARCH),ppc-32)
+	arch = ppc
+endif
+
+ifeq ($(ARCH),ppc-64)
+	arch = ppc64
+	bits = 64
 endif
 
 
@@ -168,87 +139,72 @@ endif
 ### ==========================================================================
 
 ### 3.1 Selecting compiler (default = gcc)
+
+CXXFLAGS += -Wall -Wcast-qual -fno-exceptions -fno-rtti $(EXTRACXXFLAGS)
+LDFLAGS += $(EXTRALDFLAGS)
+
 ifeq ($(COMP),)
 	COMP=gcc
 endif
 
-ifeq ($(COMP),mingw)
-	comp=mingw
-	CXX=g++
-	profile_prepare = gcc-profile-prepare
-	profile_make = gcc-profile-make
-	profile_use = gcc-profile-use
-	profile_clean = gcc-profile-clean
-endif
-
 ifeq ($(COMP),gcc)
 	comp=gcc
 	CXX=g++
-	profile_prepare = gcc-profile-prepare
-	profile_make = gcc-profile-make
-	profile_use = gcc-profile-use
-	profile_clean = gcc-profile-clean
+	CXXFLAGS += -ansi -pedantic -Wno-long-long -Wextra -Wshadow
+endif
+
+ifeq ($(COMP),mingw)
+	comp=mingw
+	CXX=g++
+	CXXFLAGS += -Wextra -Wshadow
+	LDFLAGS += -static-libstdc++ -static-libgcc
 endif
 
 ifeq ($(COMP),icc)
 	comp=icc
 	CXX=icpc
-	profile_prepare = icc-profile-prepare
-	profile_make = icc-profile-make
-	profile_use = icc-profile-use
-	profile_clean = icc-profile-clean
+	CXXFLAGS += -diag-disable 1476,10120 -Wcheck -Wabi -Wdeprecated -strict-ansi
 endif
 
 ifeq ($(COMP),clang)
 	comp=clang
 	CXX=clang++
+	CXXFLAGS += -pedantic -Wno-long-long -Wextra -Wshadow
+endif
+
+ifeq ($(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
 	profile_make = gcc-profile-make
 	profile_use = gcc-profile-use
 	profile_clean = gcc-profile-clean
 endif
 
-### 3.2 General compiler settings
-CXXFLAGS = -g -Wall -Wcast-qual -fno-exceptions -fno-rtti $(EXTRACXXFLAGS)
-
-ifeq ($(comp),gcc)
-	CXXFLAGS += -ansi -pedantic -Wno-long-long -Wextra -Wshadow
+ifeq ($(UNAME),Darwin)
+	CXXFLAGS += -arch $(arch) -mmacosx-version-min=10.6
+	LDFLAGS += -arch $(arch) -mmacosx-version-min=10.6
 endif
 
-ifeq ($(comp),mingw)
-	CXXFLAGS += -Wextra -Wshadow
-endif
-
-ifeq ($(comp),icc)
-	CXXFLAGS += -wd383,981,1418,1419,10187,10188,11505,11503 -Wcheck -Wabi -Wdeprecated -strict-ansi
-endif
-
-ifeq ($(comp),clang)
-	CXXFLAGS += -ansi -pedantic -Wno-long-long -Wextra -Wshadow
-endif
-
-ifeq ($(os),osx)
-	CXXFLAGS += -arch $(arch)
-endif
-
-### 3.3 General linker settings
-LDFLAGS = $(EXTRALDFLAGS)
-
 ### On mingw use Windows threads, otherwise POSIX
 ifneq ($(comp),mingw)
-	# Haiku has pthreads in its libroot, so only link it in on other platforms
-	ifneq ($(UNAME),Haiku)
-		LDFLAGS += -lpthread
+	# On Android Bionic's C library comes with its own pthread implementation bundled in
+	ifneq ($(arch),armv7)
+		# Haiku has pthreads in its libroot, so only link it in on other platforms
+		ifneq ($(UNAME),Haiku)
+			LDFLAGS += -lpthread
+		endif
 	endif
 endif
 
-ifeq ($(os),osx)
-	LDFLAGS += -arch $(arch)
-endif
-
 ### 3.4 Debugging
 ifeq ($(debug),no)
 	CXXFLAGS += -DNDEBUG
+else
+	CXXFLAGS += -g
 endif
 
 ### 3.5 Optimization
@@ -257,7 +213,7 @@ ifeq ($(optimize),yes)
 	ifeq ($(comp),gcc)
 		CXXFLAGS += -O3
 
-		ifeq ($(os),osx)
+		ifeq ($(UNAME),Darwin)
 			ifeq ($(arch),i386)
 				CXXFLAGS += -mdynamic-no-pic
 			endif
@@ -265,6 +221,10 @@ ifeq ($(optimize),yes)
 				CXXFLAGS += -mdynamic-no-pic
 			endif
 		endif
+
+		ifeq ($(arch),armv7)
+			CXXFLAGS += -fno-gcse -mthumb -march=armv7-a -mfloat-abi=softfp
+		endif
 	endif
 
 	ifeq ($(comp),mingw)
@@ -272,18 +232,21 @@ ifeq ($(optimize),yes)
 	endif
 
 	ifeq ($(comp),icc)
-		ifeq ($(os),osx)
+		ifeq ($(UNAME),Darwin)
 			CXXFLAGS += -fast -mdynamic-no-pic
 		else
-			CXXFLAGS += -O3
+			CXXFLAGS += -fast
 		endif
 	endif
 
 	ifeq ($(comp),clang)
-		### -O4 requires a linker that supports LLVM's LTO
 		CXXFLAGS += -O3
 
-		ifeq ($(os),osx)
+		ifeq ($(UNAME),Darwin)
+			ifeq ($(pext),no)
+				CXXFLAGS += -flto
+				LDFLAGS += $(CXXFLAGS)
+			endif
 			ifeq ($(arch),i386)
 				CXXFLAGS += -mdynamic-no-pic
 			endif
@@ -301,8 +264,10 @@ endif
 
 ### 3.7 prefetch
 ifeq ($(prefetch),yes)
-	CXXFLAGS += -msse
-	DEPENDFLAGS += -msse
+	ifeq ($(sse),yes)
+		CXXFLAGS += -msse
+		DEPENDFLAGS += -msse
+	endif
 else
 	CXXFLAGS += -DNO_PREFETCH
 endif
@@ -314,14 +279,27 @@ endif
 
 ### 3.9 popcnt
 ifeq ($(popcnt),yes)
-	CXXFLAGS += -msse3 -DUSE_POPCNT
+	ifeq ($(comp),icc)
+		CXXFLAGS += -msse3 -DUSE_POPCNT
+	else
+		CXXFLAGS += -msse3 -mpopcnt -DUSE_POPCNT
+	endif
 endif
 
-### 3.10 Link Time Optimization, it works since gcc 4.5 but not on mingw.
+### 3.10 pext
+ifeq ($(pext),yes)
+	CXXFLAGS += -DUSE_PEXT
+	ifeq ($(comp),$(filter $(comp),gcc clang mingw))
+		CXXFLAGS += -mbmi -mbmi2
+	endif
+endif
+
+### 3.11 Link Time Optimization, it works since gcc 4.5 but not on mingw.
 ### This is a mix of compile and link time options because the lto link phase
 ### needs access to the optimization flags.
 ifeq ($(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 \( $(GCC_MAJOR) \> 4 \) \| \( $(GCC_MAJOR) \= 4 \& $(GCC_MINOR) \>= 5 \)))
@@ -329,8 +307,17 @@ ifeq ($(comp),gcc)
 			LDFLAGS += $(CXXFLAGS)
 		endif
 	endif
+	endif
 endif
 
+### 3.12 Android 5 can only run position independent executables. Note that this
+### breaks Android 4.0 and earlier.
+ifeq ($(arch),armv7)
+	CXXFLAGS += -fPIE
+	LDFLAGS += -fPIE -pie
+endif
+
+
 ### ==========================================================================
 ### Section 4. Public targets
 ### ==========================================================================
@@ -343,43 +330,39 @@ help:
 	@echo ""
 	@echo "Supported targets:"
 	@echo ""
-	@echo "build                > Build unoptimized version"
-	@echo "profile-build        > Build PGO-optimized version"
-	@echo "strip                > Strip executable"
-	@echo "install              > Install executable"
-	@echo "clean                > Clean up"
-	@echo "testrun              > Make sample run"
+	@echo "build                   > Standard build"
+	@echo "profile-build           > PGO build"
+	@echo "strip                   > Strip executable"
+	@echo "install                 > Install executable"
+	@echo "clean                   > Clean up"
 	@echo ""
 	@echo "Supported archs:"
 	@echo ""
-	@echo "x86-64               > x86 64-bit"
-	@echo "x86-64-modern        > x86 64-bit with runtime support for popcnt instruction"
-	@echo "x86-32               > x86 32-bit excluding old hardware without SSE-support"
-	@echo "x86-32-old           > x86 32-bit including also very old hardware"
-	@echo "osx-ppc-64           > PPC-Mac OS X 64 bit"
-	@echo "osx-ppc-32           > PPC-Mac OS X 32 bit"
-	@echo "osx-x86-64           > x86-Mac OS X 64 bit"
-	@echo "osx-x86-32           > x86-Mac OS X 32 bit"
-	@echo "general-64           > unspecified 64-bit"
-	@echo "general-32           > unspecified 32-bit"
+	@echo "x86-64                  > x86 64-bit"
+	@echo "x86-64-modern           > x86 64-bit with popcnt support"
+	@echo "x86-64-bmi2             > x86 64-bit with pext support"
+	@echo "x86-32                  > x86 32-bit with SSE support"
+	@echo "x86-32-old              > x86 32-bit fall back for old hardware"
+	@echo "ppc-64                  > PPC 64-bit"
+	@echo "ppc-32                  > PPC 32-bit"
+	@echo "armv7                   > ARMv7 32-bit"
+	@echo "general-64              > unspecified 64-bit"
+	@echo "general-32              > unspecified 32-bit"
 	@echo ""
-	@echo "Supported comps:"
+	@echo "Supported compilers:"
 	@echo ""
-	@echo "gcc                  > Gnu compiler (default)"
-	@echo "icc                  > Intel compiler"
-	@echo "mingw                > Gnu compiler with MinGW under Windows"
-	@echo "clang                > LLVM Clang compiler"
-	@echo ""
-	@echo "Non-standard targets:"
-	@echo ""
-	@echo "make hpux           >  Compile for HP-UX. Compiler = aCC"
+	@echo "gcc                     > Gnu compiler (default)"
+	@echo "mingw                   > Gnu compiler with MinGW under Windows"
+	@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 ""
-	@echo "make profile-build ARCH=x86-64    (This is for 64-bit systems)"
-	@echo "make profile-build ARCH=x86-32    (This is for 32-bit systems)"
+	@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 ""
 
+.PHONY: build profile-build
 build:
 	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) config-sanity
 	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) all
@@ -391,14 +374,14 @@ profile-build:
 	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) $(profile_prepare)
 	@echo ""
 	@echo "Step 1/4. Building executable for benchmark ..."
-	@touch *.cpp *.h
+	@touch *.cpp *.h syzygy/*.cpp syzygy/*.h
 	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) $(profile_make)
 	@echo ""
 	@echo "Step 2/4. Running benchmark for pgo-build ..."
 	@$(PGOBENCH) > /dev/null
 	@echo ""
 	@echo "Step 3/4. Building final executable ..."
-	@touch *.cpp
+	@touch *.cpp *.h syzygy/*.cpp syzygy/*.h
 	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) $(profile_use)
 	@echo ""
 	@echo "Step 4/4. Deleting profile data ..."
@@ -413,10 +396,7 @@ install:
 	-strip $(BINDIR)/$(EXE)
 
 clean:
-	$(RM) $(EXE) $(EXE).exe *.o .depend *~ core bench.txt *.gcda
-
-testrun:
-	@$(PGOBENCH)
+	$(RM) $(EXE) $(EXE).exe *.o .depend *~ core bench.txt *.gcda ./syzygy/*.o ./syzygy/*.gcda
 
 default:
 	help
@@ -433,11 +413,12 @@ config-sanity:
 	@echo "debug: '$(debug)'"
 	@echo "optimize: '$(optimize)'"
 	@echo "arch: '$(arch)'"
-	@echo "os: '$(os)'"
 	@echo "bits: '$(bits)'"
 	@echo "prefetch: '$(prefetch)'"
 	@echo "bsfq: '$(bsfq)'"
 	@echo "popcnt: '$(popcnt)'"
+	@echo "sse: '$(sse)'"
+	@echo "pext: '$(pext)'"
 	@echo ""
 	@echo "Flags:"
 	@echo "CXX: $(CXX)"
@@ -449,12 +430,13 @@ config-sanity:
 	@test "$(debug)" = "yes" || test "$(debug)" = "no"
 	@test "$(optimize)" = "yes" || test "$(optimize)" = "no"
 	@test "$(arch)" = "any" || test "$(arch)" = "x86_64" || test "$(arch)" = "i386" || \
-	 test "$(arch)" = "ppc64" || test "$(arch)" = "ppc"
-	@test "$(os)" = "any" || test "$(os)" = "osx"
+	 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 "$(pext)" = "no"
 	@test "$(comp)" = "gcc" || test "$(comp)" = "icc" || test "$(comp)" = "mingw" || test "$(comp)" = "clang"
 
 $(EXE): $(OBJS)
@@ -465,18 +447,21 @@ gcc-profile-prepare:
 
 gcc-profile-make:
 	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) \
-	EXTRACXXFLAGS='-fprofile-generate' \
+	EXTRACXXFLAGS='-fprofile-arcs' \
 	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='-fprofile-use' \
+	EXTRACXXFLAGS='-fbranch-probabilities' \
 	EXTRALDFLAGS='-lgcov' \
 	all
 
 gcc-profile-clean:
-	@rm -rf *.gcda *.gcno bench.txt
+	@rm -rf *.gcda *.gcno syzygy/*.gcda syzygy/*.gcno bench.txt
 
 icc-profile-prepare:
 	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) icc-profile-clean
@@ -500,15 +485,3 @@ icc-profile-clean:
 
 -include .depend
 
-
-### ==========================================================================
-### Section 6. Non-standard targets
-### ==========================================================================
-
-hpux:
-	$(MAKE) \
-	CXX='/opt/aCC/bin/aCC -AA +hpxstd98 -mt +O3 -DNDEBUG -DNO_PREFETCH' \
-	CXXFLAGS="" \
-	LDFLAGS="" \
-	all
-

src/benchmark.cpp

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -17,6 +17,7 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include <algorithm>
 #include <fstream>
 #include <iostream>
 #include <istream>
@@ -27,11 +28,13 @@
 #include "search.h"
 #include "thread.h"
 #include "tt.h"
-#include "ucioption.h"
+#include "uci.h"
 
 using namespace std;
 
-static const char* Defaults[] = {
+namespace {
+
+const char* Defaults[] = {
   "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",
@@ -47,17 +50,45 @@ static const char* Defaults[] = {
   "3r1rk1/p5pp/bpp1pp2/8/q1PP1P2/b3P3/P2NQRPP/1R2B1K1 b - - 6 22",
   "r1q2rk1/2p1bppp/2Pp4/p6b/Q1PNp3/4B3/PP1R1PPP/2K4R w - - 2 18",
   "4k2r/1pb2ppp/1p2p3/1R1p4/3P4/2r1PN2/P4PPP/1R4K1 b - - 3 22",
-  "3q2k1/pb3p1p/4pbp1/2r5/PpN2N2/1P2P2P/5PP1/Q2R2K1 b - - 4 26"
+  "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",
+  "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",
+  "8/1p3pp1/7p/5P1P/2k3P1/8/2K2P2/8 w - - 0 1",
+  "8/pp2r1k1/2p1p3/3pP2p/1P1P1P1P/P5KR/8/8 w - - 0 1",
+  "8/3p4/p1bk3p/Pp6/1Kp1PpPp/2P2P1P/2P5/5B2 b - - 0 1",
+  "5k2/7R/4P2p/5K2/p1r2P1p/8/8/8 b - - 0 1",
+  "6k1/6p1/P6p/r1N5/5p2/7P/1b3PP1/4R1K1 w - - 0 1",
+  "1r3k2/4q3/2Pp3b/3Bp3/2Q2p2/1p1P2P1/1P2KP2/3N4 w - - 0 1",
+  "6k1/4pp1p/3p2p1/P1pPb3/R7/1r2P1PP/3B1P2/6K1 w - - 0 1",
+  "8/3p3B/5p2/5P2/p7/PP5b/k7/6K1 w - - 0 1",
+
+  // 5-man positions
+  "8/8/8/8/5kp1/P7/8/1K1N4 w - - 0 1",     // Kc2 - mate
+  "8/8/8/5N2/8/p7/8/2NK3k w - - 0 1",      // Na2 - mate
+  "8/3k4/8/8/8/4B3/4KB2/2B5 w - - 0 1",    // draw
+
+  // 6-man positions
+  "8/8/1P6/5pr1/8/4R3/7k/2K5 w - - 0 1",   // Re5 - mate
+  "8/2p4P/8/kr6/6R1/8/8/1K6 w - - 0 1",    // Ka2 - mate
+  "8/8/3P3k/8/1p6/8/1P6/1K3n2 b - - 0 1",  // Nd2 - draw
+
+  // 7-man positions
+  "8/R7/2q5/8/6k1/8/1P5p/K6R w - - 0 124", // Draw
 };
 
+} // namespace
 
 /// benchmark() runs a simple benchmark by letting Stockfish analyze a set
-/// of positions for a given limit each. There are five parameters; the
+/// 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 12), an optional file name where to look for positions in fen
+/// 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 secs or number of nodes.
+/// limit value: depth (default), time in millisecs or number of nodes.
 
 void benchmark(const Position& current, istream& is) {
 
@@ -66,9 +97,9 @@ void benchmark(const Position& current, istream& is) {
   vector<string> fens;
 
   // Assign default values to missing arguments
-  string ttSize    = (is >> token) ? token : "128";
+  string ttSize    = (is >> token) ? token : "16";
   string threads   = (is >> token) ? token : "1";
-  string limit     = (is >> token) ? token : "12";
+  string limit     = (is >> token) ? token : "13";
   string fenFile   = (is >> token) ? token : "default";
   string limitType = (is >> token) ? token : "depth";
 
@@ -77,19 +108,22 @@ void benchmark(const Position& current, istream& is) {
   TT.clear();
 
   if (limitType == "time")
-      limits.movetime = 1000 * atoi(limit.c_str()); // movetime is in ms
+      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());
 
   if (fenFile == "default")
-      fens.assign(Defaults, Defaults + 16);
+      fens.assign(Defaults, Defaults + 37);
 
   else if (fenFile == "current")
-      fens.push_back(current.to_fen());
+      fens.push_back(current.fen());
 
   else
   {
@@ -99,7 +133,7 @@ void benchmark(const Position& current, istream& is) {
       if (!file.is_open())
       {
           cerr << "Unable to open file " << fenFile << endl;
-          exit(EXIT_FAILURE);
+          return;
       }
 
       while (getline(file, fen))
@@ -109,31 +143,30 @@ void benchmark(const Position& current, istream& is) {
       file.close();
   }
 
-  int64_t nodes = 0;
+  uint64_t nodes = 0;
   Search::StateStackPtr st;
   Time::point elapsed = Time::now();
 
-  for (size_t i = 0; i < fens.size(); i++)
+  for (size_t i = 0; i < fens.size(); ++i)
   {
-      Position pos(fens[i], Options["UCI_Chess960"], Threads.main_thread());
+      Position pos(fens[i], Options["UCI_Chess960"], Threads.main());
 
       cerr << "\nPosition: " << i + 1 << '/' << fens.size() << endl;
 
       if (limitType == "perft")
-      {
-          size_t cnt = Search::perft(pos, limits.depth * ONE_PLY);
-          cerr << "\nPerft " << limits.depth  << " leaf nodes: " << cnt << endl;
-          nodes += cnt;
-      }
+          nodes += Search::perft<true>(pos, limits.depth * ONE_PLY);
+
       else
       {
-          Threads.start_searching(pos, limits, vector<Move>(), st);
-          Threads.wait_for_search_finished();
-          nodes += Search::RootPosition.nodes_searched();
+          Threads.start_thinking(pos, limits, st);
+          Threads.wait_for_think_finished();
+          nodes += Search::RootPos.nodes_searched();
       }
   }
 
-  elapsed = Time::now() - elapsed + 1; // Assure positive to avoid a 'divide by zero'
+  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

src/bitbase.cpp

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -18,12 +18,32 @@
 */
 
 #include <cassert>
+#include <vector>
 
 #include "bitboard.h"
 #include "types.h"
 
 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
+
+  // Each uint32_t stores results of 32 positions, one per bit
+  uint32_t KPKBitbase[MAX_INDEX / 32];
+
+  // A KPK bitbase index is an integer in [0, IndexMax] range
+  //
+  // Information is mapped in a way that minimizes the number of iterations:
+  //
+  // bit  0- 5: white king square (from SQ_A1 to SQ_H8)
+  // bit  6-11: black king square (from SQ_A1 to SQ_H8)
+  // bit    12: side to move (WHITE or BLACK)
+  // bit 13-14: white pawn file (from FILE_A to FILE_D)
+  // bit 15-17: white pawn RANK_7 - rank (from RANK_7 - RANK_7 to RANK_7 - RANK_2)
+  unsigned index(Color us, Square bksq, Square wksq, Square psq) {
+    return wksq | (bksq << 6) | (us << 12) | (file_of(psq) << 13) | ((RANK_7 - rank_of(psq)) << 15);
+  }
+
   enum Result {
     INVALID = 0,
     UNKNOWN = 1,
@@ -35,196 +55,121 @@ namespace {
 
   struct KPKPosition {
 
-    Result classify_leaf(int idx);
-    Result classify(int idx, Result db[]);
+    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 Result db[]) const;
+    template<Color Us> Result classify(const std::vector<KPKPosition>& db);
 
-    template<Color Us> Bitboard k_attacks() const {
-      return Us == WHITE ? StepAttacksBB[W_KING][wksq] : StepAttacksBB[B_KING][bksq];
-    }
-
-    Bitboard p_attacks() const { return StepAttacksBB[W_PAWN][psq]; }
-    void decode_index(int idx);
-
-    Square wksq, bksq, psq;
-    Color stm;
+    Color us;
+    Square bksq, wksq, psq;
+    Result result;
   };
 
-  // The possible pawns squares are 24, the first 4 files and ranks from 2 to 7
-  const int IndexMax = 2 * 24 * 64 * 64; // stm * wp_sq * wk_sq * bk_sq = 196608
+} // namespace
 
-  // Each uint32_t stores results of 32 positions, one per bit
-  uint32_t KPKBitbase[IndexMax / 32];
 
-  int index(Square wksq, Square bksq, Square psq, Color stm);
+bool Bitbases::probe(Square wksq, Square wpsq, Square bksq, Color us) {
+
+  assert(file_of(wpsq) <= FILE_D);
+
+  unsigned idx = index(us, bksq, wksq, wpsq);
+  return KPKBitbase[idx / 32] & (1 << (idx & 0x1F));
 }
 
 
-uint32_t Bitbases::probe_kpk(Square wksq, Square wpsq, Square bksq, Color stm) {
+void Bitbases::init() {
 
-  int idx = index(wksq, bksq, wpsq, stm);
-  return KPKBitbase[idx / 32] & (1 << (idx & 31));
-}
+  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));
 
-void Bitbases::init_kpk() {
-
-  Result db[IndexMax];
-  KPKPosition pos;
-  int idx, bit, repeat = 1;
-
-  // Initialize table with known win / draw positions
-  for (idx = 0; idx < IndexMax; idx++)
-      db[idx] = pos.classify_leaf(idx);
-
-  // Iterate until all positions are classified (30 cycles needed)
+  // Iterate through the positions until none of the unknown positions can be
+  // changed to either wins or draws (15 cycles needed).
   while (repeat)
-      for (repeat = idx = 0; idx < IndexMax; idx++)
-          if (db[idx] == UNKNOWN && (db[idx] = pos.classify(idx, db)) != UNKNOWN)
-              repeat = 1;
+      for (repeat = idx = 0; idx < MAX_INDEX; ++idx)
+          repeat |= (db[idx] == UNKNOWN && db[idx].classify(db) != UNKNOWN);
 
-  // Map 32 position results into one KPKBitbase[] entry
-  for (idx = 0; idx < IndexMax / 32; idx++)
-      for (bit = 0; bit < 32; bit++)
-          if (db[32 * idx + bit] == WIN)
-              KPKBitbase[idx] |= 1 << bit;
+  // Map 32 results into one KPKBitbase[] entry
+  for (idx = 0; idx < MAX_INDEX; ++idx)
+      if (db[idx] == WIN)
+          KPKBitbase[idx / 32] |= 1 << (idx & 0x1F);
 }
 
 
 namespace {
 
-  // A KPK bitbase index is an integer in [0, IndexMax] range
-  //
-  // Information is mapped in this way
-  //
-  // bit     0: side to move (WHITE or BLACK)
-  // bit  1- 6: black king square (from SQ_A1 to SQ_H8)
-  // bit  7-12: white king square (from SQ_A1 to SQ_H8)
-  // bit 13-14: white pawn file (from FILE_A to FILE_D)
-  // bit 15-17: white pawn rank - 1 (from RANK_2 - 1 to RANK_7 - 1)
+  KPKPosition::KPKPosition(unsigned idx) {
 
-  int index(Square w, Square b, Square p, Color c) {
-
-    assert(file_of(p) <= FILE_D);
-
-    return c + (b << 1) + (w << 7) + (file_of(p) << 13) + ((rank_of(p) - 1) << 15);
-  }
-
-  void KPKPosition::decode_index(int idx) {
-
-    stm  = Color(idx & 1);
-    bksq = Square((idx >> 1) & 63);
-    wksq = Square((idx >> 7) & 63);
-    psq  = File((idx >> 13) & 3) | Rank((idx >> 15) + 1);
-  }
-
-  Result KPKPosition::classify_leaf(int idx) {
-
-    decode_index(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;
 
     // Check if two pieces are on the same square or if a king can be captured
-    if (   wksq == psq || wksq == bksq || bksq == psq
-        || (k_attacks<WHITE>() & bksq)
-        || (stm == WHITE && (p_attacks() & bksq)))
-        return INVALID;
+    if (   distance(wksq, bksq) <= 1
+        || wksq == psq
+        || bksq == psq
+        || (us == WHITE && (StepAttacksBB[PAWN][psq] & bksq)))
+        result = INVALID;
 
-    // The position is an immediate win if it is white to move and the white
-    // pawn can be promoted without getting captured.
-    if (   rank_of(psq) == RANK_7
-        && stm == WHITE
-        && wksq != psq + DELTA_N
-        && (   square_distance(bksq, psq + DELTA_N) > 1
-            ||(k_attacks<WHITE>() & (psq + DELTA_N))))
-        return WIN;
-
-    // Check for known draw positions
-    //
-    // Case 1: Stalemate
-    if (   stm == BLACK
-        && !(k_attacks<BLACK>() & ~(k_attacks<WHITE>() | p_attacks())))
-        return DRAW;
-
-    // Case 2: King can capture undefended pawn
-    if (   stm == BLACK
-        && (k_attacks<BLACK>() & psq & ~k_attacks<WHITE>()))
-        return DRAW;
-
-    // Case 3: Black king in front of white pawn
-    if (   bksq == psq + DELTA_N
-        && rank_of(psq) < RANK_7)
-        return DRAW;
-
-    // Case 4: White king in front of pawn and black has opposition
-    if (   stm == WHITE
-        && wksq == psq + DELTA_N
-        && bksq == wksq + DELTA_N + DELTA_N
-        && rank_of(psq) < RANK_5)
-        return DRAW;
-
-    // Case 5: Stalemate with rook pawn
-    if (   bksq == SQ_A8
-        && file_of(psq) == FILE_A)
-        return DRAW;
-
-    // Case 6: White king trapped on the rook file
-    if (   file_of(wksq) == FILE_A
-        && file_of(psq) == FILE_A
-        && rank_of(wksq) > rank_of(psq)
-        && bksq == wksq + 2)
-        return DRAW;
-
-    return UNKNOWN;
+    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 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]))
+        result = DRAW;
   }
 
   template<Color Us>
-  Result KPKPosition::classify(const Result db[]) const {
+  Result KPKPosition::classify(const std::vector<KPKPosition>& db) {
 
-    // White to Move: If one move leads to a position classified as RESULT_WIN,
-    // the result of the current position is RESULT_WIN. If all moves lead to
-    // positions classified as RESULT_DRAW, the current position is classified
-    // RESULT_DRAW otherwise the current position is classified as RESULT_UNKNOWN.
+    // 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 RESULT_DRAW,
-    // the result of the current position is RESULT_DRAW. If all moves lead to
-    // positions classified as RESULT_WIN, the position is classified RESULT_WIN.
-    // Otherwise, the current position is classified as RESULT_UNKNOWN.
+    // Black to Move: If one move leads to a position classified as DRAW, the result
+    // of the current position is DRAW. If all moves lead to positions classified
+    // as WIN, the position is classified as WIN, otherwise the current position is
+    // classified as UNKNOWN.
+
+    const Color Them = (Us == WHITE ? BLACK : WHITE);
 
     Result r = INVALID;
-    Bitboard b = k_attacks<Us>();
+    Bitboard b = StepAttacksBB[KING][Us == WHITE ? wksq : bksq];
 
     while (b)
-    {
-        r |= Us == WHITE ? db[index(pop_lsb(&b), bksq, psq, BLACK)]
-                         : db[index(wksq, pop_lsb(&b), psq, WHITE)];
-
-        if (Us == WHITE && (r & WIN))
-            return WIN;
-
-        if (Us == BLACK && (r & DRAW))
-            return DRAW;
-    }
+        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(wksq, bksq, s, BLACK)]; // Single push
+        r |= db[index(BLACK, bksq, wksq, s)]; // Single push
 
-        if (rank_of(s) == RANK_3 && s != wksq && s != bksq)
-            r |= db[index(wksq, bksq, s + DELTA_N, BLACK)]; // Double push
-
-        if (r & WIN)
-            return WIN;
+        if (rank_of(psq) == RANK_2 && s != wksq && s != bksq)
+            r |= db[index(BLACK, bksq, wksq, s + DELTA_N)]; // Double push
     }
 
-    return r & UNKNOWN ? UNKNOWN : Us == WHITE ? DRAW : WIN;
+    if (Us == WHITE)
+        return result = r & WIN  ? WIN  : r & UNKNOWN ? UNKNOWN : DRAW;
+    else
+        return result = r & DRAW ? DRAW : r & UNKNOWN ? UNKNOWN : WIN;
   }
 
-  Result KPKPosition::classify(int idx, Result db[]) {
-
-    decode_index(idx);
-    return stm == WHITE ? classify<WHITE>(db) : classify<BLACK>(db);
-  }
-
-}
+} // namespace

src/bitboard.cpp

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -18,84 +18,70 @@
 */
 
 #include <algorithm>
-#include <cstring>
-#include <iostream>
+#include <cstring>   // For std::memset
 
 #include "bitboard.h"
 #include "bitcount.h"
 #include "misc.h"
-#include "rkiss.h"
 
-CACHE_LINE_ALIGNMENT
+int SquareDistance[SQUARE_NB][SQUARE_NB];
 
-Bitboard RMasks[64];
-Bitboard RMagics[64];
-Bitboard* RAttacks[64];
-unsigned RShifts[64];
+Bitboard  RookMasks  [SQUARE_NB];
+Bitboard  RookMagics [SQUARE_NB];
+Bitboard* RookAttacks[SQUARE_NB];
+unsigned  RookShifts [SQUARE_NB];
 
-Bitboard BMasks[64];
-Bitboard BMagics[64];
-Bitboard* BAttacks[64];
-unsigned BShifts[64];
+Bitboard  BishopMasks  [SQUARE_NB];
+Bitboard  BishopMagics [SQUARE_NB];
+Bitboard* BishopAttacks[SQUARE_NB];
+unsigned  BishopShifts [SQUARE_NB];
 
-Bitboard SquareBB[64];
-Bitboard FileBB[8];
-Bitboard RankBB[8];
-Bitboard AdjacentFilesBB[8];
-Bitboard ThisAndAdjacentFilesBB[8];
-Bitboard InFrontBB[2][8];
-Bitboard StepAttacksBB[16][64];
-Bitboard BetweenBB[64][64];
-Bitboard DistanceRingsBB[64][8];
-Bitboard ForwardBB[2][64];
-Bitboard PassedPawnMask[2][64];
-Bitboard AttackSpanMask[2][64];
-Bitboard PseudoAttacks[6][64];
-
-int SquareDistance[64][64];
+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 BetweenBB[SQUARE_NB][SQUARE_NB];
+Bitboard LineBB[SQUARE_NB][SQUARE_NB];
+Bitboard DistanceRingBB[SQUARE_NB][8];
+Bitboard ForwardBB[COLOR_NB][SQUARE_NB];
+Bitboard PassedPawnMask[COLOR_NB][SQUARE_NB];
+Bitboard PawnAttackSpan[COLOR_NB][SQUARE_NB];
+Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB];
 
 namespace {
 
   // De Bruijn sequences. See chessprogramming.wikispaces.com/BitScan
-  const uint64_t DeBruijn_64 = 0x218A392CD3D5DBFULL;
-  const uint32_t DeBruijn_32 = 0x783A9B23;
+  const uint64_t DeBruijn64 = 0x3F79D71B4CB0A89ULL;
+  const uint32_t DeBruijn32 = 0x783A9B23;
 
-  CACHE_LINE_ALIGNMENT
-
-  int MS1BTable[256];
-  Square BSFTable[64];
-  Bitboard RTable[0x19000]; // Storage space for rook attacks
-  Bitboard BTable[0x1480];  // Storage space for bishop attacks
-  uint8_t BitCount8Bit[256];
+  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[], Bitboard* attacks[], Bitboard magics[],
                    Bitboard masks[], unsigned shifts[], Square deltas[], Fn index);
 
+  // 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) {
-
-    if (Is64Bit)
-        return ((b & -b) * DeBruijn_64) >> 58;
-
-    // Use Matt Taylor's folding trick for 32 bit systems
-    b ^= (b - 1);
-    return ((unsigned(b) ^ unsigned(b >> 32)) * DeBruijn_32) >> 26;
+    b ^= b - 1;
+    return Is64Bit ? (b * DeBruijn64) >> 58
+                   : ((unsigned(b) ^ unsigned(b >> 32)) * DeBruijn32) >> 26;
   }
 }
 
-/// lsb()/msb() finds the least/most significant bit in a nonzero bitboard.
-/// pop_lsb() finds and clears the least significant bit in a nonzero bitboard.
+#ifndef USE_BSFQ
 
-#if !defined(USE_BSFQ)
+/// Software fall-back of lsb() and msb() for CPU lacking hardware support
 
-Square lsb(Bitboard b) { return BSFTable[bsf_index(b)]; }
-
-Square pop_lsb(Bitboard* b) {
-
-  Bitboard bb = *b;
-  *b = bb & (bb - 1);
-  return BSFTable[bsf_index(bb)];
+Square lsb(Bitboard b) {
+  return BSFTable[bsf_index(b)];
 }
 
 Square msb(Bitboard b) {
@@ -123,121 +109,110 @@ Square msb(Bitboard b) {
       result += 8;
   }
 
-  return (Square)(result + MS1BTable[b32]);
+  return Square(result + MS1BTable[b32]);
 }
 
-#endif // !defined(USE_BSFQ)
+#endif // ifndef USE_BSFQ
 
 
-/// Bitboards::print() prints a bitboard in an easily readable format to the
-/// standard output. This is sometimes useful for debugging.
+/// Bitboards::pretty() returns an ASCII representation of a bitboard suitable
+/// to be printed to standard output. Useful for debugging.
 
-void Bitboards::print(Bitboard b) {
+const std::string Bitboards::pretty(Bitboard b) {
 
-  sync_cout;
+  std::string s = "+---+---+---+---+---+---+---+---+\n";
 
-  for (Rank rank = RANK_8; rank >= RANK_1; rank--)
+  for (Rank r = RANK_8; r >= RANK_1; --r)
   {
-      std::cout << "+---+---+---+---+---+---+---+---+" << '\n';
+      for (File f = FILE_A; f <= FILE_H; ++f)
+          s.append(b & make_square(f, r) ? "| X " : "|   ");
 
-      for (File file = FILE_A; file <= FILE_H; file++)
-          std::cout << "| " << (b & (file | rank) ? "X " : "  ");
-
-      std::cout << "|\n";
+      s.append("|\n+---+---+---+---+---+---+---+---+\n");
   }
-  std::cout << "+---+---+---+---+---+---+---+---+" << sync_endl;
+
+  return s;
 }
 
 
-/// Bitboards::init() initializes various bitboard arrays. It is called during
-/// program initialization.
+/// Bitboards::init() initializes various bitboard tables. It is called at
+/// startup and relies on global objects to be already zero-initialized.
 
 void Bitboards::init() {
 
-  for (int k = 0, i = 0; i < 8; i++)
-      while (k < (2 << i))
-          MS1BTable[k++] = i;
-
-  for (int i = 0; i < 64; i++)
-      BSFTable[bsf_index(1ULL << i)] = Square(i);
-
-  for (Bitboard b = 0; b < 256; b++)
-      BitCount8Bit[b] = (uint8_t)popcount<Max15>(b);
-
-  for (Square s = SQ_A1; s <= SQ_H8; s++)
+  for (Square s = SQ_A1; s <= SQ_H8; ++s)
+  {
       SquareBB[s] = 1ULL << s;
-
-  FileBB[FILE_A] = FileABB;
-  RankBB[RANK_1] = Rank1BB;
-
-  for (int i = 1; i < 8; i++)
-  {
-      FileBB[i] = FileBB[i - 1] << 1;
-      RankBB[i] = RankBB[i - 1] << 8;
+      BSFTable[bsf_index(SquareBB[s])] = s;
   }
 
-  for (File f = FILE_A; f <= FILE_H; f++)
-  {
+  for (Bitboard b = 1; b < 256; ++b)
+      MS1BTable[b] = more_than_one(b) ? MS1BTable[b - 1] : lsb(b);
+
+  for (File f = FILE_A; f <= FILE_H; ++f)
+      FileBB[f] = f > FILE_A ? FileBB[f - 1] << 1 : FileABB;
+
+  for (Rank r = RANK_1; r <= RANK_8; ++r)
+      RankBB[r] = r > RANK_1 ? RankBB[r - 1] << 8 : Rank1BB;
+
+  for (File f = FILE_A; f <= FILE_H; ++f)
       AdjacentFilesBB[f] = (f > FILE_A ? FileBB[f - 1] : 0) | (f < FILE_H ? FileBB[f + 1] : 0);
-      ThisAndAdjacentFilesBB[f] = FileBB[f] | AdjacentFilesBB[f];
-  }
 
-  for (Rank r = RANK_1; r < RANK_8; r++)
+  for (Rank r = RANK_1; r < RANK_8; ++r)
       InFrontBB[WHITE][r] = ~(InFrontBB[BLACK][r + 1] = InFrontBB[BLACK][r] | RankBB[r]);
 
-  for (Color c = WHITE; c <= BLACK; c++)
-      for (Square s = SQ_A1; s <= SQ_H8; s++)
+  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)];
-          PassedPawnMask[c][s] = InFrontBB[c][rank_of(s)] & ThisAndAdjacentFilesBB[file_of(s)];
-          AttackSpanMask[c][s] = InFrontBB[c][rank_of(s)] & AdjacentFilesBB[file_of(s)];
+          PawnAttackSpan[c][s] = InFrontBB[c][rank_of(s)] & AdjacentFilesBB[file_of(s)];
+          PassedPawnMask[c][s] = ForwardBB[c][s] | PawnAttackSpan[c][s];
       }
 
-  for (Square s1 = SQ_A1; s1 <= SQ_H8; s1++)
-      for (Square s2 = SQ_A1; s2 <= SQ_H8; s2++)
-          SquareDistance[s1][s2] = std::max(file_distance(s1, s2), rank_distance(s1, s2));
-
-  for (Square s1 = SQ_A1; s1 <= SQ_H8; s1++)
-      for (int d = 1; d < 8; d++)
-          for (Square s2 = SQ_A1; s2 <= SQ_H8; s2++)
-              if (SquareDistance[s1][s2] == d)
-                  DistanceRingsBB[s1][d - 1] |= s2;
+  for (Square s1 = SQ_A1; s1 <= SQ_H8; ++s1)
+      for (Square s2 = SQ_A1; s2 <= SQ_H8; ++s2)
+          if (s1 != s2)
+          {
+              SquareDistance[s1][s2] = std::max(distance<File>(s1, s2), distance<Rank>(s1, s2));
+              DistanceRingBB[s1][SquareDistance[s1][s2] - 1] |= s2;
+          }
 
   int steps[][9] = { {}, { 7, 9 }, { 17, 15, 10, 6, -6, -10, -15, -17 },
                      {}, {}, {}, { 9, 7, -7, -9, 8, 1, -1, -8 } };
 
-  for (Color c = WHITE; c <= BLACK; c++)
-      for (PieceType pt = PAWN; pt <= KING; pt++)
-          for (Square s = SQ_A1; s <= SQ_H8; s++)
-              for (int k = 0; steps[pt][k]; k++)
+  for (Color c = WHITE; c <= BLACK; ++c)
+      for (PieceType pt = PAWN; pt <= KING; ++pt)
+          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][k] : -steps[pt][k]);
+                  Square to = s + Square(c == WHITE ? steps[pt][i] : -steps[pt][i]);
 
-                  if (is_ok(to) && square_distance(s, to) < 3)
+                  if (is_ok(to) && distance(s, to) < 3)
                       StepAttacksBB[make_piece(c, pt)][s] |= to;
               }
 
-  Square RDeltas[] = { DELTA_N,  DELTA_E,  DELTA_S,  DELTA_W  };
-  Square BDeltas[] = { DELTA_NE, DELTA_SE, DELTA_SW, DELTA_NW };
+  Square RookDeltas[] = { DELTA_N,  DELTA_E,  DELTA_S,  DELTA_W  };
+  Square BishopDeltas[] = { DELTA_NE, DELTA_SE, DELTA_SW, DELTA_NW };
 
-  init_magics(RTable, RAttacks, RMagics, RMasks, RShifts, RDeltas, magic_index<ROOK>);
-  init_magics(BTable, BAttacks, BMagics, BMasks, BShifts, BDeltas, magic_index<BISHOP>);
+  init_magics(RookTable, RookAttacks, RookMagics, RookMasks, RookShifts, RookDeltas, magic_index<ROOK>);
+  init_magics(BishopTable, BishopAttacks, BishopMagics, BishopMasks, BishopShifts, BishopDeltas, magic_index<BISHOP>);
 
-  for (Square s = SQ_A1; s <= SQ_H8; s++)
+  for (Square s1 = SQ_A1; s1 <= SQ_H8; ++s1)
   {
-      PseudoAttacks[QUEEN][s]  = PseudoAttacks[BISHOP][s] = attacks_bb<BISHOP>(s, 0);
-      PseudoAttacks[QUEEN][s] |= PseudoAttacks[  ROOK][s] = attacks_bb<  ROOK>(s, 0);
+      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;
+
+          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]);
+      }
   }
-
-  for (Square s1 = SQ_A1; s1 <= SQ_H8; s1++)
-      for (Square s2 = SQ_A1; s2 <= SQ_H8; s2++)
-          if (PseudoAttacks[QUEEN][s1] & s2)
-          {
-              Square delta = (s2 - s1) / square_distance(s1, s2);
-
-              for (Square s = s1 + delta; s != s2; s += delta)
-                  BetweenBB[s1][s2] |= s;
-          }
 }
 
 
@@ -247,9 +222,9 @@ namespace {
 
     Bitboard attack = 0;
 
-    for (int i = 0; i < 4; i++)
+    for (int i = 0; i < 4; ++i)
         for (Square s = sq + deltas[i];
-             is_ok(s) && square_distance(s, s - deltas[i]) == 1;
+             is_ok(s) && distance(s, s - deltas[i]) == 1;
              s += deltas[i])
         {
             attack |= s;
@@ -262,20 +237,6 @@ namespace {
   }
 
 
-  Bitboard pick_random(RKISS& rk, int booster) {
-
-    // Values s1 and s2 are used to rotate the candidate magic of a
-    // quantity known to be the optimal to quickly find the magics.
-    int s1 = booster & 63, s2 = (booster >> 6) & 63;
-
-    Bitboard m = rk.rand<Bitboard>();
-    m = (m >> s1) | (m << (64 - s1));
-    m &= rk.rand<Bitboard>();
-    m = (m >> s2) | (m << (64 - s2));
-    return m & rk.rand<Bitboard>();
-  }
-
-
   // init_magics() computes all rook and bishop attacks at startup. Magic
   // bitboards are used to look up attacks of sliding pieces. As a reference see
   // chessprogramming.wikispaces.com/Magic+Bitboards. In particular, here we
@@ -284,16 +245,16 @@ namespace {
   void init_magics(Bitboard table[], Bitboard* attacks[], Bitboard magics[],
                    Bitboard masks[], unsigned shifts[], Square deltas[], Fn index) {
 
-    int MagicBoosters[][8] = { { 3191, 2184, 1310, 3618, 2091, 1308, 2452, 3996 },
-                               { 1059, 3608,  605, 3234, 3326,   38, 2029, 3043 } };
-    RKISS rk;
+    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, booster;
+    int i, size;
 
     // attacks[s] is a pointer to the beginning of the attacks table for square 's'
     attacks[SQ_A1] = table;
 
-    for (Square s = SQ_A1; s <= SQ_H8; s++)
+    for (Square s = SQ_A1; s <= SQ_H8; ++s)
     {
         // Board edges are not considered in the relevant occupancies
         edges = ((Rank1BB | Rank8BB) & ~rank_bb(s)) | ((FileABB | FileHBB) & ~file_bb(s));
@@ -311,7 +272,12 @@ namespace {
         b = size = 0;
         do {
             occupancy[size] = b;
-            reference[size++] = sliding_attack(deltas, s, b);
+            reference[size] = sliding_attack(deltas, s, b);
+
+            if (HasPext)
+                attacks[s][pext(b, masks[s])] = reference[size];
+
+            size++;
             b = (b - masks[s]) & masks[s];
         } while (b);
 
@@ -320,32 +286,36 @@ namespace {
         if (s < SQ_H8)
             attacks[s + 1] = attacks[s] + size;
 
-        booster = MagicBoosters[Is64Bit][rank_of(s)];
+        if (HasPext)
+            continue;
+
+        PRNG rng(seeds[Is64Bit][rank_of(s)]);
 
         // 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] = pick_random(rk, booster);
-            while (BitCount8Bit[(magics[s] * masks[s]) >> 56] < 6);
+            do
+                magics[s] = rng.sparse_rand<Bitboard>();
+            while (popcount<Max15>((magics[s] * masks[s]) >> 56) < 6);
 
-            memset(attacks[s], 0, size * sizeof(Bitboard));
+            std::memset(attacks[s], 0, size * sizeof(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++)
+            for (i = 0; i < size; ++i)
             {
                 Bitboard& attack = attacks[s][index(s, occupancy[i])];
 
                 if (attack && attack != reference[i])
                     break;
 
-                assert(reference[i] != 0);
+                assert(reference[i]);
 
                 attack = reference[i];
             }
-        } while (i != size);
+        } while (i < size);
     }
   }
 }

src/bitboard.h

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -18,50 +18,72 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#if !defined(BITBOARD_H_INCLUDED)
+#ifndef BITBOARD_H_INCLUDED
 #define BITBOARD_H_INCLUDED
 
+#include <string>
+
 #include "types.h"
 
+namespace Bitbases {
+
+void init();
+bool probe(Square wksq, Square wpsq, Square bksq, Color us);
+
+}
+
 namespace Bitboards {
 
 void init();
-void print(Bitboard b);
+const std::string pretty(Bitboard b);
 
 }
 
-namespace Bitbases {
+const Bitboard DarkSquares = 0xAA55AA55AA55AA55ULL;
 
-void init_kpk();
-uint32_t probe_kpk(Square wksq, Square wpsq, Square bksq, Color stm);
+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;
 
-}
+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);
 
-CACHE_LINE_ALIGNMENT
+extern int SquareDistance[SQUARE_NB][SQUARE_NB];
 
-extern Bitboard RMasks[64];
-extern Bitboard RMagics[64];
-extern Bitboard* RAttacks[64];
-extern unsigned RShifts[64];
+extern Bitboard  RookMasks  [SQUARE_NB];
+extern Bitboard  RookMagics [SQUARE_NB];
+extern Bitboard* RookAttacks[SQUARE_NB];
+extern unsigned  RookShifts [SQUARE_NB];
 
-extern Bitboard BMasks[64];
-extern Bitboard BMagics[64];
-extern Bitboard* BAttacks[64];
-extern unsigned BShifts[64];
+extern Bitboard  BishopMasks  [SQUARE_NB];
+extern Bitboard  BishopMagics [SQUARE_NB];
+extern Bitboard* BishopAttacks[SQUARE_NB];
+extern unsigned  BishopShifts [SQUARE_NB];
 
-extern Bitboard SquareBB[64];
-extern Bitboard FileBB[8];
-extern Bitboard RankBB[8];
-extern Bitboard AdjacentFilesBB[8];
-extern Bitboard ThisAndAdjacentFilesBB[8];
-extern Bitboard InFrontBB[2][8];
-extern Bitboard StepAttacksBB[16][64];
-extern Bitboard BetweenBB[64][64];
-extern Bitboard DistanceRingsBB[64][8];
-extern Bitboard ForwardBB[2][64];
-extern Bitboard PassedPawnMask[2][64];
-extern Bitboard AttackSpanMask[2][64];
-extern Bitboard PseudoAttacks[6][64];
+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 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 PassedPawnMask[COLOR_NB][SQUARE_NB];
+extern Bitboard PawnAttackSpan[COLOR_NB][SQUARE_NB];
+extern Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB];
 
 
 /// Overloads of bitwise operators between a Bitboard and a Square for testing
@@ -71,14 +93,6 @@ inline Bitboard operator&(Bitboard b, Square s) {
   return b & SquareBB[s];
 }
 
-inline Bitboard& operator|=(Bitboard& b, Square s) {
-  return b |= SquareBB[s];
-}
-
-inline Bitboard& operator^=(Bitboard& b, Square s) {
-  return b ^= SquareBB[s];
-}
-
 inline Bitboard operator|(Bitboard b, Square s) {
   return b | SquareBB[s];
 }
@@ -87,16 +101,21 @@ inline Bitboard operator^(Bitboard b, Square s) {
   return b ^ SquareBB[s];
 }
 
+inline Bitboard& operator|=(Bitboard& b, Square s) {
+  return b |= SquareBB[s];
+}
 
-/// more_than_one() returns true if in 'b' there is more than one bit set
+inline Bitboard& operator^=(Bitboard& b, Square s) {
+  return b ^= SquareBB[s];
+}
 
 inline bool more_than_one(Bitboard b) {
   return b & (b - 1);
 }
 
 
-/// rank_bb() and file_bb() take a file or a square as input and return
-/// a bitboard representing all squares on the given file or rank.
+/// rank_bb() and file_bb() return a bitboard representing all the squares on
+/// the given file or rank.
 
 inline Bitboard rank_bb(Rank r) {
   return RankBB[r];
@@ -115,166 +134,207 @@ inline Bitboard file_bb(Square s) {
 }
 
 
-/// adjacent_files_bb takes a file as input and returns a bitboard representing
-/// all squares on the adjacent files.
+/// shift_bb() moves a bitboard one step along direction Delta. 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
+        : 0;
+}
+
+
+/// adjacent_files_bb() returns a bitboard representing all the squares on the
+/// adjacent files of the given one.
 
 inline Bitboard adjacent_files_bb(File f) {
   return AdjacentFilesBB[f];
 }
 
 
-/// this_and_adjacent_files_bb takes a file as input and returns a bitboard
-/// representing all squares on the given and adjacent files.
-
-inline Bitboard this_and_adjacent_files_bb(File f) {
-  return ThisAndAdjacentFilesBB[f];
-}
-
-
-/// in_front_bb() takes a color and a rank or square as input, and returns a
-/// bitboard representing all the squares on all ranks in front of the rank
-/// (or square), from the given color's point of view.  For instance,
-/// in_front_bb(WHITE, RANK_5) will give all squares on ranks 6, 7 and 8, while
-/// in_front_bb(BLACK, SQ_D3) will give all squares on ranks 1 and 2.
-
-inline Bitboard in_front_bb(Color c, Rank r) {
-  return InFrontBB[c][r];
-}
-
-inline Bitboard in_front_bb(Color c, Square s) {
-  return InFrontBB[c][rank_of(s)];
-}
-
-
-/// between_bb returns a bitboard representing all squares between two squares.
-/// For instance, between_bb(SQ_C4, SQ_F7) returns a bitboard with the bits for
-/// square d5 and e6 set.  If s1 and s2 are not on the same line, file or diagonal,
-/// 0 is returned.
+/// between_bb() returns a bitboard representing all the squares between the two
+/// given ones. For instance, between_bb(SQ_C4, SQ_F7) returns a bitboard with
+/// the bits for square d5 and e6 set. If s1 and s2 are not on the same rank, file
+/// or diagonal, 0 is returned.
 
 inline Bitboard between_bb(Square s1, Square s2) {
   return BetweenBB[s1][s2];
 }
 
 
-/// forward_bb takes a color and a square as input, and returns a bitboard
-/// representing all squares along the line in front of the square, from the
-/// point of view of the given color. Definition of the table is:
-/// ForwardBB[c][s] = in_front_bb(c, s) & file_bb(s)
+/// 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.
+
+inline Bitboard in_front_bb(Color c, Rank r) {
+  return InFrontBB[c][r];
+}
+
+
+/// forward_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)
 
 inline Bitboard forward_bb(Color c, Square s) {
   return ForwardBB[c][s];
 }
 
 
-/// passed_pawn_mask takes a color and a square as input, and returns a
-/// bitboard mask which can be used to test if a pawn of the given color on
-/// the given square is a passed pawn. Definition of the table is:
-/// PassedPawnMask[c][s] = in_front_bb(c, s) & this_and_adjacent_files_bb(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);
+
+inline Bitboard pawn_attack_span(Color c, Square s) {
+  return PawnAttackSpan[c][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)
 
 inline Bitboard passed_pawn_mask(Color c, Square s) {
   return PassedPawnMask[c][s];
 }
 
 
-/// attack_span_mask takes a color and a square as input, and returns a bitboard
-/// representing all squares that can be attacked by a pawn of the given color
-/// when it moves along its file starting from the given square. Definition is:
-/// AttackSpanMask[c][s] = in_front_bb(c, s) & adjacent_files_bb(s);
+/// squares_of_color() returns a bitboard representing all the squares of the
+/// same color of the given one.
 
-inline Bitboard attack_span_mask(Color c, Square s) {
-  return AttackSpanMask[c][s];
+inline Bitboard squares_of_color(Square s) {
+  return DarkSquares & s ? DarkSquares : ~DarkSquares;
 }
 
 
-/// squares_aligned returns true if the squares s1, s2 and s3 are aligned
-/// either on a straight or on a diagonal line.
+/// aligned() returns true if the squares s1, s2 and s3 are aligned either on a
+/// straight or on a diagonal line.
 
-inline bool squares_aligned(Square s1, Square s2, Square s3) {
-  return  (BetweenBB[s1][s2] | BetweenBB[s1][s3] | BetweenBB[s2][s3])
-        & (     SquareBB[s1] |      SquareBB[s2] |      SquareBB[s3]);
+inline bool aligned(Square s1, Square s2, Square s3) {
+  return LineBB[s1][s2] & s3;
 }
 
 
-/// same_color_squares() returns a bitboard representing all squares with
-/// the same color of the given square.
+/// distance() functions return the distance between x and y, defined as the
+/// number of steps for a king in x to reach y. Works with squares, ranks, files.
 
-inline Bitboard same_color_squares(Square s) {
-  return Bitboard(0xAA55AA55AA55AA55ULL) & s ?  0xAA55AA55AA55AA55ULL
-                                             : ~0xAA55AA55AA55AA55ULL;
-}
+template<typename T> inline int distance(T x, T y) { return x < y ? y - x : x - y; }
+template<> inline int distance<Square>(Square x, Square y) { return SquareDistance[x][y]; }
+
+template<typename T1, typename T2> inline int distance(T2 x, T2 y);
+template<> inline int distance<File>(Square x, Square y) { return distance(file_of(x), file_of(y)); }
+template<> inline int distance<Rank>(Square x, Square y) { return distance(rank_of(x), rank_of(y)); }
 
 
-/// Functions for computing sliding attack bitboards. Function attacks_bb() takes
-/// a square and a bitboard of occupied squares as input, and returns a bitboard
-/// representing all squares attacked by Pt (bishop or rook) on the given square.
+/// 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 occ) {
+FORCE_INLINE unsigned magic_index(Square s, Bitboard occupied) {
 
-  Bitboard* const Masks  = Pt == ROOK ? RMasks  : BMasks;
-  Bitboard* const Magics = Pt == ROOK ? RMagics : BMagics;
-  unsigned* const Shifts = Pt == ROOK ? RShifts : BShifts;
+  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(((occ & Masks[s]) * Magics[s]) >> Shifts[s]);
+      return unsigned(((occupied & Masks[s]) * Magics[s]) >> Shifts[s]);
 
-  unsigned lo = unsigned(occ) & unsigned(Masks[s]);
-  unsigned hi = unsigned(occ >> 32) & unsigned(Masks[s] >> 32);
+  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];
 }
 
 template<PieceType Pt>
-inline Bitboard attacks_bb(Square s, Bitboard occ) {
-  return (Pt == ROOK ? RAttacks : BAttacks)[s][magic_index<Pt>(s, occ)];
+inline Bitboard attacks_bb(Square s, Bitboard occupied) {
+  return (Pt == ROOK ? RookAttacks : BishopAttacks)[s][magic_index<Pt>(s, occupied)];
+}
+
+inline Bitboard attacks_bb(Piece pc, Square s, Bitboard occupied) {
+
+  switch (type_of(pc))
+  {
+  case BISHOP: return attacks_bb<BISHOP>(s, occupied);
+  case ROOK  : return attacks_bb<ROOK>(s, occupied);
+  case QUEEN : return attacks_bb<BISHOP>(s, occupied) | attacks_bb<ROOK>(s, occupied);
+  default    : return StepAttacksBB[pc][s];
+  }
 }
 
 
-/// lsb()/msb() finds the least/most significant bit in a nonzero bitboard.
-/// pop_lsb() finds and clears the least significant bit in a nonzero bitboard.
+/// lsb() and msb() return the least/most significant bit in a non-zero bitboard
 
-#if defined(USE_BSFQ)
+#ifdef USE_BSFQ
 
 #  if defined(_MSC_VER) && !defined(__INTEL_COMPILER)
 
 FORCE_INLINE Square lsb(Bitboard b) {
-  unsigned long index;
-  _BitScanForward64(&index, b);
-  return (Square) index;
+  unsigned long idx;
+  _BitScanForward64(&idx, b);
+  return (Square) idx;
 }
 
 FORCE_INLINE Square msb(Bitboard b) {
-  unsigned long index;
-  _BitScanReverse64(&index, b);
-  return (Square) index;
+  unsigned long idx;
+  _BitScanReverse64(&idx, b);
+  return (Square) idx;
 }
 
-#  else
+#  elif defined(__arm__)
+
+FORCE_INLINE int lsb32(uint32_t v) {
+  __asm__("rbit %0, %1" : "=r"(v) : "r"(v));
+  return __builtin_clz(v);
+}
+
+FORCE_INLINE Square msb(Bitboard b) {
+  return (Square) (63 - __builtin_clzll(b));
+}
+
+FORCE_INLINE Square lsb(Bitboard b) {
+  return (Square) (uint32_t(b) ? lsb32(uint32_t(b)) : 32 + lsb32(uint32_t(b >> 32)));
+}
+
+#  else // Assumed gcc or compatible compiler
 
 FORCE_INLINE Square lsb(Bitboard b) { // Assembly code by Heinz van Saanen
-  Bitboard index;
-  __asm__("bsfq %1, %0": "=r"(index): "rm"(b) );
-  return (Square) index;
+  Bitboard idx;
+  __asm__("bsfq %1, %0": "=r"(idx): "rm"(b) );
+  return (Square) idx;
 }
 
 FORCE_INLINE Square msb(Bitboard b) {
-  Bitboard index;
-  __asm__("bsrq %1, %0": "=r"(index): "rm"(b) );
-  return (Square) index;
+  Bitboard idx;
+  __asm__("bsrq %1, %0": "=r"(idx): "rm"(b) );
+  return (Square) idx;
 }
 
 #  endif
 
-FORCE_INLINE Square pop_lsb(Bitboard* b) {
-  const Square s = lsb(*b);
-  *b &= ~(1ULL << s);
-  return s;
-}
+#else // ifdef(USE_BSFQ)
 
-#else // if !defined(USE_BSFQ)
-
-extern Square msb(Bitboard b);
-extern Square lsb(Bitboard b);
-extern Square pop_lsb(Bitboard* b);
+Square lsb(Bitboard b);
+Square msb(Bitboard b);
 
 #endif
 
-#endif // !defined(BITBOARD_H_INCLUDED)
+
+/// pop_lsb() finds and clears the least significant bit in a non-zero bitboard
+
+FORCE_INLINE Square pop_lsb(Bitboard* b) {
+  const Square s = lsb(*b);
+  *b &= *b - 1;
+  return s;
+}
+
+
+/// frontmost_sq() and backmost_sq() return the square corresponding to the
+/// most/least advanced bit relative to the given color.
+
+inline Square frontmost_sq(Color c, Bitboard b) { return c == WHITE ? msb(b) : lsb(b); }
+inline Square  backmost_sq(Color c, Bitboard b) { return c == WHITE ? lsb(b) : msb(b); }
+
+#endif // #ifndef BITBOARD_H_INCLUDED

src/bitcount.h

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -18,10 +18,11 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#if !defined(BITCOUNT_H_INCLUDED)
+#ifndef BITCOUNT_H_INCLUDED
 #define BITCOUNT_H_INCLUDED
 
 #include <cassert>
+
 #include "types.h"
 
 enum BitCountType {
@@ -32,62 +33,56 @@ enum BitCountType {
   CNT_HW_POPCNT
 };
 
-/// Determine at compile time the best popcount<> specialization according if
-/// platform is 32 or 64 bits, to the maximum number of nonzero bits to count or
-/// use hardware popcnt instruction when available.
-const BitCountType Full  = HasPopCnt ? CNT_HW_POPCNT : Is64Bit ? CNT_64 : CNT_32;
+/// 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 nonzero bits in a bitboard
+/// 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;
-  b *= 0x0101010101010101ULL;
-  return int(b >> 56);
+  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);
-  b *= 0x1111111111111111ULL;
-  return int(b >> 60);
+  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) & 0x0F0F0F0F; // 0-8 in 8 bits
-  v += (((w >> 4) + w) & 0x0F0F0F0F);  // 0-16 in 8 bits
-  v *= 0x01010101; // mul is fast on amd procs
-  return int(v >> 24);
+  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);
-  v += w; // 0-8 in 4 bits
-  v *= 0x11111111;
-  return int(v >> 28);
+  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) {
 
-#if !defined(USE_POPCNT)
+#ifndef USE_POPCNT
 
   assert(false);
   return b != 0; // Avoid 'b not used' warning
@@ -100,13 +95,11 @@ inline int popcount<CNT_HW_POPCNT>(Bitboard b) {
 
   return (int)__popcnt64(b);
 
-#else
+#else // Assumed gcc or compatible compiler
 
-  unsigned long ret;
-  __asm__("popcnt %1, %0" : "=r" (ret) : "r" (b));
-  return ret;
+  return __builtin_popcountll(b);
 
 #endif
 }
 
-#endif // !defined(BITCOUNT_H_INCLUDED)
+#endif // #ifndef BITCOUNT_H_INCLUDED

src/book.cpp

@@ -1,481 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 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/>.
-*/
-
-/*
-  The code in this file is based on the opening book code in PolyGlot
-  by Fabien Letouzey. PolyGlot is available under the GNU General
-  Public License, and can be downloaded from http://wbec-ridderkerk.nl
-*/
-
-#include <algorithm>
-#include <cassert>
-#include <iostream>
-
-#include "book.h"
-#include "misc.h"
-#include "movegen.h"
-
-using namespace std;
-
-namespace {
-
-  // A Polyglot book is a series of "entries" of 16 bytes. All integers are
-  // stored in big-endian format, with highest byte first (regardless of size).
-  // The entries are ordered according to the key in ascending order.
-  struct BookEntry {
-    uint64_t key;
-    uint16_t move;
-    uint16_t count;
-    uint32_t learn;
-  };
-
-  // Random numbers from PolyGlot, used to compute book hash keys
-  const Key PolyGlotRandoms[781] = {
-    0x9D39247E33776D41ULL, 0x2AF7398005AAA5C7ULL, 0x44DB015024623547ULL,
-    0x9C15F73E62A76AE2ULL, 0x75834465489C0C89ULL, 0x3290AC3A203001BFULL,
-    0x0FBBAD1F61042279ULL, 0xE83A908FF2FB60CAULL, 0x0D7E765D58755C10ULL,
-    0x1A083822CEAFE02DULL, 0x9605D5F0E25EC3B0ULL, 0xD021FF5CD13A2ED5ULL,
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-    0xD39BB9C3A48DB6CFULL, 0x2738259634305C14ULL, 0x61CF4F94C97DF93DULL,
-    0x1B6BACA2AE4E125BULL, 0x758F450C88572E0BULL, 0x959F587D507A8359ULL,
-    0xB063E962E045F54DULL, 0x60E8ED72C0DFF5D1ULL, 0x7B64978555326F9FULL,
-    0xFD080D236DA814BAULL, 0x8C90FD9B083F4558ULL, 0x106F72FE81E2C590ULL,
-    0x7976033A39F7D952ULL, 0xA4EC0132764CA04BULL, 0x733EA705FAE4FA77ULL,
-    0xB4D8F77BC3E56167ULL, 0x9E21F4F903B33FD9ULL, 0x9D765E419FB69F6DULL,
-    0xD30C088BA61EA5EFULL, 0x5D94337FBFAF7F5BULL, 0x1A4E4822EB4D7A59ULL,
-    0x6FFE73E81B637FB3ULL, 0xDDF957BC36D8B9CAULL, 0x64D0E29EEA8838B3ULL,
-    0x08DD9BDFD96B9F63ULL, 0x087E79E5A57D1D13ULL, 0xE328E230E3E2B3FBULL,
-    0x1C2559E30F0946BEULL, 0x720BF5F26F4D2EAAULL, 0xB0774D261CC609DBULL,
-    0x443F64EC5A371195ULL, 0x4112CF68649A260EULL, 0xD813F2FAB7F5C5CAULL,
-    0x660D3257380841EEULL, 0x59AC2C7873F910A3ULL, 0xE846963877671A17ULL,
-    0x93B633ABFA3469F8ULL, 0xC0C0F5A60EF4CDCFULL, 0xCAF21ECD4377B28CULL,
-    0x57277707199B8175ULL, 0x506C11B9D90E8B1DULL, 0xD83CC2687A19255FULL,
-    0x4A29C6465A314CD1ULL, 0xED2DF21216235097ULL, 0xB5635C95FF7296E2ULL,
-    0x22AF003AB672E811ULL, 0x52E762596BF68235ULL, 0x9AEBA33AC6ECC6B0ULL,
-    0x944F6DE09134DFB6ULL, 0x6C47BEC883A7DE39ULL, 0x6AD047C430A12104ULL,
-    0xA5B1CFDBA0AB4067ULL, 0x7C45D833AFF07862ULL, 0x5092EF950A16DA0BULL,
-    0x9338E69C052B8E7BULL, 0x455A4B4CFE30E3F5ULL, 0x6B02E63195AD0CF8ULL,
-    0x6B17B224BAD6BF27ULL, 0xD1E0CCD25BB9C169ULL, 0xDE0C89A556B9AE70ULL,
-    0x50065E535A213CF6ULL, 0x9C1169FA2777B874ULL, 0x78EDEFD694AF1EEDULL,
-    0x6DC93D9526A50E68ULL, 0xEE97F453F06791EDULL, 0x32AB0EDB696703D3ULL,
-    0x3A6853C7E70757A7ULL, 0x31865CED6120F37DULL, 0x67FEF95D92607890ULL,
-    0x1F2B1D1F15F6DC9CULL, 0xB69E38A8965C6B65ULL, 0xAA9119FF184CCCF4ULL,
-    0xF43C732873F24C13ULL, 0xFB4A3D794A9A80D2ULL, 0x3550C2321FD6109CULL,
-    0x371F77E76BB8417EULL, 0x6BFA9AAE5EC05779ULL, 0xCD04F3FF001A4778ULL,
-    0xE3273522064480CAULL, 0x9F91508BFFCFC14AULL, 0x049A7F41061A9E60ULL,
-    0xFCB6BE43A9F2FE9BULL, 0x08DE8A1C7797DA9BULL, 0x8F9887E6078735A1ULL,
-    0xB5B4071DBFC73A66ULL, 0x230E343DFBA08D33ULL, 0x43ED7F5A0FAE657DULL,
-    0x3A88A0FBBCB05C63ULL, 0x21874B8B4D2DBC4FULL, 0x1BDEA12E35F6A8C9ULL,
-    0x53C065C6C8E63528ULL, 0xE34A1D250E7A8D6BULL, 0xD6B04D3B7651DD7EULL,
-    0x5E90277E7CB39E2DULL, 0x2C046F22062DC67DULL, 0xB10BB459132D0A26ULL,
-    0x3FA9DDFB67E2F199ULL, 0x0E09B88E1914F7AFULL, 0x10E8B35AF3EEAB37ULL,
-    0x9EEDECA8E272B933ULL, 0xD4C718BC4AE8AE5FULL, 0x81536D601170FC20ULL,
-    0x91B534F885818A06ULL, 0xEC8177F83F900978ULL, 0x190E714FADA5156EULL,
-    0xB592BF39B0364963ULL, 0x89C350C893AE7DC1ULL, 0xAC042E70F8B383F2ULL,
-    0xB49B52E587A1EE60ULL, 0xFB152FE3FF26DA89ULL, 0x3E666E6F69AE2C15ULL,
-    0x3B544EBE544C19F9ULL, 0xE805A1E290CF2456ULL, 0x24B33C9D7ED25117ULL,
-    0xE74733427B72F0C1ULL, 0x0A804D18B7097475ULL, 0x57E3306D881EDB4FULL,
-    0x4AE7D6A36EB5DBCBULL, 0x2D8D5432157064C8ULL, 0xD1E649DE1E7F268BULL,
-    0x8A328A1CEDFE552CULL, 0x07A3AEC79624C7DAULL, 0x84547DDC3E203C94ULL,
-    0x990A98FD5071D263ULL, 0x1A4FF12616EEFC89ULL, 0xF6F7FD1431714200ULL,
-    0x30C05B1BA332F41CULL, 0x8D2636B81555A786ULL, 0x46C9FEB55D120902ULL,
-    0xCCEC0A73B49C9921ULL, 0x4E9D2827355FC492ULL, 0x19EBB029435DCB0FULL,
-    0x4659D2B743848A2CULL, 0x963EF2C96B33BE31ULL, 0x74F85198B05A2E7DULL,
-    0x5A0F544DD2B1FB18ULL, 0x03727073C2E134B1ULL, 0xC7F6AA2DE59AEA61ULL,
-    0x352787BAA0D7C22FULL, 0x9853EAB63B5E0B35ULL, 0xABBDCDD7ED5C0860ULL,
-    0xCF05DAF5AC8D77B0ULL, 0x49CAD48CEBF4A71EULL, 0x7A4C10EC2158C4A6ULL,
-    0xD9E92AA246BF719EULL, 0x13AE978D09FE5557ULL, 0x730499AF921549FFULL,
-    0x4E4B705B92903BA4ULL, 0xFF577222C14F0A3AULL, 0x55B6344CF97AAFAEULL,
-    0xB862225B055B6960ULL, 0xCAC09AFBDDD2CDB4ULL, 0xDAF8E9829FE96B5FULL,
-    0xB5FDFC5D3132C498ULL, 0x310CB380DB6F7503ULL, 0xE87FBB46217A360EULL,
-    0x2102AE466EBB1148ULL, 0xF8549E1A3AA5E00DULL, 0x07A69AFDCC42261AULL,
-    0xC4C118BFE78FEAAEULL, 0xF9F4892ED96BD438ULL, 0x1AF3DBE25D8F45DAULL,
-    0xF5B4B0B0D2DEEEB4ULL, 0x962ACEEFA82E1C84ULL, 0x046E3ECAAF453CE9ULL,
-    0xF05D129681949A4CULL, 0x964781CE734B3C84ULL, 0x9C2ED44081CE5FBDULL,
-    0x522E23F3925E319EULL, 0x177E00F9FC32F791ULL, 0x2BC60A63A6F3B3F2ULL,
-    0x222BBFAE61725606ULL, 0x486289DDCC3D6780ULL, 0x7DC7785B8EFDFC80ULL,
-    0x8AF38731C02BA980ULL, 0x1FAB64EA29A2DDF7ULL, 0xE4D9429322CD065AULL,
-    0x9DA058C67844F20CULL, 0x24C0E332B70019B0ULL, 0x233003B5A6CFE6ADULL,
-    0xD586BD01C5C217F6ULL, 0x5E5637885F29BC2BULL, 0x7EBA726D8C94094BULL,
-    0x0A56A5F0BFE39272ULL, 0xD79476A84EE20D06ULL, 0x9E4C1269BAA4BF37ULL,
-    0x17EFEE45B0DEE640ULL, 0x1D95B0A5FCF90BC6ULL, 0x93CBE0B699C2585DULL,
-    0x65FA4F227A2B6D79ULL, 0xD5F9E858292504D5ULL, 0xC2B5A03F71471A6FULL,
-    0x59300222B4561E00ULL, 0xCE2F8642CA0712DCULL, 0x7CA9723FBB2E8988ULL,
-    0x2785338347F2BA08ULL, 0xC61BB3A141E50E8CULL, 0x150F361DAB9DEC26ULL,
-    0x9F6A419D382595F4ULL, 0x64A53DC924FE7AC9ULL, 0x142DE49FFF7A7C3DULL,
-    0x0C335248857FA9E7ULL, 0x0A9C32D5EAE45305ULL, 0xE6C42178C4BBB92EULL,
-    0x71F1CE2490D20B07ULL, 0xF1BCC3D275AFE51AULL, 0xE728E8C83C334074ULL,
-    0x96FBF83A12884624ULL, 0x81A1549FD6573DA5ULL, 0x5FA7867CAF35E149ULL,
-    0x56986E2EF3ED091BULL, 0x917F1DD5F8886C61ULL, 0xD20D8C88C8FFE65FULL,
-    0x31D71DCE64B2C310ULL, 0xF165B587DF898190ULL, 0xA57E6339DD2CF3A0ULL,
-    0x1EF6E6DBB1961EC9ULL, 0x70CC73D90BC26E24ULL, 0xE21A6B35DF0C3AD7ULL,
-    0x003A93D8B2806962ULL, 0x1C99DED33CB890A1ULL, 0xCF3145DE0ADD4289ULL,
-    0xD0E4427A5514FB72ULL, 0x77C621CC9FB3A483ULL, 0x67A34DAC4356550BULL,
-    0xF8D626AAAF278509ULL
-  };
-
-  // Offsets to the PolyGlotRandoms[] array of zobrist keys
-  const Key* ZobPiece     = PolyGlotRandoms;
-  const Key* ZobCastle    = ZobPiece     + 12 * 64; // Pieces * squares
-  const Key* ZobEnPassant = ZobCastle    + 4;       // Castle flags
-  const Key* ZobTurn      = ZobEnPassant + 8;       // Number of files
-
-  // book_key() returns the PolyGlot hash key of the given position
-  uint64_t book_key(const Position& pos) {
-
-    uint64_t key = 0;
-    Bitboard b = pos.pieces();
-
-    while (b)
-    {
-        // In PolyGlotRandoms[] pieces are stored in the following sequence:
-        // BP = 0, WP = 1, BN = 2, WN = 3, ... BK = 10, WK = 11
-        Square s = pop_lsb(&b);
-        Piece p = pos.piece_on(s);
-        int pieceOfs = 2 * (type_of(p) - 1) + (color_of(p) == WHITE);
-        key ^= ZobPiece[64 * pieceOfs + s];
-    }
-
-    b = pos.can_castle(ALL_CASTLES);
-
-    while (b)
-        key ^= ZobCastle[pop_lsb(&b)];
-
-    if (pos.ep_square() != SQ_NONE)
-        key ^= ZobEnPassant[file_of(pos.ep_square())];
-
-    if (pos.side_to_move() == WHITE)
-        key ^= ZobTurn[0];
-
-    return key;
-  }
-
-} // namespace
-
-PolyglotBook::PolyglotBook() {
-
-  for (int i = Time::now() % 10000; i > 0; i--)
-      RKiss.rand<unsigned>(); // Make random number generation less deterministic
-}
-
-PolyglotBook::~PolyglotBook() { if (is_open()) close(); }
-
-
-/// operator>>() reads sizeof(T) chars from the file's binary byte stream and
-/// converts them in a number of type T. A Polyglot book stores numbers in
-/// big-endian format.
-
-template<typename T> PolyglotBook& PolyglotBook::operator>>(T& n) {
-
-  n = 0;
-  for (size_t i = 0; i < sizeof(T); i++)
-      n = T((n << 8) + ifstream::get());
-
-  return *this;
-}
-
-template<> PolyglotBook& PolyglotBook::operator>>(BookEntry& e) {
-  return *this >> e.key >> e.move >> e.count >> e.learn;
-}
-
-
-/// open() tries to open a book file with the given name after closing any
-/// exsisting one.
-
-bool PolyglotBook::open(const char* fName) {
-
-  if (is_open()) // Cannot close an already closed file
-      close();
-
-  ifstream::open(fName, ifstream::in | ifstream::binary);
-
-  fileName = is_open() ? fName : "";
-  ifstream::clear(); // Reset any error flag to allow retry ifstream::open()
-  return !fileName.empty();
-}
-
-
-/// probe() tries to find a book move for the given position. If no move is
-/// found returns MOVE_NONE. If pickBest is true returns always the highest
-/// rated move, otherwise randomly chooses one, based on the move score.
-
-Move PolyglotBook::probe(const Position& pos, const string& fName, bool pickBest) {
-
-  if (fileName != fName && !open(fName.c_str()))
-      return MOVE_NONE;
-
-  BookEntry e;
-  uint16_t best = 0;
-  unsigned sum = 0;
-  Move move = MOVE_NONE;
-  uint64_t key = book_key(pos);
-
-  seekg(find_first(key) * sizeof(BookEntry), ios_base::beg);
-
-  while (*this >> e, e.key == key && good())
-  {
-      best = max(best, e.count);
-      sum += e.count;
-
-      // Choose book move according to its score. If a move has a very
-      // high score it has higher probability to be choosen than a move
-      // with lower score. Note that first entry is always chosen.
-      if (   (sum && RKiss.rand<unsigned>() % sum < e.count)
-          || (pickBest && e.count == best))
-          move = Move(e.move);
-  }
-
-  if (!move)
-      return MOVE_NONE;
-
-  // A PolyGlot book move is encoded as follows:
-  //
-  // bit  0- 5: destination square (from 0 to 63)
-  // bit  6-11: origin square (from 0 to 63)
-  // bit 12-14: promotion piece (from KNIGHT == 1 to QUEEN == 4)
-  //
-  // Castling moves follow "king captures rook" representation. So in case book
-  // move is a promotion we have to convert to our representation, in all the
-  // other cases we can directly compare with a Move after having masked out
-  // the special Move's flags (bit 14-15) that are not supported by PolyGlot.
-  int pt = (move >> 12) & 7;
-  if (pt)
-      move = make<PROMOTION>(from_sq(move), to_sq(move), PieceType(pt + 1));
-
-  // Add 'special move' flags and verify it is legal
-  for (MoveList<LEGAL> ml(pos); !ml.end(); ++ml)
-      if (move == (ml.move() & 0x3FFF))
-          return ml.move();
-
-  return MOVE_NONE;
-}
-
-
-/// find_first() takes a book key as input, and does a binary search through
-/// the book file for the given key. Returns the index of the leftmost book
-/// entry with the same key as the input.
-
-size_t PolyglotBook::find_first(uint64_t key) {
-
-  seekg(0, ios::end); // Move pointer to end, so tellg() gets file's size
-
-  size_t low = 0, mid, high = (size_t)tellg() / sizeof(BookEntry) - 1;
-  BookEntry e;
-
-  assert(low <= high);
-
-  while (low < high && good())
-  {
-      mid = (low + high) / 2;
-
-      assert(mid >= low && mid < high);
-
-      seekg(mid * sizeof(BookEntry), ios_base::beg);
-      *this >> e;
-
-      if (key <= e.key)
-          high = mid;
-      else
-          low = mid + 1;
-  }
-
-  assert(low == high);
-
-  return low;
-}

src/book.h

@@ -1,45 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 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/>.
-*/
-
-#if !defined(BOOK_H_INCLUDED)
-#define BOOK_H_INCLUDED
-
-#include <fstream>
-#include <string>
-
-#include "position.h"
-#include "rkiss.h"
-
-class PolyglotBook : private std::ifstream {
-public:
-  PolyglotBook();
- ~PolyglotBook();
-  Move probe(const Position& pos, const std::string& fName, bool pickBest);
-
-private:
-  template<typename T> PolyglotBook& operator>>(T& n);
-
-  bool open(const char* fName);
-  size_t find_first(uint64_t key);
-
-  RKISS RKiss;
-  std::string fileName;
-};
-
-#endif // !defined(BOOK_H_INCLUDED)

src/endgame.h

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -17,7 +17,7 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#if !defined(ENDGAME_H_INCLUDED)
+#ifndef ENDGAME_H_INCLUDED
 #define ENDGAME_H_INCLUDED
 
 #include <map>
@@ -33,37 +33,38 @@ enum EndgameType {
 
   // Evaluation functions
 
+  KNNK,  // KNN vs K
   KXK,   // Generic "mate lone king" eval
   KBNK,  // KBN vs K
   KPK,   // KP vs K
   KRKP,  // KR vs KP
   KRKB,  // KR vs KB
   KRKN,  // KR vs KN
+  KQKP,  // KQ vs KP
   KQKR,  // KQ vs KR
-  KBBKN, // KBB vs KN
-  KNNK,  // KNN vs K
-  KmmKm, // K and two minors vs K and one or two minors
 
 
   // Scaling functions
-  SCALE_FUNS,
+  SCALING_FUNCTIONS,
 
-  KBPsK,   // KB+pawns vs K
-  KQKRPs,  // KQ vs KR+pawns
+  KBPsK,   // KB and pawns vs K
+  KQKRPs,  // KQ vs KR and pawns
   KRPKR,   // KRP vs KR
+  KRPKB,   // KRP vs KB
   KRPPKRP, // KRPP vs KRP
-  KPsK,    // King and pawns vs king
+  KPsK,    // K and pawns vs K
   KBPKB,   // KBP vs KB
   KBPPKB,  // KBPP vs KB
   KBPKN,   // KBP vs KN
   KNPK,    // KNP vs K
+  KNPKB,   // KNP vs KB
   KPKP     // KP vs KP
 };
 
 
-/// Endgame functions can be of two types according if return a Value or a
-/// ScaleFactor. Type eg_fun<int>::type equals to either ScaleFactor or Value
-/// depending if the template parameter is 0 or 1.
+/// 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.
 
 template<int> struct eg_fun { typedef Value type; };
 template<> struct eg_fun<1> { typedef ScaleFactor type; };
@@ -75,26 +76,26 @@ template<typename T>
 struct EndgameBase {
 
   virtual ~EndgameBase() {}
-  virtual Color color() const = 0;
+  virtual Color strong_side() const = 0;
   virtual T operator()(const Position&) const = 0;
 };
 
 
-template<EndgameType E, typename T = typename eg_fun<(E > SCALE_FUNS)>::type>
+template<EndgameType E, typename T = typename eg_fun<(E > SCALING_FUNCTIONS)>::type>
 struct Endgame : public EndgameBase<T> {
 
-  explicit Endgame(Color c) : strongerSide(c), weakerSide(~c) {}
-  Color color() const { return strongerSide; }
+  explicit Endgame(Color c) : strongSide(c), weakSide(~c) {}
+  Color strong_side() const { return strongSide; }
   T operator()(const Position&) const;
 
 private:
-  Color strongerSide, weakerSide;
+  Color strongSide, weakSide;
 };
 
 
-/// Endgames class stores in two std::map the pointers to endgame evaluation
-/// and scaling base objects. Then we use polymorphism to invoke the actual
-/// endgame function calling its operator() that is virtual.
+/// The Endgames class stores the pointers to endgame evaluation and scaling
+/// base objects in two std::map. We use polymorphism to invoke the actual
+/// endgame function by calling its virtual operator().
 
 class Endgames {
 
@@ -111,10 +112,11 @@ class Endgames {
 
 public:
   Endgames();
-  ~Endgames();
+ ~Endgames();
 
-  template<typename T> T probe(Key key, T& eg)
-  { return eg = map(eg).count(key) ? map(eg)[key] : NULL; }
+  template<typename T> T probe(Key key, T& eg) {
+    return eg = map(eg).count(key) ? map(eg)[key] : NULL;
+  }
 };
 
-#endif // !defined(ENDGAME_H_INCLUDED)
+#endif // #ifndef ENDGAME_H_INCLUDED

src/evaluate.h

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -17,21 +17,23 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#if !defined(EVALUATE_H_INCLUDED)
+#ifndef EVALUATE_H_INCLUDED
 #define EVALUATE_H_INCLUDED
 
+#include <string>
+
 #include "types.h"
 
 class Position;
 
 namespace Eval {
 
-extern Color RootColor;
+const Value Tempo = Value(17); // Must be visible to search
 
-extern void init();
-extern Value evaluate(const Position& pos, Value& margin);
-extern std::string trace(const Position& pos);
+void init();
+Value evaluate(const Position& pos);
+std::string trace(const Position& pos);
 
 }
 
-#endif // !defined(EVALUATE_H_INCLUDED)
+#endif // #ifndef EVALUATE_H_INCLUDED

src/history.h

@@ -1,72 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 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/>.
-*/
-
-#if !defined(HISTORY_H_INCLUDED)
-#define HISTORY_H_INCLUDED
-
-#include <algorithm>
-#include <cstring>
-
-#include "types.h"
-
-/// The History class stores statistics about how often different moves
-/// have been successful or unsuccessful during the current search. These
-/// statistics are used for reduction and move ordering decisions. History
-/// entries are stored according only to moving piece and destination square,
-/// in particular two moves with different origin but same destination and
-/// same piece will be considered identical.
-
-class History {
-
-public:
-  void clear();
-  Value value(Piece p, Square to) const;
-  void add(Piece p, Square to, Value bonus);
-  Value gain(Piece p, Square to) const;
-  void update_gain(Piece p, Square to, Value g);
-
-  static const Value MaxValue = Value(2000);
-
-private:
-  Value history[16][64];  // [piece][to_square]
-  Value maxGains[16][64]; // [piece][to_square]
-};
-
-inline void History::clear() {
-  memset(history,  0, 16 * 64 * sizeof(Value));
-  memset(maxGains, 0, 16 * 64 * sizeof(Value));
-}
-
-inline Value History::value(Piece p, Square to) const {
-  return history[p][to];
-}
-
-inline void History::add(Piece p, Square to, Value bonus) {
-  if (abs(history[p][to] + bonus) < MaxValue) history[p][to] += bonus;
-}
-
-inline Value History::gain(Piece p, Square to) const {
-  return maxGains[p][to];
-}
-
-inline void History::update_gain(Piece p, Square to, Value g) {
-  maxGains[p][to] = std::max(g, maxGains[p][to] - 1);
-}
-
-#endif // !defined(HISTORY_H_INCLUDED)

src/main.cpp

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -18,7 +18,6 @@
 */
 
 #include <iostream>
-#include <string>
 
 #include "bitboard.h"
 #include "evaluate.h"
@@ -26,7 +25,8 @@
 #include "search.h"
 #include "thread.h"
 #include "tt.h"
-#include "ucioption.h"
+#include "uci.h"
+#include "syzygy/tbprobe.h"
 
 int main(int argc, char* argv[]) {
 
@@ -34,19 +34,16 @@ int main(int argc, char* argv[]) {
 
   UCI::init(Options);
   Bitboards::init();
-  Zobrist::init();
-  Bitbases::init_kpk();
+  Position::init();
+  Bitbases::init();
   Search::init();
   Eval::init();
+  Pawns::init();
   Threads.init();
-  TT.set_size(Options["Hash"]);
+  Tablebases::init(Options["SyzygyPath"]);
+  TT.resize(Options["Hash"]);
 
-  std::string args;
-
-  for (int i = 1; i < argc; i++)
-      args += std::string(argv[i]) + " ";
-
-  UCI::loop(args);
+  UCI::loop(argc, argv);
 
   Threads.exit();
 }

src/material.cpp

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -17,41 +17,47 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <algorithm>
+#include <algorithm> // For std::min
 #include <cassert>
-#include <cstring>
+#include <cstring>   // For std::memset
 
 #include "material.h"
+#include "thread.h"
 
 using namespace std;
 
 namespace {
 
-  // Values modified by Joona Kiiski
-  const Value MidgameLimit = Value(15581);
-  const Value EndgameLimit = Value(3998);
+  // Polynomial material imbalance parameters
 
-  // Scale factors used when one side has no more pawns
-  const int NoPawnsSF[4] = { 6, 12, 32 };
+  //                      pair  pawn knight bishop rook queen
+  const int Linear[6] = { 1852, -162, -1122, -183,  249, -154 };
 
-  // Polynomial material balance parameters
-  const Value RedundantQueenPenalty = Value(320);
-  const Value RedundantRookPenalty  = Value(554);
+  const 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
+  };
 
-  const int LinearCoefficients[6] = { 1617, -162, -1172, -190, 105, 26 };
+  const 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
+  };
 
-  const int QuadraticCoefficientsSameColor[][8] = {
-  { 7, 7, 7, 7, 7, 7 }, { 39, 2, 7, 7, 7, 7 }, { 35, 271, -4, 7, 7, 7 },
-  { 7, 25, 4, 7, 7, 7 }, { -27, -2, 46, 100, 56, 7 }, { 58, 29, 83, 148, -3, -25 } };
-
-  const int QuadraticCoefficientsOppositeColor[][8] = {
-  { 41, 41, 41, 41, 41, 41 }, { 37, 41, 41, 41, 41, 41 }, { 10, 62, 41, 41, 41, 41 },
-  { 57, 64, 39, 41, 41, 41 }, { 50, 40, 23, -22, 41, 41 }, { 106, 101, 3, 151, 171, 41 } };
-
-  // Endgame evaluation and scaling functions accessed direcly and not through
-  // the function maps because correspond to more then one material hash key.
-  Endgame<KmmKm> EvaluateKmmKm[] = { Endgame<KmmKm>(WHITE), Endgame<KmmKm>(BLACK) };
-  Endgame<KXK>   EvaluateKXK[]   = { Endgame<KXK>(WHITE),   Endgame<KXK>(BLACK) };
+  // Endgame evaluation and scaling functions are accessed directly and not through
+  // the function maps because they correspond to more than one material hash key.
+  Endgame<KXK>    EvaluateKXK[] = { Endgame<KXK>(WHITE),    Endgame<KXK>(BLACK) };
 
   Endgame<KBPsK>  ScaleKBPsK[]  = { Endgame<KBPsK>(WHITE),  Endgame<KBPsK>(BLACK) };
   Endgame<KQKRPs> ScaleKQKRPs[] = { Endgame<KQKRPs>(WHITE), Endgame<KQKRPs>(BLACK) };
@@ -61,54 +67,79 @@ namespace {
   // 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   pos.non_pawn_material(Them) == VALUE_ZERO
-          && pos.piece_count(Them, PAWN) == 0
-          && pos.non_pawn_material(Us)   >= RookValueMg;
+    return  !more_than_one(pos.pieces(Them))
+          && pos.non_pawn_material(Us) >= RookValueMg;
   }
 
   template<Color Us> bool is_KBPsKs(const Position& pos) {
-    return   pos.non_pawn_material(Us)   == BishopValueMg
-          && pos.piece_count(Us, BISHOP) == 1
-          && pos.piece_count(Us, PAWN)   >= 1;
+    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.piece_count(Us, PAWN)    == 0
-          && pos.non_pawn_material(Us)    == QueenValueMg
-          && pos.piece_count(Us, QUEEN)   == 1
-          && pos.piece_count(Them, ROOK)  == 1
-          && pos.piece_count(Them, PAWN)  >= 1;
+    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;
+  }
+
+  /// 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);
+
+    int bonus = 0;
+
+    // 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];
+
+        for (int pt2 = NO_PIECE_TYPE; pt2 <= pt1; ++pt2)
+            v +=  QuadraticOurs[pt1][pt2] * pieceCount[Us][pt2]
+                + QuadraticTheirs[pt1][pt2] * pieceCount[Them][pt2];
+
+        bonus += pieceCount[Us][pt1] * v;
+    }
+
+    return bonus;
   }
 
 } // namespace
 
+namespace Material {
 
-/// MaterialTable::probe() takes a position object as input, looks up a MaterialEntry
-/// object, and returns a pointer to it. If the material configuration is not
-/// already present in the table, it is computed and stored there, so we don't
-/// have to recompute everything when the same material configuration occurs again.
+/// Material::probe() looks up the current position's material configuration in
+/// the material hash table. It returns a pointer to the Entry if the position
+/// is found. Otherwise a new Entry is computed and stored there, so we don't
+/// have to recompute all when the same material configuration occurs again.
 
-MaterialEntry* MaterialTable::probe(const Position& pos) {
+Entry* probe(const Position& pos) {
 
   Key key = pos.material_key();
-  MaterialEntry* e = entries[key];
+  Entry* e = pos.this_thread()->materialTable[key];
 
-  // If e->key matches the position's material hash key, it means that we
-  // have analysed this material configuration before, and we can simply
-  // return the information we found the last time instead of recomputing it.
   if (e->key == key)
       return e;
 
-  memset(e, 0, sizeof(MaterialEntry));
+  std::memset(e, 0, sizeof(Entry));
   e->key = key;
   e->factor[WHITE] = e->factor[BLACK] = (uint8_t)SCALE_FACTOR_NORMAL;
-  e->gamePhase = MaterialTable::game_phase(pos);
+  e->gamePhase = pos.game_phase();
 
-  // Let's look if we have a specialized evaluation function for this
-  // particular material configuration. First we look for a fixed
-  // configuration one, then a generic one if previous search failed.
-  if (endgames.probe(key, e->evaluationFunction))
+  // 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))
       return e;
 
   if (is_KXK<WHITE>(pos))
@@ -123,37 +154,19 @@ MaterialEntry* MaterialTable::probe(const Position& pos) {
       return e;
   }
 
-  if (!pos.pieces(PAWN) && !pos.pieces(ROOK) && !pos.pieces(QUEEN))
-  {
-      // Minor piece endgame with at least one minor piece per side and
-      // no pawns. Note that the case KmmK is already handled by KXK.
-      assert((pos.pieces(WHITE, KNIGHT) | pos.pieces(WHITE, BISHOP)));
-      assert((pos.pieces(BLACK, KNIGHT) | pos.pieces(BLACK, BISHOP)));
-
-      if (   pos.piece_count(WHITE, BISHOP) + pos.piece_count(WHITE, KNIGHT) <= 2
-          && pos.piece_count(BLACK, BISHOP) + pos.piece_count(BLACK, KNIGHT) <= 2)
-      {
-          e->evaluationFunction = &EvaluateKmmKm[pos.side_to_move()];
-          return e;
-      }
-  }
-
-  // OK, we didn't find any special evaluation function for the current
-  // material configuration. Is there a suitable scaling function?
-  //
-  // We face problems when there are several conflicting applicable
-  // scaling functions and we need to decide which one to use.
+  // OK, we didn't find any special evaluation function for the current material
+  // configuration. Is there a suitable specialized scaling function?
   EndgameBase<ScaleFactor>* sf;
 
-  if (endgames.probe(key, sf))
+  if (pos.this_thread()->endgames.probe(key, sf))
   {
-      e->scalingFunction[sf->color()] = sf;
+      e->scalingFunction[sf->strong_side()] = sf; // Only strong color assigned
       return e;
   }
 
-  // Generic scaling functions that refer to more then one material
-  // distribution. Should be probed after the specialized ones.
-  // Note that these ones don't return after setting the function.
+  // 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];
 
@@ -169,19 +182,21 @@ MaterialEntry* MaterialTable::probe(const Position& pos) {
   Value npm_w = pos.non_pawn_material(WHITE);
   Value npm_b = pos.non_pawn_material(BLACK);
 
-  if (npm_w + npm_b == VALUE_ZERO)
+  if (npm_w + npm_b == VALUE_ZERO && pos.pieces(PAWN)) // Only pawns on the board
   {
-      if (pos.piece_count(BLACK, PAWN) == 0)
+      if (!pos.count<PAWN>(BLACK))
       {
-          assert(pos.piece_count(WHITE, PAWN) >= 2);
+          assert(pos.count<PAWN>(WHITE) >= 2);
+
           e->scalingFunction[WHITE] = &ScaleKPsK[WHITE];
       }
-      else if (pos.piece_count(WHITE, PAWN) == 0)
+      else if (!pos.count<PAWN>(WHITE))
       {
-          assert(pos.piece_count(BLACK, PAWN) >= 2);
+          assert(pos.count<PAWN>(BLACK) >= 2);
+
           e->scalingFunction[BLACK] = &ScaleKPsK[BLACK];
       }
-      else if (pos.piece_count(WHITE, PAWN) == 1 && pos.piece_count(BLACK, PAWN) == 1)
+      else if (pos.count<PAWN>(WHITE) == 1 && pos.count<PAWN>(BLACK) == 1)
       {
           // This is a special case because we set scaling functions
           // for both colors instead of only one.
@@ -190,87 +205,34 @@ MaterialEntry* MaterialTable::probe(const Position& pos) {
       }
   }
 
-  // No pawns makes it difficult to win, even with a material advantage
-  if (pos.piece_count(WHITE, PAWN) == 0 && npm_w - npm_b <= BishopValueMg)
-  {
-      e->factor[WHITE] = (uint8_t)
-      (npm_w == npm_b || npm_w < RookValueMg ? 0 : NoPawnsSF[std::min(pos.piece_count(WHITE, BISHOP), 2)]);
-  }
+  // Zero or just one pawn makes it difficult to win, even with a small material
+  // advantage. This catches some trivial draws like KK, KBK and KNK and gives a
+  // drawish scale factor for cases such as KRKBP and KmmKm (except for KBBKN).
+  if (!pos.count<PAWN>(WHITE) && npm_w - npm_b <= BishopValueMg)
+      e->factor[WHITE] = uint8_t(npm_w <  RookValueMg   ? SCALE_FACTOR_DRAW :
+                                 npm_b <= BishopValueMg ? 4 : 12);
 
-  if (pos.piece_count(BLACK, PAWN) == 0 && npm_b - npm_w <= BishopValueMg)
-  {
-      e->factor[BLACK] = (uint8_t)
-      (npm_w == npm_b || npm_b < RookValueMg ? 0 : NoPawnsSF[std::min(pos.piece_count(BLACK, BISHOP), 2)]);
-  }
+  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);
 
-  // Compute the space weight
-  if (npm_w + npm_b >= 2 * QueenValueMg + 4 * RookValueMg + 2 * KnightValueMg)
-  {
-      int minorPieceCount =  pos.piece_count(WHITE, KNIGHT) + pos.piece_count(WHITE, BISHOP)
-                           + pos.piece_count(BLACK, KNIGHT) + pos.piece_count(BLACK, BISHOP);
+  if (pos.count<PAWN>(WHITE) == 1 && npm_w - npm_b <= BishopValueMg)
+      e->factor[WHITE] = (uint8_t) SCALE_FACTOR_ONEPAWN;
 
-      e->spaceWeight = minorPieceCount * minorPieceCount;
-  }
+  if (pos.count<PAWN>(BLACK) == 1 && npm_b - npm_w <= BishopValueMg)
+      e->factor[BLACK] = (uint8_t) SCALE_FACTOR_ONEPAWN;
 
   // Evaluate the material imbalance. We use PIECE_TYPE_NONE as a place holder
-  // for the bishop pair "extended piece", this allow us to be more flexible
+  // for the bishop pair "extended piece", which allows us to be more flexible
   // in defining bishop pair bonuses.
-  const int pieceCount[2][8] = {
-  { pos.piece_count(WHITE, BISHOP) > 1, pos.piece_count(WHITE, PAWN), pos.piece_count(WHITE, KNIGHT),
-    pos.piece_count(WHITE, BISHOP)    , pos.piece_count(WHITE, ROOK), pos.piece_count(WHITE, QUEEN) },
-  { pos.piece_count(BLACK, BISHOP) > 1, pos.piece_count(BLACK, PAWN), pos.piece_count(BLACK, KNIGHT),
-    pos.piece_count(BLACK, BISHOP)    , pos.piece_count(BLACK, ROOK), pos.piece_count(BLACK, QUEEN) } };
+  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;
 }
 
-
-/// MaterialTable::imbalance() calculates imbalance comparing piece count of each
-/// piece type for both colors.
-
-template<Color Us>
-int MaterialTable::imbalance(const int pieceCount[][8]) {
-
-  const Color Them = (Us == WHITE ? BLACK : WHITE);
-
-  int pt1, pt2, pc, v;
-  int value = 0;
-
-  // Redundancy of major pieces, formula based on Kaufman's paper
-  // "The Evaluation of Material Imbalances in Chess"
-  if (pieceCount[Us][ROOK] > 0)
-      value -=  RedundantRookPenalty * (pieceCount[Us][ROOK] - 1)
-              + RedundantQueenPenalty * pieceCount[Us][QUEEN];
-
-  // Second-degree polynomial material imbalance by Tord Romstad
-  for (pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; pt1++)
-  {
-      pc = pieceCount[Us][pt1];
-      if (!pc)
-          continue;
-
-      v = LinearCoefficients[pt1];
-
-      for (pt2 = NO_PIECE_TYPE; pt2 <= pt1; pt2++)
-          v +=  QuadraticCoefficientsSameColor[pt1][pt2] * pieceCount[Us][pt2]
-              + QuadraticCoefficientsOppositeColor[pt1][pt2] * pieceCount[Them][pt2];
-
-      value += pc * v;
-  }
-  return value;
-}
-
-
-/// MaterialTable::game_phase() calculates the phase given the current
-/// position. Because the phase is strictly a function of the material, it
-/// is stored in MaterialEntry.
-
-Phase MaterialTable::game_phase(const Position& pos) {
-
-  Value npm = pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK);
-
-  return  npm >= MidgameLimit ? PHASE_MIDGAME
-        : npm <= EndgameLimit ? PHASE_ENDGAME
-        : Phase(((npm - EndgameLimit) * 128) / (MidgameLimit - EndgameLimit));
-}
+} // namespace Material

src/material.h

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -17,7 +17,7 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#if !defined(MATERIAL_H_INCLUDED)
+#ifndef MATERIAL_H_INCLUDED
 #define MATERIAL_H_INCLUDED
 
 #include "endgame.h"
@@ -25,96 +25,48 @@
 #include "position.h"
 #include "types.h"
 
-const int MaterialTableSize = 8192;
+namespace Material {
 
-/// Game phase
-enum Phase {
-  PHASE_ENDGAME = 0,
-  PHASE_MIDGAME = 128
-};
-
-
-/// MaterialEntry is a class which contains various information about a
-/// material configuration. It contains a material balance evaluation,
-/// a function pointer to a special endgame evaluation function (which in
-/// most cases is NULL, meaning that the standard evaluation function will
-/// be used), and "scale factors" for black and white.
+/// Material::Entry contains various information about a material configuration.
+/// It contains a material imbalance evaluation, a function pointer to a special
+/// endgame evaluation function (which in most cases is NULL, meaning that the
+/// standard evaluation function will be used), and scale factors.
 ///
-/// The scale factors are used to scale the evaluation score up or down.
-/// For instance, in KRB vs KR endgames, the score is scaled down by a factor
-/// of 4, which will result in scores of absolute value less than one pawn.
+/// The scale factors are used to scale the evaluation score up or down. For
+/// instance, in KRB vs KR endgames, the score is scaled down by a factor of 4,
+/// which will result in scores of absolute value less than one pawn.
 
-class MaterialEntry {
+struct Entry {
 
-  friend struct MaterialTable;
+  Score imbalance() const { return make_score(value, value); }
+  Phase game_phase() const { return gamePhase; }
+  bool specialized_eval_exists() const { return evaluationFunction != NULL; }
+  Value evaluate(const Position& pos) const { return (*evaluationFunction)(pos); }
 
-public:
-  Score material_value() const;
-  ScaleFactor scale_factor(const Position& pos, Color c) const;
-  int space_weight() const;
-  Phase game_phase() const;
-  bool specialized_eval_exists() const;
-  Value evaluate(const Position& pos) const;
+  // scale_factor takes a position and a color as input and returns a scale factor
+  // for the given color. We have to provide the position in addition to the color
+  // because the scale factor may also be a function which should be applied to
+  // the position. For instance, in KBP vs K endgames, the scaling function looks
+  // for rook pawns and wrong-colored bishops.
+  ScaleFactor scale_factor(const Position& pos, Color c) const {
+    return   !scalingFunction[c]
+          || (*scalingFunction[c])(pos) == SCALE_FACTOR_NONE ? ScaleFactor(factor[c])
+                                                             : (*scalingFunction[c])(pos);
+  }
 
-private:
   Key key;
   int16_t value;
-  uint8_t factor[2];
+  uint8_t factor[COLOR_NB];
   EndgameBase<Value>* evaluationFunction;
-  EndgameBase<ScaleFactor>* scalingFunction[2];
-  int spaceWeight;
+  EndgameBase<ScaleFactor>* scalingFunction[COLOR_NB]; // Could be one for each
+                                                       // side (e.g. KPKP, KBPsKs)
   Phase gamePhase;
 };
 
+typedef HashTable<Entry, 8192> Table;
 
-/// The MaterialTable class represents a material hash table. The most important
-/// method is probe(), which returns a pointer to a MaterialEntry object.
+Entry* probe(const Position& pos);
 
-struct MaterialTable {
+} // namespace Material
 
-  MaterialEntry* probe(const Position& pos);
-  static Phase game_phase(const Position& pos);
-  template<Color Us> static int imbalance(const int pieceCount[][8]);
-
-  HashTable<MaterialEntry, MaterialTableSize> entries;
-  Endgames endgames;
-};
-
-
-/// MaterialEntry::scale_factor takes a position and a color as input, and
-/// returns a scale factor for the given color. We have to provide the
-/// position in addition to the color, because the scale factor need not
-/// to be a constant: It can also be a function which should be applied to
-/// the position. For instance, in KBP vs K endgames, a scaling function
-/// which checks for draws with rook pawns and wrong-colored bishops.
-
-inline ScaleFactor MaterialEntry::scale_factor(const Position& pos, Color c) const {
-
-  if (!scalingFunction[c])
-      return ScaleFactor(factor[c]);
-
-  ScaleFactor sf = (*scalingFunction[c])(pos);
-  return sf == SCALE_FACTOR_NONE ? ScaleFactor(factor[c]) : sf;
-}
-
-inline Value MaterialEntry::evaluate(const Position& pos) const {
-  return (*evaluationFunction)(pos);
-}
-
-inline Score MaterialEntry::material_value() const {
-  return make_score(value, value);
-}
-
-inline int MaterialEntry::space_weight() const {
-  return spaceWeight;
-}
-
-inline Phase MaterialEntry::game_phase() const {
-  return gamePhase;
-}
-
-inline bool MaterialEntry::specialized_eval_exists() const {
-  return evaluationFunction != NULL;
-}
-
-#endif // !defined(MATERIAL_H_INCLUDED)
+#endif // #ifndef MATERIAL_H_INCLUDED

src/misc.cpp

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -17,6 +17,7 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include <fstream>
 #include <iomanip>
 #include <iostream>
 #include <sstream>
@@ -24,81 +25,21 @@
 #include "misc.h"
 #include "thread.h"
 
-#if defined(__hpux)
-#    include <sys/pstat.h>
-#endif
-
 using namespace std;
 
-/// Version number. If Version is left empty, then Tag plus current
-/// date (in the format YYMMDD) is used as a version number.
+namespace {
 
-static const string Version = "2.3.1";
-static const string Tag = "";
-
-
-/// engine_info() returns the full name of the current Stockfish version.
-/// This will be either "Stockfish YYMMDD" (where YYMMDD is the date when
-/// the program was compiled) or "Stockfish <version number>", depending
-/// on whether Version is empty.
-
-const string engine_info(bool to_uci) {
-
-  const string months("Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec");
-  const string cpu64(Is64Bit ? " 64bit" : "");
-  const string popcnt(HasPopCnt ? " SSE4.2" : "");
-
-  string month, day, year;
-  stringstream s, date(__DATE__); // From compiler, format is "Sep 21 2008"
-
-  s << "Stockfish " << Version;
-
-  if (Version.empty())
-  {
-      date >> month >> day >> year;
-
-      s << Tag << setfill('0') << " " << year.substr(2)
-        << setw(2) << (1 + months.find(month) / 4) << setw(2) << day;
-  }
-
-  s << cpu64 << popcnt << (to_uci ? "\nid author ": " by ")
-    << "Tord Romstad, Marco Costalba and Joona Kiiski";
-
-  return s.str();
-}
-
-
-/// Convert system time to milliseconds. That's all we need.
-
-Time::point Time::now() {
-  sys_time_t t; system_time(&t); return time_to_msec(t);
-}
-
-
-/// Debug functions used mainly to collect run-time statistics
-
-static uint64_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_mean_of(int v) { means[0]++; means[1] += v; }
-
-void dbg_print() {
-
-  if (hits[0])
-      cerr << "Total " << hits[0] << " Hits " << hits[1]
-           << " hit rate (%) " << 100 * hits[1] / hits[0] << endl;
-
-  if (means[0])
-      cerr << "Total " << means[0] << " Mean "
-           << (float)means[1] / means[0] << endl;
-}
+/// 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];
 
 /// 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 while preserving
-/// usual i/o functionality and without changing a single line of code!
+/// 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!
 /// Idea from http://groups.google.com/group/comp.lang.c++/msg/1d941c0f26ea0d81
 
 struct Tie: public streambuf { // MSVC requires splitted streambuf for cin and cout
@@ -152,18 +93,65 @@ public:
   }
 };
 
+} // namespace
 
-/// Used to serialize access to std::cout to avoid multiple threads to write at
+/// engine_info() returns the full name of the current Stockfish version. This
+/// will be either "Stockfish <Tag> DD-MM-YY" (where DD-MM-YY is the date when
+/// the program was compiled) or "Stockfish <Version>", depending on whether
+/// Version is empty.
+
+const string engine_info(bool to_uci) {
+
+  const string months("Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec");
+  string month, day, year;
+  stringstream ss, date(__DATE__); // From compiler, format is "Sep 21 2008"
+
+  ss << "Stockfish " << Version << setfill('0');
+
+  if (Version.empty())
+  {
+      date >> month >> day >> year;
+      ss << setw(2) << day << setw(2) << (1 + months.find(month) / 4) << year.substr(2);
+  }
+
+  ss << (Is64Bit ? " 64" : "")
+     << (HasPext ? " BMI2" : (HasPopCnt ? " POPCNT" : ""))
+     << (to_uci  ? "\nid author ": " by ")
+     << "Tord Romstad, Marco Costalba and Joona Kiiski";
+
+  return ss.str();
+}
+
+
+/// Debug functions used mainly to collect run-time statistics
+
+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_mean_of(int v) { ++means[0]; means[1] += v; }
+
+void dbg_print() {
+
+  if (hits[0])
+      cerr << "Total " << hits[0] << " Hits " << hits[1]
+           << " hit rate (%) " << 100 * hits[1] / hits[0] << endl;
+
+  if (means[0])
+      cerr << "Total " << means[0] << " Mean "
+           << (double)means[1] / means[0] << endl;
+}
+
+
+/// Used to serialize access to std::cout to avoid multiple threads writing at
 /// the same time.
 
 std::ostream& operator<<(std::ostream& os, SyncCout sc) {
 
   static Mutex m;
 
-  if (sc == io_lock)
+  if (sc == IO_LOCK)
       m.lock();
 
-  if (sc == io_unlock)
+  if (sc == IO_UNLOCK)
       m.unlock();
 
   return os;
@@ -174,37 +162,12 @@ std::ostream& operator<<(std::ostream& os, SyncCout sc) {
 void start_logger(bool b) { Logger::start(b); }
 
 
-/// cpu_count() tries to detect the number of CPU cores
-
-int cpu_count() {
-
-#if defined(_WIN32) || defined(_WIN64)
-  SYSTEM_INFO s;
-  GetSystemInfo(&s);
-  return s.dwNumberOfProcessors;
-#else
-
-#  if defined(_SC_NPROCESSORS_ONLN)
-  return sysconf(_SC_NPROCESSORS_ONLN);
-#  elif defined(__hpux)
-  struct pst_dynamic psd;
-  if (pstat_getdynamic(&psd, sizeof(psd), (size_t)1, 0) == -1)
-      return 1;
-  return psd.psd_proc_cnt;
-#  else
-  return 1;
-#  endif
-
-#endif
-}
-
-
-/// timed_wait() waits for msec milliseconds. It is mainly an helper to wrap
-/// conversion from milliseconds to struct timespec, as used by pthreads.
+/// 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) {
 
-#if defined(_WIN32) || defined(_WIN64)
+#ifdef _WIN32
   int tm = msec;
 #else
   timespec ts, *tm = &ts;
@@ -218,27 +181,28 @@ void timed_wait(WaitCondition& sleepCond, Lock& sleepLock, int msec) {
 }
 
 
-/// prefetch() preloads the given address in L1/L2 cache. This is a non
-/// blocking function and do not stalls the CPU waiting for data to be
-/// loaded from memory, that can be quite slow.
-#if defined(NO_PREFETCH)
+/// prefetch() preloads the given address in L1/L2 cache. This is a non-blocking
+/// function that doesn't stall the CPU waiting for data to be loaded from memory,
+/// which can be quite slow.
+#ifdef NO_PREFETCH
 
 void prefetch(char*) {}
 
 #else
 
-#   include <xmmintrin.h>
-
 void prefetch(char* addr) {
 
-#  if defined(__INTEL_COMPILER) || defined(__ICL)
-   // This hack prevents prefetches to be optimized away by
-   // Intel compiler. Both MSVC and gcc seems not affected.
+#  if defined(__INTEL_COMPILER)
+   // This hack prevents prefetches from being optimized away by
+   // Intel compiler. Both MSVC and gcc seem not be affected by this.
    __asm__ ("");
 #  endif
 
-  _mm_prefetch(addr, _MM_HINT_T2);
-  _mm_prefetch(addr+64, _MM_HINT_T2); // 64 bytes ahead
+#  if defined(__INTEL_COMPILER) || defined(_MSC_VER)
+  _mm_prefetch(addr, _MM_HINT_T0);
+#  else
+  __builtin_prefetch(addr);
+#  endif
 }
 
 #endif

src/misc.h

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -17,53 +17,84 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#if !defined(MISC_H_INCLUDED)
+#ifndef MISC_H_INCLUDED
 #define MISC_H_INCLUDED
 
-#include <fstream>
+#include <cassert>
+#include <ostream>
 #include <string>
 #include <vector>
 
 #include "types.h"
 
-extern const std::string engine_info(bool to_uci = false);
-extern int cpu_count();
-extern void timed_wait(WaitCondition&, Lock&, int);
-extern void prefetch(char* addr);
-extern void start_logger(bool b);
+const std::string engine_info(bool to_uci = false);
+void timed_wait(WaitCondition&, Lock&, int);
+void prefetch(char* addr);
+void start_logger(bool b);
 
-extern void dbg_hit_on(bool b);
-extern void dbg_hit_on_c(bool c, bool b);
-extern void dbg_mean_of(int v);
-extern void dbg_print();
-
-
-struct Log : public std::ofstream {
-  Log(const std::string& f = "log.txt") : std::ofstream(f.c_str(), std::ios::out | std::ios::app) {}
- ~Log() { if (is_open()) close(); }
-};
+void dbg_hit_on(bool b);
+void dbg_hit_on_c(bool c, bool b);
+void dbg_mean_of(int v);
+void dbg_print();
 
 
 namespace Time {
   typedef int64_t point;
-  point now();
+  inline point now() { return system_time_to_msec(); }
 }
 
 
 template<class Entry, int Size>
 struct HashTable {
-  HashTable() : e(Size, Entry()) {}
-  Entry* operator[](Key k) { return &e[(uint32_t)k & (Size - 1)]; }
+  HashTable() : table(Size, Entry()) {}
+  Entry* operator[](Key key) { return &table[(uint32_t)key & (Size - 1)]; }
 
 private:
-  std::vector<Entry> e;
+  std::vector<Entry> table;
 };
 
 
-enum SyncCout { io_lock, io_unlock };
+enum SyncCout { IO_LOCK, IO_UNLOCK };
 std::ostream& operator<<(std::ostream&, SyncCout);
 
-#define sync_cout std::cout << io_lock
-#define sync_endl std::endl << io_unlock
+#define sync_cout std::cout << IO_LOCK
+#define sync_endl std::endl << IO_UNLOCK
 
-#endif // !defined(MISC_H_INCLUDED)
+
+/// xorshift64star Pseudo-Random Number Generator
+/// This class is based on original code written and dedicated
+/// to the public domain by Sebastiano Vigna (2014).
+/// It has the following characteristics:
+///
+///  -  Outputs 64-bit numbers
+///  -  Passes Dieharder and SmallCrush test batteries
+///  -  Does not require warm-up, no zeroland to escape
+///  -  Internal state is a single 64-bit integer
+///  -  Period is 2^64 - 1
+///  -  Speed: 1.60 ns/call (Core i7 @3.40GHz)
+///
+/// For further analysis see
+///   <http://vigna.di.unimi.it/ftp/papers/xorshift.pdf>
+
+class PRNG {
+
+  uint64_t s;
+
+  uint64_t rand64() {
+
+    s ^= s >> 12, s ^= s << 25, s ^= s >> 27;
+    return s * 2685821657736338717LL;
+  }
+
+public:
+  PRNG(uint64_t seed) : s(seed) { assert(seed); }
+
+  template<typename T> T rand() { return T(rand64()); }
+
+  /// Special generator used to fast init magic numbers.
+  /// Output values only have 1/8th of their bits set on average.
+  template<typename T> T sparse_rand()
+  { return T(rand64() & rand64() & rand64()); }
+};
+
+#endif // #ifndef MISC_H_INCLUDED

src/movegen.cpp

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -22,99 +22,76 @@
 #include "movegen.h"
 #include "position.h"
 
-/// Simple macro to wrap a very common while loop, no facny, no flexibility,
-/// hardcoded names 'mlist' and 'from'.
-#define SERIALIZE(b) while (b) (*mlist++).move = make_move(from, pop_lsb(&b))
-
-/// Version used for pawns, where the 'from' square is given as a delta from the 'to' square
-#define SERIALIZE_PAWNS(b, d) while (b) { Square to = pop_lsb(&b); \
-                                         (*mlist++).move = make_move(to - (d), to); }
 namespace {
 
-  template<CastlingSide Side, bool Checks, bool Chess960>
-  MoveStack* generate_castle(const Position& pos, MoveStack* mlist, Color us) {
+  template<CastlingRight Cr, bool Checks, bool Chess960>
+  ExtMove* generate_castling(const Position& pos, ExtMove* moveList, Color us, const CheckInfo* ci) {
 
-    if (pos.castle_impeded(us, Side) || !pos.can_castle(make_castle_right(us, Side)))
-        return mlist;
+    static const 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 rfrom = pos.castle_rook_square(us, Side);
-    Square kto = relative_square(us, Side == KING_SIDE ? SQ_G1 : SQ_C1);
+    Square rfrom = pos.castling_rook_square(Cr);
+    Square kto = relative_square(us, KingSide ? SQ_G1 : SQ_C1);
     Bitboard enemies = pos.pieces(~us);
 
-    assert(!pos.in_check());
+    assert(!pos.checkers());
 
-    const int K = Chess960 ? kto > kfrom ? -1 : 1
-                           : Side == KING_SIDE ? -1 : 1;
+    const Square K = Chess960 ? kto > kfrom ? DELTA_W : DELTA_E
+                              : KingSide    ? DELTA_W : DELTA_E;
 
-    for (Square s = kto; s != kfrom; s += (Square)K)
+    for (Square s = kto; s != kfrom; s += K)
         if (pos.attackers_to(s) & enemies)
-            return mlist;
+            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 && (pos.attackers_to(kto, pos.pieces() ^ rfrom) & enemies))
-        return mlist;
+    if (Chess960 && (attacks_bb<ROOK>(kto, pos.pieces() ^ rfrom) & pos.pieces(~us, ROOK, QUEEN)))
+        return moveList;
 
-    (*mlist++).move = make<CASTLE>(kfrom, rfrom);
+    Move m = make<CASTLING>(kfrom, rfrom);
 
-    if (Checks && !pos.move_gives_check((mlist - 1)->move, CheckInfo(pos)))
-        mlist--;
+    if (Checks && !pos.gives_check(m, *ci))
+        return moveList;
 
-    return mlist;
-  }
+    (moveList++)->move = m;
 
-
-  template<Square Delta>
-  inline Bitboard move_pawns(Bitboard p) {
-
-    return  Delta == DELTA_N  ?  p << 8
-          : Delta == DELTA_S  ?  p >> 8
-          : Delta == DELTA_NE ? (p & ~FileHBB) << 9
-          : Delta == DELTA_SE ? (p & ~FileHBB) >> 7
-          : Delta == DELTA_NW ? (p & ~FileABB) << 7
-          : Delta == DELTA_SW ? (p & ~FileABB) >> 9 : 0;
+    return moveList;
   }
 
 
   template<GenType Type, Square Delta>
-  inline MoveStack* generate_promotions(MoveStack* mlist, Bitboard pawnsOn7,
-                                        Bitboard target, const CheckInfo* ci) {
+  inline ExtMove* make_promotions(ExtMove* moveList, Square to, const CheckInfo* ci) {
 
-    Bitboard b = move_pawns<Delta>(pawnsOn7) & target;
+    if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS)
+        (moveList++)->move = make<PROMOTION>(to - Delta, to, QUEEN);
 
-    while (b)
+    if (Type == QUIETS || Type == EVASIONS || Type == NON_EVASIONS)
     {
-        Square to = pop_lsb(&b);
-
-        if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS)
-            (*mlist++).move = make<PROMOTION>(to - Delta, to, QUEEN);
-
-        if (Type == QUIETS || Type == EVASIONS || Type == NON_EVASIONS)
-        {
-            (*mlist++).move = make<PROMOTION>(to - Delta, to, ROOK);
-            (*mlist++).move = make<PROMOTION>(to - Delta, to, BISHOP);
-            (*mlist++).move = make<PROMOTION>(to - Delta, to, KNIGHT);
-        }
-
-        // Knight-promotion is the only one that can give a direct check not
-        // already included in the queen-promotion.
-        if (Type == QUIET_CHECKS && (StepAttacksBB[W_KNIGHT][to] & ci->ksq))
-            (*mlist++).move = make<PROMOTION>(to - Delta, to, KNIGHT);
-        else
-            (void)ci; // Silence a warning under MSVC
+        (moveList++)->move = make<PROMOTION>(to - Delta, to, ROOK);
+        (moveList++)->move = make<PROMOTION>(to - Delta, to, BISHOP);
+        (moveList++)->move = make<PROMOTION>(to - Delta, to, KNIGHT);
     }
 
-    return mlist;
+    // 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);
+    else
+        (void)ci; // Silence a warning under MSVC
+
+    return moveList;
   }
 
 
   template<Color Us, GenType Type>
-  MoveStack* generate_pawn_moves(const Position& pos, MoveStack* mlist,
-                                 Bitboard target, const CheckInfo* ci) {
+  ExtMove* generate_pawn_moves(const Position& pos, ExtMove* moveList,
+                               Bitboard target, const CheckInfo* ci) {
 
     // Compute our parametrized parameters at compile time, named according to
     // the point of view of white side.
@@ -122,11 +99,11 @@ namespace {
     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);
+    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);
 
-    Bitboard b1, b2, dc1, dc2, emptySquares;
+    Bitboard emptySquares;
 
     Bitboard pawnsOn7    = pos.pieces(Us, PAWN) &  TRank7BB;
     Bitboard pawnsNotOn7 = pos.pieces(Us, PAWN) & ~TRank7BB;
@@ -139,8 +116,8 @@ namespace {
     {
         emptySquares = (Type == QUIETS || Type == QUIET_CHECKS ? target : ~pos.pieces());
 
-        b1 = move_pawns<UP>(pawnsNotOn7)   & emptySquares;
-        b2 = move_pawns<UP>(b1 & TRank3BB) & emptySquares;
+        Bitboard b1 = shift_bb<Up>(pawnsNotOn7)   & emptySquares;
+        Bitboard b2 = shift_bb<Up>(b1 & TRank3BB) & emptySquares;
 
         if (Type == EVASIONS) // Consider only blocking squares
         {
@@ -156,19 +133,28 @@ namespace {
             // 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 among captures.
+            // promotion has been already generated amongst the captures.
             if (pawnsNotOn7 & ci->dcCandidates)
             {
-                dc1 = move_pawns<UP>(pawnsNotOn7 & ci->dcCandidates) & emptySquares & ~file_bb(ci->ksq);
-                dc2 = move_pawns<UP>(dc1 & TRank3BB) & emptySquares;
+                Bitboard dc1 = shift_bb<Up>(pawnsNotOn7 & ci->dcCandidates) & emptySquares & ~file_bb(ci->ksq);
+                Bitboard dc2 = shift_bb<Up>(dc1 & TRank3BB) & emptySquares;
 
                 b1 |= dc1;
                 b2 |= dc2;
             }
         }
 
-        SERIALIZE_PAWNS(b1, UP);
-        SERIALIZE_PAWNS(b2, UP + UP);
+        while (b1)
+        {
+            Square to = pop_lsb(&b1);
+            (moveList++)->move = make_move(to - Up, to);
+        }
+
+        while (b2)
+        {
+            Square to = pop_lsb(&b2);
+            (moveList++)->move = make_move(to - Up - Up, to);
+        }
     }
 
     // Promotions and underpromotions
@@ -180,19 +166,37 @@ namespace {
         if (Type == EVASIONS)
             emptySquares &= target;
 
-        mlist = generate_promotions<Type, RIGHT>(mlist, pawnsOn7, enemies, ci);
-        mlist = generate_promotions<Type, LEFT>(mlist, pawnsOn7, enemies, ci);
-        mlist = generate_promotions<Type, UP>(mlist, pawnsOn7, emptySquares, ci);
+        Bitboard b1 = shift_bb<Right>(pawnsOn7) & enemies;
+        Bitboard b2 = shift_bb<Left >(pawnsOn7) & enemies;
+        Bitboard b3 = shift_bb<Up   >(pawnsOn7) & emptySquares;
+
+        while (b1)
+            moveList = make_promotions<Type, Right>(moveList, pop_lsb(&b1), ci);
+
+        while (b2)
+            moveList = make_promotions<Type, Left >(moveList, pop_lsb(&b2), ci);
+
+        while (b3)
+            moveList = make_promotions<Type, Up   >(moveList, pop_lsb(&b3), ci);
     }
 
     // Standard and en-passant captures
     if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS)
     {
-        b1 = move_pawns<RIGHT>(pawnsNotOn7) & enemies;
-        b2 = move_pawns<LEFT >(pawnsNotOn7) & enemies;
+        Bitboard b1 = shift_bb<Right>(pawnsNotOn7) & enemies;
+        Bitboard b2 = shift_bb<Left >(pawnsNotOn7) & enemies;
 
-        SERIALIZE_PAWNS(b1, RIGHT);
-        SERIALIZE_PAWNS(b2, LEFT);
+        while (b1)
+        {
+            Square to = pop_lsb(&b1);
+            (moveList++)->move = make_move(to - Right, to);
+        }
+
+        while (b2)
+        {
+            Square to = pop_lsb(&b2);
+            (moveList++)->move = make_move(to - Left, to);
+        }
 
         if (pos.ep_square() != SQ_NONE)
         {
@@ -201,29 +205,29 @@ namespace {
             // An en passant capture can be an evasion only if the checking piece
             // is the double pushed pawn and so is in the target. Otherwise this
             // is a discovery check and we are forced to do otherwise.
-            if (Type == EVASIONS && !(target & (pos.ep_square() - UP)))
-                return mlist;
+            if (Type == EVASIONS && !(target & (pos.ep_square() - Up)))
+                return moveList;
 
             b1 = pawnsNotOn7 & pos.attacks_from<PAWN>(pos.ep_square(), Them);
 
             assert(b1);
 
             while (b1)
-                (*mlist++).move = make<ENPASSANT>(pop_lsb(&b1), pos.ep_square());
+                (moveList++)->move = make<ENPASSANT>(pop_lsb(&b1), pos.ep_square());
         }
     }
 
-    return mlist;
+    return moveList;
   }
 
 
   template<PieceType Pt, bool Checks> FORCE_INLINE
-  MoveStack* generate_moves(const Position& pos, MoveStack* mlist, Color us,
-                            Bitboard target, const CheckInfo* ci) {
+  ExtMove* generate_moves(const Position& pos, ExtMove* moveList, Color us,
+                          Bitboard target, const CheckInfo* ci) {
 
     assert(Pt != KING && Pt != PAWN);
 
-    const Square* pl = pos.piece_list(us, Pt);
+    const Square* pl = pos.list<Pt>(us);
 
     for (Square from = *pl; from != SQ_NONE; from = *++pl)
     {
@@ -242,55 +246,51 @@ namespace {
         if (Checks)
             b &= ci->checkSq[Pt];
 
-        SERIALIZE(b);
+        while (b)
+            (moveList++)->move = make_move(from, pop_lsb(&b));
     }
 
-    return mlist;
+    return moveList;
   }
 
 
-  FORCE_INLINE MoveStack* generate_king_moves(const Position& pos, MoveStack* mlist,
-                                              Color us, Bitboard target) {
-    Square from = pos.king_square(us);
-    Bitboard b = pos.attacks_from<KING>(from) & target;
-    SERIALIZE(b);
-    return mlist;
-  }
+  template<Color Us, GenType Type> FORCE_INLINE
+  ExtMove* generate_all(const Position& pos, ExtMove* moveList, Bitboard target,
+                        const CheckInfo* ci = NULL) {
 
+    const bool Checks = Type == QUIET_CHECKS;
 
-  template<GenType Type> FORCE_INLINE
-  MoveStack* generate_all_moves(const Position& pos, MoveStack* mlist, Color us,
-                                Bitboard target, const CheckInfo* ci = NULL) {
-
-    mlist = (us == WHITE ? generate_pawn_moves<WHITE, Type>(pos, mlist, target, ci)
-                         : generate_pawn_moves<BLACK, Type>(pos, mlist, target, ci));
-
-    mlist = generate_moves<KNIGHT, Type == QUIET_CHECKS>(pos, mlist, us, target, ci);
-    mlist = generate_moves<BISHOP, Type == QUIET_CHECKS>(pos, mlist, us, target, ci);
-    mlist = generate_moves<ROOK,   Type == QUIET_CHECKS>(pos, mlist, us, target, ci);
-    mlist = generate_moves<QUEEN,  Type == QUIET_CHECKS>(pos, mlist, us, target, ci);
+    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);
 
     if (Type != QUIET_CHECKS && Type != EVASIONS)
-        mlist = generate_king_moves(pos, mlist, us, target);
+    {
+        Square ksq = pos.king_square(Us);
+        Bitboard b = pos.attacks_from<KING>(ksq) & target;
+        while (b)
+            (moveList++)->move = make_move(ksq, pop_lsb(&b));
+    }
 
-    if (Type != CAPTURES && Type != EVASIONS && pos.can_castle(us))
+    if (Type != CAPTURES && Type != EVASIONS && pos.can_castle(Us))
     {
         if (pos.is_chess960())
         {
-            mlist = generate_castle<KING_SIDE,  Type == QUIET_CHECKS, true>(pos, mlist, us);
-            mlist = generate_castle<QUEEN_SIDE, Type == QUIET_CHECKS, true>(pos, mlist, us);
+            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);
         }
         else
         {
-            mlist = generate_castle<KING_SIDE,  Type == QUIET_CHECKS, false>(pos, mlist, us);
-            mlist = generate_castle<QUEEN_SIDE, Type == QUIET_CHECKS, false>(pos, mlist, us);
+            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);
         }
     }
 
-    return mlist;
+    return moveList;
   }
 
-
 } // namespace
 
 
@@ -304,38 +304,33 @@ namespace {
 /// non-captures. Returns a pointer to the end of the move list.
 
 template<GenType Type>
-MoveStack* generate(const Position& pos, MoveStack* mlist) {
+ExtMove* generate(const Position& pos, ExtMove* moveList) {
 
   assert(Type == CAPTURES || Type == QUIETS || Type == NON_EVASIONS);
-  assert(!pos.in_check());
+  assert(!pos.checkers());
 
   Color us = pos.side_to_move();
-  Bitboard target;
 
-  if (Type == CAPTURES)
-      target = pos.pieces(~us);
+  Bitboard target =  Type == CAPTURES     ?  pos.pieces(~us)
+                   : Type == QUIETS       ? ~pos.pieces()
+                   : Type == NON_EVASIONS ? ~pos.pieces(us) : 0;
 
-  else if (Type == QUIETS)
-      target = ~pos.pieces();
-
-  else if (Type == NON_EVASIONS)
-      target = ~pos.pieces(us);
-
-  return generate_all_moves<Type>(pos, mlist, us, target);
+  return us == WHITE ? generate_all<WHITE, Type>(pos, moveList, target)
+                     : generate_all<BLACK, Type>(pos, moveList, target);
 }
 
 // Explicit template instantiations
-template MoveStack* generate<CAPTURES>(const Position&, MoveStack*);
-template MoveStack* generate<QUIETS>(const Position&, MoveStack*);
-template MoveStack* generate<NON_EVASIONS>(const Position&, MoveStack*);
+template ExtMove* generate<CAPTURES>(const Position&, ExtMove*);
+template ExtMove* generate<QUIETS>(const Position&, ExtMove*);
+template ExtMove* generate<NON_EVASIONS>(const Position&, ExtMove*);
 
 
 /// generate<QUIET_CHECKS> generates all pseudo-legal non-captures and knight
 /// underpromotions that give check. Returns a pointer to the end of the move list.
 template<>
-MoveStack* generate<QUIET_CHECKS>(const Position& pos, MoveStack* mlist) {
+ExtMove* generate<QUIET_CHECKS>(const Position& pos, ExtMove* moveList) {
 
-  assert(!pos.in_check());
+  assert(!pos.checkers());
 
   Color us = pos.side_to_move();
   CheckInfo ci(pos);
@@ -347,99 +342,77 @@ MoveStack* generate<QUIET_CHECKS>(const Position& pos, MoveStack* mlist) {
      PieceType pt = type_of(pos.piece_on(from));
 
      if (pt == PAWN)
-         continue; // Will be generated togheter with direct checks
+         continue; // Will be generated together with direct checks
 
      Bitboard b = pos.attacks_from(Piece(pt), from) & ~pos.pieces();
 
      if (pt == KING)
          b &= ~PseudoAttacks[QUEEN][ci.ksq];
 
-     SERIALIZE(b);
+     while (b)
+         (moveList++)->move = make_move(from, pop_lsb(&b));
   }
 
-  return generate_all_moves<QUIET_CHECKS>(pos, mlist, us, ~pos.pieces(), &ci);
+  return us == WHITE ? generate_all<WHITE, QUIET_CHECKS>(pos, moveList, ~pos.pieces(), &ci)
+                     : generate_all<BLACK, QUIET_CHECKS>(pos, moveList, ~pos.pieces(), &ci);
 }
 
 
 /// generate<EVASIONS> generates all pseudo-legal check evasions when the side
 /// to move is in check. Returns a pointer to the end of the move list.
 template<>
-MoveStack* generate<EVASIONS>(const Position& pos, MoveStack* mlist) {
-
-  assert(pos.in_check());
-
-  Square from, checksq;
-  int checkersCnt = 0;
-  Color us = pos.side_to_move();
-  Square ksq = pos.king_square(us);
-  Bitboard sliderAttacks = 0;
-  Bitboard b = pos.checkers();
+ExtMove* generate<EVASIONS>(const Position& pos, ExtMove* moveList) {
 
   assert(pos.checkers());
 
-  // Find squares attacked by slider checkers, we will remove them from the king
-  // evasions so to skip known illegal moves avoiding useless legality check later.
-  do
+  Color us = pos.side_to_move();
+  Square ksq = pos.king_square(us);
+  Bitboard sliderAttacks = 0;
+  Bitboard sliders = pos.checkers() & ~pos.pieces(KNIGHT, PAWN);
+
+  // Find all the squares attacked by slider checkers. We will remove them from
+  // the king evasions in order to skip known illegal moves, which avoids any
+  // useless legality checks later on.
+  while (sliders)
   {
-      checkersCnt++;
-      checksq = pop_lsb(&b);
-
-      assert(color_of(pos.piece_on(checksq)) == ~us);
-
-      switch (type_of(pos.piece_on(checksq)))
-      {
-      case BISHOP: sliderAttacks |= PseudoAttacks[BISHOP][checksq]; break;
-      case ROOK:   sliderAttacks |= PseudoAttacks[ROOK][checksq];   break;
-      case QUEEN:
-          // If queen and king are far or not on a diagonal line we can safely
-          // remove all the squares attacked in the other direction becuase are
-          // not reachable by the king anyway.
-          if (between_bb(ksq, checksq) || !(PseudoAttacks[BISHOP][checksq] & ksq))
-              sliderAttacks |= PseudoAttacks[QUEEN][checksq];
-
-          // Otherwise we need to use real rook attacks to check if king is safe
-          // to move in the other direction. For example: king in B2, queen in A1
-          // a knight in B1, and we can safely move to C1.
-          else
-              sliderAttacks |= PseudoAttacks[BISHOP][checksq] | pos.attacks_from<ROOK>(checksq);
-
-      default:
-          break;
-      }
-  } while (b);
+      Square checksq = pop_lsb(&sliders);
+      sliderAttacks |= LineBB[checksq][ksq] ^ checksq;
+  }
 
   // Generate evasions for king, capture and non capture moves
-  b = pos.attacks_from<KING>(ksq) & ~pos.pieces(us) & ~sliderAttacks;
-  from = ksq;
-  SERIALIZE(b);
+  Bitboard b = pos.attacks_from<KING>(ksq) & ~pos.pieces(us) & ~sliderAttacks;
+  while (b)
+      (moveList++)->move = make_move(ksq, pop_lsb(&b));
 
-  if (checkersCnt > 1)
-      return mlist; // Double check, only a king move can save the day
+  if (more_than_one(pos.checkers()))
+      return moveList; // Double check, only a king move can save the day
 
   // Generate blocking evasions or captures of the checking piece
-  Bitboard target = between_bb(checksq, ksq) | pos.checkers();
+  Square checksq = lsb(pos.checkers());
+  Bitboard target = between_bb(checksq, ksq) | checksq;
 
-  return generate_all_moves<EVASIONS>(pos, mlist, us, target);
+  return us == WHITE ? generate_all<WHITE, EVASIONS>(pos, moveList, target)
+                     : generate_all<BLACK, EVASIONS>(pos, moveList, target);
 }
 
 
 /// generate<LEGAL> generates all the legal moves in the given position
 
 template<>
-MoveStack* generate<LEGAL>(const Position& pos, MoveStack* mlist) {
+ExtMove* generate<LEGAL>(const Position& pos, ExtMove* moveList) {
 
-  MoveStack *end, *cur = mlist;
-  Bitboard pinned = pos.pinned_pieces();
+  Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
   Square ksq = pos.king_square(pos.side_to_move());
+  ExtMove* cur = moveList;
 
-  end = pos.in_check() ? generate<EVASIONS>(pos, mlist)
-                       : generate<NON_EVASIONS>(pos, mlist);
-  while (cur != end)
+  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.pl_move_is_legal(cur->move, pinned))
-          cur->move = (--end)->move;
+          && !pos.legal(cur->move, pinned))
+          cur->move = (--moveList)->move;
       else
-          cur++;
+          ++cur;
 
-  return end;
+  return moveList;
 }

src/movegen.h

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -17,11 +17,13 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#if !defined(MOVEGEN_H_INCLUDED)
+#ifndef MOVEGEN_H_INCLUDED
 #define MOVEGEN_H_INCLUDED
 
 #include "types.h"
 
+class Position;
+
 enum GenType {
   CAPTURES,
   QUIETS,
@@ -31,25 +33,35 @@ enum GenType {
   LEGAL
 };
 
-class Position;
+struct ExtMove {
+  Move move;
+  Value value;
+};
+
+inline bool operator<(const ExtMove& f, const ExtMove& s) {
+  return f.value < s.value;
+}
 
 template<GenType>
-MoveStack* generate(const Position& pos, MoveStack* mlist);
+ExtMove* generate(const Position& pos, ExtMove* moveList);
 
-/// The MoveList struct is a simple wrapper around generate(), sometimes comes
-/// handy to use this class instead of the low level generate() function.
+/// The MoveList struct is a simple wrapper around generate(). It sometimes comes
+/// in handy to use this class instead of the low level generate() function.
 template<GenType T>
 struct MoveList {
 
-  explicit MoveList(const Position& pos) : cur(mlist), last(generate<T>(pos, mlist)) {}
-  void operator++() { cur++; }
-  bool end() const { return cur == last; }
-  Move move() const { return cur->move; }
-  size_t size() const { return last - mlist; }
+  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; }
+  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;
+  }
 
 private:
-  MoveStack mlist[MAX_MOVES];
-  MoveStack *cur, *last;
+  ExtMove moveList[MAX_MOVES];
+  ExtMove *cur, *last;
 };
 
-#endif // !defined(MOVEGEN_H_INCLUDED)
+#endif // #ifndef MOVEGEN_H_INCLUDED

src/movepick.cpp

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -18,16 +18,14 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <algorithm>
 #include <cassert>
 
-#include "movegen.h"
 #include "movepick.h"
 #include "thread.h"
 
 namespace {
 
-  enum Sequencer {
+  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,
@@ -37,116 +35,110 @@ namespace {
     STOP
   };
 
-  // Unary predicate used by std::partition to split positive scores from remaining
-  // ones so to sort separately the two sets, and with the second sort delayed.
-  inline bool has_positive_score(const MoveStack& ms) { return ms.score > 0; }
+  // Our insertion sort, which is guaranteed (and also needed) to be stable
+  void insertion_sort(ExtMove* begin, ExtMove* end)
+  {
+    ExtMove tmp, *p, *q;
 
-  // Picks and moves to the front the best move in the range [begin, end),
-  // it is faster than sorting all the moves in advance when moves are few, as
-  // normally are the possible captures.
-  inline MoveStack* pick_best(MoveStack* begin, MoveStack* end)
+    for (p = begin + 1; p < end; ++p)
+    {
+        tmp = *p;
+        for (q = p; 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
+/// 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 about how important good
-/// move ordering is at the current node.
+/// 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 History& h,
-                       Search::Stack* s, Value beta) : pos(p), H(h), depth(d) {
+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) {
 
   assert(d > DEPTH_ZERO);
 
-  captureThreshold = 0;
   cur = end = moves;
   endBadCaptures = moves + MAX_MOVES - 1;
+  countermoves = cm;
+  followupmoves = fm;
   ss = s;
 
-  if (p.in_check())
-      phase = EVASION;
+  if (pos.checkers())
+      stage = EVASION;
 
   else
-  {
-      phase = MAIN_SEARCH;
+      stage = MAIN_SEARCH;
 
-      killers[0].move = ss->killers[0];
-      killers[1].move = ss->killers[1];
-
-      // Consider sligtly negative captures as good if at low depth and far from beta
-      if (ss && ss->eval < beta - PawnValueMg && d < 3 * ONE_PLY)
-          captureThreshold = -PawnValueMg;
-
-      // Consider negative captures as good if still enough to reach beta
-      else if (ss && ss->eval > beta)
-          captureThreshold = beta - ss->eval;
-  }
-
-  ttMove = (ttm && pos.is_pseudo_legal(ttm) ? ttm : MOVE_NONE);
+  ttMove = (ttm && pos.pseudo_legal(ttm) ? ttm : MOVE_NONE);
   end += (ttMove != MOVE_NONE);
 }
 
-MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h,
-                       Square sq) : pos(p), H(h), cur(moves), end(moves) {
+MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const HistoryStats& h,
+                       Square s) : pos(p), history(h), cur(moves), end(moves) {
 
   assert(d <= DEPTH_ZERO);
 
-  if (p.in_check())
-      phase = EVASION;
+  if (pos.checkers())
+      stage = EVASION;
 
   else if (d > DEPTH_QS_NO_CHECKS)
-      phase = QSEARCH_0;
+      stage = QSEARCH_0;
 
   else if (d > DEPTH_QS_RECAPTURES)
-  {
-      phase = QSEARCH_1;
+      stage = QSEARCH_1;
 
-      // Skip TT move if is not a capture or a promotion, this avoids qsearch
-      // tree explosion due to a possible perpetual check or similar rare cases
-      // when TT table is full.
-      if (ttm && !pos.is_capture_or_promotion(ttm))
-          ttm = MOVE_NONE;
-  }
   else
   {
-      phase = RECAPTURE;
-      recaptureSquare = sq;
+      stage = RECAPTURE;
+      recaptureSquare = s;
       ttm = MOVE_NONE;
   }
 
-  ttMove = (ttm && pos.is_pseudo_legal(ttm) ? ttm : MOVE_NONE);
+  ttMove = (ttm && pos.pseudo_legal(ttm) ? ttm : MOVE_NONE);
   end += (ttMove != MOVE_NONE);
 }
 
-MovePicker::MovePicker(const Position& p, Move ttm, const History& h, PieceType pt)
-                       : pos(p), H(h), cur(moves), end(moves) {
+MovePicker::MovePicker(const Position& p, Move ttm, const HistoryStats& h, PieceType pt)
+                       : pos(p), history(h), cur(moves), end(moves) {
 
-  assert(!pos.in_check());
+  assert(!pos.checkers());
 
-  phase = PROBCUT;
+  stage = PROBCUT;
 
-  // In ProbCut we generate only captures better than parent's captured piece
-  captureThreshold = PieceValue[Mg][pt];
-  ttMove = (ttm && pos.is_pseudo_legal(ttm) ? ttm : MOVE_NONE);
+  // 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.is_capture(ttMove) ||  pos.see(ttMove) <= captureThreshold))
+  if (ttMove && (!pos.capture(ttMove) || pos.see(ttMove) <= captureThreshold))
       ttMove = MOVE_NONE;
 
   end += (ttMove != MOVE_NONE);
 }
 
 
-/// MovePicker::score_captures(), MovePicker::score_noncaptures() and
-/// MovePicker::score_evasions() assign a numerical move ordering score
-/// to each move in a move list.  The moves with highest scores will be
-/// picked first by next_move().
-
-void MovePicker::score_captures() {
+/// 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
@@ -156,89 +148,114 @@ void MovePicker::score_captures() {
   // 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
-  // badCaptures[] array, but instead of doing it now we delay till when
-  // the move has been picked up in pick_move_from_list(), this way we save
-  // some SEE calls in case we get a cutoff (idea from Pablo Vazquez).
+  // 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;
 
-  for (MoveStack* it = moves; it != end; ++it)
+  for (ExtMove* it = moves; it != end; ++it)
   {
       m = it->move;
-      it->score =  PieceValue[Mg][pos.piece_on(to_sq(m))]
-                 - type_of(pos.piece_moved(m));
+      it->value =  PieceValue[MG][pos.piece_on(to_sq(m))]
+                 - Value(type_of(pos.moved_piece(m)));
 
-      if (type_of(m) == PROMOTION)
-          it->score += PieceValue[Mg][promotion_type(m)];
+      if (type_of(m) == ENPASSANT)
+          it->value += PieceValue[MG][PAWN];
+
+      else if (type_of(m) == PROMOTION)
+          it->value += PieceValue[MG][promotion_type(m)] - PieceValue[MG][PAWN];
   }
 }
 
-void MovePicker::score_noncaptures() {
+template<>
+void MovePicker::score<QUIETS>() {
 
   Move m;
 
-  for (MoveStack* it = moves; it != end; ++it)
+  for (ExtMove* it = moves; it != end; ++it)
   {
       m = it->move;
-      it->score = H.value(pos.piece_moved(m), to_sq(m));
+      it->value = history[pos.moved_piece(m)][to_sq(m)];
   }
 }
 
-void MovePicker::score_evasions() {
+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 score.
+  // moves with a negative SEE. This last group is ordered by the SEE value.
   Move m;
-  int seeScore;
+  Value see;
 
-  if (end < moves + 2)
-      return;
-
-  for (MoveStack* it = moves; it != end; ++it)
+  for (ExtMove* it = moves; it != end; ++it)
   {
       m = it->move;
-      if ((seeScore = pos.see_sign(m)) < 0)
-          it->score = seeScore - History::MaxValue; // Be sure we are at the bottom
-      else if (pos.is_capture(m))
-          it->score =  PieceValue[Mg][pos.piece_on(to_sq(m))]
-                     - type_of(pos.piece_moved(m)) + History::MaxValue;
+      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->score = H.value(pos.piece_moved(m), to_sq(m));
+          it->value = history[pos.moved_piece(m)][to_sq(m)];
   }
 }
 
 
-/// MovePicker::generate_next() generates, scores and sorts the next bunch of moves,
-/// when there are no more moves to try for the current phase.
+/// 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() {
+void MovePicker::generate_next_stage() {
 
   cur = moves;
 
-  switch (++phase) {
+  switch (++stage) {
 
   case CAPTURES_S1: case CAPTURES_S3: case CAPTURES_S4: case CAPTURES_S5: case CAPTURES_S6:
       end = generate<CAPTURES>(pos, moves);
-      score_captures();
+      score<CAPTURES>();
       return;
 
   case KILLERS_S1:
       cur = killers;
       end = cur + 2;
+
+      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;
+
+      // 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.
+
+      // 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];
+
+      // 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 QUIETS_1_S1:
       endQuiets = end = generate<QUIETS>(pos, moves);
-      score_noncaptures();
-      end = std::partition(cur, end, has_positive_score);
-      sort<MoveStack>(cur, end);
+      score<QUIETS>();
+      end = std::partition(cur, end, has_positive_value);
+      insertion_sort(cur, end);
       return;
 
   case QUIETS_2_S1:
       cur = end;
       end = endQuiets;
       if (depth >= 3 * ONE_PLY)
-          sort<MoveStack>(cur, end);
+          insertion_sort(cur, end);
       return;
 
   case BAD_CAPTURES_S1:
@@ -249,7 +266,8 @@ void MovePicker::generate_next() {
 
   case EVASIONS_S2:
       end = generate<EVASIONS>(pos, moves);
-      score_evasions();
+      if (end > moves + 1)
+          score<EVASIONS>();
       return;
 
   case QUIET_CHECKS_S3:
@@ -257,7 +275,9 @@ void MovePicker::generate_next() {
       return;
 
   case EVASION: case QSEARCH_0: case QSEARCH_1: case PROBCUT: case RECAPTURE:
-      phase = STOP;
+      stage = STOP;
+      /* Fall through */
+
   case STOP:
       end = cur + 1; // Avoid another next_phase() call
       return;
@@ -268,11 +288,10 @@ void MovePicker::generate_next() {
 }
 
 
-/// 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. It picks the move with the biggest score from a list
-/// of generated moves taking care not to return the tt move if has already been
-/// searched previously.
+/// 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>() {
 
@@ -281,21 +300,19 @@ Move MovePicker::next_move<false>() {
   while (true)
   {
       while (cur == end)
-          generate_next();
+          generate_next_stage();
 
-      switch (phase) {
+      switch (stage) {
 
       case MAIN_SEARCH: case EVASION: case QSEARCH_0: case QSEARCH_1: case PROBCUT:
-          cur++;
+          ++cur;
           return ttMove;
 
       case CAPTURES_S1:
           move = pick_best(cur++, end)->move;
           if (move != ttMove)
           {
-              assert(captureThreshold <= 0); // Otherwise we cannot use see_sign()
-
-              if (pos.see_sign(move) >= captureThreshold)
+              if (pos.see_sign(move) >= VALUE_ZERO)
                   return move;
 
               // Losing capture, move it to the tail of the array
@@ -306,9 +323,9 @@ Move MovePicker::next_move<false>() {
       case KILLERS_S1:
           move = (cur++)->move;
           if (    move != MOVE_NONE
-              &&  pos.is_pseudo_legal(move)
               &&  move != ttMove
-              && !pos.is_capture(move))
+              &&  pos.pseudo_legal(move)
+              && !pos.capture(move))
               return move;
           break;
 
@@ -316,7 +333,11 @@ Move MovePicker::next_move<false>() {
           move = (cur++)->move;
           if (   move != ttMove
               && move != killers[0].move
-              && move != killers[1].move)
+              && move != killers[1].move
+              && move != killers[2].move
+              && move != killers[3].move
+              && move != killers[4].move
+              && move != killers[5].move)
               return move;
           break;
 
@@ -359,6 +380,6 @@ Move MovePicker::next_move<false>() {
 
 /// 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 should be lock protected by the caller.
+/// safe so must be lock protected by the caller.
 template<>
-Move MovePicker::next_move<true>() { return ss->sp->mp->next_move<false>(); }
+Move MovePicker::next_move<true>() { return ss->splitPoint->movePicker->next_move<false>(); }

src/movepick.h

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -17,15 +17,61 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#if !defined MOVEPICK_H_INCLUDED
+#ifndef MOVEPICK_H_INCLUDED
 #define MOVEPICK_H_INCLUDED
 
-#include "history.h"
+#include <algorithm> // For std::max
+#include <cstring>   // For std::memset
+
+#include "movegen.h"
 #include "position.h"
 #include "search.h"
 #include "types.h"
 
 
+/// 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 {
+
+  static const Value Max = Value(250);
+
+  const T* operator[](Piece pc) const { return table[pc]; }
+  void clear() { std::memset(table, 0, sizeof(table)); }
+
+  void update(Piece pc, Square to, Move m) {
+
+    if (m == table[pc][to].first)
+        return;
+
+    table[pc][to].second = table[pc][to].first;
+    table[pc][to].first = m;
+  }
+
+  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;
+
+
 /// MovePicker class is used to pick one pseudo legal move at a time from the
 /// current position. The most important method is next_move(), which returns a
 /// new pseudo legal move each time it is called, until there are no moves left,
@@ -38,27 +84,29 @@ class MovePicker {
   MovePicker& operator=(const MovePicker&); // Silence a warning under MSVC
 
 public:
-  MovePicker(const Position&, Move, Depth, const History&, Search::Stack*, Value);
-  MovePicker(const Position&, Move, Depth, const History&, Square);
-  MovePicker(const Position&, Move, const History&, PieceType);
+  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();
 
 private:
-  void score_captures();
-  void score_noncaptures();
-  void score_evasions();
-  void generate_next();
+  template<GenType> void score();
+  void generate_next_stage();
 
   const Position& pos;
-  const History& H;
+  const HistoryStats& history;
   Search::Stack* ss;
+  Move* countermoves;
+  Move* followupmoves;
   Depth depth;
   Move ttMove;
-  MoveStack killers[2];
+  ExtMove killers[6];
   Square recaptureSquare;
-  int captureThreshold, phase;
-  MoveStack *cur, *end, *endQuiets, *endBadCaptures;
-  MoveStack moves[MAX_MOVES];
+  Value captureThreshold;
+  int stage;
+  ExtMove *cur, *end, *endQuiets, *endBadCaptures;
+  ExtMove moves[MAX_MOVES];
 };
 
-#endif // !defined(MOVEPICK_H_INCLUDED)
+#endif // #ifndef MOVEPICK_H_INCLUDED

src/notation.cpp

@@ -1,271 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 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/>.
-*/
-
-#include <cassert>
-#include <iomanip>
-#include <sstream>
-#include <string>
-
-#include "movegen.h"
-#include "notation.h"
-#include "position.h"
-
-using namespace std;
-
-static const char* PieceToChar = " PNBRQK  pnbrqk";
-
-
-/// score_to_uci() converts a value to a string suitable for use with the UCI
-/// protocol specifications:
-///
-/// cp <x>     The score from the engine's point of view in centipawns.
-/// mate <y>   Mate in y moves, not plies. If the engine is getting mated
-///            use negative values for y.
-
-string score_to_uci(Value v, Value alpha, Value beta) {
-
-  stringstream s;
-
-  if (abs(v) < VALUE_MATE_IN_MAX_PLY)
-      s << "cp " << v * 100 / int(PawnValueMg);
-  else
-      s << "mate " << (v > 0 ? VALUE_MATE - v + 1 : -VALUE_MATE - v) / 2;
-
-  s << (v >= beta ? " lowerbound" : v <= alpha ? " upperbound" : "");
-
-  return s.str();
-}
-
-
-/// move_to_uci() converts a move to a string in coordinate notation
-/// (g1f3, a7a8q, etc.). The only special case is castling moves, where we print
-/// in the e1g1 notation in normal chess mode, and in e1h1 notation in chess960
-/// mode. Internally castle moves are always coded as "king captures rook".
-
-const string move_to_uci(Move m, bool chess960) {
-
-  Square from = from_sq(m);
-  Square to = to_sq(m);
-
-  if (m == MOVE_NONE)
-      return "(none)";
-
-  if (m == MOVE_NULL)
-      return "0000";
-
-  if (type_of(m) == CASTLE && !chess960)
-      to = (to > from ? FILE_G : FILE_C) | rank_of(from);
-
-  string move = square_to_string(from) + square_to_string(to);
-
-  if (type_of(m) == PROMOTION)
-      move += PieceToChar[make_piece(BLACK, promotion_type(m))]; // Lower case
-
-  return move;
-}
-
-
-/// move_from_uci() takes a position and a string representing a move in
-/// simple coordinate notation and returns an equivalent legal Move if any.
-
-Move move_from_uci(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> ml(pos); !ml.end(); ++ml)
-      if (str == move_to_uci(ml.move(), pos.is_chess960()))
-          return ml.move();
-
-  return MOVE_NONE;
-}
-
-
-/// move_to_san() takes a position and a legal Move as input and returns its
-/// short algebraic notation representation.
-
-const string move_to_san(Position& pos, Move m) {
-
-  if (m == MOVE_NONE)
-      return "(none)";
-
-  if (m == MOVE_NULL)
-      return "(null)";
-
-  assert(pos.move_is_legal(m));
-
-  Bitboard attackers;
-  bool ambiguousMove, ambiguousFile, ambiguousRank;
-  string san;
-  Color us = pos.side_to_move();
-  Square from = from_sq(m);
-  Square to = to_sq(m);
-  Piece pc = pos.piece_on(from);
-  PieceType pt = type_of(pc);
-
-  if (type_of(m) == CASTLE)
-      san = to > from ? "O-O" : "O-O-O";
-  else
-  {
-      if (pt != PAWN)
-      {
-          san = PieceToChar[pt]; // Upper case
-
-          // Disambiguation if we have more then one piece with destination 'to'
-          // note that for pawns is not needed because starting file is explicit.
-          ambiguousMove = ambiguousFile = ambiguousRank = false;
-
-          attackers = (pos.attacks_from(pc, to) & pos.pieces(us, pt)) ^ from;
-
-          while (attackers)
-          {
-              Square sq = pop_lsb(&attackers);
-
-              // Pinned pieces are not included in the possible sub-set
-              if (!pos.pl_move_is_legal(make_move(sq, to), pos.pinned_pieces()))
-                  continue;
-
-              ambiguousFile |= file_of(sq) == file_of(from);
-              ambiguousRank |= rank_of(sq) == rank_of(from);
-              ambiguousMove = true;
-          }
-
-          if (ambiguousMove)
-          {
-              if (!ambiguousFile)
-                  san += file_to_char(file_of(from));
-
-              else if (!ambiguousRank)
-                  san += rank_to_char(rank_of(from));
-
-              else
-                  san += square_to_string(from);
-          }
-      }
-      else if (pos.is_capture(m))
-          san = file_to_char(file_of(from));
-
-      if (pos.is_capture(m))
-          san += 'x';
-
-      san += square_to_string(to);
-
-      if (type_of(m) == PROMOTION)
-          san += string("=") + PieceToChar[promotion_type(m)];
-  }
-
-  if (pos.move_gives_check(m, CheckInfo(pos)))
-  {
-      StateInfo st;
-      pos.do_move(m, st);
-      san += MoveList<LEGAL>(pos).size() ? "+" : "#";
-      pos.undo_move(m);
-  }
-
-  return san;
-}
-
-
-/// pretty_pv() formats human-readable search information, typically to be
-/// appended to the search log file. It uses the two helpers below to pretty
-/// format time and score respectively.
-
-static string time_to_string(int64_t msecs) {
-
-  const int MSecMinute = 1000 * 60;
-  const int MSecHour   = 1000 * 60 * 60;
-
-  int64_t hours   =   msecs / MSecHour;
-  int64_t minutes =  (msecs % MSecHour) / MSecMinute;
-  int64_t seconds = ((msecs % MSecHour) % MSecMinute) / 1000;
-
-  stringstream s;
-
-  if (hours)
-      s << hours << ':';
-
-  s << setfill('0') << setw(2) << minutes << ':' << setw(2) << seconds;
-
-  return s.str();
-}
-
-static string score_to_string(Value v) {
-
-  stringstream s;
-
-  if (v >= VALUE_MATE_IN_MAX_PLY)
-      s << "#" << (VALUE_MATE - v + 1) / 2;
-
-  else if (v <= VALUE_MATED_IN_MAX_PLY)
-      s << "-#" << (VALUE_MATE + v) / 2;
-
-  else
-      s << setprecision(2) << fixed << showpos << float(v) / PawnValueMg;
-
-  return s.str();
-}
-
-string pretty_pv(Position& pos, int depth, Value value, int64_t msecs, Move pv[]) {
-
-  const int64_t K = 1000;
-  const int64_t M = 1000000;
-
-  StateInfo state[MAX_PLY_PLUS_2], *st = state;
-  Move* m = pv;
-  string san, padding;
-  size_t length;
-  stringstream s;
-
-  s << setw(2) << depth
-    << setw(8) << score_to_string(value)
-    << setw(8) << time_to_string(msecs);
-
-  if (pos.nodes_searched() < M)
-      s << setw(8) << pos.nodes_searched() / 1 << "  ";
-
-  else if (pos.nodes_searched() < K * M)
-      s << setw(7) << pos.nodes_searched() / K << "K  ";
-
-  else
-      s << setw(7) << pos.nodes_searched() / M << "M  ";
-
-  padding = string(s.str().length(), ' ');
-  length = padding.length();
-
-  while (*m != MOVE_NONE)
-  {
-      san = move_to_san(pos, *m);
-
-      if (length + san.length() > 80)
-      {
-          s << "\n" + padding;
-          length = padding.length();
-      }
-
-      s << san << ' ';
-      length += san.length() + 1;
-
-      pos.do_move(*m++, *st++);
-  }
-
-  while (m != pv)
-      pos.undo_move(*--m);
-
-  return s.str();
-}

src/notation.h

@@ -1,35 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 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/>.
-*/
-
-#if !defined(NOTATION_H_INCLUDED)
-#define NOTATION_H_INCLUDED
-
-#include <string>
-
-#include "types.h"
-
-class Position;
-
-std::string score_to_uci(Value v, Value alpha = -VALUE_INFINITE, Value beta = VALUE_INFINITE);
-Move move_from_uci(const Position& pos, std::string& str);
-const std::string move_to_uci(Move m, bool chess960);
-const std::string move_to_san(Position& pos, Move m);
-std::string pretty_pv(Position& pos, int depth, Value score, int64_t msecs, Move pv[]);
-
-#endif // !defined(NOTATION_H_INCLUDED)

src/pawns.cpp

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -17,271 +17,296 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include <algorithm>
 #include <cassert>
 
 #include "bitboard.h"
 #include "bitcount.h"
 #include "pawns.h"
 #include "position.h"
+#include "thread.h"
 
 namespace {
 
   #define V Value
   #define S(mg, eg) make_score(mg, eg)
 
-  // Doubled pawn penalty by opposed flag and file
-  const Score DoubledPawnPenalty[2][8] = {
-  { S(13, 43), S(20, 48), S(23, 48), S(23, 48),
-    S(23, 48), S(23, 48), S(20, 48), S(13, 43) },
-  { S(13, 43), S(20, 48), S(23, 48), S(23, 48),
-    S(23, 48), S(23, 48), S(20, 48), S(13, 43) }};
+  // 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) };
 
   // Isolated pawn penalty by opposed flag and file
-  const Score IsolatedPawnPenalty[2][8] = {
+  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) }};
+    S(40, 35), S(40, 35), S(36, 35), S(25, 30) } };
 
   // Backward pawn penalty by opposed flag and file
-  const Score BackwardPawnPenalty[2][8] = {
+  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) }};
+    S(33, 31), S(33, 31), S(29, 31), S(20, 28) } };
 
-  // Pawn chain membership bonus by file
-  const Score ChainBonus[8] = {
-    S(11,-1), S(13,-1), S(13,-1), S(14,-1),
-    S(14,-1), S(13,-1), S(13,-1), S(11,-1)
-  };
+  // Connected pawn bonus by opposed, phalanx flags and rank
+  Score Connected[2][2][RANK_NB];
 
-  // Candidate passed pawn bonus by rank
-  const Score CandidateBonus[8] = {
-    S( 0, 0), S( 6, 13), S(6,13), S(14,29),
-    S(34,68), S(83,166), S(0, 0), S( 0, 0)
-  };
+  // 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) };
 
-  const Score PawnStructureWeight = S(233, 201);
+  // Unsupported pawn penalty
+  const Score UnsupportedPawnPenalty = S(20, 10);
 
-  // Weakness of our pawn shelter in front of the king indexed by [king pawn][rank]
-  const Value ShelterWeakness[2][8] =
-  { { V(141), V(0), V(38), V(102), V(128), V(141), V(141) },
-    { V( 61), V(0), V(16), V( 44), V( 56), V( 61), V( 61) } };
+  // 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 indexed by [pawn blocked][rank]
-  const Value StormDanger[2][8] =
-  { { V(26), V(0), V(128), V(51), V(26) },
-    { V(13), V(0), V( 64), V(25), V(13) } };
+  // 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 horizont.
-  const Value MaxSafetyBonus = V(263);
+  // in front of the king and no enemy pawn on the horizon.
+  const Value MaxSafetyBonus = V(257);
 
   #undef S
   #undef V
+
+  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);
+
+    Bitboard b, p, doubled, connected;
+    Square s;
+    bool passed, isolated, opposed, phalanx, backward, unsupported, lever;
+    Score score = SCORE_ZERO;
+    const Square* pl = pos.list<PAWN>(Us);
+    const Bitboard* pawnAttacksBB = StepAttacksBB[make_piece(Us, PAWN)];
+
+    Bitboard ourPawns   = pos.pieces(Us  , PAWN);
+    Bitboard theirPawns = pos.pieces(Them, PAWN);
+
+    e->passedPawns[Us] = 0;
+    e->kingSquares[Us] = SQ_NONE;
+    e->semiopenFiles[Us] = 0xFF;
+    e->pawnAttacks[Us] = shift_bb<Right>(ourPawns) | shift_bb<Left>(ourPawns);
+    e->pawnsOnSquares[Us][BLACK] = popcount<Max15>(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
+    while ((s = *pl++) != SQ_NONE)
+    {
+        assert(pos.piece_on(s) == make_piece(Us, PAWN));
+
+        File f = file_of(s);
+
+        // This file cannot be semi-open
+        e->semiopenFiles[Us] &= ~(1 << f);
+
+        // Previous rank
+        p = rank_bb(s - pawn_push(Us));
+
+        // 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));
+
+        // 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)
+            e->passedPawns[Us] |= s;
+
+        // Score this pawn
+        if (isolated)
+            score -= Isolated[opposed][f];
+
+        if (unsupported && !isolated)
+            score -= UnsupportedPawnPenalty;
+
+        if (doubled)
+            score -= Doubled[f] / distance<Rank>(s, frontmost_sq(Us, doubled));
+
+        if (backward)
+            score -= Backward[opposed][f];
+
+        if (connected)
+            score += Connected[opposed][phalanx][relative_rank(Us, s)];
+
+        if (lever)
+            score += Lever[relative_rank(Us, s)];
+    }
+
+    b = e->semiopenFiles[Us] ^ 0xFF;
+    e->pawnSpan[Us] = b ? int(msb(b) - lsb(b)) : 0;
+
+    return score;
+  }
+
+} // namespace
+
+namespace Pawns {
+
+/// Pawns::init() initializes some tables needed by evaluation. Instead of using
+/// 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 };
+
+  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);
+          }
 }
 
 
-/// PawnTable::probe() takes a position object as input, computes a PawnEntry
-/// object, and returns a pointer to it. The result is also stored in a hash
-/// table, so we don't have to recompute everything when the same pawn structure
-/// occurs again.
+/// Pawns::probe() looks up the current position's pawns configuration in
+/// the pawns hash table. It returns a pointer to the Entry if the position
+/// is found. Otherwise a new Entry is computed and stored there, so we don't
+/// have to recompute all when the same pawns configuration occurs again.
 
-PawnEntry* PawnTable::probe(const Position& pos) {
+Entry* probe(const Position& pos) {
 
   Key key = pos.pawn_key();
-  PawnEntry* e = entries[key];
+  Entry* e = pos.this_thread()->pawnsTable[key];
 
-  // If e->key matches the position's pawn hash key, it means that we
-  // have analysed this pawn structure before, and we can simply return
-  // the information we found the last time instead of recomputing it.
   if (e->key == key)
       return e;
 
   e->key = key;
-  e->passedPawns[WHITE] = e->passedPawns[BLACK] = 0;
-  e->kingSquares[WHITE] = e->kingSquares[BLACK] = SQ_NONE;
-  e->halfOpenFiles[WHITE] = e->halfOpenFiles[BLACK] = 0xFF;
-
-  Bitboard wPawns = pos.pieces(WHITE, PAWN);
-  Bitboard bPawns = pos.pieces(BLACK, PAWN);
-  e->pawnAttacks[WHITE] = ((wPawns & ~FileHBB) << 9) | ((wPawns & ~FileABB) << 7);
-  e->pawnAttacks[BLACK] = ((bPawns & ~FileHBB) >> 7) | ((bPawns & ~FileABB) >> 9);
-
-  e->value =  evaluate_pawns<WHITE>(pos, wPawns, bPawns, e)
-            - evaluate_pawns<BLACK>(pos, bPawns, wPawns, e);
-
-  e->value = apply_weight(e->value, PawnStructureWeight);
-
+  e->score = evaluate<WHITE>(pos, e) - evaluate<BLACK>(pos, e);
   return e;
 }
 
 
-/// PawnTable::evaluate_pawns() evaluates each pawn of the given color
-
-template<Color Us>
-Score PawnTable::evaluate_pawns(const Position& pos, Bitboard ourPawns,
-                                Bitboard theirPawns, PawnEntry* e) {
-
-  const Color Them = (Us == WHITE ? BLACK : WHITE);
-
-  Bitboard b;
-  Square s;
-  File f;
-  Rank r;
-  bool passed, isolated, doubled, opposed, chain, backward, candidate;
-  Score value = SCORE_ZERO;
-  const Square* pl = pos.piece_list(Us, PAWN);
-
-  // Loop through all pawns of the current color and score each pawn
-  while ((s = *pl++) != SQ_NONE)
-  {
-      assert(pos.piece_on(s) == make_piece(Us, PAWN));
-
-      f = file_of(s);
-      r = rank_of(s);
-
-      // This file cannot be half open
-      e->halfOpenFiles[Us] &= ~(1 << f);
-
-      // Our rank plus previous one. Used for chain detection
-      b = rank_bb(r) | rank_bb(Us == WHITE ? r - Rank(1) : r + Rank(1));
-
-      // Flag the pawn as passed, isolated, doubled or member of a pawn
-      // chain (but not the backward one).
-      chain    =   ourPawns   & adjacent_files_bb(f) & b;
-      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));
-
-      // Test for backward pawn
-      backward = false;
-
-      // If the pawn is passed, isolated, or member of a pawn chain it cannot
-      // be backward. If there are friendly pawns behind on adjacent files
-      // or if can capture an enemy pawn it cannot be backward either.
-      if (   !(passed | isolated | chain)
-          && !(ourPawns & attack_span_mask(Them, s))
-          && !(pos.attacks_from<PAWN>(s, Us) & theirPawns))
-      {
-          // 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 seeing whether we meet a friendly or an enemy pawn first.
-          b = pos.attacks_from<PAWN>(s, Us);
-
-          // Note that we are sure to find something because pawn is not passed
-          // nor isolated, so loop is potentially infinite, but it isn't.
-          while (!(b & (ourPawns | theirPawns)))
-              Us == WHITE ? b <<= 8 : b >>= 8;
-
-          // The friendly pawn needs to be at least two ranks closer than the
-          // enemy pawn in order to help the potentially backward pawn advance.
-          backward = (b | (Us == WHITE ? b << 8 : b >> 8)) & theirPawns;
-      }
-
-      assert(opposed | passed | (attack_span_mask(Us, s) & theirPawns));
-
-      // A not passed pawn is a candidate to become passed if it is free to
-      // advance and if the number of friendly pawns beside or behind this
-      // pawn on adjacent files is higher or equal than the number of
-      // enemy pawns in the forward direction on the adjacent files.
-      candidate =   !(opposed | passed | backward | isolated)
-                 && (b = attack_span_mask(Them, s + pawn_push(Us)) & ourPawns) != 0
-                 &&  popcount<Max15>(b) >= popcount<Max15>(attack_span_mask(Us, s) & theirPawns);
-
-      // 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)
-          e->passedPawns[Us] |= s;
-
-      // Score this pawn
-      if (isolated)
-          value -= IsolatedPawnPenalty[opposed][f];
-
-      if (doubled)
-          value -= DoubledPawnPenalty[opposed][f];
-
-      if (backward)
-          value -= BackwardPawnPenalty[opposed][f];
-
-      if (chain)
-          value += ChainBonus[f];
-
-      if (candidate)
-          value += CandidateBonus[relative_rank(Us, s)];
-  }
-
-  return value;
-}
-
-
-/// PawnEntry::shelter_storm() calculates shelter and storm penalties for the file
+/// Entry::shelter_storm() calculates shelter and storm penalties for the file
 /// the king is on, as well as the two adjacent files.
 
 template<Color Us>
-Value PawnEntry::shelter_storm(const Position& pos, Square ksq) {
+Value Entry::shelter_storm(const Position& pos, Square ksq) {
 
   const Color Them = (Us == WHITE ? BLACK : WHITE);
 
-  Value safety = MaxSafetyBonus;
-  Bitboard b = pos.pieces(PAWN) & (in_front_bb(Us, ksq) | rank_bb(ksq));
-  Bitboard ourPawns = b & pos.pieces(Us) & ~rank_bb(ksq);
+  enum { NoFriendlyPawn, Unblocked, BlockedByPawn, BlockedByKing };
+
+  Bitboard b = pos.pieces(PAWN) & (in_front_bb(Us, rank_of(ksq)) | rank_bb(ksq));
+  Bitboard ourPawns = b & pos.pieces(Us);
   Bitboard theirPawns = b & pos.pieces(Them);
-  Rank rkUs, rkThem;
-  File kf = file_of(ksq);
+  Value safety = MaxSafetyBonus;
+  File center = std::max(FILE_B, std::min(FILE_G, file_of(ksq)));
 
-  kf = (kf == FILE_A) ? kf++ : (kf == FILE_H) ? kf-- : kf;
-
-  for (int f = kf - 1; f <= kf + 1; f++)
+  for (File f = center - File(1); f <= center + File(1); ++f)
   {
-      // Shelter penalty is higher for the pawn in front of the king
-      b = ourPawns & FileBB[f];
-      rkUs = b ? rank_of(Us == WHITE ? lsb(b) : ~msb(b)) : RANK_1;
-      safety -= ShelterWeakness[f != kf][rkUs];
+      b = ourPawns & file_bb(f);
+      Rank rkUs = b ? relative_rank(Us, backmost_sq(Us, b)) : RANK_1;
 
-      // Storm danger is smaller if enemy pawn is blocked
-      b  = theirPawns & FileBB[f];
-      rkThem = b ? rank_of(Us == WHITE ? lsb(b) : ~msb(b)) : RANK_1;
-      safety -= StormDanger[rkThem == rkUs + 1][rkThem];
+      b  = theirPawns & file_bb(f);
+      Rank rkThem = b ? relative_rank(Us, frontmost_sq(Them, b)) : RANK_1;
+
+      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];
   }
 
   return safety;
 }
 
 
-/// PawnEntry::update_safety() calculates and caches a bonus for king safety. It is
-/// called only when king square changes, about 20% of total king_safety() calls.
+/// Entry::do_king_safety() calculates a bonus for king safety. It is called only
+/// when king square changes, which is about 20% of total king_safety() calls.
 
 template<Color Us>
-Score PawnEntry::update_safety(const Position& pos, Square ksq) {
+Score Entry::do_king_safety(const Position& pos, Square ksq) {
 
   kingSquares[Us] = ksq;
-  castleRights[Us] = pos.can_castle(Us);
-  minKPdistance[Us] = 0;
+  castlingRights[Us] = pos.can_castle(Us);
+  minKingPawnDistance[Us] = 0;
 
   Bitboard pawns = pos.pieces(Us, PAWN);
   if (pawns)
-      while (!(DistanceRingsBB[ksq][minKPdistance[Us]++] & pawns)) {}
+      while (!(DistanceRingBB[ksq][minKingPawnDistance[Us]++] & pawns)) {}
 
   if (relative_rank(Us, ksq) > RANK_4)
-      return kingSafety[Us] = make_score(0, -16 * minKPdistance[Us]);
+      return make_score(0, -16 * minKingPawnDistance[Us]);
 
   Value bonus = shelter_storm<Us>(pos, ksq);
 
-  // If we can castle use the bonus after the castle if is bigger
-  if (pos.can_castle(make_castle_right(Us, KING_SIDE)))
+  // 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(make_castle_right(Us, QUEEN_SIDE)))
+  if (pos.can_castle(MakeCastling<Us, QUEEN_SIDE>::right))
       bonus = std::max(bonus, shelter_storm<Us>(pos, relative_square(Us, SQ_C1)));
 
-  return kingSafety[Us] = make_score(bonus, -16 * minKPdistance[Us]);
+  return make_score(bonus, -16 * minKingPawnDistance[Us]);
 }
 
 // Explicit template instantiation
-template Score PawnEntry::update_safety<WHITE>(const Position& pos, Square ksq);
-template Score PawnEntry::update_safety<BLACK>(const Position& pos, Square ksq);
+template Score Entry::do_king_safety<WHITE>(const Position& pos, Square ksq);
+template Score Entry::do_king_safety<BLACK>(const Position& pos, Square ksq);
+
+} // namespace Pawns

src/pawns.h

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -17,99 +17,68 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#if !defined(PAWNS_H_INCLUDED)
+#ifndef PAWNS_H_INCLUDED
 #define PAWNS_H_INCLUDED
 
 #include "misc.h"
 #include "position.h"
 #include "types.h"
 
-const int PawnTableSize = 16384;
+namespace Pawns {
 
-/// PawnEntry is a class which contains various information about a pawn
-/// structure. Currently, it only includes a middle game and an end game
-/// pawn structure evaluation, and a bitboard of passed pawns. We may want
-/// to add further information in the future. A lookup to the pawn hash
-/// table (performed by calling the probe method in a PawnTable object)
-/// returns a pointer to a PawnEntry object.
+/// Pawns::Entry contains various information about a pawn structure. A lookup
+/// to the pawn hash table (performed by calling the probe function) returns a
+/// pointer to an Entry object.
 
-class PawnEntry {
+struct Entry {
 
-  friend struct PawnTable;
+  Score pawns_score() const { return score; }
+  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]; }
 
-public:
-  Score pawns_value() const;
-  Bitboard pawn_attacks(Color c) const;
-  Bitboard passed_pawns(Color c) const;
-  int file_is_half_open(Color c, File f) const;
-  int has_open_file_to_left(Color c, File f) const;
-  int has_open_file_to_right(Color c, File f) const;
+  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)];
+  }
 
   template<Color Us>
-  Score king_safety(const Position& pos, Square ksq);
+  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));
+  }
 
-private:
   template<Color Us>
-  Score update_safety(const Position& pos, Square ksq);
+  Score do_king_safety(const Position& pos, Square ksq);
 
   template<Color Us>
   Value shelter_storm(const Position& pos, Square ksq);
 
   Key key;
-  Bitboard passedPawns[2];
-  Bitboard pawnAttacks[2];
-  Square kingSquares[2];
-  int minKPdistance[2];
-  int castleRights[2];
-  Score value;
-  int halfOpenFiles[2];
-  Score kingSafety[2];
+  Score score;
+  Bitboard passedPawns[COLOR_NB];
+  Bitboard pawnAttacks[COLOR_NB];
+  Square kingSquares[COLOR_NB];
+  Score kingSafety[COLOR_NB];
+  int minKingPawnDistance[COLOR_NB];
+  int castlingRights[COLOR_NB];
+  int semiopenFiles[COLOR_NB];
+  int pawnSpan[COLOR_NB];
+  int pawnsOnSquares[COLOR_NB][COLOR_NB]; // [color][light/dark squares]
 };
 
+typedef HashTable<Entry, 16384> Table;
 
-/// The PawnTable class represents a pawn hash table. The most important
-/// method is probe, which returns a pointer to a PawnEntry object.
+void init();
+Entry* probe(const Position& pos);
 
-struct PawnTable {
+} // namespace Pawns
 
-  PawnEntry* probe(const Position& pos);
-
-  template<Color Us>
-  static Score evaluate_pawns(const Position& pos, Bitboard ourPawns,
-                              Bitboard theirPawns, PawnEntry* e);
-
-  HashTable<PawnEntry, PawnTableSize> entries;
-};
-
-
-inline Score PawnEntry::pawns_value() const {
-  return value;
-}
-
-inline Bitboard PawnEntry::pawn_attacks(Color c) const {
-  return pawnAttacks[c];
-}
-
-inline Bitboard PawnEntry::passed_pawns(Color c) const {
-  return passedPawns[c];
-}
-
-inline int PawnEntry::file_is_half_open(Color c, File f) const {
-  return halfOpenFiles[c] & (1 << int(f));
-}
-
-inline int PawnEntry::has_open_file_to_left(Color c, File f) const {
-  return halfOpenFiles[c] & ((1 << int(f)) - 1);
-}
-
-inline int PawnEntry::has_open_file_to_right(Color c, File f) const {
-  return halfOpenFiles[c] & ~((1 << int(f+1)) - 1);
-}
-
-template<Color Us>
-inline Score PawnEntry::king_safety(const Position& pos, Square ksq) {
-  return kingSquares[Us] == ksq && castleRights[Us] == pos.can_castle(Us)
-       ? kingSafety[Us] : update_safety<Us>(pos, ksq);
-}
-
-#endif // !defined(PAWNS_H_INCLUDED)
+#endif // #ifndef PAWNS_H_INCLUDED

src/platform.h

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -17,12 +17,12 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#if !defined(PLATFORM_H_INCLUDED)
+#ifndef PLATFORM_H_INCLUDED
 #define PLATFORM_H_INCLUDED
 
-#if defined(_MSC_VER)
+#ifdef _MSC_VER
 
-// Disable some silly and noisy warning from MSVC compiler
+// 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'
@@ -42,13 +42,15 @@ typedef unsigned __int64 uint64_t;
 #  include <inttypes.h>
 #endif
 
-#if !defined(_WIN32) && !defined(_WIN64) // Linux - Unix
+#ifndef _WIN32 // Linux - Unix
 
 #  include <sys/time.h>
-typedef timeval sys_time_t;
 
-inline void system_time(sys_time_t* t) { gettimeofday(t, NULL); }
-inline int64_t time_to_msec(const sys_time_t& t) { return t.tv_sec * 1000LL + t.tv_usec / 1000; }
+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;
@@ -65,18 +67,20 @@ typedef void*(*pt_start_fn)(void*);
 #  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_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>
-typedef _timeb sys_time_t;
 
-inline void system_time(sys_time_t* t) { _ftime(t); }
-inline int64_t time_to_msec(const sys_time_t& t) { return t.time * 1000LL + t.millitm; }
+inline int64_t system_time_to_msec() {
+  _timeb t;
+  _ftime(&t);
+  return t.time * 1000LL + t.millitm;
+}
 
-#if !defined(NOMINMAX)
+#ifndef NOMINMAX
 #  define NOMINMAX // disable macros min() and max()
 #endif
 
@@ -85,13 +89,16 @@ inline int64_t time_to_msec(const sys_time_t& t) { return t.time * 1000LL + t.mi
 #undef WIN32_LEAN_AND_MEAN
 #undef NOMINMAX
 
-// We use critical sections on Windows to support Windows XP and older versions,
-// unfortunatly cond_wait() is racy between lock_release() and WaitForSingleObject()
+// 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))
@@ -101,9 +108,9 @@ typedef HANDLE NativeHandle;
 #  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,NULL), x != NULL)
+#  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 // !defined(PLATFORM_H_INCLUDED)
+#endif // #ifndef PLATFORM_H_INCLUDED

src/position.h

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -17,19 +17,21 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#if !defined(POSITION_H_INCLUDED)
+#ifndef POSITION_H_INCLUDED
 #define POSITION_H_INCLUDED
 
 #include <cassert>
+#include <cstddef>  // For offsetof()
+#include <string>
 
 #include "bitboard.h"
 #include "types.h"
 
-
-/// The checkInfo struct is initialized at c'tor time and keeps info used
-/// to detect if a move gives check.
 class Position;
-class Thread;
+struct Thread;
+
+/// CheckInfo struct is initialized at c'tor time and keeps info used to detect
+/// if a move gives check.
 
 struct CheckInfo {
 
@@ -37,71 +39,62 @@ struct CheckInfo {
 
   Bitboard dcCandidates;
   Bitboard pinned;
-  Bitboard checkSq[8];
-  Square ksq;
+  Bitboard checkSq[PIECE_TYPE_NB];
+  Square   ksq;
 };
 
 
-/// The StateInfo struct stores information we need to restore a Position
-/// object to its previous state when we retract a move. Whenever a move
-/// is made on the board (by calling Position::do_move), an StateInfo object
-/// must be passed as a parameter.
+/// StateInfo struct stores information needed to restore a Position object to
+/// its previous state when we retract a move. Whenever a move is made on the
+/// board (by calling Position::do_move), a StateInfo object must be passed.
 
 struct StateInfo {
-  Key pawnKey, materialKey;
-  Value npMaterial[2];
-  int castleRights, rule50, pliesFromNull;
-  Score psqScore;
+
+  // Copied when making a move
+  Key    pawnKey;
+  Key    materialKey;
+  Value  nonPawnMaterial[COLOR_NB];
+  int    castlingRights;
+  int    rule50;
+  int    pliesFromNull;
+  Score  psq;
   Square epSquare;
 
-  Key key;
-  Bitboard checkersBB;
-  PieceType capturedType;
+  // Not copied when making a move
+  Key        key;
+  Bitboard   checkersBB;
+  PieceType  capturedType;
   StateInfo* previous;
 };
 
-struct ReducedStateInfo {
-  Key pawnKey, materialKey;
-  Value npMaterial[2];
-  int castleRights, rule50, pliesFromNull;
-  Score psqScore;
-  Square epSquare;
-};
+
+/// 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;
 
 
-/// The position data structure. A position consists of the following data:
-///
-///    * For each piece type, a bitboard representing the squares occupied
-///      by pieces of that type.
-///    * For each color, a bitboard representing the squares occupied by
-///      pieces of that color.
-///    * A bitboard of all occupied squares.
-///    * A bitboard of all checking pieces.
-///    * A 64-entry array of pieces, indexed by the squares of the board.
-///    * The current side to move.
-///    * Information about the castling rights for both sides.
-///    * The initial files of the kings and both pairs of rooks. This is
-///      used to implement the Chess960 castling rules.
-///    * The en passant square (which is SQ_NONE if no en passant capture is
-///      possible).
-///    * The squares of the kings for both sides.
-///    * Hash keys for the position itself, the current pawn structure, and
-///      the current material situation.
-///    * Hash keys for all previous positions in the game for detecting
-///      repetition draws.
-///    * A counter for detecting 50 move rule draws.
+/// Position class stores information regarding the board representation as
+/// pieces, side to move, hash keys, castling info, etc. Important methods are
+/// do_move() and undo_move(), used by the search to update node info when
+/// traversing the search tree.
 
 class Position {
-public:
-  Position() {}
-  Position(const Position& p, Thread* t) { *this = p; thisThread = t; }
-  Position(const std::string& f, bool c960, Thread* t) { from_fen(f, c960, t); }
-  Position& operator=(const Position&);
 
-  // Text input/output
-  void from_fen(const std::string& fen, bool isChess960, Thread* th);
-  const std::string to_fen() const;
-  void print(Move m = MOVE_NONE) const;
+  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
+
+  // FEN string input/output
+  void set(const std::string& fenStr, bool isChess960, Thread* th);
+  const std::string fen() const;
 
   // Position representation
   Bitboard pieces() const;
@@ -113,146 +106,127 @@ public:
   Piece piece_on(Square s) const;
   Square king_square(Color c) const;
   Square ep_square() const;
-  bool is_empty(Square s) const;
-  const Square* piece_list(Color c, PieceType pt) const;
-  int piece_count(Color c, PieceType pt) const;
+  bool empty(Square s) const;
+  template<PieceType Pt> int count(Color c) const;
+  template<PieceType Pt> const Square* list(Color c) const;
 
   // Castling
-  int can_castle(CastleRight f) const;
   int can_castle(Color c) const;
-  bool castle_impeded(Color c, CastlingSide s) const;
-  Square castle_rook_square(Color c, CastlingSide s) const;
+  int can_castle(CastlingRight cr) const;
+  bool castling_impeded(CastlingRight cr) const;
+  Square castling_rook_square(CastlingRight cr) const;
 
   // Checking
-  bool in_check() const;
   Bitboard checkers() const;
   Bitboard discovered_check_candidates() const;
-  Bitboard pinned_pieces() const;
+  Bitboard pinned_pieces(Color c) const;
 
   // Attacks to/from a given square
   Bitboard attackers_to(Square s) const;
-  Bitboard attackers_to(Square s, Bitboard occ) const;
-  Bitboard attacks_from(Piece p, Square s) const;
-  static Bitboard attacks_from(Piece p, Square s, Bitboard occ);
+  Bitboard attackers_to(Square s, Bitboard occupied) const;
+  Bitboard attacks_from(Piece pc, Square s) const;
   template<PieceType> Bitboard attacks_from(Square s) const;
   template<PieceType> Bitboard attacks_from(Square s, Color c) const;
 
   // Properties of moves
-  bool move_gives_check(Move m, const CheckInfo& ci) const;
-  bool move_attacks_square(Move m, Square s) const;
-  bool move_is_legal(const Move m) const;
-  bool pl_move_is_legal(Move m, Bitboard pinned) const;
-  bool is_pseudo_legal(const Move m) const;
-  bool is_capture(Move m) const;
-  bool is_capture_or_promotion(Move m) const;
-  bool is_passed_pawn_push(Move m) const;
-  Piece piece_moved(Move m) const;
+  bool legal(Move m, Bitboard pinned) 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 advanced_pawn_push(Move m) const;
+  Piece moved_piece(Move m) const;
   PieceType captured_piece_type() const;
 
   // Piece specific
-  bool pawn_is_passed(Color c, Square s) const;
+  bool pawn_passed(Color c, Square s) const;
   bool pawn_on_7th(Color c) const;
   bool opposite_bishops() const;
-  bool bishop_pair(Color c) 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 undo_move(Move m);
-  template<bool Do> void do_null_move(StateInfo& st);
+  void do_null_move(StateInfo& st);
+  void undo_null_move();
 
   // Static exchange evaluation
-  int see(Move m) const;
-  int see_sign(Move m) const;
+  Value see(Move m) const;
+  Value see_sign(Move m) const;
 
   // Accessing hash keys
   Key key() const;
+  Key key_after(Move m) const;
   Key exclusion_key() const;
-  Key pawn_key() const;
   Key material_key() const;
-
-  // Incremental piece-square evaluation
-  Score psq_score() const;
-  Score psq_delta(Piece p, Square from, Square to) const;
-  Value non_pawn_material(Color c) const;
+  Key pawn_key() const;
 
   // Other properties of the position
   Color side_to_move() const;
-  int startpos_ply_counter() const;
+  Phase game_phase() const;
+  int game_ply() const;
   bool is_chess960() const;
   Thread* this_thread() const;
-  int64_t nodes_searched() const;
-  void set_nodes_searched(int64_t n);
-  template<bool SkipRepetition> bool is_draw() const;
+  uint64_t nodes_searched() const;
+  void set_nodes_searched(uint64_t n);
+  bool is_draw() const;
+  int rule50_count() const;
+  Score psq_score() const;
+  Value non_pawn_material(Color c) const;
 
   // Position consistency check, for debugging
-  bool pos_is_ok(int* failedStep = NULL) const;
+  bool pos_is_ok(int* step = NULL) const;
   void flip();
 
 private:
   // Initialization helpers (used while setting up a position)
   void clear();
-  void put_piece(Piece p, Square s);
-  void set_castle_right(Color c, Square rfrom);
+  void set_castling_right(Color c, Square rfrom);
+  void set_state(StateInfo* si) const;
 
-  // Helper template functions
-  template<bool Do> void do_castle_move(Move m);
-  template<bool FindPinned> Bitboard hidden_checkers() 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);
+  template<bool Do>
+  void do_castling(Square from, Square& to, Square& rfrom, Square& rto);
 
-  // Computing hash keys from scratch (for initialization and debugging)
-  Key compute_key() const;
-  Key compute_pawn_key() const;
-  Key compute_material_key() const;
-
-  // Computing incremental evaluation scores and material counts
-  Score compute_psq_score() const;
-  Value compute_non_pawn_material(Color c) const;
-
-  // Board and pieces
-  Piece board[64];             // [square]
-  Bitboard byTypeBB[8];        // [pieceType]
-  Bitboard byColorBB[2];       // [color]
-  int pieceCount[2][8];        // [color][pieceType]
-  Square pieceList[2][8][16];  // [color][pieceType][index]
-  int index[64];               // [square]
-
-  // Other info
-  int castleRightsMask[64];      // [square]
-  Square castleRookSquare[2][2]; // [color][side]
-  Bitboard castlePath[2][2];     // [color][side]
+  // 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 index[SQUARE_NB];
+  int castlingRightsMask[SQUARE_NB];
+  Square castlingRookSquare[CASTLING_RIGHT_NB];
+  Bitboard castlingPath[CASTLING_RIGHT_NB];
   StateInfo startState;
-  int64_t nodes;
-  int startPosPly;
+  uint64_t nodes;
+  int gamePly;
   Color sideToMove;
   Thread* thisThread;
   StateInfo* st;
-  int chess960;
+  bool chess960;
 };
 
-inline int64_t Position::nodes_searched() const {
-  return nodes;
+inline Color Position::side_to_move() const {
+  return sideToMove;
 }
 
-inline void Position::set_nodes_searched(int64_t n) {
-  nodes = n;
+inline bool Position::empty(Square s) const {
+  return board[s] == NO_PIECE;
 }
 
 inline Piece Position::piece_on(Square s) const {
   return board[s];
 }
 
-inline Piece Position::piece_moved(Move m) const {
+inline Piece Position::moved_piece(Move m) const {
   return board[from_sq(m)];
 }
 
-inline bool Position::is_empty(Square s) const {
-  return board[s] == NO_PIECE;
-}
-
-inline Color Position::side_to_move() const {
-  return sideToMove;
-}
-
 inline Bitboard Position::pieces() const {
   return byTypeBB[ALL_PIECES];
 }
@@ -277,42 +251,41 @@ inline Bitboard Position::pieces(Color c, PieceType pt1, PieceType pt2) const {
   return byColorBB[c] & (byTypeBB[pt1] | byTypeBB[pt2]);
 }
 
-inline int Position::piece_count(Color c, PieceType pt) const {
-  return pieceCount[c][pt];
+template<PieceType Pt> inline int Position::count(Color c) const {
+  return pieceCount[c][Pt];
 }
 
-inline const Square* Position::piece_list(Color c, PieceType pt) const {
-  return pieceList[c][pt];
-}
-
-inline Square Position::ep_square() const {
-  return st->epSquare;
+template<PieceType Pt> inline const Square* Position::list(Color c) const {
+  return pieceList[c][Pt];
 }
 
 inline Square Position::king_square(Color c) const {
   return pieceList[c][KING][0];
 }
 
-inline int Position::can_castle(CastleRight f) const {
-  return st->castleRights & f;
+inline Square Position::ep_square() const {
+  return st->epSquare;
+}
+
+inline int Position::can_castle(CastlingRight cr) const {
+  return st->castlingRights & cr;
 }
 
 inline int Position::can_castle(Color c) const {
-  return st->castleRights & ((WHITE_OO | WHITE_OOO) << (2 * c));
+  return st->castlingRights & ((WHITE_OO | WHITE_OOO) << (2 * c));
 }
 
-inline bool Position::castle_impeded(Color c, CastlingSide s) const {
-  return byTypeBB[ALL_PIECES] & castlePath[c][s];
+inline bool Position::castling_impeded(CastlingRight cr) const {
+  return byTypeBB[ALL_PIECES] & castlingPath[cr];
 }
 
-inline Square Position::castle_rook_square(Color c, CastlingSide s) const {
-  return castleRookSquare[c][s];
+inline Square Position::castling_rook_square(CastlingRight cr) const {
+  return castlingRookSquare[cr];
 }
 
 template<PieceType Pt>
 inline Bitboard Position::attacks_from(Square s) const {
-
-  return  Pt == BISHOP || Pt == ROOK ? attacks_bb<Pt>(s, pieces())
+  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];
 }
@@ -322,8 +295,8 @@ inline Bitboard Position::attacks_from<PAWN>(Square s, Color c) const {
   return StepAttacksBB[make_piece(c, PAWN)][s];
 }
 
-inline Bitboard Position::attacks_from(Piece p, Square s) const {
-  return attacks_from(p, s, byTypeBB[ALL_PIECES]);
+inline Bitboard Position::attacks_from(Piece pc, Square s) const {
+  return attacks_bb(pc, s, byTypeBB[ALL_PIECES]);
 }
 
 inline Bitboard Position::attackers_to(Square s) const {
@@ -334,30 +307,27 @@ inline Bitboard Position::checkers() const {
   return st->checkersBB;
 }
 
-inline bool Position::in_check() const {
-  return st->checkersBB != 0;
-}
-
 inline Bitboard Position::discovered_check_candidates() const {
-  return hidden_checkers<false>();
+  return check_blockers(sideToMove, ~sideToMove);
 }
 
-inline Bitboard Position::pinned_pieces() const {
-  return hidden_checkers<true>();
+inline Bitboard Position::pinned_pieces(Color c) const {
+  return check_blockers(c, c);
 }
 
-inline bool Position::pawn_is_passed(Color c, Square s) const {
+inline bool Position::pawn_passed(Color c, Square s) const {
   return !(pieces(~c, PAWN) & passed_pawn_mask(c, s));
 }
 
+inline bool Position::advanced_pawn_push(Move m) const {
+  return   type_of(moved_piece(m)) == PAWN
+        && relative_rank(sideToMove, from_sq(m)) > RANK_4;
+}
+
 inline Key Position::key() const {
   return st->key;
 }
 
-inline Key Position::exclusion_key() const {
-  return st->key ^ Zobrist::exclusion;
-}
-
 inline Key Position::pawn_key() const {
   return st->pawnKey;
 }
@@ -366,41 +336,36 @@ inline Key Position::material_key() const {
   return st->materialKey;
 }
 
-inline Score Position::psq_delta(Piece p, Square from, Square to) const {
-  return pieceSquareTable[p][to] - pieceSquareTable[p][from];
-}
-
 inline Score Position::psq_score() const {
-  return st->psqScore;
+  return st->psq;
 }
 
 inline Value Position::non_pawn_material(Color c) const {
-  return st->npMaterial[c];
+  return st->nonPawnMaterial[c];
 }
 
-inline bool Position::is_passed_pawn_push(Move m) const {
-
-  return   type_of(piece_moved(m)) == PAWN
-        && pawn_is_passed(sideToMove, to_sq(m));
+inline int Position::game_ply() const {
+  return gamePly;
 }
 
-inline int Position::startpos_ply_counter() const {
-  return startPosPly + st->pliesFromNull; // HACK
+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::bishop_pair(Color c) const {
-
-  return   pieceCount[c][BISHOP] >= 2
-        && opposite_colors(pieceList[c][BISHOP][0], pieceList[c][BISHOP][1]);
-}
-
 inline bool Position::pawn_on_7th(Color c) const {
   return pieces(c, PAWN) & rank_bb(relative_rank(c, RANK_7));
 }
@@ -409,17 +374,17 @@ inline bool Position::is_chess960() const {
   return chess960;
 }
 
-inline bool Position::is_capture_or_promotion(Move m) const {
+inline bool Position::capture_or_promotion(Move m) const {
 
   assert(is_ok(m));
-  return type_of(m) ? type_of(m) != CASTLE : !is_empty(to_sq(m));
+  return type_of(m) != NORMAL ? type_of(m) != CASTLING : !empty(to_sq(m));
 }
 
-inline bool Position::is_capture(Move m) const {
+inline bool Position::capture(Move m) const {
 
-  // Note that castle is coded as "king captures the rook"
+  // Castling is encoded as "king captures the rook"
   assert(is_ok(m));
-  return (!is_empty(to_sq(m)) && type_of(m) != CASTLE) || type_of(m) == ENPASSANT;
+  return (!empty(to_sq(m)) && type_of(m) != CASTLING) || type_of(m) == ENPASSANT;
 }
 
 inline PieceType Position::captured_piece_type() const {
@@ -430,4 +395,46 @@ inline Thread* Position::this_thread() const {
   return thisThread;
 }
 
-#endif // !defined(POSITION_H_INCLUDED)
+inline void Position::put_piece(Square s, Color c, PieceType pt) {
+
+  board[s] = make_piece(c, pt);
+  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]++;
+}
+
+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) {
+
+  // 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.
+  byTypeBB[ALL_PIECES] ^= s;
+  byTypeBB[pt] ^= s;
+  byColorBB[c] ^= s;
+  /* board[s] = NO_PIECE;  Not needed, overwritten by the capturing one */
+  Square lastSquare = pieceList[c][pt][--pieceCount[c][pt]];
+  index[lastSquare] = index[s];
+  pieceList[c][pt][index[lastSquare]] = lastSquare;
+  pieceList[c][pt][pieceCount[c][pt]] = SQ_NONE;
+  pieceCount[c][ALL_PIECES]--;
+}
+
+#endif // #ifndef POSITION_H_INCLUDED

src/psqtab.h

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -17,7 +17,7 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#if !defined(PSQTAB_H_INCLUDED)
+#ifndef PSQTAB_H_INCLUDED
 #define PSQTAB_H_INCLUDED
 
 #include "types.h"
@@ -26,73 +26,73 @@
 
 
 /// PSQT[PieceType][Square] contains Piece-Square scores. For each piece type on
-/// a given square a (midgame, endgame) score pair is assigned. PSQT is defined
-/// for white side, for black side the tables are symmetric.
+/// 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[][64] = {
+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(-28,-8), S(-6,-8), S( 4,-8), S(14,-8), S(14,-8), S( 4,-8), S(-6,-8), S(-28,-8),
-   S(-28,-8), S(-6,-8), S( 9,-8), S(36,-8), S(36,-8), S( 9,-8), S(-6,-8), S(-28,-8),
-   S(-28,-8), S(-6,-8), S(17,-8), S(58,-8), S(58,-8), S(17,-8), S(-6,-8), S(-28,-8),
-   S(-28,-8), S(-6,-8), S(17,-8), S(36,-8), S(36,-8), S(17,-8), S(-6,-8), S(-28,-8),
-   S(-28,-8), S(-6,-8), S( 9,-8), S(14,-8), S(14,-8), S( 9,-8), S(-6,-8), S(-28,-8),
-   S(-28,-8), S(-6,-8), S( 4,-8), S(14,-8), S(14,-8), S( 4,-8), S(-6,-8), S(-28,-8),
+   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(-135,-104), S(-107,-79), S(-80,-55), S(-67,-42), S(-67,-42), S(-80,-55), S(-107,-79), S(-135,-104),
-   S( -93, -79), S( -67,-55), S(-39,-30), S(-25,-17), S(-25,-17), S(-39,-30), S( -67,-55), S( -93, -79),
-   S( -53, -55), S( -25,-30), S(  1, -6), S( 13,  5), S( 13,  5), S(  1, -6), S( -25,-30), S( -53, -55),
-   S( -25, -42), S(   1,-17), S( 27,  5), S( 41, 18), S( 41, 18), S( 27,  5), S(   1,-17), S( -25, -42),
-   S( -11, -42), S(  13,-17), S( 41,  5), S( 55, 18), S( 55, 18), S( 41,  5), S(  13,-17), S( -11, -42),
-   S( -11, -55), S(  13,-30), S( 41, -6), S( 55,  5), S( 55,  5), S( 41, -6), S(  13,-30), S( -11, -55),
-   S( -53, -79), S( -25,-55), S(  1,-30), S( 13,-17), S( 13,-17), S(  1,-30), S( -25,-55), S( -53, -79),
-   S(-193,-104), S( -67,-79), S(-39,-55), S(-25,-42), S(-25,-42), S(-39,-55), S( -67,-79), S(-193,-104)
+   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(-40,-59), S(-40,-42), S(-35,-35), S(-30,-26), S(-30,-26), S(-35,-35), S(-40,-42), S(-40,-59),
-   S(-17,-42), S(  0,-26), S( -4,-18), S(  0,-11), S(  0,-11), S( -4,-18), S(  0,-26), S(-17,-42),
-   S(-13,-35), S( -4,-18), S(  8,-11), S(  4, -4), S(  4, -4), S(  8,-11), S( -4,-18), S(-13,-35),
-   S( -8,-26), S(  0,-11), S(  4, -4), S( 17,  4), S( 17,  4), S(  4, -4), S(  0,-11), S( -8,-26),
-   S( -8,-26), S(  0,-11), S(  4, -4), S( 17,  4), S( 17,  4), S(  4, -4), S(  0,-11), S( -8,-26),
-   S(-13,-35), S( -4,-18), S(  8,-11), S(  4, -4), S(  4, -4), S(  8,-11), S( -4,-18), S(-13,-35),
-   S(-17,-42), S(  0,-26), S( -4,-18), S(  0,-11), S(  0,-11), S( -4,-18), S(  0,-26), S(-17,-42),
-   S(-17,-59), S(-17,-42), S(-13,-35), S( -8,-26), S( -8,-26), S(-13,-35), S(-17,-42), S(-17,-59)
+   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(-12, 3), S(-7, 3), S(-2, 3), S(2, 3), S(2, 3), S(-2, 3), S(-7, 3), S(-12, 3),
-   S(-12, 3), S(-7, 3), S(-2, 3), S(2, 3), S(2, 3), S(-2, 3), S(-7, 3), S(-12, 3),
-   S(-12, 3), S(-7, 3), S(-2, 3), S(2, 3), S(2, 3), S(-2, 3), S(-7, 3), S(-12, 3),
-   S(-12, 3), S(-7, 3), S(-2, 3), S(2, 3), S(2, 3), S(-2, 3), S(-7, 3), S(-12, 3),
-   S(-12, 3), S(-7, 3), S(-2, 3), S(2, 3), S(2, 3), S(-2, 3), S(-7, 3), S(-12, 3),
-   S(-12, 3), S(-7, 3), S(-2, 3), S(2, 3), S(2, 3), S(-2, 3), S(-7, 3), S(-12, 3),
-   S(-12, 3), S(-7, 3), S(-2, 3), S(2, 3), S(2, 3), S(-2, 3), S(-7, 3), S(-12, 3),
-   S(-12, 3), S(-7, 3), S(-2, 3), S(2, 3), S(2, 3), S(-2, 3), S(-7, 3), S(-12, 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),
+   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(8,-80), S(8,-54), S(8,-42), S(8,-30), S(8,-30), S(8,-42), S(8,-54), S(8,-80),
-   S(8,-54), S(8,-30), S(8,-18), S(8, -6), S(8, -6), S(8,-18), S(8,-30), S(8,-54),
-   S(8,-42), S(8,-18), S(8, -6), S(8,  6), S(8,  6), S(8, -6), S(8,-18), S(8,-42),
-   S(8,-30), S(8, -6), S(8,  6), S(8, 18), S(8, 18), S(8,  6), S(8, -6), S(8,-30),
-   S(8,-30), S(8, -6), S(8,  6), S(8, 18), S(8, 18), S(8,  6), S(8, -6), S(8,-30),
-   S(8,-42), S(8,-18), S(8, -6), S(8,  6), S(8,  6), S(8, -6), S(8,-18), S(8,-42),
-   S(8,-54), S(8,-30), S(8,-18), S(8, -6), S(8, -6), S(8,-18), S(8,-30), S(8,-54),
-   S(8,-80), S(8,-54), S(8,-42), S(8,-30), S(8,-30), S(8,-42), S(8,-54), S(8,-80)
+   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(287, 18), S(311, 77), S(262,105), S(214,135), S(214,135), S(262,105), S(311, 77), S(287, 18),
-   S(262, 77), S(287,135), S(238,165), S(190,193), S(190,193), S(238,165), S(287,135), S(262, 77),
-   S(214,105), S(238,165), S(190,193), S(142,222), S(142,222), S(190,193), S(238,165), S(214,105),
-   S(190,135), S(214,193), S(167,222), S(119,251), S(119,251), S(167,222), S(214,193), S(190,135),
-   S(167,135), S(190,193), S(142,222), S( 94,251), S( 94,251), S(142,222), S(190,193), S(167,135),
-   S(142,105), S(167,165), S(119,193), S( 69,222), S( 69,222), S(119,193), S(167,165), S(142,105),
-   S(119, 77), S(142,135), S( 94,165), S( 46,193), S( 46,193), S( 94,165), S(142,135), S(119, 77),
-   S(94,  18), S(119, 77), S( 69,105), S( 21,135), S( 21,135), S( 69,105), S(119, 77), S( 94, 18)
+   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 // !defined(PSQTAB_H_INCLUDED)
+#endif // #ifndef PSQTAB_H_INCLUDED

src/rkiss.h

@@ -1,78 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 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/>.
-
-  This file is based on original code by Heinz van Saanen and is
-  available under 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.
-*/
-
-#if !defined(RKISS_H_INCLUDED)
-#define RKISS_H_INCLUDED
-
-#include "types.h"
-
-/// RKISS is our pseudo random number generator (PRNG) used to compute hash keys.
-/// George Marsaglia invented the RNG-Kiss-family in the early 90's. This is a
-/// specific version that Heinz van Saanen derived from some public domain code
-/// by Bob Jenkins. Following the feature list, as tested by Heinz.
-///
-/// - Quite platform independent
-/// - Passes ALL dieharder tests! Here *nix sys-rand() e.g. fails miserably:-)
-/// - ~12 times faster than my *nix sys-rand()
-/// - ~4 times faster than SSE2-version of Mersenne twister
-/// - Average cycle length: ~2^126
-/// - 64 bit seed
-/// - Return doubles with a full 53 bit mantissa
-/// - Thread safe
-
-class RKISS {
-
-  // Keep variables always together
-  struct S { uint64_t a, b, c, d; } s;
-
-  uint64_t rotate(uint64_t x, uint64_t k) const {
-    return (x << k) | (x >> (64 - k));
-  }
-
-  // Return 64 bit unsigned integer in between [0, 2^64 - 1]
-  uint64_t rand64() {
-
-    const uint64_t
-      e = s.a - rotate(s.b,  7);
-    s.a = s.b ^ rotate(s.c, 13);
-    s.b = s.c + rotate(s.d, 37);
-    s.c = s.d + e;
-    return s.d = e + s.a;
-  }
-
-  // Init seed and scramble a few rounds
-  void raninit() {
-
-    s.a = 0xf1ea5eed;
-    s.b = s.c = s.d = 0xd4e12c77;
-    for (int i = 0; i < 73; i++)
-        rand64();
-  }
-
-public:
-  RKISS() { raninit(); }
-  template<typename T> T rand() { return T(rand64()); }
-};
-
-#endif // !defined(RKISS_H_INCLUDED)

src/search.h

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -17,11 +17,10 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#if !defined(SEARCH_H_INCLUDED)
+#ifndef SEARCH_H_INCLUDED
 #define SEARCH_H_INCLUDED
 
-#include <cstring>
-#include <memory>
+#include <memory>  // For std::auto_ptr
 #include <stack>
 #include <vector>
 
@@ -33,79 +32,83 @@ struct SplitPoint;
 
 namespace Search {
 
-/// The Stack struct keeps track of the information we need to remember from
-/// nodes shallower and deeper in the tree during the search. Each search thread
-/// has its own array of Stack objects, indexed by the current ply.
+/// Stack struct keeps track of the information we need to remember from nodes
+/// shallower and deeper in the tree during the search. Each search thread has
+/// its own array of Stack objects, indexed by the current ply.
 
 struct Stack {
-  SplitPoint* sp;
+  SplitPoint* splitPoint;
+  Move* pv;
   int ply;
   Move currentMove;
+  Move ttMove;
   Move excludedMove;
   Move killers[2];
   Depth reduction;
-  Value eval;
-  Value evalMargin;
-  int skipNullMove;
+  Value staticEval;
+  bool skipEarlyPruning;
 };
 
+/// RootMove struct is used for moves at the root of the tree. For each root move
+/// we store a score and a PV (really a refutation in the case of moves which
+/// fail low). Score is normally set at -VALUE_INFINITE for all non-pv moves.
 
-/// RootMove struct is used for moves at the root of the tree. For each root
-/// move we store a score, a node count, 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(){} // Needed by sort()
-  RootMove(Move m) : score(-VALUE_INFINITE), prevScore(-VALUE_INFINITE) {
-    pv.push_back(m); pv.push_back(MOVE_NONE);
-  }
+  RootMove(Move m) : score(-VALUE_INFINITE), previousScore(-VALUE_INFINITE), pv(1, m) {}
 
-  bool operator<(const RootMove& m) const { return score < m.score; }
+  bool operator<(const RootMove& m) const { return score > m.score; } // Ascending sort
   bool operator==(const Move& m) const { return pv[0] == m; }
-
-  void extract_pv_from_tt(Position& pos);
   void insert_pv_in_tt(Position& pos);
+  Move extract_ponder_from_tt(Position& pos);
 
   Value score;
-  Value prevScore;
+  Value previousScore;
   std::vector<Move> pv;
 };
 
+typedef std::vector<RootMove> RootMoveVector;
 
-/// The 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 is our opponent's side to move.
+/// 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.
 
 struct LimitsType {
 
-  LimitsType() { memset(this, 0, sizeof(LimitsType)); }
-  bool use_time_management() const { return !(movetime | depth | nodes | infinite); }
+  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;
+  }
 
-  int time[2], inc[2], movestogo, depth, nodes, movetime, infinite, ponder;
+  bool use_time_management() const {
+    return !(mate | movetime | depth | nodes | infinite);
+  }
+
+  std::vector<Move> searchmoves;
+  int time[COLOR_NB], inc[COLOR_NB], movestogo, depth, movetime, mate, infinite, ponder;
+  int64_t nodes;
 };
 
-
 /// The SignalsType struct stores volatile flags updated during the search
-/// typically in an async fashion, for instance to stop the search by the GUI.
+/// typically in an async fashion e.g. to stop the search by the GUI.
 
 struct SignalsType {
-  bool stopOnPonderhit, firstRootMove, stop, failedLowAtRoot;
+  bool stop, stopOnPonderhit, firstRootMove, failedLowAtRoot;
 };
 
 typedef std::auto_ptr<std::stack<StateInfo> > StateStackPtr;
 
 extern volatile SignalsType Signals;
 extern LimitsType Limits;
-extern std::vector<RootMove> RootMoves;
-extern Position RootPosition;
+extern RootMoveVector RootMoves;
+extern Position RootPos;
 extern Time::point SearchTime;
 extern StateStackPtr SetupStates;
 
-extern void init();
-extern size_t perft(Position& pos, Depth depth);
-extern void think();
+void init();
+void think();
+template<bool Root> uint64_t perft(Position& pos, Depth depth);
 
 } // namespace Search
 
-#endif // !defined(SEARCH_H_INCLUDED)
+#endif // #ifndef SEARCH_H_INCLUDED

src/syzygy/tbcore.h

@@ -0,0 +1,169 @@
+/*
+  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.cpp

@@ -0,0 +1,831 @@
+/*
+  Copyright (c) 2013 Ronald de Man
+  This file may be redistributed and/or modified without restrictions.
+
+  tbprobe.cpp contains the Stockfish-specific routines of the
+  tablebase probing code. It should be relatively easy to adapt
+  this code to other chess engines.
+*/
+
+#include <algorithm>
+
+#include "../position.h"
+#include "../movegen.h"
+#include "../bitboard.h"
+#include "../search.h"
+#include "../bitcount.h"
+
+#include "tbprobe.h"
+#include "tbcore.h"
+
+#include "tbcore.cpp"
+
+namespace Zobrist {
+  extern Key psq[COLOR_NB][PIECE_TYPE_NB][SQUARE_NB];
+}
+
+int Tablebases::MaxCardinality = 0;
+
+// Given a position with 6 or fewer pieces, produce a text string
+// of the form KQPvKRP, where "KQP" represents the white pieces if
+// mirror == 0 and the black pieces if mirror == 1.
+static void prt_str(Position& pos, char *str, int mirror)
+{
+  Color color;
+  PieceType pt;
+  int i;
+
+  color = !mirror ? WHITE : BLACK;
+  for (pt = KING; pt >= PAWN; --pt)
+    for (i = popcount<Max15>(pos.pieces(color, pt)); i > 0; i--)
+      *str++ = pchr[6 - pt];
+  *str++ = 'v';
+  color = ~color;
+  for (pt = KING; pt >= PAWN; --pt)
+    for (i = popcount<Max15>(pos.pieces(color, pt)); i > 0; i--)
+      *str++ = pchr[6 - pt];
+  *str++ = 0;
+}
+
+// Given a position, produce a 64-bit material signature key.
+// If the engine supports such a key, it should equal the engine's key.
+static uint64 calc_key(Position& pos, int mirror)
+{
+  Color color;
+  PieceType pt;
+  int i;
+  uint64 key = 0;
+
+  color = !mirror ? WHITE : BLACK;
+  for (pt = PAWN; pt <= KING; ++pt)
+    for (i = popcount<Max15>(pos.pieces(color, pt)); i > 0; i--)
+      key ^= Zobrist::psq[WHITE][pt][i - 1];
+  color = ~color;
+  for (pt = PAWN; pt <= KING; ++pt)
+    for (i = popcount<Max15>(pos.pieces(color, pt)); i > 0; i--)
+      key ^= Zobrist::psq[BLACK][pt][i - 1];
+
+  return key;
+}
+
+// Produce a 64-bit material key corresponding to the material combination
+// defined by pcs[16], where pcs[1], ..., pcs[6] is the number of white
+// pawns, ..., kings and pcs[9], ..., pcs[14] is the number of black
+// pawns, ..., kings.
+static uint64 calc_key_from_pcs(int *pcs, int mirror)
+{
+  int color;
+  PieceType pt;
+  int i;
+  uint64 key = 0;
+
+  color = !mirror ? 0 : 8;
+  for (pt = PAWN; pt <= KING; ++pt)
+    for (i = 0; i < pcs[color + pt]; i++)
+      key ^= Zobrist::psq[WHITE][pt][i];
+  color ^= 8;
+  for (pt = PAWN; pt <= KING; ++pt)
+    for (i = 0; i < pcs[color + pt]; i++)
+      key ^= Zobrist::psq[BLACK][pt][i];
+
+  return key;
+}
+
+bool is_little_endian() {
+  union {
+    int i;
+    char c[sizeof(int)];
+  } x;
+  x.i = 1;
+  return x.c[0] == 1;
+}
+
+static ubyte decompress_pairs(struct PairsData *d, uint64 idx)
+{
+  static const bool isLittleEndian = is_little_endian();
+  return isLittleEndian ? decompress_pairs<true >(d, idx)
+                        : decompress_pairs<false>(d, idx);
+}
+
+// probe_wdl_table and probe_dtz_table require similar adaptations.
+static int probe_wdl_table(Position& pos, int *success)
+{
+  struct TBEntry *ptr;
+  struct TBHashEntry *ptr2;
+  uint64 idx;
+  uint64 key;
+  int i;
+  ubyte res;
+  int p[TBPIECES];
+
+  // Obtain the position's material signature key.
+  key = pos.material_key();
+
+  // Test for KvK.
+  if (key == (Zobrist::psq[WHITE][KING][0] ^ Zobrist::psq[BLACK][KING][0]))
+    return 0;
+
+  ptr2 = TB_hash[key >> (64 - TBHASHBITS)];
+  for (i = 0; i < HSHMAX; i++)
+    if (ptr2[i].key == key) break;
+  if (i == HSHMAX) {
+    *success = 0;
+    return 0;
+  }
+
+  ptr = ptr2[i].ptr;
+  if (!ptr->ready) {
+    LOCK(TB_mutex);
+    if (!ptr->ready) {
+      char str[16];
+      prt_str(pos, str, ptr->key != key);
+      if (!init_table_wdl(ptr, str)) {
+        ptr2[i].key = 0ULL;
+        *success = 0;
+        UNLOCK(TB_mutex);
+        return 0;
+      }
+      // Memory barrier to ensure ptr->ready = 1 is not reordered.
+#ifdef _MSC_VER
+      _ReadWriteBarrier();
+#else
+      __asm__ __volatile__ ("" ::: "memory");
+#endif
+      ptr->ready = 1;
+    }
+    UNLOCK(TB_mutex);
+  }
+
+  int bside, mirror, cmirror;
+  if (!ptr->symmetric) {
+    if (key != ptr->key) {
+      cmirror = 8;
+      mirror = 0x38;
+      bside = (pos.side_to_move() == WHITE);
+    } else {
+      cmirror = mirror = 0;
+      bside = !(pos.side_to_move() == WHITE);
+    }
+  } else {
+    cmirror = pos.side_to_move() == WHITE ? 0 : 8;
+    mirror = pos.side_to_move() == WHITE ? 0 : 0x38;
+    bside = 0;
+  }
+
+  // p[i] is to contain the square 0-63 (A1-H8) for a piece of type
+  // pc[i] ^ cmirror, where 1 = white pawn, ..., 14 = black king.
+  // Pieces of the same type are guaranteed to be consecutive.
+  if (!ptr->has_pawns) {
+    struct TBEntry_piece *entry = (struct TBEntry_piece *)ptr;
+    ubyte *pc = entry->pieces[bside];
+    for (i = 0; i < entry->num;) {
+      Bitboard bb = pos.pieces((Color)((pc[i] ^ cmirror) >> 3),
+                                      (PieceType)(pc[i] & 0x07));
+      do {
+        p[i++] = pop_lsb(&bb);
+      } while (bb);
+    }
+    idx = encode_piece(entry, entry->norm[bside], p, entry->factor[bside]);
+    res = decompress_pairs(entry->precomp[bside], idx);
+  } else {
+    struct TBEntry_pawn *entry = (struct TBEntry_pawn *)ptr;
+    int k = entry->file[0].pieces[0][0] ^ cmirror;
+    Bitboard bb = pos.pieces((Color)(k >> 3), (PieceType)(k & 0x07));
+    i = 0;
+    do {
+      p[i++] = pop_lsb(&bb) ^ mirror;
+    } while (bb);
+    int f = pawn_file(entry, p);
+    ubyte *pc = entry->file[f].pieces[bside];
+    for (; i < entry->num;) {
+      bb = pos.pieces((Color)((pc[i] ^ cmirror) >> 3),
+                                    (PieceType)(pc[i] & 0x07));
+      do {
+        p[i++] = pop_lsb(&bb) ^ mirror;
+      } while (bb);
+    }
+    idx = encode_pawn(entry, entry->file[f].norm[bside], p, entry->file[f].factor[bside]);
+    res = decompress_pairs(entry->file[f].precomp[bside], idx);
+  }
+
+  return ((int)res) - 2;
+}
+
+static int probe_dtz_table(Position& pos, int wdl, int *success)
+{
+  struct TBEntry *ptr;
+  uint64 idx;
+  int i, res;
+  int p[TBPIECES];
+
+  // Obtain the position's material signature key.
+  uint64 key = pos.material_key();
+
+  if (DTZ_table[0].key1 != key && DTZ_table[0].key2 != key) {
+    for (i = 1; i < DTZ_ENTRIES; i++)
+      if (DTZ_table[i].key1 == key) break;
+    if (i < DTZ_ENTRIES) {
+      struct DTZTableEntry table_entry = DTZ_table[i];
+      for (; i > 0; i--)
+        DTZ_table[i] = DTZ_table[i - 1];
+      DTZ_table[0] = table_entry;
+    } else {
+      struct TBHashEntry *ptr2 = TB_hash[key >> (64 - TBHASHBITS)];
+      for (i = 0; i < HSHMAX; i++)
+        if (ptr2[i].key == key) break;
+      if (i == HSHMAX) {
+        *success = 0;
+        return 0;
+      }
+      ptr = ptr2[i].ptr;
+      char str[16];
+      int mirror = (ptr->key != key);
+      prt_str(pos, str, mirror);
+      if (DTZ_table[DTZ_ENTRIES - 1].entry)
+        free_dtz_entry(DTZ_table[DTZ_ENTRIES-1].entry);
+      for (i = DTZ_ENTRIES - 1; i > 0; i--)
+        DTZ_table[i] = DTZ_table[i - 1];
+      load_dtz_table(str, calc_key(pos, mirror), calc_key(pos, !mirror));
+    }
+  }
+
+  ptr = DTZ_table[0].entry;
+  if (!ptr) {
+    *success = 0;
+    return 0;
+  }
+
+  int bside, mirror, cmirror;
+  if (!ptr->symmetric) {
+    if (key != ptr->key) {
+      cmirror = 8;
+      mirror = 0x38;
+      bside = (pos.side_to_move() == WHITE);
+    } else {
+      cmirror = mirror = 0;
+      bside = !(pos.side_to_move() == WHITE);
+    }
+  } else {
+    cmirror = pos.side_to_move() == WHITE ? 0 : 8;
+    mirror = pos.side_to_move() == WHITE ? 0 : 0x38;
+    bside = 0;
+  }
+
+  if (!ptr->has_pawns) {
+    struct DTZEntry_piece *entry = (struct DTZEntry_piece *)ptr;
+    if ((entry->flags & 1) != bside && !entry->symmetric) {
+      *success = -1;
+      return 0;
+    }
+    ubyte *pc = entry->pieces;
+    for (i = 0; i < entry->num;) {
+      Bitboard bb = pos.pieces((Color)((pc[i] ^ cmirror) >> 3),
+                                    (PieceType)(pc[i] & 0x07));
+      do {
+        p[i++] = pop_lsb(&bb);
+      } while (bb);
+    }
+    idx = encode_piece((struct TBEntry_piece *)entry, entry->norm, p, entry->factor);
+    res = decompress_pairs(entry->precomp, idx);
+
+    if (entry->flags & 2)
+      res = entry->map[entry->map_idx[wdl_to_map[wdl + 2]] + res];
+
+    if (!(entry->flags & pa_flags[wdl + 2]) || (wdl & 1))
+      res *= 2;
+  } else {
+    struct DTZEntry_pawn *entry = (struct DTZEntry_pawn *)ptr;
+    int k = entry->file[0].pieces[0] ^ cmirror;
+    Bitboard bb = pos.pieces((Color)(k >> 3), (PieceType)(k & 0x07));
+    i = 0;
+    do {
+      p[i++] = pop_lsb(&bb) ^ mirror;
+    } while (bb);
+    int f = pawn_file((struct TBEntry_pawn *)entry, p);
+    if ((entry->flags[f] & 1) != bside) {
+      *success = -1;
+      return 0;
+    }
+    ubyte *pc = entry->file[f].pieces;
+    for (; i < entry->num;) {
+      bb = pos.pieces((Color)((pc[i] ^ cmirror) >> 3),
+                            (PieceType)(pc[i] & 0x07));
+      do {
+        p[i++] = pop_lsb(&bb) ^ mirror;
+      } while (bb);
+    }
+    idx = encode_pawn((struct TBEntry_pawn *)entry, entry->file[f].norm, p, entry->file[f].factor);
+    res = decompress_pairs(entry->file[f].precomp, idx);
+
+    if (entry->flags[f] & 2)
+      res = entry->map[entry->map_idx[f][wdl_to_map[wdl + 2]] + res];
+
+    if (!(entry->flags[f] & pa_flags[wdl + 2]) || (wdl & 1))
+      res *= 2;
+  }
+
+  return res;
+}
+
+// Add underpromotion captures to list of captures.
+static ExtMove *add_underprom_caps(Position& pos, ExtMove *stack, ExtMove *end)
+{
+  ExtMove *moves, *extra = end;
+
+  for (moves = stack; moves < end; moves++) {
+    Move move = moves->move;
+    if (type_of(move) == PROMOTION && !pos.empty(to_sq(move))) {
+      (*extra++).move = (Move)(move - (1 << 12));
+      (*extra++).move = (Move)(move - (2 << 12));
+      (*extra++).move = (Move)(move - (3 << 12));
+    }
+  }
+
+  return extra;
+}
+
+static int probe_ab(Position& pos, int alpha, int beta, int *success)
+{
+  int v;
+  ExtMove stack[64];
+  ExtMove *moves, *end;
+  StateInfo st;
+
+  // Generate (at least) all legal non-ep captures including (under)promotions.
+  // It is OK to generate more, as long as they are filtered out below.
+  if (!pos.checkers()) {
+    end = generate<CAPTURES>(pos, stack);
+    // Since underpromotion captures are not included, we need to add them.
+    end = add_underprom_caps(pos, stack, end);
+  } else
+    end = generate<EVASIONS>(pos, stack);
+
+  CheckInfo ci(pos);
+
+  for (moves = stack; moves < end; moves++) {
+    Move capture = moves->move;
+    if (!pos.capture(capture) || type_of(capture) == ENPASSANT
+                        || !pos.legal(capture, ci.pinned))
+      continue;
+    pos.do_move(capture, st, ci, pos.gives_check(capture, ci));
+    v = -probe_ab(pos, -beta, -alpha, success);
+    pos.undo_move(capture);
+    if (*success == 0) return 0;
+    if (v > alpha) {
+      if (v >= beta) {
+        *success = 2;
+        return v;
+      }
+      alpha = v;
+    }
+  }
+
+  v = probe_wdl_table(pos, success);
+  if (*success == 0) return 0;
+  if (alpha >= v) {
+    *success = 1 + (alpha > 0);
+    return alpha;
+  } else {
+    *success = 1;
+    return v;
+  }
+}
+
+// Probe the WDL table for a particular position.
+// If *success != 0, the probe was successful.
+// The return value is from the point of view of the side to move:
+// -2 : loss
+// -1 : loss, but draw under 50-move rule
+//  0 : draw
+//  1 : win, but draw under 50-move rule
+//  2 : win
+int Tablebases::probe_wdl(Position& pos, int *success)
+{
+  int v;
+
+  *success = 1;
+  v = probe_ab(pos, -2, 2, success);
+
+  // If en passant is not possible, we are done.
+  if (pos.ep_square() == SQ_NONE)
+    return v;
+  if (!(*success)) return 0;
+
+  // Now handle en passant.
+  int v1 = -3;
+  // Generate (at least) all legal en passant captures.
+  ExtMove stack[192];
+  ExtMove *moves, *end;
+  StateInfo st;
+
+  if (!pos.checkers())
+    end = generate<CAPTURES>(pos, stack);
+  else
+    end = generate<EVASIONS>(pos, stack);
+
+  CheckInfo ci(pos);
+
+  for (moves = stack; moves < end; moves++) {
+    Move capture = moves->move;
+    if (type_of(capture) != ENPASSANT
+          || !pos.legal(capture, ci.pinned))
+      continue;
+    pos.do_move(capture, st, ci, pos.gives_check(capture, ci));
+    int v0 = -probe_ab(pos, -2, 2, success);
+    pos.undo_move(capture);
+    if (*success == 0) return 0;
+    if (v0 > v1) v1 = v0;
+  }
+  if (v1 > -3) {
+    if (v1 >= v) v = v1;
+    else if (v == 0) {
+      // Check whether there is at least one legal non-ep move.
+      for (moves = stack; moves < end; moves++) {
+        Move capture = moves->move;
+        if (type_of(capture) == ENPASSANT) continue;
+        if (pos.legal(capture, ci.pinned)) break;
+      }
+      if (moves == end && !pos.checkers()) {
+        end = generate<QUIETS>(pos, end);
+        for (; moves < end; moves++) {
+          Move move = moves->move;
+          if (pos.legal(move, ci.pinned))
+            break;
+        }
+      }
+      // If not, then we are forced to play the losing ep capture.
+      if (moves == end)
+        v = v1;
+    }
+  }
+
+  return v;
+}
+
+// This routine treats a position with en passant captures as one without.
+static int probe_dtz_no_ep(Position& pos, int *success)
+{
+  int wdl, dtz;
+
+  wdl = probe_ab(pos, -2, 2, success);
+  if (*success == 0) return 0;
+
+  if (wdl == 0) return 0;
+
+  if (*success == 2)
+    return wdl == 2 ? 1 : 101;
+
+  ExtMove stack[192];
+  ExtMove *moves, *end = NULL;
+  StateInfo st;
+  CheckInfo ci(pos);
+
+  if (wdl > 0) {
+    // Generate at least all legal non-capturing pawn moves
+    // including non-capturing promotions.
+    if (!pos.checkers())
+      end = generate<NON_EVASIONS>(pos, stack);
+    else
+      end = generate<EVASIONS>(pos, stack);
+
+    for (moves = stack; moves < end; moves++) {
+      Move move = moves->move;
+      if (type_of(pos.moved_piece(move)) != PAWN || pos.capture(move)
+                || !pos.legal(move, ci.pinned))
+        continue;
+      pos.do_move(move, st, ci, pos.gives_check(move, ci));
+      int v = -probe_ab(pos, -2, -wdl + 1, success);
+      pos.undo_move(move);
+      if (*success == 0) return 0;
+      if (v == wdl)
+        return v == 2 ? 1 : 101;
+    }
+  }
+
+  dtz = 1 + probe_dtz_table(pos, wdl, success);
+  if (*success >= 0) {
+    if (wdl & 1) dtz += 100;
+    return wdl >= 0 ? dtz : -dtz;
+  }
+
+  if (wdl > 0) {
+    int best = 0xffff;
+    for (moves = stack; moves < end; moves++) {
+      Move move = moves->move;
+      if (pos.capture(move) || type_of(pos.moved_piece(move)) == PAWN
+                || !pos.legal(move, ci.pinned))
+        continue;
+      pos.do_move(move, st, ci, pos.gives_check(move, ci));
+      int v = -Tablebases::probe_dtz(pos, success);
+      pos.undo_move(move);
+      if (*success == 0) return 0;
+      if (v > 0 && v + 1 < best)
+        best = v + 1;
+    }
+    return best;
+  } else {
+    int best = -1;
+    if (!pos.checkers())
+      end = generate<NON_EVASIONS>(pos, stack);
+    else
+      end = generate<EVASIONS>(pos, stack);
+    for (moves = stack; moves < end; moves++) {
+      int v;
+      Move move = moves->move;
+      if (!pos.legal(move, ci.pinned))
+        continue;
+      pos.do_move(move, st, ci, pos.gives_check(move, ci));
+      if (st.rule50 == 0) {
+        if (wdl == -2) v = -1;
+        else {
+          v = probe_ab(pos, 1, 2, success);
+          v = (v == 2) ? 0 : -101;
+        }
+      } else {
+        v = -Tablebases::probe_dtz(pos, success) - 1;
+      }
+      pos.undo_move(move);
+      if (*success == 0) return 0;
+      if (v < best)
+        best = v;
+    }
+    return best;
+  }
+}
+
+static int wdl_to_dtz[] = {
+  -1, -101, 0, 101, 1
+};
+
+// Probe the DTZ table for a particular position.
+// If *success != 0, the probe was successful.
+// The return value is from the point of view of the side to move:
+//         n < -100 : loss, but draw under 50-move rule
+// -100 <= n < -1   : loss in n ply (assuming 50-move counter == 0)
+//         0        : draw
+//     1 < n <= 100 : win in n ply (assuming 50-move counter == 0)
+//   100 < n        : win, but draw under 50-move rule
+//
+// The return value n can be off by 1: a return value -n can mean a loss
+// in n+1 ply and a return value +n can mean a win in n+1 ply. This
+// cannot happen for tables with positions exactly on the "edge" of
+// the 50-move rule.
+//
+// This implies that if dtz > 0 is returned, the position is certainly
+// a win if dtz + 50-move-counter <= 99. Care must be taken that the engine
+// picks moves that preserve dtz + 50-move-counter <= 99.
+//
+// If n = 100 immediately after a capture or pawn move, then the position
+// is also certainly a win, and during the whole phase until the next
+// capture or pawn move, the inequality to be preserved is
+// dtz + 50-movecounter <= 100.
+//
+// In short, if a move is available resulting in dtz + 50-move-counter <= 99,
+// then do not accept moves leading to dtz + 50-move-counter == 100.
+//
+int Tablebases::probe_dtz(Position& pos, int *success)
+{
+  *success = 1;
+  int v = probe_dtz_no_ep(pos, success);
+
+  if (pos.ep_square() == SQ_NONE)
+    return v;
+  if (*success == 0) return 0;
+
+  // Now handle en passant.
+  int v1 = -3;
+
+  ExtMove stack[192];
+  ExtMove *moves, *end;
+  StateInfo st;
+
+  if (!pos.checkers())
+    end = generate<CAPTURES>(pos, stack);
+  else
+    end = generate<EVASIONS>(pos, stack);
+  CheckInfo ci(pos);
+
+  for (moves = stack; moves < end; moves++) {
+    Move capture = moves->move;
+    if (type_of(capture) != ENPASSANT
+                || !pos.legal(capture, ci.pinned))
+      continue;
+    pos.do_move(capture, st, ci, pos.gives_check(capture, ci));
+    int v0 = -probe_ab(pos, -2, 2, success);
+    pos.undo_move(capture);
+    if (*success == 0) return 0;
+    if (v0 > v1) v1 = v0;
+  }
+  if (v1 > -3) {
+    v1 = wdl_to_dtz[v1 + 2];
+    if (v < -100) {
+      if (v1 >= 0)
+        v = v1;
+    } else if (v < 0) {
+      if (v1 >= 0 || v1 < 100)
+        v = v1;
+    } else if (v > 100) {
+      if (v1 > 0)
+        v = v1;
+    } else if (v > 0) {
+      if (v1 == 1)
+        v = v1;
+    } else if (v1 >= 0) {
+      v = v1;
+    } else {
+      for (moves = stack; moves < end; moves++) {
+        Move move = moves->move;
+        if (type_of(move) == ENPASSANT) continue;
+        if (pos.legal(move, ci.pinned)) break;
+      }
+      if (moves == end && !pos.checkers()) {
+        end = generate<QUIETS>(pos, end);
+        for (; moves < end; moves++) {
+          Move move = moves->move;
+          if (pos.legal(move, ci.pinned))
+            break;
+        }
+      }
+      if (moves == end)
+        v = v1;
+    }
+  }
+
+  return v;
+}
+
+// Check whether there has been at least one repetition of positions
+// since the last capture or pawn move.
+static int has_repeated(StateInfo *st)
+{
+  while (1) {
+    int i = 4, e = std::min(st->rule50, st->pliesFromNull);
+    if (e < i)
+      return 0;
+    StateInfo *stp = st->previous->previous;
+    do {
+      stp = stp->previous->previous;
+      if (stp->key == st->key)
+        return 1;
+      i += 2;
+    } while (i <= e);
+    st = st->previous;
+  }
+}
+
+static Value wdl_to_Value[5] = {
+  -VALUE_MATE + MAX_PLY + 1,
+  VALUE_DRAW - 2,
+  VALUE_DRAW,
+  VALUE_DRAW + 2,
+  VALUE_MATE - MAX_PLY - 1
+};
+
+// Use the DTZ tables to filter out moves that don't preserve the win or draw.
+// If the position is lost, but DTZ is fairly high, only keep moves that
+// maximise DTZ.
+//
+// A return value false indicates that not all probes were successful and that
+// no moves were filtered out.
+bool Tablebases::root_probe(Position& pos, Search::RootMoveVector& rootMoves, Value& score)
+{
+  int success;
+
+  int dtz = probe_dtz(pos, &success);
+  if (!success) return false;
+
+  StateInfo st;
+  CheckInfo ci(pos);
+
+  // Probe each move.
+  for (size_t i = 0; i < rootMoves.size(); i++) {
+    Move move = rootMoves[i].pv[0];
+    pos.do_move(move, st, ci, pos.gives_check(move, ci));
+    int v = 0;
+    if (pos.checkers() && dtz > 0) {
+      ExtMove s[192];
+      if (generate<LEGAL>(pos, s) == s)
+        v = 1;
+    }
+    if (!v) {
+      if (st.rule50 != 0) {
+        v = -Tablebases::probe_dtz(pos, &success);
+        if (v > 0) v++;
+        else if (v < 0) v--;
+      } else {
+        v = -Tablebases::probe_wdl(pos, &success);
+        v = wdl_to_dtz[v + 2];
+      }
+    }
+    pos.undo_move(move);
+    if (!success) return false;
+    rootMoves[i].score = (Value)v;
+  }
+
+  // Obtain 50-move counter for the root position.
+  // In Stockfish there seems to be no clean way, so we do it like this:
+  int cnt50 = st.previous->rule50;
+
+  // Use 50-move counter to determine whether the root position is
+  // won, lost or drawn.
+  int wdl = 0;
+  if (dtz > 0)
+    wdl = (dtz + cnt50 <= 100) ? 2 : 1;
+  else if (dtz < 0)
+    wdl = (-dtz + cnt50 <= 100) ? -2 : -1;
+
+  // Determine the score to report to the user.
+  score = wdl_to_Value[wdl + 2];
+  // If the position is winning or losing, but too few moves left, adjust the
+  // score to show how close it is to winning or losing.
+  // NOTE: int(PawnValueEg) is used as scaling factor in score_to_uci().
+  if (wdl == 1 && dtz <= 100)
+    score = (Value)(((200 - dtz - cnt50) * int(PawnValueEg)) / 200);
+  else if (wdl == -1 && dtz >= -100)
+    score = -(Value)(((200 + dtz - cnt50) * int(PawnValueEg)) / 200);
+
+  // Now be a bit smart about filtering out moves.
+  size_t j = 0;
+  if (dtz > 0) { // winning (or 50-move rule draw)
+    int best = 0xffff;
+    for (size_t i = 0; i < rootMoves.size(); i++) {
+      int v = rootMoves[i].score;
+      if (v > 0 && v < best)
+        best = v;
+    }
+    int max = best;
+    // If the current phase has not seen repetitions, then try all moves
+    // that stay safely within the 50-move budget, if there are any.
+    if (!has_repeated(st.previous) && best + cnt50 <= 99)
+      max = 99 - cnt50;
+    for (size_t i = 0; i < rootMoves.size(); i++) {
+      int v = rootMoves[i].score;
+      if (v > 0 && v <= max)
+        rootMoves[j++] = rootMoves[i];
+    }
+  } else if (dtz < 0) { // losing (or 50-move rule draw)
+    int best = 0;
+    for (size_t i = 0; i < rootMoves.size(); i++) {
+      int v = rootMoves[i].score;
+      if (v < best)
+        best = v;
+    }
+    // Try all moves, unless we approach or have a 50-move rule draw.
+    if (-best * 2 + cnt50 < 100)
+      return true;
+    for (size_t i = 0; i < rootMoves.size(); i++) {
+      if (rootMoves[i].score == best)
+        rootMoves[j++] = rootMoves[i];
+    }
+  } else { // drawing
+    // Try all moves that preserve the draw.
+    for (size_t i = 0; i < rootMoves.size(); i++) {
+      if (rootMoves[i].score == 0)
+        rootMoves[j++] = rootMoves[i];
+    }
+  }
+  rootMoves.resize(j, Search::RootMove(MOVE_NONE));
+
+  return true;
+}
+
+// Use the WDL tables to filter out moves that don't preserve the win or draw.
+// This is a fallback for the case that some or all DTZ tables are missing.
+//
+// A return value false indicates that not all probes were successful and that
+// no moves were filtered out.
+bool Tablebases::root_probe_wdl(Position& pos, Search::RootMoveVector& rootMoves, Value& score)
+{
+  int success;
+
+  int wdl = Tablebases::probe_wdl(pos, &success);
+  if (!success) return false;
+  score = wdl_to_Value[wdl + 2];
+
+  StateInfo st;
+  CheckInfo ci(pos);
+
+  int best = -2;
+
+  // Probe each move.
+  for (size_t i = 0; i < rootMoves.size(); i++) {
+    Move move = rootMoves[i].pv[0];
+    pos.do_move(move, st, ci, pos.gives_check(move, ci));
+    int v = -Tablebases::probe_wdl(pos, &success);
+    pos.undo_move(move);
+    if (!success) return false;
+    rootMoves[i].score = (Value)v;
+    if (v > best)
+      best = v;
+  }
+
+  size_t j = 0;
+  for (size_t i = 0; i < rootMoves.size(); i++) {
+    if (rootMoves[i].score == best)
+      rootMoves[j++] = rootMoves[i];
+  }
+  rootMoves.resize(j, Search::RootMove(MOVE_NONE));
+
+  return true;
+}
+

src/syzygy/tbprobe.h

@@ -0,0 +1,18 @@
+#ifndef TBPROBE_H
+#define TBPROBE_H
+
+#include "../search.h"
+
+namespace Tablebases {
+
+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);
+
+}
+
+#endif

src/thread.cpp

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -17,113 +17,55 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include <algorithm> // For std::count
 #include <cassert>
-#include <iostream>
 
 #include "movegen.h"
 #include "search.h"
 #include "thread.h"
-#include "ucioption.h"
+#include "uci.h"
 
 using namespace Search;
 
 ThreadPool Threads; // Global object
 
-namespace { extern "C" {
-
- // start_routine() is the C function which is called when a new thread
- // is launched. It is a wrapper to member function pointed by start_fn.
-
- long start_routine(Thread* th) { (th->*(th->start_fn))(); return 0; }
-
-} }
-
-
-// Thread c'tor starts a newly-created thread of execution that will call
-// the idle loop function pointed by start_fn going immediately to sleep.
-
-Thread::Thread(Fn fn) {
-
-  is_searching = do_exit = false;
-  maxPly = splitPointsCnt = 0;
-  curSplitPoint = NULL;
-  start_fn = fn;
-  idx = Threads.size();
-
-  do_sleep = (fn != &Thread::main_loop); // Avoid a race with start_searching()
-
-  if (!thread_create(handle, start_routine, this))
-  {
-      std::cerr << "Failed to create thread number " << idx << std::endl;
-      ::exit(EXIT_FAILURE);
-  }
-}
-
-
-// Thread d'tor waits for thread termination before to return.
-
-Thread::~Thread() {
-
-  assert(do_sleep);
-
-  do_exit = true; // Search must be already finished
-  wake_up();
-  thread_join(handle); // Wait for thread termination
-}
-
-
-// Thread::timer_loop() is where the timer thread waits maxPly milliseconds and
-// then calls check_time(). If maxPly is 0 thread sleeps until is woken up.
 extern void check_time();
 
-void Thread::timer_loop() {
+namespace {
+
+ // 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;
+ }
 
-  while (!do_exit)
-  {
-      mutex.lock();
-      sleepCondition.wait_for(mutex, maxPly ? maxPly : INT_MAX);
-      mutex.unlock();
-      check_time();
-  }
 }
 
 
-// Thread::main_loop() is where the main thread is parked waiting to be started
-// when there is a new search. Main thread will launch all the slave threads.
+// ThreadBase::notify_one() wakes up the thread when there is some work to do
 
-void Thread::main_loop() {
-
-  while (true)
-  {
-      mutex.lock();
-
-      do_sleep = true; // Always return to sleep after a search
-      is_searching = false;
-
-      while (do_sleep && !do_exit)
-      {
-          Threads.sleepCondition.notify_one(); // Wake up UI thread if needed
-          sleepCondition.wait(mutex);
-      }
-
-      mutex.unlock();
-
-      if (do_exit)
-          return;
-
-      is_searching = true;
-
-      Search::think();
-
-      assert(is_searching);
-  }
-}
-
-
-// Thread::wake_up() wakes up the thread, normally at the beginning of the search
-// or, if "sleeping threads" is used at split time.
-
-void Thread::wake_up() {
+void ThreadBase::notify_one() {
 
   mutex.lock();
   sleepCondition.notify_one();
@@ -131,29 +73,35 @@ void Thread::wake_up() {
 }
 
 
-// Thread::wait_for_stop_or_ponderhit() is called when the maximum depth is
-// reached while the program is pondering. The point is to work around a wrinkle
-// in the UCI protocol: When pondering, the engine is not allowed to give a
-// "bestmove" before the GUI sends it a "stop" or "ponderhit" command. We simply
-// wait here until one of these commands (that raise StopRequest) is sent and
-// then return, after which the bestmove and pondermove will be printed.
+// ThreadBase::wait_for() set the thread to sleep until 'condition' turns true
 
-void Thread::wait_for_stop_or_ponderhit() {
-
-  Signals.stopOnPonderhit = true;
+void ThreadBase::wait_for(volatile const bool& condition) {
 
   mutex.lock();
-  while (!Signals.stop) sleepCondition.wait(mutex);;
+  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 = curSplitPoint; sp; sp = sp->parent)
+  for (SplitPoint* sp = activeSplitPoint; sp; sp = sp->parentSplitPoint)
       if (sp->cutoff)
           return true;
 
@@ -161,276 +109,277 @@ bool Thread::cutoff_occurred() const {
 }
 
 
-// Thread::is_available_to() checks whether the thread is available to help the
+// 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 active split point, it is only available as a slave to the
-// slaves which are busy searching the split point at the top of slaves split
-// point stack (the "helpful master concept" in YBWC terminology).
+// 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::is_available_to(Thread* master) const {
+bool Thread::available_to(const Thread* master) const {
 
-  if (is_searching)
+  if (searching)
       return false;
 
-  // Make a local copy to be sure doesn't become zero under our feet while
-  // testing next condition and so leading to an out of bound access.
-  int spCnt = splitPointsCnt;
+  // 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 active split points means that the thread is available as a slave for any
+  // 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 !spCnt || (splitPoints[spCnt - 1].slavesMask & (1ULL << master->idx));
+  return !size || splitPoints[size - 1].slavesMask.test(master->idx);
 }
 
 
-// init() is called at startup. Initializes lock and condition variable and
-// launches requested threads sending them immediately to sleep. We cannot use
-// a c'tor becuase Threads is a static object and we need a fully initialized
-// engine at this point due to allocation of endgames in Thread c'tor.
+// 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();
+
+  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();
+}
+
+
+// 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.
+
+void TimerThread::idle_loop() {
+
+  while (!exit)
+  {
+      mutex.lock();
+
+      if (!exit)
+          sleepCondition.wait_for(mutex, run ? Resolution : INT_MAX);
+
+      mutex.unlock();
+
+      if (run)
+          check_time();
+  }
+}
+
+
+// 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 MainThread::idle_loop() {
+
+  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(&Thread::timer_loop);
-  threads.push_back(new Thread(&Thread::main_loop));
+  timer = new_thread<TimerThread>();
+  push_back(new_thread<MainThread>());
   read_uci_options();
 }
 
 
-// exit() cleanly terminates the threads before the program exits.
+// 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() {
 
-  for (size_t i = 0; i < threads.size(); i++)
-      delete threads[i];
+  delete_thread(timer); // As first because check_time() accesses threads data
 
-  delete timer;
+  for (iterator it = begin(); it != end(); ++it)
+      delete_thread(*it);
 }
 
 
-// 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 in advance all possible
-// threads, with included pawns and material tables, if only few are used.
+// 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() {
 
-  maxThreadsPerSplitPoint = Options["Max Threads per Split Point"];
-  minimumSplitDepth       = Options["Min Split Depth"] * ONE_PLY;
-  useSleepingThreads      = Options["Use Sleeping Threads"];
-  size_t requested        = Options["Threads"];
+  minimumSplitDepth = Options["Min Split Depth"] * ONE_PLY;
+  size_t requested  = Options["Threads"];
 
   assert(requested > 0);
 
-  while (threads.size() < requested)
-      threads.push_back(new Thread(&Thread::idle_loop));
+  // If zero (default) then set best minimum split depth automatically
+  if (!minimumSplitDepth)
+      minimumSplitDepth = requested < 8 ? 4 * ONE_PLY : 7 * ONE_PLY;
 
-  while (threads.size() > requested)
+  while (size() < requested)
+      push_back(new_thread<Thread>());
+
+  while (size() > requested)
   {
-      delete threads.back();
-      threads.pop_back();
+      delete_thread(back());
+      pop_back();
   }
 }
 
 
-// wake_up() is called before a new search to start the threads that are waiting
-// on the sleep condition and to reset maxPly. When useSleepingThreads is set
-// threads will be woken up at split time.
+// ThreadPool::available_slave() tries to find an idle thread which is available
+// as a slave for the thread 'master'.
 
-void ThreadPool::wake_up() const {
+Thread* ThreadPool::available_slave(const Thread* master) const {
 
-  for (size_t i = 0; i < threads.size(); i++)
-  {
-      threads[i]->maxPly = 0;
-      threads[i]->do_sleep = false;
+  for (const_iterator it = begin(); it != end(); ++it)
+      if ((*it)->available_to(master))
+          return *it;
 
-      if (!useSleepingThreads)
-          threads[i]->wake_up();
-  }
+  return NULL;
 }
 
 
-// sleep() is called after the search finishes to ask all the threads but the
-// main one to go waiting on a sleep condition.
+// ThreadPool::wait_for_think_finished() waits for main thread to finish the search
 
-void ThreadPool::sleep() const {
+void ThreadPool::wait_for_think_finished() {
 
-  // Main thread will go to sleep by itself to avoid a race with start_searching()
-  for (size_t i = 1; i < threads.size(); i++)
-      threads[i]->do_sleep = true;
+  MainThread* th = main();
+  th->mutex.lock();
+  while (th->thinking) sleepCondition.wait(th->mutex);
+  th->mutex.unlock();
 }
 
 
-// available_slave_exists() tries to find an idle thread which is available as
-// a slave for the thread 'master'.
+// ThreadPool::start_thinking() wakes up the main thread sleeping in
+// MainThread::idle_loop() and starts a new search, then returns immediately.
 
-bool ThreadPool::available_slave_exists(Thread* master) const {
-
-  for (size_t i = 0; i < threads.size(); i++)
-      if (threads[i]->is_available_to(master))
-          return true;
-
-  return false;
-}
-
-
-// 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, or because we have no unused split
-// point objects), 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 told 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.
-
-template <bool Fake>
-Value ThreadPool::split(Position& pos, Stack* ss, Value alpha, Value beta,
-                        Value bestValue, Move* bestMove, Depth depth,
-                        Move threatMove, int moveCount, MovePicker* mp, int nodeType) {
-
-  assert(pos.pos_is_ok());
-  assert(bestValue > -VALUE_INFINITE);
-  assert(bestValue <= alpha);
-  assert(alpha < beta);
-  assert(beta <= VALUE_INFINITE);
-  assert(depth > DEPTH_ZERO);
-
-  Thread* master = pos.this_thread();
-
-  if (master->splitPointsCnt >= MAX_SPLITPOINTS_PER_THREAD)
-      return bestValue;
-
-  // Pick the next available split point from the split point stack
-  SplitPoint& sp = master->splitPoints[master->splitPointsCnt];
-
-  sp.parent = master->curSplitPoint;
-  sp.master = master;
-  sp.cutoff = false;
-  sp.slavesMask = 1ULL << master->idx;
-  sp.depth = depth;
-  sp.bestMove = *bestMove;
-  sp.threatMove = threatMove;
-  sp.alpha = alpha;
-  sp.beta = beta;
-  sp.nodeType = nodeType;
-  sp.bestValue = bestValue;
-  sp.mp = mp;
-  sp.moveCount = moveCount;
-  sp.pos = &pos;
-  sp.nodes = 0;
-  sp.ss = ss;
-
-  assert(master->is_searching);
-
-  master->curSplitPoint = &sp;
-  int slavesCnt = 0;
-
-  // Try to allocate available threads and ask them to start searching setting
-  // is_searching flag. This must be done under lock protection to avoid concurrent
-  // allocation of the same slave by another master.
-  sp.mutex.lock();
-  mutex.lock();
-
-  for (size_t i = 0; i < threads.size() && !Fake; ++i)
-      if (threads[i]->is_available_to(master))
-      {
-          sp.slavesMask |= 1ULL << i;
-          threads[i]->curSplitPoint = &sp;
-          threads[i]->is_searching = true; // Slave leaves idle_loop()
-
-          if (useSleepingThreads)
-              threads[i]->wake_up();
-
-          if (++slavesCnt + 1 >= maxThreadsPerSplitPoint) // Master is always included
-              break;
-      }
-
-  master->splitPointsCnt++;
-
-  mutex.unlock();
-  sp.mutex.unlock();
-
-  // Everything is set up. The master thread enters the idle loop, from which
-  // it will instantly launch a search, because its is_searching flag is set.
-  // The thread will return from the idle loop when all slaves have finished
-  // their work at this split point.
-  if (slavesCnt || Fake)
-  {
-      master->idle_loop();
-
-      // In helpful master concept a master can help only a sub-tree of its split
-      // point, and because here is all finished is not possible master is booked.
-      assert(!master->is_searching);
-  }
-
-  // We have returned from the idle loop, which means that all threads are
-  // finished. Note that setting is_searching and decreasing splitPointsCnt is
-  // done under lock protection to avoid a race with Thread::is_available_to().
-  sp.mutex.lock(); // To protect sp.nodes
-  mutex.lock();
-
-  master->is_searching = true;
-  master->splitPointsCnt--;
-  master->curSplitPoint = sp.parent;
-  pos.set_nodes_searched(pos.nodes_searched() + sp.nodes);
-  *bestMove = sp.bestMove;
-
-  mutex.unlock();
-  sp.mutex.unlock();
-
-  return sp.bestValue;
-}
-
-// Explicit template instantiations
-template Value ThreadPool::split<false>(Position&, Stack*, Value, Value, Value, Move*, Depth, Move, int, MovePicker*, int);
-template Value ThreadPool::split<true>(Position&, Stack*, Value, Value, Value, Move*, Depth, Move, int, MovePicker*, int);
-
-
-// set_timer() is used to set the timer to trigger after msec milliseconds.
-// If msec is 0 then timer is stopped.
-
-void ThreadPool::set_timer(int msec) {
-
-  timer->mutex.lock();
-  timer->maxPly = msec;
-  timer->sleepCondition.notify_one(); // Wake up and restart the timer
-  timer->mutex.unlock();
-}
-
-
-// wait_for_search_finished() waits for main thread to go to sleep, this means
-// search is finished. Then returns.
-
-void ThreadPool::wait_for_search_finished() {
-
-  Thread* t = main_thread();
-  t->mutex.lock();
-  t->sleepCondition.notify_one(); // In case is waiting for stop or ponderhit
-  while (!t->do_sleep) sleepCondition.wait(t->mutex);
-  t->mutex.unlock();
-}
-
-
-// start_searching() wakes up the main thread sleeping in  main_loop() so to start
-// a new search, then returns immediately.
-
-void ThreadPool::start_searching(const Position& pos, const LimitsType& limits,
-                                 const std::vector<Move>& searchMoves, StateStackPtr& states) {
-  wait_for_search_finished();
+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;
 
-  RootPosition = pos;
-  Limits = limits;
-  SetupStates = states; // Ownership transfer here
   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());
+  }
 
-  for (MoveList<LEGAL> ml(pos); !ml.end(); ++ml)
-      if (searchMoves.empty() || count(searchMoves.begin(), searchMoves.end(), ml.move()))
-          RootMoves.push_back(RootMove(ml.move()));
+  for (MoveList<LEGAL> it(pos); *it; ++it)
+      if (   limits.searchmoves.empty()
+          || std::count(limits.searchmoves.begin(), limits.searchmoves.end(), *it))
+          RootMoves.push_back(RootMove(*it));
 
-  main_thread()->do_sleep = false;
-  main_thread()->wake_up();
+  main()->thinking = true;
+  main()->notify_one(); // Starts main thread
 }

src/thread.h

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -17,9 +17,10 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#if !defined(THREAD_H_INCLUDED)
+#ifndef THREAD_H_INCLUDED
 #define THREAD_H_INCLUDED
 
+#include <bitset>
 #include <vector>
 
 #include "material.h"
@@ -28,9 +29,14 @@
 #include "position.h"
 #include "search.h"
 
-const int MAX_THREADS = 32;
+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); }
@@ -56,27 +62,30 @@ private:
   WaitCondition c;
 };
 
-class Thread;
+
+/// SplitPoint struct stores information shared by the threads searching in
+/// parallel below the same split point. It is populated at splitting time.
 
 struct SplitPoint {
 
   // Const data after split point has been setup
   const Position* pos;
-  const Search::Stack* ss;
+  Search::Stack* ss;
+  Thread* masterThread;
   Depth depth;
   Value beta;
   int nodeType;
-  Thread* master;
-  Move threatMove;
+  bool cutNode;
 
   // Const pointers to shared data
-  MovePicker* mp;
-  SplitPoint* parent;
+  MovePicker* movePicker;
+  SplitPoint* parentSplitPoint;
 
-  // Shared data
+  // Shared variable data
   Mutex mutex;
-  volatile uint64_t slavesMask;
-  volatile int64_t nodes;
+  std::bitset<MAX_THREADS> slavesMask;
+  volatile bool allSlavesSearching;
+  volatile uint64_t nodes;
   volatile Value alpha;
   volatile Value bestValue;
   volatile Move bestMove;
@@ -85,84 +94,93 @@ struct SplitPoint {
 };
 
 
+/// 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);
+
+  Mutex mutex;
+  ConditionVariable sleepCondition;
+  NativeHandle handle;
+  volatile bool exit;
+};
+
+
 /// 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.
 
-class Thread {
+struct Thread : public ThreadBase {
 
-  typedef void (Thread::* Fn) (); // Pointer to member function
-
-public:
-  Thread(Fn fn);
- ~Thread();
-
-  void wake_up();
+  Thread();
+  virtual void idle_loop();
   bool cutoff_occurred() const;
-  bool is_available_to(Thread* master) const;
-  void idle_loop();
-  void main_loop();
-  void timer_loop();
-  void wait_for_stop_or_ponderhit();
+  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];
-  MaterialTable materialTable;
-  PawnTable pawnTable;
+  Pawns::Table pawnsTable;
+  Material::Table materialTable;
+  Endgames endgames;
+  Position* activePosition;
   size_t idx;
   int maxPly;
-  Mutex mutex;
-  ConditionVariable sleepCondition;
-  NativeHandle handle;
-  Fn start_fn;
-  SplitPoint* volatile curSplitPoint;
-  volatile int splitPointsCnt;
-  volatile bool is_searching;
-  volatile bool do_sleep;
-  volatile bool do_exit;
+  SplitPoint* volatile activeSplitPoint;
+  volatile int splitPointsSize;
+  volatile bool searching;
 };
 
 
-/// ThreadPool class handles all the threads related stuff like init, starting,
-/// parking and, the most important, launching a slave thread at a split point.
+/// MainThread and TimerThread are derived classes used to characterize the two
+/// special threads: the main one and the recurring timer.
+
+struct MainThread : public Thread {
+  MainThread() : thinking(true) {} // Avoid a race with start_thinking()
+  virtual void idle_loop();
+  volatile bool thinking;
+};
+
+struct TimerThread : public ThreadBase {
+
+  static const int Resolution = 5; // Millisec between two check_time() calls
+
+  TimerThread() : run(false) {}
+  virtual void idle_loop();
+
+  bool run;
+};
+
+
+/// 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.
 
-class ThreadPool {
+struct ThreadPool : public std::vector<Thread*> {
 
-public:
-  void init(); // No c'tor and d'tor, threads rely on globals that should
-  void exit(); // be initialized and valid during the whole thread lifetime.
+  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.
 
-  Thread& operator[](size_t id) { return *threads[id]; }
-  bool use_sleeping_threads() const { return useSleepingThreads; }
-  int min_split_depth() const { return minimumSplitDepth; }
-  size_t size() const { return threads.size(); }
-  Thread* main_thread() { return threads[0]; }
-
-  void wake_up() const;
-  void sleep() const;
+  MainThread* main() { return static_cast<MainThread*>(at(0)); }
   void read_uci_options();
-  bool available_slave_exists(Thread* master) const;
-  void set_timer(int msec);
-  void wait_for_search_finished();
-  void start_searching(const Position&, const Search::LimitsType&,
-                       const std::vector<Move>&, Search::StateStackPtr&);
+  Thread* available_slave(const Thread* master) const;
+  void wait_for_think_finished();
+  void start_thinking(const Position&, const Search::LimitsType&, Search::StateStackPtr&);
 
-  template <bool Fake>
-  Value split(Position& pos, Search::Stack* ss, Value alpha, Value beta, Value bestValue, Move* bestMove,
-              Depth depth, Move threatMove, int moveCount, MovePicker* mp, int nodeType);
-private:
-  friend class Thread;
-
-  std::vector<Thread*> threads;
-  Thread* timer;
+  Depth minimumSplitDepth;
   Mutex mutex;
   ConditionVariable sleepCondition;
-  Depth minimumSplitDepth;
-  int maxThreadsPerSplitPoint;
-  bool useSleepingThreads;
+  TimerThread* timer;
 };
 
 extern ThreadPool Threads;
 
-#endif // !defined(THREAD_H_INCLUDED)
+#endif // #ifndef THREAD_H_INCLUDED

src/timeman.cpp

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -17,146 +17,100 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <cmath>
 #include <algorithm>
+#include <cfloat>
+#include <cmath>
 
 #include "search.h"
 #include "timeman.h"
-#include "ucioption.h"
+#include "uci.h"
 
 namespace {
 
-  /// Constants
-
-  const int MoveHorizon  = 50;    // Plan time management at most this many moves ahead
-  const float MaxRatio   = 3.0f;  // When in trouble, we can step over reserved time with this ratio
-  const float StealRatio = 0.33f; // However we must not steal time from remaining moves over this ratio
-
-
-  // MoveImportance[] is 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.
-  const int MoveImportance[512] = {
-    7780, 7780, 7780, 7780, 7780, 7780, 7780, 7780, 7780, 7780, 7780, 7780, 7780, 7780, 7780, 7780,
-    7780, 7780, 7780, 7780, 7778, 7778, 7776, 7776, 7776, 7773, 7770, 7768, 7766, 7763, 7757, 7751,
-    7743, 7735, 7724, 7713, 7696, 7689, 7670, 7656, 7627, 7605, 7571, 7549, 7522, 7493, 7462, 7425,
-    7385, 7350, 7308, 7272, 7230, 7180, 7139, 7094, 7055, 7010, 6959, 6902, 6841, 6778, 6705, 6651,
-    6569, 6508, 6435, 6378, 6323, 6253, 6152, 6085, 5995, 5931, 5859, 5794, 5717, 5646, 5544, 5462,
-    5364, 5282, 5172, 5078, 4988, 4901, 4831, 4764, 4688, 4609, 4536, 4443, 4365, 4293, 4225, 4155,
-    4085, 4005, 3927, 3844, 3765, 3693, 3634, 3560, 3479, 3404, 3331, 3268, 3207, 3146, 3077, 3011,
-    2947, 2894, 2828, 2776, 2727, 2676, 2626, 2589, 2538, 2490, 2442, 2394, 2345, 2302, 2243, 2192,
-    2156, 2115, 2078, 2043, 2004, 1967, 1922, 1893, 1845, 1809, 1772, 1736, 1702, 1674, 1640, 1605,
-    1566, 1536, 1509, 1479, 1452, 1423, 1388, 1362, 1332, 1304, 1289, 1266, 1250, 1228, 1206, 1180,
-    1160, 1134, 1118, 1100, 1080, 1068, 1051, 1034, 1012, 1001, 980, 960, 945, 934, 916, 900, 888,
-    878, 865, 852, 828, 807, 787, 770, 753, 744, 731, 722, 706, 700, 683, 676, 671, 664, 652, 641,
-    634, 627, 613, 604, 591, 582, 568, 560, 552, 540, 534, 529, 519, 509, 495, 484, 474, 467, 460,
-    450, 438, 427, 419, 410, 406, 399, 394, 387, 382, 377, 372, 366, 359, 353, 348, 343, 337, 333,
-    328, 321, 315, 309, 303, 298, 293, 287, 284, 281, 277, 273, 265, 261, 255, 251, 247, 241, 240,
-    235, 229, 218, 217, 213, 212, 208, 206, 197, 193, 191, 189, 185, 184, 180, 177, 172, 170, 170,
-    170, 166, 163, 159, 158, 156, 155, 151, 146, 141, 138, 136, 132, 130, 128, 125, 123, 122, 118,
-    118, 118, 117, 115, 114, 108, 107, 105, 105, 105, 102, 97, 97, 95, 94, 93, 91, 88, 86, 83, 80,
-    80, 79, 79, 79, 78, 76, 75, 72, 72, 71, 70, 68, 65, 63, 61, 61, 59, 59, 59, 58, 56, 55, 54, 54,
-    52, 49, 48, 48, 48, 48, 45, 45, 45, 44, 43, 41, 41, 41, 41, 40, 40, 38, 37, 36, 34, 34, 34, 33,
-    31, 29, 29, 29, 28, 28, 28, 28, 28, 28, 28, 27, 27, 27, 27, 27, 24, 24, 23, 23, 22, 21, 20, 20,
-    19, 19, 19, 19, 19, 18, 18, 18, 18, 17, 17, 17, 17, 17, 16, 16, 15, 15, 14, 14, 14, 12, 12, 11,
-    9, 9, 9, 9, 9, 9, 9, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
-    8, 8, 8, 8, 7, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 5, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
-    4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 3, 3, 2, 2, 2, 2,
-    2, 1, 1, 1, 1, 1, 1, 1 };
-
-  int move_importance(int ply) { return MoveImportance[std::min(ply, 511)]; }
-
-
-  /// Function Prototypes
-
   enum TimeType { OptimumTime, MaxTime };
 
-  template<TimeType>
-  int remaining(int myTime, int movesToGo, int fullMoveNumber, int slowMover);
-}
+  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
 
 
-void TimeManager::pv_instability(int curChanges, int prevChanges) {
+  // 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.
 
-  unstablePVExtraTime =  curChanges  * (optimumSearchTime / 2)
-                       + prevChanges * (optimumSearchTime / 3);
-}
+  double move_importance(int ply) {
 
+    const double XScale = 9.3;
+    const double XShift = 59.8;
+    const double Skew   = 0.172;
 
-void TimeManager::init(const Search::LimitsType& limits, int currentPly, Color us)
-{
-  /* We support four different kind of time controls:
+    return pow((1 + exp((ply - XShift) / XScale)), -Skew) + DBL_MIN; // Ensure non-zero
+  }
 
-      increment == 0 && movesToGo == 0 means: x basetime  [sudden death!]
-      increment == 0 && movesToGo != 0 means: x moves in y minutes
-      increment >  0 && movesToGo == 0 means: x basetime + z increment
-      increment >  0 && movesToGo != 0 means: x moves in y minutes + z increment
-
-    Time management is adjusted by following UCI parameters:
-
-      emergencyMoveHorizon: Be prepared to always play at least this many moves
-      emergencyBaseTime   : Always attempt to keep at least this much time (in ms) at clock
-      emergencyMoveTime   : Plus attempt to keep at least this much time for each remaining emergency move
-      minThinkingTime     : No matter what, use at least this much thinking before doing the move
-  */
-
-  int hypMTG, hypMyTime, t1, t2;
-
-  // Read uci parameters
-  int emergencyMoveHorizon = Options["Emergency Move Horizon"];
-  int emergencyBaseTime    = Options["Emergency Base Time"];
-  int emergencyMoveTime    = Options["Emergency Move Time"];
-  int minThinkingTime      = Options["Minimum Thinking Time"];
-  int slowMover            = Options["Slow Mover"];
-
-  // Initialize to maximum values but unstablePVExtraTime that is reset
-  unstablePVExtraTime = 0;
-  optimumSearchTime = maximumSearchTime = limits.time[us];
-
-  // We calculate optimum time usage for different hypothetic "moves to go"-values and choose the
-  // minimum of calculated search time values. Usually the greatest hypMTG gives the minimum values.
-  for (hypMTG = 1; hypMTG <= (limits.movestogo ? std::min(limits.movestogo, MoveHorizon) : MoveHorizon); hypMTG++)
+  template<TimeType T>
+  int remaining(int myTime, int movesToGo, int ply, int slowMover)
   {
-      // Calculate thinking time for hypothetic "moves to go"-value
-      hypMyTime =  limits.time[us]
-                 + limits.inc[us] * (hypMTG - 1)
-                 - emergencyBaseTime
-                 - emergencyMoveTime * std::min(hypMTG, emergencyMoveHorizon);
+    const double TMaxRatio   = (T == OptimumTime ? 1 : MaxRatio);
+    const double TStealRatio = (T == OptimumTime ? 0 : StealRatio);
+
+    double moveImportance = (move_importance(ply) * slowMover) / 100;
+    double otherMovesImportance = 0;
+
+    for (int i = 1; i < movesToGo; ++i)
+        otherMovesImportance += move_importance(ply + 2 * i);
+
+    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
+  }
+
+} // namespace
+
+
+/// init() is called at the beginning of the search and calculates the allowed
+/// thinking time out of the time control and current game ply. We support four
+/// different kinds of time controls, passed in 'limits':
+///
+///  inc == 0 && movestogo == 0 means: x basetime  [sudden death!]
+///  inc == 0 && movestogo != 0 means: x moves in y minutes
+///  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"];
+
+  // Initialize unstablePvFactor to 1 and search times to maximum values
+  unstablePvFactor = 1;
+  optimumSearchTime = maximumSearchTime = 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)
+  {
+      // 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 = std::max(hypMyTime, 0);
 
-      t1 = minThinkingTime + remaining<OptimumTime>(hypMyTime, hypMTG, currentPly, slowMover);
-      t2 = minThinkingTime + remaining<MaxTime>(hypMyTime, hypMTG, currentPly, slowMover);
+      int t1 = minThinkingTime + remaining<OptimumTime>(hypMyTime, hypMTG, ply, slowMover);
+      int t2 = minThinkingTime + remaining<MaxTime    >(hypMyTime, hypMTG, ply, slowMover);
 
-      optimumSearchTime = std::min(optimumSearchTime, t1);
-      maximumSearchTime = std::min(maximumSearchTime, t2);
+      optimumSearchTime = std::min(t1, optimumSearchTime);
+      maximumSearchTime = std::min(t2, maximumSearchTime);
   }
 
   if (Options["Ponder"])
       optimumSearchTime += optimumSearchTime / 4;
 
-  // Make sure that maxSearchTime is not over absoluteMaxSearchTime
   optimumSearchTime = std::min(optimumSearchTime, maximumSearchTime);
 }
-
-
-namespace {
-
-  template<TimeType T>
-  int remaining(int myTime, int movesToGo, int currentPly, int slowMover)
-  {
-    const float TMaxRatio   = (T == OptimumTime ? 1 : MaxRatio);
-    const float TStealRatio = (T == OptimumTime ? 0 : StealRatio);
-
-    int thisMoveImportance = move_importance(currentPly) * slowMover / 100;
-    int otherMovesImportance = 0;
-
-    for (int i = 1; i < movesToGo; i++)
-        otherMovesImportance += move_importance(currentPly + 2 * i);
-
-    float ratio1 = (TMaxRatio * thisMoveImportance) / float(TMaxRatio * thisMoveImportance + otherMovesImportance);
-    float ratio2 = (thisMoveImportance + TStealRatio * otherMovesImportance) / float(thisMoveImportance + otherMovesImportance);
-
-    return int(floor(myTime * std::min(ratio1, ratio2)));
-  }
-}

src/timeman.h

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -17,23 +17,23 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#if !defined(TIMEMAN_H_INCLUDED)
+#ifndef TIMEMAN_H_INCLUDED
 #define TIMEMAN_H_INCLUDED
 
 /// The TimeManager class computes the optimal time to think depending on the
-/// maximum available time, the move game number and other parameters.
+/// maximum available time, the game move number and other parameters.
 
 class TimeManager {
 public:
-  void init(const Search::LimitsType& limits, int currentPly, Color us);
-  void pv_instability(int curChanges, int prevChanges);
-  int available_time() const { return optimumSearchTime + unstablePVExtraTime; }
+  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; }
 
 private:
   int optimumSearchTime;
   int maximumSearchTime;
-  int unstablePVExtraTime;
+  double unstablePvFactor;
 };
 
-#endif // !defined(TIMEMAN_H_INCLUDED)
+#endif // #ifndef TIMEMAN_H_INCLUDED

src/tt.cpp

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -17,7 +17,7 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <cstring>
+#include <cstring>   // For std::memset
 #include <iostream>
 
 #include "bitboard.h"
@@ -25,117 +25,74 @@
 
 TranspositionTable TT; // Our global transposition table
 
-TranspositionTable::TranspositionTable() {
 
-  size = generation = 0;
-  entries = NULL;
-}
+/// TranspositionTable::resize() sets the size of the transposition table,
+/// measured in megabytes. Transposition table consists of a power of 2 number
+/// of clusters and each cluster consists of ClusterSize number of TTEntry.
 
-TranspositionTable::~TranspositionTable() {
+void TranspositionTable::resize(size_t mbSize) {
 
-  delete [] entries;
-}
+  assert(sizeof(Cluster) == CacheLineSize / 2);
 
+  size_t newClusterCount = size_t(1) << msb((mbSize * 1024 * 1024) / sizeof(Cluster));
 
-/// TranspositionTable::set_size() sets the size of the transposition table,
-/// measured in megabytes. Transposition table consists of a power of 2 number of
-/// TTCluster and each cluster consists of ClusterSize number of TTEntries. Each
-/// non-empty entry contains information of exactly one position.
-
-void TranspositionTable::set_size(size_t mbSize) {
-
-  size_t newSize = 1ULL << msb((mbSize << 20) / sizeof(TTCluster));
-
-  if (newSize == size)
+  if (newClusterCount == clusterCount)
       return;
 
-  size = newSize;
-  delete [] entries;
-  entries = new (std::nothrow) TTCluster[size];
+  clusterCount = newClusterCount;
 
-  if (!entries)
+  free(mem);
+  mem = calloc(clusterCount * sizeof(Cluster) + CacheLineSize - 1, 1);
+
+  if (!mem)
   {
       std::cerr << "Failed to allocate " << mbSize
                 << "MB for transposition table." << std::endl;
       exit(EXIT_FAILURE);
   }
 
-  clear(); // Operator new is not guaranteed to initialize memory to zero
+  table = (Cluster*)((uintptr_t(mem) + CacheLineSize - 1) & ~(CacheLineSize - 1));
 }
 
 
 /// TranspositionTable::clear() overwrites the entire transposition table
-/// with zeroes. It is called whenever the table is resized, or when the
+/// 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).
 
 void TranspositionTable::clear() {
 
-  memset(entries, 0, size * sizeof(TTCluster));
+  std::memset(table, 0, clusterCount * sizeof(Cluster));
 }
 
 
-/// TranspositionTable::store() writes a new entry containing position key and
-/// valuable information of current position. The lowest order bits of position
-/// key are used to decide on which cluster the position will be placed.
-/// When a new entry is written and there are no empty entries available in cluster,
-/// it replaces the least valuable of entries. 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.
+/// 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.
 
-void TranspositionTable::store(const Key posKey, Value v, Bound t, Depth d, Move m, Value statV, Value kingD) {
+TTEntry* TranspositionTable::probe(const Key key, bool& found) const {
 
-  int c1, c2, c3;
-  TTEntry *tte, *replace;
-  uint32_t posKey32 = posKey >> 32; // Use the high 32 bits as key inside the cluster
+  TTEntry* const tte = first_entry(key);
+  const uint16_t key16 = key >> 48;  // Use the high 16 bits as key inside the cluster
 
-  tte = replace = first_entry(posKey);
-
-  for (int i = 0; i < ClusterSize; i++, tte++)
-  {
-      if (!tte->key() || tte->key() == posKey32) // Empty or overwrite old
+  for (int i = 0; i < ClusterSize; ++i)
+      if (!tte[i].key16 || tte[i].key16 == key16)
       {
-          // Preserve any existing ttMove
-          if (m == MOVE_NONE)
-              m = tte->move();
+          if (tte[i].key16)
+              tte[i].genBound8 = uint8_t(generation8 | tte[i].bound()); // Refresh
 
-          tte->save(posKey32, v, t, d, m, generation, statV, kingD);
-          return;
+          return found = (bool)tte[i].key16, &tte[i];
       }
 
-      // Implement replace strategy
-      c1 = (replace->generation() == generation ?  2 : 0);
-      c2 = (tte->generation() == generation || tte->type() == BOUND_EXACT ? -2 : 0);
-      c3 = (tte->depth() < replace->depth() ?  1 : 0);
+  // 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)
+          replace = &tte[i];
 
-      if (c1 + c2 + c3 > 0)
-          replace = tte;
-  }
-  replace->save(posKey32, v, t, d, m, generation, statV, kingD);
-}
-
-
-/// TranspositionTable::probe() looks up the current position in the
-/// transposition table. Returns a pointer to the TTEntry or NULL if
-/// position is not found.
-
-TTEntry* TranspositionTable::probe(const Key posKey) const {
-
-  uint32_t posKey32 = posKey >> 32;
-  TTEntry* tte = first_entry(posKey);
-
-  for (int i = 0; i < ClusterSize; i++, tte++)
-      if (tte->key() == posKey32)
-          return tte;
-
-  return NULL;
-}
-
-
-/// TranspositionTable::new_search() is called at the beginning of every new
-/// search. It increments the "generation" variable, which is used to
-/// distinguish transposition table entries from previous searches from
-/// entries from the current search.
-
-void TranspositionTable::new_search() {
-  generation++;
+  return found = false, replace;
 }

src/tt.h

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -17,120 +17,90 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#if !defined(TT_H_INCLUDED)
+#ifndef TT_H_INCLUDED
 #define TT_H_INCLUDED
 
 #include "misc.h"
 #include "types.h"
 
-/// The TTEntry is the class of transposition table entries
+/// TTEntry struct is the 10 bytes transposition table entry, defined as below:
 ///
-/// A TTEntry needs 128 bits to be stored
-///
-/// bit  0-31: key
-/// bit 32-63: data
-/// bit 64-79: value
-/// bit 80-95: depth
-/// bit 96-111: static value
-/// bit 112-127: margin of static value
-///
-/// the 32 bits of the data field are so defined
-///
-/// bit  0-15: move
-/// bit 16-20: not used
-/// bit 21-22: value type
-/// bit 23-31: generation
+/// key        16 bit
+/// move       16 bit
+/// value      16 bit
+/// eval value 16 bit
+/// generation  6 bit
+/// bound type  2 bit
+/// depth       8 bit
 
-class TTEntry {
+struct TTEntry {
 
-public:
-  void save(uint32_t k, Value v, Bound b, Depth d, Move m, int g, Value statV, Value statM) {
+  Move  move()  const { return (Move )move16; }
+  Value value() const { return (Value)value16; }
+  Value eval()  const { return (Value)eval16; }
+  Depth depth() const { return (Depth)depth8; }
+  Bound bound() const { return (Bound)(genBound8 & 0x3); }
 
-    key32        = (uint32_t)k;
-    move16       = (uint16_t)m;
-    bound        = (uint8_t)b;
-    generation8  = (uint8_t)g;
-    value16      = (int16_t)v;
-    depth16      = (int16_t)d;
-    staticValue  = (int16_t)statV;
-    staticMargin = (int16_t)statM;
+  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 set_generation(int g) { generation8 = (uint8_t)g; }
-
-  uint32_t key() const              { return key32; }
-  Depth depth() const               { return (Depth)depth16; }
-  Move move() const                 { return (Move)move16; }
-  Value value() const               { return (Value)value16; }
-  Bound type() const                { return (Bound)bound; }
-  int generation() const            { return (int)generation8; }
-  Value static_value() const        { return (Value)staticValue; }
-  Value static_value_margin() const { return (Value)staticMargin; }
 
 private:
-  uint32_t key32;
+  friend class TranspositionTable;
+
+  uint16_t key16;
   uint16_t move16;
-  uint8_t bound, generation8;
-  int16_t value16, depth16, staticValue, staticMargin;
+  int16_t  value16;
+  int16_t  eval16;
+  uint8_t  genBound8;
+  int8_t   depth8;
 };
 
 
-/// This is the number of TTEntry slots for each cluster
-const int ClusterSize = 4;
-
-
-/// TTCluster consists of ClusterSize number of TTEntries. Size of TTCluster
-/// must not be bigger than a cache line size. In case it is less, it should
-/// be padded to guarantee always aligned accesses.
-
-struct TTCluster {
-  TTEntry data[ClusterSize];
-};
-
-
-/// The transposition table class. This is basically just a huge array containing
-/// TTCluster objects, and a few methods for writing and reading entries.
+/// 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.
 
 class TranspositionTable {
 
-  TranspositionTable(const TranspositionTable&);
-  TranspositionTable& operator=(const TranspositionTable&);
+  static const int CacheLineSize = 64;
+  static const int ClusterSize = 3;
+
+  struct Cluster {
+    TTEntry entry[ClusterSize];
+    char padding[2]; // Align to the cache line size
+  };
 
 public:
-  TranspositionTable();
-  ~TranspositionTable();
-  void set_size(size_t mbSize);
+ ~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;
+  void resize(size_t mbSize);
   void clear();
-  void store(const Key posKey, Value v, Bound type, Depth d, Move m, Value statV, Value kingD);
-  TTEntry* probe(const Key posKey) const;
-  void new_search();
-  TTEntry* first_entry(const Key posKey) const;
-  void refresh(const TTEntry* tte) const;
+
+  // The 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];
+  }
 
 private:
-  size_t size;
-  TTCluster* entries;
-  uint8_t generation; // Size must be not bigger then TTEntry::generation8
+  size_t clusterCount;
+  Cluster* table;
+  void* mem;
+  uint8_t generation8; // Size must be not bigger than TTEntry::genBound8
 };
 
 extern TranspositionTable TT;
 
-
-/// TranspositionTable::first_entry() returns a pointer to the first entry of
-/// a cluster given a position. The lowest order bits of the key are used to
-/// get the index of the cluster.
-
-inline TTEntry* TranspositionTable::first_entry(const Key posKey) const {
-
-  return entries[((uint32_t)posKey) & (size - 1)].data;
-}
-
-
-/// TranspositionTable::refresh() updates the 'generation' value of the TTEntry
-/// to avoid aging. Normally called after a TT hit.
-
-inline void TranspositionTable::refresh(const TTEntry* tte) const {
-
-  const_cast<TTEntry*>(tte)->set_generation(generation);
-}
-
-#endif // !defined(TT_H_INCLUDED)
+#endif // #ifndef TT_H_INCLUDED

src/types.h

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -17,47 +17,60 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#if !defined(TYPES_H_INCLUDED)
+#ifndef TYPES_H_INCLUDED
 #define TYPES_H_INCLUDED
 
-/// For Linux and OSX configuration is done automatically using Makefile. To get
-/// started type 'make help'.
+/// When compiling with provided Makefile (e.g. for Linux and OSX), configuration
+/// is done automatically. To get started type 'make help'.
 ///
-/// For Windows, part of the configuration is detected automatically, but some
-/// switches need to be set manually:
+/// When Makefile is not used (e.g. with Microsoft Visual Studio) some switches
+/// need to be set manually:
 ///
-/// -DNDEBUG      | Disable debugging mode. Use always.
+/// -DNDEBUG      | Disable debugging mode. Always use this for release.
 ///
-/// -DNO_PREFETCH | Disable use of prefetch asm-instruction. A must if you want
-///               | the executable to run on some very old machines.
+/// -DNO_PREFETCH | Disable use of prefetch asm-instruction. You may need this to
+///               | run on some very old machines.
 ///
 /// -DUSE_POPCNT  | Add runtime support for use of popcnt asm-instruction. Works
-///               | only in 64-bit mode. For compiling requires hardware with
-///               | popcnt support.
+///               | only in 64-bit mode and requires hardware with popcnt support.
 
+#include <cassert>
 #include <cctype>
 #include <climits>
 #include <cstdlib>
 
 #include "platform.h"
 
-#if defined(_WIN64)
+/// Predefined macros hell:
+///
+/// __GNUC__           Compiler is gcc, Clang or Intel on Linux
+/// __INTEL_COMPILER   Compiler is Intel
+/// _MSC_VER           Compiler is MSVC or Intel on Windows
+/// _WIN32             Building on Windows (any)
+/// _WIN64             Building on Windows 64 bit
+
+#if defined(_WIN64) && !defined(IS_64BIT) // Last condition means Makefile is not used
 #  include <intrin.h> // MSVC popcnt and bsfq instrinsics
 #  define IS_64BIT
 #  define USE_BSFQ
 #endif
 
-#if defined(USE_POPCNT) && defined(_MSC_VER) && defined(__INTEL_COMPILER)
+#if defined(USE_POPCNT) && defined(__INTEL_COMPILER) && defined(_MSC_VER)
 #  include <nmmintrin.h> // Intel header for _mm_popcnt_u64() intrinsic
 #endif
 
-#if defined(_MSC_VER) || defined(__INTEL_COMPILER)
-#  define CACHE_LINE_ALIGNMENT __declspec(align(64))
-#else
-#  define CACHE_LINE_ALIGNMENT  __attribute__ ((aligned(64)))
+#if !defined(NO_PREFETCH) && (defined(__INTEL_COMPILER) || defined(_MSC_VER))
+#  include <xmmintrin.h> // Intel and Microsoft header for _mm_prefetch()
 #endif
 
-#if defined(_MSC_VER)
+#if defined(USE_PEXT)
+#  include <immintrin.h> // Header for _pext_u64() intrinsic
+#  define pext(b, m) _pext_u64(b, m)
+#else
+#  define pext(b, m) (0)
+#endif
+
+#ifdef _MSC_VER
 #  define FORCE_INLINE  __forceinline
 #elif defined(__GNUC__)
 #  define FORCE_INLINE  inline __attribute__((always_inline))
@@ -65,13 +78,19 @@
 #  define FORCE_INLINE  inline
 #endif
 
-#if defined(USE_POPCNT)
+#ifdef USE_POPCNT
 const bool HasPopCnt = true;
 #else
 const bool HasPopCnt = false;
 #endif
 
-#if defined(IS_64BIT)
+#ifdef USE_PEXT
+const bool HasPext = true;
+#else
+const bool HasPext = false;
+#endif
+
+#ifdef IS_64BIT
 const bool Is64Bit = true;
 #else
 const bool Is64Bit = false;
@@ -80,128 +99,125 @@ const bool Is64Bit = false;
 typedef uint64_t Key;
 typedef uint64_t Bitboard;
 
-const int MAX_MOVES      = 192;
-const int MAX_PLY        = 100;
-const int MAX_PLY_PLUS_2 = MAX_PLY + 2;
-
-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;
-
-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);
-
+const int MAX_MOVES = 256;
+const int MAX_PLY   = 128;
 
 /// A move needs 16 bits to be stored
 ///
 /// bit  0- 5: destination square (from 0 to 63)
 /// bit  6-11: origin square (from 0 to 63)
 /// bit 12-13: promotion piece type - 2 (from KNIGHT-2 to QUEEN-2)
-/// bit 14-15: special move flag: promotion (1), en passant (2), castle (3)
+/// bit 14-15: special move flag: promotion (1), en passant (2), castling (3)
+/// NOTE: EN-PASSANT bit is set only when a pawn can be captured
 ///
 /// Special cases are MOVE_NONE and MOVE_NULL. We can sneak these in because in
 /// any normal move destination square is always different from origin square
 /// while MOVE_NONE and MOVE_NULL have the same origin and destination square.
 
 enum Move {
-  MOVE_NONE = 0,
+  MOVE_NONE,
   MOVE_NULL = 65
 };
 
 enum MoveType {
-  NORMAL    = 0,
+  NORMAL,
   PROMOTION = 1 << 14,
   ENPASSANT = 2 << 14,
-  CASTLE    = 3 << 14
+  CASTLING  = 3 << 14
 };
 
-enum CastleRight {  // Defined as in PolyGlot book hash key
-  CASTLES_NONE = 0,
-  WHITE_OO     = 1,
-  WHITE_OOO    = 2,
-  BLACK_OO     = 4,
-  BLACK_OOO    = 8,
-  ALL_CASTLES  = 15
+enum Color {
+  WHITE, BLACK, NO_COLOR, COLOR_NB = 2
 };
 
 enum CastlingSide {
-  KING_SIDE,
-  QUEEN_SIDE
+  KING_SIDE, QUEEN_SIDE, CASTLING_SIDE_NB = 2
+};
+
+enum CastlingRight {
+  NO_CASTLING,
+  WHITE_OO,
+  WHITE_OOO = WHITE_OO << 1,
+  BLACK_OO  = WHITE_OO << 2,
+  BLACK_OOO = WHITE_OO << 3,
+  ANY_CASTLING = WHITE_OO | WHITE_OOO | BLACK_OO | BLACK_OOO,
+  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,
+  MG = 0, EG = 1, PHASE_NB = 2
 };
 
 enum ScaleFactor {
-  SCALE_FACTOR_DRAW   = 0,
-  SCALE_FACTOR_NORMAL = 64,
-  SCALE_FACTOR_MAX    = 128,
-  SCALE_FACTOR_NONE   = 255
+  SCALE_FACTOR_DRAW    = 0,
+  SCALE_FACTOR_ONEPAWN = 48,
+  SCALE_FACTOR_NORMAL  = 64,
+  SCALE_FACTOR_MAX     = 128,
+  SCALE_FACTOR_NONE    = 255
 };
 
 enum Bound {
-  BOUND_NONE  = 0,
-  BOUND_UPPER = 1,
-  BOUND_LOWER = 2,
+  BOUND_NONE,
+  BOUND_UPPER,
+  BOUND_LOWER,
   BOUND_EXACT = BOUND_UPPER | BOUND_LOWER
 };
 
 enum Value {
   VALUE_ZERO      = 0,
   VALUE_DRAW      = 0,
-  VALUE_KNOWN_WIN = 15000,
-  VALUE_MATE      = 30000,
-  VALUE_INFINITE  = 30001,
-  VALUE_NONE      = 30002,
+  VALUE_KNOWN_WIN = 10000,
+  VALUE_MATE      = 32000,
+  VALUE_INFINITE  = 32001,
+  VALUE_NONE      = 32002,
 
-  VALUE_MATE_IN_MAX_PLY  =  VALUE_MATE - MAX_PLY,
-  VALUE_MATED_IN_MAX_PLY = -VALUE_MATE + MAX_PLY,
+  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,
 
-  Mg = 0, Eg = 1,
-
   PawnValueMg   = 198,   PawnValueEg   = 258,
   KnightValueMg = 817,   KnightValueEg = 846,
   BishopValueMg = 836,   BishopValueEg = 857,
   RookValueMg   = 1270,  RookValueEg   = 1278,
-  QueenValueMg  = 2521,  QueenValueEg  = 2558
+  QueenValueMg  = 2521,  QueenValueEg  = 2558,
+
+  MidgameLimit  = 15581, EndgameLimit  = 3998
 };
 
 enum PieceType {
-  NO_PIECE_TYPE = 0, ALL_PIECES = 0,
-  PAWN = 1, KNIGHT = 2, BISHOP = 3, ROOK = 4, QUEEN = 5, KING = 6
+  NO_PIECE_TYPE, PAWN, KNIGHT, BISHOP, ROOK, QUEEN, KING,
+  ALL_PIECES = 0,
+  PIECE_TYPE_NB = 8
 };
 
 enum Piece {
-  NO_PIECE = 16, // color_of(NO_PIECE) == NO_COLOR
-  W_PAWN = 1, W_KNIGHT =  2, W_BISHOP =  3, W_ROOK =  4, W_QUEEN =  5, W_KING =  6,
-  B_PAWN = 9, B_KNIGHT = 10, B_BISHOP = 11, B_ROOK = 12, B_QUEEN = 13, B_KING = 14
-};
-
-enum Color {
-  WHITE, BLACK, NO_COLOR
+  NO_PIECE,
+  W_PAWN = 1, W_KNIGHT, W_BISHOP, W_ROOK, W_QUEEN, W_KING,
+  B_PAWN = 9, B_KNIGHT, B_BISHOP, B_ROOK, B_QUEEN, B_KING,
+  PIECE_NB = 16
 };
 
 enum Depth {
 
-  ONE_PLY = 2,
+  ONE_PLY = 1,
 
-  DEPTH_ZERO          =  0 * ONE_PLY,
-  DEPTH_QS_CHECKS     = -1 * ONE_PLY,
-  DEPTH_QS_NO_CHECKS  = -2 * ONE_PLY,
-  DEPTH_QS_RECAPTURES = -5 * ONE_PLY,
+  DEPTH_ZERO          =  0,
+  DEPTH_QS_CHECKS     =  0,
+  DEPTH_QS_NO_CHECKS  = -1,
+  DEPTH_QS_RECAPTURES = -5,
 
-  DEPTH_NONE = -127 * ONE_PLY
+  DEPTH_NONE = -6,
+  DEPTH_MAX  = MAX_PLY
 };
 
 enum Square {
@@ -215,6 +231,8 @@ 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,
@@ -229,76 +247,81 @@ enum Square {
 };
 
 enum File {
-  FILE_A, FILE_B, FILE_C, FILE_D, FILE_E, FILE_F, FILE_G, FILE_H
+  FILE_A, FILE_B, FILE_C, FILE_D, FILE_E, FILE_F, FILE_G, FILE_H, FILE_NB
 };
 
 enum Rank {
-  RANK_1, RANK_2, RANK_3, RANK_4, RANK_5, RANK_6, RANK_7, RANK_8
+  RANK_1, RANK_2, RANK_3, RANK_4, RANK_5, RANK_6, RANK_7, RANK_8, RANK_NB
 };
 
 
-/// Score enum keeps a midgame and an endgame value in a single integer (enum),
-/// first LSB 16 bits are used to store endgame value, while upper bits are used
-/// for midgame value. Compiler is free to choose the enum type as long as can
-/// keep its data, so ensure Score to be an integer type.
+/// 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 = 0,
+  SCORE_ZERO,
   SCORE_ENSURE_INTEGER_SIZE_P = INT_MAX,
   SCORE_ENSURE_INTEGER_SIZE_N = INT_MIN
 };
 
-inline Score make_score(int mg, int eg) { return Score((mg << 16) + eg); }
-
-/// Extracting the signed lower and upper 16 bits it 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) { return Value(((s + 32768) & ~0xffff) / 0x10000); }
-
-/// On Intel 64 bit we have a small speed regression with the standard conforming
-/// version, so use a faster code in this case that, although not 100% standard
-/// compliant it seems to work for Intel and MSVC.
-#if defined(IS_64BIT) && (!defined(__GNUC__) || defined(__INTEL_COMPILER))
-
-inline Value eg_value(Score s) { return Value(int16_t(s & 0xffff)); }
-
-#else
-
-inline Value eg_value(Score s) {
-  return Value((int)(unsigned(s) & 0x7fffu) - (int)(unsigned(s) & 0x8000u));
+inline Score make_score(int mg, int eg) {
+  return Score((mg << 16) + eg);
 }
 
-#endif
+/// 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) {
 
-#define ENABLE_SAFE_OPERATORS_ON(T)                                         \
-inline T operator+(const T d1, const T d2) { return T(int(d1) + int(d2)); } \
-inline T operator-(const T d1, const T d2) { return T(int(d1) - int(d2)); } \
-inline T operator*(int i, const T d) { return T(i * int(d)); }              \
-inline T operator*(const T d, int i) { return T(int(d) * i); }              \
-inline T operator-(const T d) { return T(-int(d)); }                        \
-inline T& operator+=(T& d1, const T d2) { d1 = d1 + d2; return d1; }        \
-inline T& operator-=(T& d1, const T d2) { d1 = d1 - d2; return d1; }        \
-inline T& operator*=(T& d, int i) { d = T(int(d) * i); return d; }
+  union { uint16_t u; int16_t s; } mg = { uint16_t(unsigned(s + 0x8000) >> 16) };
+  return Value(mg.s);
+}
 
-#define ENABLE_OPERATORS_ON(T) ENABLE_SAFE_OPERATORS_ON(T)                  \
-inline T operator++(T& d, int) { d = T(int(d) + 1); return d; }             \
-inline T operator--(T& d, int) { d = T(int(d) - 1); return d; }             \
-inline T operator/(const T d, int i) { return T(int(d) / i); }              \
-inline T& operator/=(T& d, int i) { d = T(int(d) / i); return d; }
+inline Value eg_value(Score s) {
 
-ENABLE_OPERATORS_ON(Value)
-ENABLE_OPERATORS_ON(PieceType)
-ENABLE_OPERATORS_ON(Piece)
-ENABLE_OPERATORS_ON(Color)
-ENABLE_OPERATORS_ON(Depth)
-ENABLE_OPERATORS_ON(Square)
-ENABLE_OPERATORS_ON(File)
-ENABLE_OPERATORS_ON(Rank)
+  union { uint16_t u; int16_t s; } eg = { uint16_t(unsigned(s)) };
+  return Value(eg.s);
+}
 
-/// Added operators for adding integers to a Value
+#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); }
+
+#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); }  \
+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_BASE_OPERATORS_ON(Score)
+
+#undef ENABLE_FULL_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); }
-
-ENABLE_SAFE_OPERATORS_ON(Score)
+inline Value& operator+=(Value& v, int i) { return v = v + i; }
+inline Value& operator-=(Value& v, int i) { return v = v - i; }
 
 /// 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.
@@ -309,51 +332,18 @@ inline Score operator/(Score s, int i) {
   return make_score(mg_value(s) / i, eg_value(s) / i);
 }
 
-/// Weight score v by score w trying to prevent overflow
-inline Score apply_weight(Score v, Score w) {
-  return make_score((int(mg_value(v)) * mg_value(w)) / 0x100,
-                    (int(eg_value(v)) * eg_value(w)) / 0x100);
-}
-
-#undef ENABLE_OPERATORS_ON
-#undef ENABLE_SAFE_OPERATORS_ON
-
-namespace Zobrist {
-
-  extern Key psq[2][8][64]; // [color][pieceType][square / piece count]
-  extern Key enpassant[8];  // [file]
-  extern Key castle[16];    // [castleRight]
-  extern Key side;
-  extern Key exclusion;
-
-  void init();
-}
-
-CACHE_LINE_ALIGNMENT
-
-extern Score pieceSquareTable[16][64]; // [piece][square]
-extern Value PieceValue[2][18];        // [Mg / Eg][piece / pieceType]
-extern int SquareDistance[64][64];     // [square][square]
-
-struct MoveStack {
-  Move move;
-  int score;
-};
-
-inline bool operator<(const MoveStack& f, const MoveStack& s) {
-  return f.score < s.score;
-}
+extern Value PieceValue[PHASE_NB][PIECE_NB];
 
 inline Color operator~(Color c) {
-  return Color(c ^ 1);
+  return Color(c ^ BLACK);
 }
 
 inline Square operator~(Square s) {
-  return Square(s ^ 56); // Vertical flip SQ_A1 -> SQ_A8
+  return Square(s ^ SQ_A8); // Vertical flip SQ_A1 -> SQ_A8
 }
 
-inline Square operator|(File f, Rank r) {
-  return Square((r << 3) | f);
+inline CastlingRight operator|(Color c, CastlingSide s) {
+  return CastlingRight(WHITE_OO << ((s == QUEEN_SIDE) + 2 * c));
 }
 
 inline Value mate_in(int ply) {
@@ -364,20 +354,21 @@ inline Value mated_in(int ply) {
   return -VALUE_MATE + ply;
 }
 
+inline 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);
 }
 
-inline CastleRight make_castle_right(Color c, CastlingSide s) {
-  return CastleRight(WHITE_OO << ((s == QUEEN_SIDE) + 2 * c));
+inline PieceType type_of(Piece pc)  {
+  return PieceType(pc & 7);
 }
 
-inline PieceType type_of(Piece p)  {
-  return PieceType(p & 7);
-}
-
-inline Color color_of(Piece p) {
-  return Color(p >> 3);
+inline Color color_of(Piece pc) {
+  assert(pc != NO_PIECE);
+  return Color(pc >> 3);
 }
 
 inline bool is_ok(Square s) {
@@ -392,10 +383,6 @@ inline Rank rank_of(Square s) {
   return Rank(s >> 3);
 }
 
-inline Square mirror(Square s) {
-  return Square(s ^ 7); // Horizontal flip SQ_A1 -> SQ_H1
-}
-
 inline Square relative_square(Color c, Square s) {
   return Square(s ^ (c * 56));
 }
@@ -413,26 +400,6 @@ inline bool opposite_colors(Square s1, Square s2) {
   return ((s >> 3) ^ s) & 1;
 }
 
-inline int file_distance(Square s1, Square s2) {
-  return abs(file_of(s1) - file_of(s2));
-}
-
-inline int rank_distance(Square s1, Square s2) {
-  return abs(rank_of(s1) - rank_of(s2));
-}
-
-inline int square_distance(Square s1, Square s2) {
-  return SquareDistance[s1][s2];
-}
-
-inline char file_to_char(File f) {
-  return char(f - FILE_A + int('a'));
-}
-
-inline char rank_to_char(Rank r) {
-  return char(r - RANK_1 + int('1'));
-}
-
 inline Square pawn_push(Color c) {
   return c == WHITE ? DELTA_N : DELTA_S;
 }
@@ -459,35 +426,11 @@ inline Move make_move(Square from, Square to) {
 
 template<MoveType T>
 inline Move make(Square from, Square to, PieceType pt = KNIGHT) {
-  return Move(to | (from << 6) | T | ((pt - KNIGHT) << 12)) ;
+  return Move(to | (from << 6) | T | ((pt - KNIGHT) << 12));
 }
 
 inline bool is_ok(Move m) {
-  return from_sq(m) != to_sq(m); // Catches also MOVE_NULL and MOVE_NONE
+  return from_sq(m) != to_sq(m); // Catch MOVE_NULL and MOVE_NONE
 }
 
-#include <string>
-
-inline const std::string square_to_string(Square s) {
-  char ch[] = { file_to_char(file_of(s)), rank_to_char(rank_of(s)), 0 };
-  return ch;
-}
-
-/// Our insertion sort implementation, works with pointers and iterators and is
-/// guaranteed to be stable, as is needed.
-template<typename T, typename K>
-void sort(K first, K last)
-{
-  T tmp;
-  K p, q;
-
-  for (p = first + 1; p < last; p++)
-  {
-      tmp = *p;
-      for (q = p; q != first && *(q-1) < tmp; --q)
-          *q = *(q-1);
-      *q = tmp;
-  }
-}
-
-#endif // !defined(TYPES_H_INCLUDED)
+#endif // #ifndef TYPES_H_INCLUDED

src/uci.cpp

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -22,11 +22,12 @@
 #include <string>
 
 #include "evaluate.h"
-#include "notation.h"
+#include "movegen.h"
 #include "position.h"
 #include "search.h"
 #include "thread.h"
-#include "ucioption.h"
+#include "tt.h"
+#include "uci.h"
 
 using namespace std;
 
@@ -37,125 +38,18 @@ namespace {
   // FEN string of the initial position, normal chess
   const char* StartFEN = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
 
-  // Keep track of position keys along the setup moves (from start position to the
-  // position just before to start searching). Needed by repetition draw detection.
+  // 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;
 
-  void set_option(istringstream& up);
-  void set_position(Position& pos, istringstream& up);
-  void go(Position& pos, istringstream& up);
-}
 
-
-/// Wait for a command from the user, parse this text string as an UCI command,
-/// and call the appropriate functions. Also intercepts EOF from stdin to ensure
-/// that we exit gracefully if the GUI dies unexpectedly. In addition to the UCI
-/// commands, the function also supports a few debug commands.
-
-void UCI::loop(const string& args) {
-
-  Position pos(StartFEN, false, Threads.main_thread()); // The root position
-  string cmd, token;
-
-  while (token != "quit")
-  {
-      if (!args.empty())
-          cmd = args;
-
-      else if (!getline(cin, cmd)) // Block here waiting for input
-          cmd = "quit";
-
-      istringstream is(cmd);
-
-      is >> skipws >> token;
-
-      if (token == "quit" || token == "stop")
-      {
-          Search::Signals.stop = true;
-          Threads.wait_for_search_finished(); // Cannot quit while threads are running
-      }
-
-      else if (token == "ponderhit")
-      {
-          // The opponent has played the expected move. GUI sends "ponderhit" if
-          // we were told to ponder on the same move the opponent has played. We
-          // should continue searching but switching from pondering to normal search.
-          Search::Limits.ponder = false;
-
-          if (Search::Signals.stopOnPonderhit)
-          {
-              Search::Signals.stop = true;
-              Threads.main_thread()->wake_up(); // Could be sleeping
-          }
-      }
-
-      else if (token == "go")
-          go(pos, is);
-
-      else if (token == "ucinewgame")
-      { /* Avoid returning "Unknown command" */ }
-
-      else if (token == "isready")
-          sync_cout << "readyok" << sync_endl;
-
-      else if (token == "position")
-          set_position(pos, is);
-
-      else if (token == "setoption")
-          set_option(is);
-
-      else if (token == "d")
-          pos.print();
-
-      else if (token == "flip")
-          pos.flip();
-
-      else if (token == "eval")
-          sync_cout << Eval::trace(pos) << sync_endl;
-
-      else if (token == "bench")
-          benchmark(pos, is);
-
-      else if (token == "key")
-          sync_cout << "key: " << hex     << pos.key()
-                    << "\nmaterial key: " << pos.material_key()
-                    << "\npawn key: "     << pos.pawn_key() << sync_endl;
-
-      else if (token == "uci")
-          sync_cout << "id name " << engine_info(true)
-                    << "\n"       << Options
-                    << "\nuciok"  << sync_endl;
-
-      else if (token == "perft" && (is >> token)) // Read depth
-      {
-          stringstream ss;
-
-          ss << Options["Hash"]    << " "
-             << Options["Threads"] << " " << token << " current perft";
-
-          benchmark(pos, ss);
-      }
-
-      else
-          sync_cout << "Unknown command: " << cmd << sync_endl;
-
-      if (!args.empty()) // Command line arguments have one-shot behaviour
-      {
-          Threads.wait_for_search_finished();
-          break;
-      }
-  }
-}
-
-
-namespace {
-
-  // set_position() is called when engine receives the "position" UCI command.
-  // The function sets up the position described in the given fen string ("fen")
+  // 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 set_position(Position& pos, istringstream& is) {
+  void position(Position& pos, istringstream& is) {
 
     Move m;
     string token, fen;
@@ -173,11 +67,11 @@ namespace {
     else
         return;
 
-    pos.from_fen(fen, Options["UCI_Chess960"], Threads.main_thread());
+    pos.set(fen, Options["UCI_Chess960"], Threads.main());
     SetupStates = Search::StateStackPtr(new std::stack<StateInfo>());
 
     // Parse move list (if any)
-    while (is >> token && (m = move_from_uci(pos, token)) != MOVE_NONE)
+    while (is >> token && (m = UCI::to_move(pos, token)) != MOVE_NONE)
     {
         SetupStates->push(StateInfo());
         pos.do_move(m, SetupStates->top());
@@ -185,10 +79,10 @@ namespace {
   }
 
 
-  // set_option() is called when engine receives the "setoption" UCI command. The
+  // setoption() is called when engine receives the "setoption" UCI command. The
   // function updates the UCI option ("name") to the given value ("value").
 
-  void set_option(istringstream& is) {
+  void setoption(istringstream& is) {
 
     string token, name, value;
 
@@ -210,42 +104,179 @@ namespace {
 
 
   // go() is called when engine receives the "go" UCI command. The function sets
-  // the thinking time and other parameters from the input string, and then starts
+  // the thinking time and other parameters from the input string, then starts
   // the search.
 
-  void go(Position& pos, istringstream& is) {
+  void go(const Position& pos, istringstream& is) {
 
     Search::LimitsType limits;
-    vector<Move> searchMoves;
     string token;
 
     while (is >> token)
-    {
-        if (token == "wtime")
-            is >> limits.time[WHITE];
-        else if (token == "btime")
-            is >> limits.time[BLACK];
-        else if (token == "winc")
-            is >> limits.inc[WHITE];
-        else if (token == "binc")
-            is >> limits.inc[BLACK];
-        else if (token == "movestogo")
-            is >> limits.movestogo;
-        else if (token == "depth")
-            is >> limits.depth;
-        else if (token == "nodes")
-            is >> limits.nodes;
-        else if (token == "movetime")
-            is >> limits.movetime;
-        else if (token == "infinite")
-            limits.infinite = true;
-        else if (token == "ponder")
-            limits.ponder = true;
-        else if (token == "searchmoves")
+        if (token == "searchmoves")
             while (is >> token)
-                searchMoves.push_back(move_from_uci(pos, token));
-    }
+                limits.searchmoves.push_back(UCI::to_move(pos, token));
 
-    Threads.start_searching(pos, limits, searchMoves, SetupStates);
+        else if (token == "wtime")     is >> limits.time[WHITE];
+        else if (token == "btime")     is >> limits.time[BLACK];
+        else if (token == "winc")      is >> limits.inc[WHITE];
+        else if (token == "binc")      is >> limits.inc[BLACK];
+        else if (token == "movestogo") is >> limits.movestogo;
+        else if (token == "depth")     is >> limits.depth;
+        else if (token == "nodes")     is >> limits.nodes;
+        else if (token == "movetime")  is >> limits.movetime;
+        else if (token == "mate")      is >> limits.mate;
+        else if (token == "infinite")  limits.infinite = true;
+        else if (token == "ponder")    limits.ponder = true;
+
+    Threads.start_thinking(pos, limits, SetupStates);
   }
+
+} // namespace
+
+
+/// UCI::loop() waits for a command from stdin, parses it and calls the appropriate
+/// function. Also intercepts EOF from stdin to ensure gracefully exiting if the
+/// GUI dies unexpectedly. When called with some command line arguments, e.g. to
+/// run 'bench', once the command is executed the function returns immediately.
+/// In addition to the UCI ones, also some additional debug commands are supported.
+
+void UCI::loop(int argc, char* argv[]) {
+
+  Position pos(StartFEN, false, Threads.main()); // The root position
+  string token, cmd;
+
+  for (int i = 1; i < argc; ++i)
+      cmd += std::string(argv[i]) + " ";
+
+  do {
+      if (argc == 1 && !getline(cin, cmd)) // Block here waiting for input or EOF
+          cmd = "quit";
+
+      istringstream is(cmd);
+
+      token.clear(); // getline() could return 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.
+      if (    token == "quit"
+          ||  token == "stop"
+          || (token == "ponderhit" && Search::Signals.stopOnPonderhit))
+      {
+          Search::Signals.stop = true;
+          Threads.main()->notify_one(); // Could be sleeping
+      }
+      else if (token == "ponderhit")
+          Search::Limits.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);
+
+      // 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);
+      }
+      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
+}
+
+
+/// UCI::value() converts a Value to a string suitable for use with the UCI
+/// protocol specification:
+///
+/// cp <x>    The score from the engine's point of view in centipawns.
+/// mate <y>  Mate in y moves, not plies. If the engine is getting mated
+///           use negative values for y.
+
+string UCI::value(Value v) {
+
+  stringstream ss;
+
+  if (abs(v) < VALUE_MATE - MAX_PLY)
+      ss << "cp " << v * 100 / PawnValueEg;
+  else
+      ss << "mate " << (v > 0 ? VALUE_MATE - v + 1 : -VALUE_MATE - v) / 2;
+
+  return ss.str();
+}
+
+
+/// 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;
+}
+
+
+/// UCI::move() converts a Move to a string in coordinate notation (g1f3, a7a8q).
+/// The only special case is castling, where we print in the e1g1 notation in
+/// normal chess mode, and in e1h1 notation in chess960 mode. Internally all
+/// castling moves are always encoded as 'king captures rook'.
+
+string UCI::move(Move m, bool chess960) {
+
+  Square from = from_sq(m);
+  Square to = to_sq(m);
+
+  if (m == MOVE_NONE)
+      return "(none)";
+
+  if (m == MOVE_NULL)
+      return "0000";
+
+  if (type_of(m) == CASTLING && !chess960)
+      to = make_square(to > from ? FILE_G : FILE_C, rank_of(from));
+
+  string move = UCI::square(from) + UCI::square(to);
+
+  if (type_of(m) == PROMOTION)
+      move += " pnbrqk"[promotion_type(m)];
+
+  return move;
+}
+
+
+/// UCI::to_move() converts a string representing a move in coordinate notation
+/// (g1f3, a7a8q) to the corresponding legal Move, if any.
+
+Move UCI::to_move(const Position& pos, string& str) {
+
+  if (str.length() == 5) // Junior could send promotion piece in uppercase
+      str[4] = char(tolower(str[4]));
+
+  for (MoveList<LEGAL> it(pos); *it; ++it)
+      if (str == UCI::move(*it, pos.is_chess960()))
+          return *it;
+
+  return MOVE_NONE;
 }

src/uci.h

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -17,12 +17,16 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#if !defined(UCIOPTION_H_INCLUDED)
+#ifndef UCIOPTION_H_INCLUDED
 #define UCIOPTION_H_INCLUDED
 
 #include <map>
 #include <string>
 
+#include "types.h"
+
+class Position;
+
 namespace UCI {
 
 class Option;
@@ -38,15 +42,16 @@ typedef std::map<std::string, Option, CaseInsensitiveLess> OptionsMap;
 /// Option class implements an option as defined by UCI protocol
 class Option {
 
-  typedef void (Fn)(const Option&);
+  typedef void (*OnChange)(const Option&);
 
 public:
-  Option(Fn* = NULL);
-  Option(bool v, Fn* = NULL);
-  Option(const char* v, Fn* = NULL);
-  Option(int v, int min, int max, Fn* = NULL);
+  Option(OnChange = NULL);
+  Option(bool v, OnChange = NULL);
+  Option(const char* v, OnChange = NULL);
+  Option(int v, int min, int max, OnChange = NULL);
 
-  Option& operator=(const std::string& v);
+  Option& operator=(const std::string&);
+  void operator<<(const Option&);
   operator int() const;
   operator std::string() const;
 
@@ -56,14 +61,18 @@ private:
   std::string defaultValue, currentValue, type;
   int min, max;
   size_t idx;
-  Fn* on_change;
+  OnChange on_change;
 };
 
 void init(OptionsMap&);
-void loop(const std::string&);
+void loop(int argc, char* argv[]);
+std::string value(Value v);
+std::string square(Square s);
+std::string move(Move m, bool chess960);
+Move to_move(const Position& pos, std::string& str);
 
 } // namespace UCI
 
 extern UCI::OptionsMap Options;
 
-#endif // !defined(UCIOPTION_H_INCLUDED)
+#endif // #ifndef UCIOPTION_H_INCLUDED

src/ucioption.cpp

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -22,11 +22,11 @@
 #include <cstdlib>
 #include <sstream>
 
-#include "evaluate.h"
 #include "misc.h"
 #include "thread.h"
 #include "tt.h"
-#include "ucioption.h"
+#include "uci.h"
+#include "syzygy/tbprobe.h"
 
 using std::string;
 
@@ -35,11 +35,11 @@ UCI::OptionsMap Options; // Global object
 namespace UCI {
 
 /// 'On change' actions, triggered by an option's value change
-void on_logger(const Option& o) { start_logger(o); }
-void on_eval(const Option&) { Eval::init(); }
-void on_threads(const Option&) { Threads.read_uci_options(); }
-void on_hash_size(const Option& o) { TT.set_size(o); }
 void on_clear_hash(const Option&) { TT.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_tb_path(const Option& o) { Tablebases::init(o); }
 
 
 /// Our case insensitive less() function as required by UCI protocol
@@ -50,44 +50,29 @@ bool CaseInsensitiveLess::operator() (const string& s1, const string& s2) const
 }
 
 
-/// init() initializes the UCI options to their hard coded default values
-/// and initializes the default value of "Threads" and "Min Split Depth"
-/// parameters according to the number of CPU cores detected.
+/// init() initializes the UCI options to their hard-coded default values
 
 void init(OptionsMap& o) {
 
-  int cpus = std::min(cpu_count(), MAX_THREADS);
-  int msd = cpus < 8 ? 4 : 7;
+  const int MaxHashMB = Is64Bit ? 1024 * 1024 : 2048;
 
-  o["Use Debug Log"]               = Option(false, on_logger);
-  o["Use Search Log"]              = Option(false);
-  o["Search Log Filename"]         = Option("SearchLog.txt");
-  o["Book File"]                   = Option("book.bin");
-  o["Best Book Move"]              = Option(false);
-  o["Mobility (Middle Game)"]      = Option(100, 0, 200, on_eval);
-  o["Mobility (Endgame)"]          = Option(100, 0, 200, on_eval);
-  o["Passed Pawns (Middle Game)"]  = Option(100, 0, 200, on_eval);
-  o["Passed Pawns (Endgame)"]      = Option(100, 0, 200, on_eval);
-  o["Space"]                       = Option(100, 0, 200, on_eval);
-  o["Aggressiveness"]              = Option(100, 0, 200, on_eval);
-  o["Cowardice"]                   = Option(100, 0, 200, on_eval);
-  o["Min Split Depth"]             = Option(msd, 4, 7, on_threads);
-  o["Max Threads per Split Point"] = Option(5, 4, 8, on_threads);
-  o["Threads"]                     = Option(cpus, 1, MAX_THREADS, on_threads);
-  o["Use Sleeping Threads"]        = Option(false, on_threads);
-  o["Hash"]                        = Option(32, 4, 8192, on_hash_size);
-  o["Clear Hash"]                  = Option(on_clear_hash);
-  o["Ponder"]                      = Option(true);
-  o["OwnBook"]                     = Option(false);
-  o["MultiPV"]                     = Option(1, 1, 500);
-  o["Skill Level"]                 = Option(20, 0, 20);
-  o["Emergency Move Horizon"]      = Option(40, 0, 50);
-  o["Emergency Base Time"]         = Option(200, 0, 30000);
-  o["Emergency Move Time"]         = Option(70, 0, 5000);
-  o["Minimum Thinking Time"]       = Option(20, 0, 5000);
-  o["Slow Mover"]                  = Option(100, 10, 1000);
-  o["UCI_Chess960"]                = Option(false);
-  o["UCI_AnalyseMode"]             = Option(false, on_eval);
+  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["Hash"]                  << Option(16, 1, MaxHashMB, on_hash_size);
+  o["Clear Hash"]            << Option(on_clear_hash);
+  o["Ponder"]                << Option(true);
+  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["UCI_Chess960"]          << 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);
 }
 
 
@@ -96,7 +81,7 @@ void init(OptionsMap& o) {
 
 std::ostream& operator<<(std::ostream& os, const OptionsMap& om) {
 
-  for (size_t idx = 0; idx < om.size(); idx++)
+  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)
           {
@@ -115,18 +100,18 @@ std::ostream& operator<<(std::ostream& os, const OptionsMap& om) {
 }
 
 
-/// Option c'tors and conversion operators
+/// Option class constructors and conversion operators
 
-Option::Option(const char* v, Fn* f) : type("string"), min(0), max(0), idx(Options.size()), on_change(f)
+Option::Option(const char* v, OnChange f) : type("string"), min(0), max(0), on_change(f)
 { defaultValue = currentValue = v; }
 
-Option::Option(bool v, Fn* f) : type("check"), min(0), max(0), idx(Options.size()), on_change(f)
+Option::Option(bool v, OnChange f) : type("check"), min(0), max(0), on_change(f)
 { defaultValue = currentValue = (v ? "true" : "false"); }
 
-Option::Option(Fn* f) : type("button"), min(0), max(0), idx(Options.size()), on_change(f)
+Option::Option(OnChange f) : type("button"), min(0), max(0), on_change(f)
 {}
 
-Option::Option(int v, int minv, int maxv, Fn* f) : type("spin"), min(minv), max(maxv), idx(Options.size()), 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(); }
 
 
@@ -141,6 +126,17 @@ Option::operator std::string() const {
 }
 
 
+/// operator<<() inits options and assigns idx in the correct printing order
+
+void Option::operator<<(const Option& o) {
+
+  static size_t insert_order = 0;
+
+  *this = o;
+  idx = insert_order++;
+}
+
+
 /// operator=() updates currentValue and triggers on_change() action. It's up to
 /// the GUI to check for option's limits, but we could receive the new value from
 /// the user by console window, so let's check the bounds anyway.
@@ -158,7 +154,7 @@ Option& Option::operator=(const string& v) {
       currentValue = v;
 
   if (on_change)
-      (*on_change)(*this);
+      on_change(*this);
 
   return *this;
 }