Stockfish 1.8 beta 2

Signed-off-by: Marco Costalba <mcostalba@gmail.com>

polyglot.ini

@@ -1,63 +1,48 @@
-
-[PolyGlot]
-
-EngineDir = .
-EngineCommand = ./stockfish
-
-Book = false
-BookFile = book.bin
-
-Log = true
-LogFile = stockfish.log
-
-Resign = true
-ResignScore = 600
-
-[Engine]
-
-Hash = 128
-Threads = 1
-OwnBook = false
-Book File = book.bin
-Use Search Log = false
-Mobility (Middle Game) = 100
-Mobility (Endgame) = 100
-Pawn Structure (Middle Game) = 100
-Pawn Structure (Endgame) = 100
-Passed Pawns (Middle Game) = 100
-Passed Pawns (Endgame) = 100
-Aggressiveness = 100
-Cowardice = 100
-King Safety Curve = Quadratic
-Quadratic = Linear
-King Safety Coefficient = 40
-King Safety X Intercept = 0
-King Safety Max Slope = 30
-King Safety Max Value = 500
-Queen Contact Check Bonus = 3
-Queen Check Bonus = 2
-Rook Check Bonus = 1
-Bishop Check Bonus = 1
-Knight Check Bonus = 1
-Discovered Check Bonus = 3
-Mate Threat Bonus = 3
-Check Extension (PV nodes) = 2
-Check Extension (non-PV nodes) = 1
-Single Reply Extension (PV nodes) = 2
-Single Reply Extension (non-PV nodes) = 2
-Mate Threat Extension (PV nodes) = 0
-Mate Threat Extension (non-PV nodes) = 0
-Pawn Push to 7th Extension (PV nodes) = 1
-Pawn Push to 7th Extension (non-PV nodes) = 1
-Passed Pawn Extension (PV nodes) = 1
-Passed Pawn Extension (non-PV nodes) = 0
-Pawn Endgame Extension (PV nodes) = 2
-Pawn Endgame Extension (non-PV nodes) = 2
-Full Depth Moves (PV nodes) = 14
-Full Depth Moves (non-PV nodes) = 3
-Threat Depth = 5
-Futility Pruning (Main Search) = true
-Futility Pruning (Quiescence Search) = true
-Randomness = 0
-Minimum Split Depth = 4
-Maximum Number of Threads per Split Point = 5
+
+[PolyGlot]
+
+EngineDir = .
+EngineCommand = ./stockfish
+
+Book = false
+BookFile = book.bin
+
+Log = false
+LogFile = stockfish.log
+
+Resign = true
+ResignScore = 600
+
+[Engine]
+
+Hash = 128
+Threads = 1
+OwnBook = false
+Book File = book.bin
+Best Book Move = false
+Use Search Log = false
+Search Log Filename = SearchLog.txt
+Mobility (Middle Game) = 100
+Mobility (Endgame) = 100
+Pawn Structure (Middle Game) = 100
+Pawn Structure (Endgame) = 100
+Passed Pawns (Middle Game) = 100
+Passed Pawns (Endgame) = 100
+Space = 100
+Aggressiveness = 100
+Cowardice = 100
+Check Extension (PV nodes) = 2
+Check Extension (non-PV nodes) = 1
+Single Reply Extension (PV nodes) = 2
+Single Reply Extension (non-PV nodes) = 2
+Mate Threat Extension (PV nodes) = 0
+Mate Threat Extension (non-PV nodes) = 0
+Pawn Push to 7th Extension (PV nodes) = 1
+Pawn Push to 7th Extension (non-PV nodes) = 1
+Passed Pawn Extension (PV nodes) = 1
+Passed Pawn Extension (non-PV nodes) = 0
+Pawn Endgame Extension (PV nodes) = 2
+Pawn Endgame Extension (non-PV nodes) = 2
+Randomness = 0
+Minimum Split Depth = 4
+Maximum Number of Threads per Split Point = 5

src/Makefile

@@ -1,7 +1,7 @@
 # Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-# Copyright (C) 2004-2007 Tord Romstad
-# Copyright (C) 2008 Marco Costalba
-
+# Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
+# Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
+#
 # This file is part of Stockfish.
 #
 # Stockfish is free software: you can redistribute it and/or modify
@@ -18,293 +18,485 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 
-### Executable name. Do not change
+### ==========================================================================
+### Section 1. General Configuration
+### ==========================================================================
+
+### Executable name
 EXE = stockfish
 
 ### Installation dir definitions
 PREFIX = /usr/local
 BINDIR = $(PREFIX)/bin
 
-
-### ==========================================================================
-### Compiler speed switches for both GCC and ICC. These settings are generally
-### fast on a broad range of systems, but may be changed experimentally
-### ==========================================================================
-GCCFLAGS = -O3 -msse
-ICCFLAGS = -fast -msse
-ICCFLAGS-OSX = -fast -mdynamic-no-pic
-
-
-### ==========================================================================
-### Enable/disable debugging, disabled by default
-### ==========================================================================
-GCCFLAGS += -DNDEBUG
-ICCFLAGS += -DNDEBUG
-ICCFLAGS-OSX += -DNDEBUG
-
-
-### ==========================================================================
-### Remove below comments to compile for a big-endian machine
-### ==========================================================================
-#GCCFLAGS += -DBIGENDIAN
-#ICCFLAGS += -DBIGENDIAN
-#ICCFLAGS-OSX += -DBIGENDIAN
-
-
-### ==========================================================================
-### Run built-in benchmark for pgo-builds with:  32MB hash  1 thread  10 depth
-### These settings are generally fast, but may be changed experimentally
-### ==========================================================================
+### Built-in benchmark for pgo-builds
 PGOBENCH = ./$(EXE) bench 32 1 10 default depth
 
-
-### General compiler settings. Do not change
-GCCFLAGS += -g -Wall -fno-exceptions -fno-rtti
-ICCFLAGS += -g -Wall -fno-exceptions -fno-rtti -wd383,869,981,10187,10188,11505,11503
-ICCFLAGS-OSX += -g -Wall -fno-exceptions -fno-rtti -wd383,869,981,10187,10188,11505,11503
-
-
-### General linker settings. Do not change
-LDFLAGS  = -lpthread
-
-
-### Object files. Do not change
+### Object files
 OBJS = application.o bitboard.o pawns.o material.o endgame.o evaluate.o main.o \
 	misc.o move.o movegen.o history.o movepick.o search.o piece.o \
 	position.o direction.o tt.o value.o uci.o ucioption.o \
 	mersenne.o book.o bitbase.o san.o benchmark.o
 
 
-### General rules. Do not change
+### ==========================================================================
+### Section 2. High-level Configuration
+### ==========================================================================
+#
+# flag                --- Comp switch --- Description
+# ----------------------------------------------------------------------------
+#
+# debug = no/yes      --- -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
+# bigendian = no/yes  --- -DBIGENDIAN --- big/little-endian byte order
+# prefetch = no/yes   --- -DUSE_PREFETCH  --- Use prefetch x86 asm-instruction
+# bsfq = no/yes       --- -DUSE_BSFQ  --- Use bsfq x86_64 asm-instruction
+#                                     --- (Works only with GCC and ICC 64-bit)
+# popcnt = no/yes     --- -DUSE_POPCNT --- Use popcnt 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
+optimize = yes
+
+### 2.2 Architecture specific
+
+# General-section
+ifeq ($(ARCH),general-64)
+	arch = any
+	os = any
+	bits = 64
+	bigendian = no
+	prefetch = no
+	bsfq = no
+	popcnt = no
+endif
+
+ifeq ($(ARCH),general-32)
+	arch = any
+	os = any
+	bits = 32
+	bigendian = no
+	prefetch = no
+	bsfq = no
+	popcnt = no
+endif
+
+ifeq ($(ARCH),bigendian-64)
+	arch = any
+	os = any
+	bits = 64
+	bigendian = yes
+	prefetch = no
+	bsfq = no
+	popcnt = no
+endif
+
+ifeq ($(ARCH),bigendian-32)
+	arch = any
+	os = any
+	bits = 32
+	bigendian = yes
+	prefetch = no
+	bsfq = no
+	popcnt = no
+endif
+
+# x86-section
+ifeq ($(ARCH),x86-64)
+	arch = x86_64
+	os = any
+	bits = 64
+	bigendian = no
+	prefetch = yes
+	bsfq = yes
+	popcnt = no
+endif
+
+ifeq ($(ARCH),x86-64-modern)
+	arch = x86_64
+	os = any
+	bits = 64
+	bigendian = no
+	prefetch = yes
+	bsfq = yes
+	popcnt = yes
+endif
+
+ifeq ($(ARCH),x86-32)
+	arch = i386
+	os = any
+	bits = 32
+	bigendian = no
+	prefetch = yes
+	bsfq = no
+	popcnt = no
+endif
+
+ifeq ($(ARCH),x86-32-old)
+	arch = i386
+	os = any
+	bits = 32
+	bigendian = no
+	prefetch = no
+	bsfq = no
+	popcnt = no
+endif
+
+# osx-section
+ifeq ($(ARCH),osx-ppc-64)
+	arch = ppc64
+	os = osx
+	bits = 64
+	bigendian = yes
+	prefetch = no
+	bsfq = no
+	popcnt = no
+endif
+
+ifeq ($(ARCH),osx-ppc-32)
+	arch = ppc
+	os = osx
+	bits = 32
+	bigendian = yes
+	prefetch = no
+	bsfq = no
+	popcnt = no
+endif
+
+ifeq ($(ARCH),osx-x86-64)
+	arch = x86_64
+	os = osx
+	bits = 64
+	bigendian = no
+	prefetch = yes
+	bsfq = yes
+	popcnt = no
+endif
+
+ifeq ($(ARCH),osx-x86-32)
+	arch = i386
+	os = osx
+	bits = 32
+	bigendian = no
+	prefetch = yes
+	bsfq = no
+	popcnt = no
+endif
+
+
+### ==========================================================================
+### Section 3. Low-level configuration
+### ==========================================================================
+
+### 3.1 Selecting compiler (default = gcc)
+ifeq ($(COMP),)
+	COMP=gcc
+endif
+
+ifeq ($(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
+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
+endif
+
+### 3.2 General compiler settings
+CXXFLAGS += -g -Wall -fno-exceptions -fno-rtti $(EXTRACXXFLAGS)
+
+ifeq ($(comp),icc)
+	CXXFLAGS += -wd383,869,981,10187,10188,11505,11503
+endif
+
+ifeq ($(os),osx)
+	CXXFLAGS += -arch $(arch)
+endif
+
+### 3.3 General linker settings
+LDFLAGS += -lpthread $(EXTRALDFLAGS)
+
+ifeq ($(os),osx)
+	LDFLAGS += -arch $(arch)
+endif
+
+### 3.4 Debugging
+ifeq ($(debug),no)
+	CXXFLAGS += -DNDEBUG
+endif
+
+### 3.5 Optimization
+ifeq ($(optimize),yes)
+
+	ifeq ($(comp),gcc)
+		CXXFLAGS += -O3
+
+		ifeq ($(os),osx)
+			ifeq ($(arch),i386)
+				CXXFLAGS += -mdynamic-no-pic
+			endif
+			ifeq ($(arch),x86_64)
+				CXXFLAGS += -mdynamic-no-pic
+			endif
+		endif
+	endif
+
+	ifeq ($(comp),icc)
+		CXXFLAGS += -fast
+
+		ifeq ($(os),osx)
+			CXXFLAGS += -mdynamic-no-pic
+		endif
+	endif
+endif
+
+### 3.6. Bits
+ifeq ($(bits),64)
+	CXXFLAGS += -DIS_64BIT
+endif
+
+### 3.7 Endianess
+ifeq ($(bigendian),yes)
+	CXXFLAGS += -DBIGENDIAN
+endif
+
+### 3.8 prefetch
+ifeq ($(prefetch),yes)
+	CXXFLAGS += -msse
+	DEPENDFLAGS += -msse
+else
+	CXXFLAGS += -DNO_PREFETCH
+endif
+
+### 3.9 bsfq
+ifeq ($(bsfq),yes)
+	CXXFLAGS += -DUSE_BSFQ
+endif
+
+### 3.10 popcnt
+ifeq ($(popcnt),yes)
+	CXXFLAGS += -DUSE_POPCNT
+endif
+
+### ==========================================================================
+### Section 4. Public targets
+### ==========================================================================
+
 default:
-	$(MAKE) gcc
+	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) build
 
 help:
 	@echo ""
-	@echo "Makefile options:"
+	@echo "To compile stockfish, type: "
 	@echo ""
-	@echo "make                >  Default: Compiler = g++"
-	@echo "make gcc-popcnt     >  Compiler = g++ + popcnt-support"
-	@echo "make icc            >  Compiler = icpc"
-	@echo "make icc-profile    >  Compiler = icpc + automatic pgo-build"
-	@echo "make icc-profile-popcnt >  Compiler = icpc + automatic pgo-build + popcnt-support"
-	@echo "make osx-ppc32      >  PPC-Mac OS X 32 bit. Compiler = g++"
-	@echo "make osx-ppc64      >  PPC-Mac OS X 64 bit. Compiler = g++"
-	@echo "make osx-x86        >  x86-Mac OS X 32 bit. Compiler = g++"
-	@echo "make osx-x86_64     >  x86-Mac OS X 64 bit. Compiler = g++"
-	@echo "make osx-icc32      >  x86-Mac OS X 32 bit. Compiler = icpc"
-	@echo "make osx-icc64      >  x86-Mac OS X 64 bit. Compiler = icpc"
-	@echo "make osx-icc32-profile > OSX 32 bit. Compiler = icpc + automatic pgo-build"
-	@echo "make osx-icc64-profile > OSX 64 bit. Compiler = icpc + automatic pgo-build"
-	@echo "make hpux           >  HP-UX. Compiler = aCC"
-	@echo "make strip          >  Strip executable"
-	@echo "make clean          >  Clean up"
+	@echo "make target ARCH=arch [COMP=comp]"
 	@echo ""
+	@echo "Supported targets:"
+	@echo ""
+	@echo "build                > Build unoptimized version"
+	@echo "profile-build        > Build PGO-optimized version"
+	@echo "popcnt-profile-build > Build PGO-optimized version with optional popcnt-support"
+	@echo "strip                > Strip executable"
+	@echo "install              > Install executable"
+	@echo "clean                > Clean up"
+	@echo "testrun              > Make sample run"
+	@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 very 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 "bigendian-64         > unspecified 64-bit with bigendian byte order"
+	@echo "bigendian-32         > unspecified 32-bit with bigendian byte order"
+	@echo ""
+	@echo "Supported comps:"
+	@echo ""
+	@echo "gcc                  > Gnu compiler (default)"
+	@echo "icc                  > Intel compiler"
+	@echo ""
+	@echo "Non-standard targets:"
+	@echo ""
+	@echo "make hpux           >  Compile for HP-UX. Compiler = aCC"
+	@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 ""
+
+build:
+	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) config-sanity
+	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) all
+
+profile-build:
+	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) config-sanity
+	@echo ""
+	@echo "Step 0/4. Preparing for profile build."
+	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) $(profile_prepare)
+	@echo ""
+	@echo "Step 1/4. Building executable for benchmark ..."
+	@touch *.cpp *.h
+	$(MAKE) ARCH=$(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
+	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) $(profile_use)
+	@echo ""
+	@echo "Step 4/4. Deleting profile data ..."
+	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) $(profile_clean)
+
+popcnt-profile-build:
+	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) config-sanity
+	@echo ""
+	@echo "Step 0/6. Preparing for profile build."
+	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) $(profile_prepare)
+	@echo ""
+	@echo "Step 1/6. Building executable for benchmark (popcnt disabled)..."
+	@touch *.cpp *.h
+	$(MAKE) ARCH=x86-64 COMP=$(COMP) $(profile_make)
+	@echo ""
+	@echo "Step 2/6. Running benchmark for pgo-build (popcnt disabled)..."
+	@$(PGOBENCH) > /dev/null
+	@echo ""
+	@echo "Step 3/6. Building executable for benchmark (popcnt enabled)..."
+	@touch *.cpp *.h
+	$(MAKE) ARCH=x86-64-modern COMP=$(COMP) $(profile_make)
+	@echo ""
+	@echo "Step 4/6. Running benchmark for pgo-build (popcnt enabled)..."
+	@$(PGOBENCH) > /dev/null
+	@echo ""
+	@echo "Step 5/6. Building final executable ..."
+	@touch *.cpp *.h
+	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) $(profile_use)
+	@echo ""
+	@echo "Step 6/6. Deleting profile data ..."
+	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) $(profile_clean)
+	@echo ""
+
+strip:
+	strip $(EXE)
+
+install:
+	-mkdir -p -m 755 $(BINDIR)
+	-cp $(EXE) $(BINDIR)
+	-strip $(BINDIR)/$(EXE)
+
+clean:
+	$(RM) $(EXE) *.o .depend *~ core bench.txt
+
+testrun:
+	@$(PGOBENCH)
+
+### ==========================================================================
+### Section 5. Private targets
+### ==========================================================================
 
 all: $(EXE) .depend
 
-test check: default
-	@$(PGOBENCH)
+config-sanity:
+	@echo ""
+	@echo "Config:"
+	@echo "debug: '$(debug)'"
+	@echo "optimize: '$(optimize)'"
+	@echo "arch: '$(arch)'"
+	@echo "os: '$(os)'"
+	@echo "bits: '$(bits)'"
+	@echo "bigendian: '$(bigendian)'"
+	@echo "prefetch: '$(prefetch)'"
+	@echo "bsfq: '$(bsfq)'"
+	@echo "popcnt: '$(popcnt)'"
+	@echo ""
+	@echo "Flags:"
+	@echo "CXX: $(CXX)"
+	@echo "CXXFLAGS: $(CXXFLAGS)"
+	@echo "LDFLAGS: $(LDFLAGS)"
+	@echo ""
+	@echo "Testing config sanity. If this fails, try 'make help' ..."
+	@echo ""
+	@test "$(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 "$(bits)" = "32" || test "$(bits)" = "64"
+	@test "$(bigendian)" = "yes" || test "$(bigendian)" = "no"
+	@test "$(prefetch)" = "yes" || test "$(prefetch)" = "no"
+	@test "$(bsfq)" = "yes" || test "$(bsfq)" = "no"
+	@test "$(popcnt)" = "yes" || test "$(popcnt)" = "no"
+	@test "$(comp)" = "gcc" || test "$(comp)" = "icc"
 
-clean:
-	$(RM) *.o .depend *~ $(EXE) core bench.txt
+$(EXE): $(OBJS)
+	$(CXX) -o $@ $(OBJS) $(LDFLAGS)
 
+gcc-profile-prepare:
+	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) gcc-profile-clean
 
-### Possible targets. You may add your own ones here
-gcc:
-	$(MAKE) \
-	CXX='g++' \
-	CXXFLAGS="$(GCCFLAGS)" \
+gcc-profile-make:
+	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) \
+	EXTRACXXFLAGS='-fprofile-generate' \
+	EXTRALDFLAGS='-lgcov' \
 	all
 
-gcc-popcnt:
-	$(MAKE) \
-	CXX='g++' \
-	CXXFLAGS="$(GCCFLAGS) -DUSE_POPCNT" \
+gcc-profile-use:
+	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) \
+	EXTRACXXFLAGS='-fprofile-use' \
 	all
 
+gcc-profile-clean:
+	@rm -rf *.gcda *.gcno bench.txt
 
-icc:
-	$(MAKE) \
-	CXX='icpc' \
-	CXXFLAGS="$(ICCFLAGS)" \
-	all
+icc-profile-prepare:
+	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) icc-profile-clean
+	@mkdir profdir
 
 icc-profile-make:
-	$(MAKE) \
-	CXX='icpc' \
-	CXXFLAGS="$(ICCFLAGS)" \
-	CXXFLAGS+='-prof-gen=srcpos -prof_dir ./profdir' \
+	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) \
+	EXTRACXXFLAGS='-prof-gen=srcpos -prof_dir ./profdir' \
 	all
 
 icc-profile-use:
-	$(MAKE) \
-	CXX='icpc' \
-	CXXFLAGS="$(ICCFLAGS)" \
-	CXXFLAGS+='-prof_use -prof_dir ./profdir' \
+	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) \
+	EXTRACXXFLAGS='-prof_use -prof_dir ./profdir' \
 	all
 
-icc-profile:
-	@rm -rf profdir
-	@mkdir profdir
-	@touch *.cpp *.h
-	$(MAKE) icc-profile-make
-	@echo ""
-	@echo "Running benchmark for pgo-build ..."
-	@$(PGOBENCH) > /dev/null
-	@echo "Benchmark finished. Build final executable now ..."
-	@echo ""
-	@touch *.cpp *.h
-	$(MAKE) icc-profile-use
+icc-profile-clean:
 	@rm -rf profdir bench.txt
 
-icc-profile-make-with-popcnt:
-	$(MAKE) \
-	CXX='icpc' \
-	CXXFLAGS="$(ICCFLAGS) -DUSE_POPCNT" \
-	CXXFLAGS+='-prof-gen=srcpos -prof_dir ./profdir' \
-	all
+.depend:
+	-@$(CXX) $(DEPENDFLAGS) -MM $(OBJS:.o=.cpp) > $@ 2> /dev/null
 
-icc-profile-use-with-popcnt:
-	$(MAKE) \
-	CXX='icpc' \
-	CXXFLAGS="$(ICCFLAGS) -DUSE_POPCNT" \
-	CXXFLAGS+='-prof_use -prof_dir ./profdir' \
-	all
-
-icc-profile-popcnt:
-	@rm -rf profdir
-	@mkdir profdir
-	@touch *.cpp *.h
-	$(MAKE) icc-profile-make
-	@echo ""
-	@echo "Running benchmark for pgo-build (popcnt disabled)..."
-	@$(PGOBENCH) > /dev/null
-	@touch *.cpp *.h
-	$(MAKE) icc-profile-make-with-popcnt
-	@echo ""
-	@echo "Running benchmark for pgo-build (popcnt enabled)..."
-	@$(PGOBENCH) > /dev/null
-	@echo "Benchmarks finished. Build final executable now ..."
-	@echo ""
-	@touch *.cpp *.h
-	$(MAKE) icc-profile-use-with-popcnt
-	@rm -rf profdir bench.txt
+-include .depend
 
 
-osx-ppc32:
-	$(MAKE) \
-	CXX='g++' \
-	CXXFLAGS="$(GCCFLAGS)" \
-	CXXFLAGS+='-arch ppc' \
-	CXXFLAGS+='-DBIGENDIAN' \
-	LDFLAGS+='-arch ppc' \
-	all
-
-osx-ppc64:
-	$(MAKE) \
-	CXX='g++' \
-	CXXFLAGS="$(GCCFLAGS)" \
-	CXXFLAGS+='-arch ppc64' \
-	CXXFLAGS+='-DBIGENDIAN' \
-	LDFLAGS+='-arch ppc64' \
-	all
-
-osx-x86:
-	$(MAKE) \
-	CXX='g++' \
-	CXXFLAGS="$(GCCFLAGS)" \
-	CXXFLAGS+='-arch i386 -mdynamic-no-pic' \
-	LDFLAGS+='-arch i386 -mdynamic-no-pic' \
-	all
-
-osx-x86_64:
-	$(MAKE) \
-	CXX='g++' \
-	CXXFLAGS="$(GCCFLAGS)" \
-	CXXFLAGS+='-arch x86_64 -mdynamic-no-pic' \
-	LDFLAGS+='-arch x86_64 -mdynamic-no-pic' \
-	all
-	
-osx-icc32:
-	$(MAKE) \
-	CXX='icpc' \
-	CXXFLAGS="$(ICCFLAGS-OSX)" \
-	CXXFLAGS+='-arch i386' \
-	LDFLAGS+='-arch i386' \
-	all
-
-osx-icc64:
-	$(MAKE) \
-	CXX='icpc' \
-	CXXFLAGS="$(ICCFLAGS-OSX)" \
-	CXXFLAGS+='-arch x86_64' \
-	LDFLAGS+='-arch x86_64' \
-	all
-
-osx-icc32-profile-make:
-	$(MAKE) \
-	CXX='icpc' \
-	CXXFLAGS="$(ICCFLAGS-OSX)" \
-	CXXFLAGS+='-arch i386' \
-	CXXFLAGS+='-prof_gen -prof_dir ./profdir' \
-	LDFLAGS+='-arch i386' \
-	all
-
-osx-icc32-profile-use:
-	$(MAKE) \
-	CXX='icpc' \
-	CXXFLAGS="$(ICCFLAGS-OSX)" \
-	CXXFLAGS+='-arch i386' \
-	CXXFLAGS+='-prof_use -prof_dir ./profdir' \
-	LDFLAGS+='-arch i386' \
-	all
-
-osx-icc32-profile:
-	@rm -rf profdir
-	@mkdir profdir
-	@touch *.cpp *.h
-	$(MAKE) osx-icc32-profile-make
-	@echo ""
-	@echo "Running benchmark for pgo-build ..."
-	@$(PGOBENCH) > /dev/null
-	@echo "Benchmark finished. Build final executable now ..."
-	@echo ""
-	@touch *.cpp *.h
-	$(MAKE) osx-icc32-profile-use
-	@rm -rf profdir bench.txt
-
-osx-icc64-profile-make:
-	$(MAKE) \
-	CXX='icpc' \
-	CXXFLAGS="$(ICCFLAGS-OSX)" \
-	CXXFLAGS+='-arch x86_64' \
-	CXXFLAGS+='-prof_gen -prof_dir ./profdir' \
-	LDFLAGS+='-arch x86_64' \
-	all
-
-osx-icc64-profile-use:
-	$(MAKE) \
-	CXX='icpc' \
-	CXXFLAGS="$(ICCFLAGS-OSX)" \
-	CXXFLAGS+='-arch x86_64' \
-	CXXFLAGS+='-prof_use -prof_dir ./profdir' \
-	LDFLAGS+='-arch x86_64' \
-	all
-
-osx-icc64-profile:
-	@rm -rf profdir
-	@mkdir profdir
-	@touch *.cpp *.h
-	$(MAKE) osx-icc64-profile-make
-	@echo ""
-	@echo "Running benchmark for pgo-build ..."
-	@$(PGOBENCH) > /dev/null
-	@echo "Benchmark finished. Build final executable now ..."
-	@echo ""
-	@touch *.cpp *.h
-	$(MAKE) osx-icc64-profile-use
-	@rm -rf profdir bench.txt
+### ==========================================================================
+### Section 6. Non-standard targets
+### ==========================================================================
 
 hpux:
 	$(MAKE) \
@@ -313,23 +505,3 @@ hpux:
 	LDFLAGS="" \
 	all
 
-
-strip:
-	strip $(EXE)
-
-
-### Compilation. Do not change
-$(EXE): $(OBJS)
-	$(CXX) $(LDFLAGS) -o $@ $(OBJS)
-
-### Installation
-install: default
-	-mkdir -p -m 755 $(BINDIR)
-	-cp $(EXE) $(BINDIR)
-	-strip $(BINDIR)/$(EXE)
-
-### Dependencies. Do not change
-.depend:
-	-@$(CXX) -msse -MM $(OBJS:.o=.cpp) > $@ 2> /dev/null
-
--include .depend

src/application.cpp

@@ -57,12 +57,6 @@ Application::Application() {
         genrand_int32();
 }
 
-Application::~Application() {
-
-  exit_threads();
-  quit_eval();
-}
-
 void Application::initialize() {
 
   // A static Application object is allocated
@@ -70,7 +64,15 @@ void Application::initialize() {
   static Application singleton;
 }
 
+void Application::free_resources() {
+
+  // Warning, following functions reference global objects that
+  // must be still alive when free_resources() is called.
+  exit_threads();
+  quit_eval();
+}
+
 void Application::exit_with_failure() {
 
-  exit(EXIT_FAILURE); // d'tor will be called automatically
+  exit(EXIT_FAILURE);
 }

src/application.h

@@ -29,10 +29,10 @@ class Application {
 
   Application();
   Application(const Application&);
- ~Application();
 
 public:
   static void initialize();
+  static void free_resources();
   static void exit_with_failure();
 };
 

src/benchmark.cpp

@@ -38,8 +38,8 @@ using namespace std;
 
 const string BenchmarkPositions[] = {
   "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1",
-  "r4rk1/1b2qppp/p1n1p3/1p6/1b1PN3/3BRN2/PP3PPP/R2Q2K1 b - - 7 16",
-  "4r1k1/ppq3pp/3b4/2pP4/2Q1p3/4B1P1/PP5P/R5K1 b - - 0 20",
+  "r3k2r/p1ppqpb1/bn2pnp1/3PN3/1p2P3/2N2Q1p/PPPBBPPP/R3K2R w KQkq -",
+  "8/2p5/3p4/KP5r/1R3p1k/8/4P1P1/8 w - -",
   "4rrk1/pp1n3p/3q2pQ/2p1pb2/2PP4/2P3N1/P2B2PP/4RRK1 b - - 7 19",
   "rq3rk1/ppp2ppp/1bnpb3/3N2B1/3NP3/7P/PPPQ1PP1/2KR3R w - - 7 14",
   "r1bq1r1k/1pp1n1pp/1p1p4/4p2Q/4Pp2/1BNP4/PPP2PPP/3R1RK1 w - - 2 14",
@@ -151,13 +151,18 @@ void benchmark(const string& commandLine) {
   {
       Move moves[1] = {MOVE_NONE};
       int dummy[2] = {0, 0};
-      Position pos(*it);
+      Position pos(*it, 0);
       cerr << "\nBench position: " << cnt << '/' << positions.size() << endl << endl;
       if (limitType == "perft")
-          totalNodes += perft(pos, maxDepth * OnePly);
-      else if (!think(pos, false, false, 0, dummy, dummy, 0, maxDepth, maxNodes, secsPerPos, moves))
-          break;
-      totalNodes += nodes_searched();
+      {
+          int64_t perftCnt = perft(pos, maxDepth * OnePly);
+          cerr << "\nPerft " << maxDepth << " result (nodes searched): " << perftCnt << endl << endl;
+          totalNodes += perftCnt;
+      } else {
+          if (!think(pos, false, false, 0, dummy, dummy, 0, maxDepth, maxNodes, secsPerPos, moves))
+              break;
+          totalNodes += nodes_searched();
+      }
   }
 
   cnt = get_system_time() - startTime;

src/bitboard.cpp

@@ -226,8 +226,9 @@ Bitboard StepAttackBB[16][64];
 Bitboard RayBB[64][8];
 Bitboard BetweenBB[64][64];
 
+Bitboard SquaresInFrontMask[2][64];
 Bitboard PassedPawnMask[2][64];
-Bitboard OutpostMask[2][64];
+Bitboard AttackSpanMask[2][64];
 
 Bitboard BishopPseudoAttacks[64];
 Bitboard RookPseudoAttacks[64];
@@ -246,14 +247,12 @@ namespace {
   void init_ray_bitboards();
   void init_attacks();
   void init_between_bitboards();
+  void init_pseudo_attacks();
+  Bitboard index_to_bitboard(int index, Bitboard mask);
   Bitboard sliding_attacks(int sq, Bitboard block, int dirs, int deltas[][2],
                            int fmin, int fmax, int rmin, int rmax);
-  Bitboard index_to_bitboard(int index, Bitboard mask);
-  void init_sliding_attacks(Bitboard attacks[],
-                            int attackIndex[], Bitboard mask[],
-                            const int shift[2], const Bitboard mult[],
-                            int deltas[][2]);
-  void init_pseudo_attacks();
+  void init_sliding_attacks(Bitboard attacks[], int attackIndex[], Bitboard mask[],
+                            const int shift[], const Bitboard mult[], int deltas[][2]);
 }
 
 
@@ -265,11 +264,14 @@ namespace {
 /// standard output.  This is sometimes useful for debugging.
 
 void print_bitboard(Bitboard b) {
-  for(Rank r = RANK_8; r >= RANK_1; r--) {
-    std::cout << "+---+---+---+---+---+---+---+---+" << std::endl;
-    for(File f = FILE_A; f <= FILE_H; f++)
-      std::cout << "| " << (bit_is_set(b, make_square(f, r))? 'X' : ' ') << ' ';
-    std::cout << "|" << std::endl;
+
+  for (Rank r = RANK_8; r >= RANK_1; r--)
+  {
+      std::cout << "+---+---+---+---+---+---+---+---+" << std::endl;
+      for (File f = FILE_A; f <= FILE_H; f++)
+          std::cout << "| " << (bit_is_set(b, make_square(f, r))? 'X' : ' ') << ' ';
+
+      std::cout << "|" << std::endl;
   }
   std::cout << "+---+---+---+---+---+---+---+---+" << std::endl;
 }
@@ -279,8 +281,10 @@ void print_bitboard(Bitboard b) {
 /// program initialization.
 
 void init_bitboards() {
+
   int rookDeltas[4][2] = {{0,1},{0,-1},{1,0},{-1,0}};
   int bishopDeltas[4][2] = {{1,1},{-1,1},{1,-1},{-1,-1}};
+
   init_masks();
   init_ray_bitboards();
   init_attacks();
@@ -326,6 +330,7 @@ const int BitTable[64] = {
 };
 
 Square first_1(Bitboard b) {
+
   b ^= (b - 1);
   uint32_t fold = int(b) ^ int(b >> 32);
   return Square(BitTable[(fold * 0x783a9b23) >> 26]);
@@ -368,39 +373,6 @@ Square pop_1st_bit(Bitboard* bb) {
 
 #endif
 
-// Optimized bitScanReverse32() implementation by Pascal Georges. Note
-// that first bit is 1, this allow to differentiate between 0 and 1.
-static CACHE_LINE_ALIGNMENT
-const char MsbTable[256] = {
-  0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5,
-  5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
-  6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7,
-  7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
-  7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
-  7, 7, 7, 7, 7, 7, 7, 7, 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, 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, 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, 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, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8
-};
-
-int bitScanReverse32(uint32_t b)
-{
-   int result = 0;
-
-   if (b > 0xFFFF)
-   {
-      b >>= 16;
-      result += 16;
-   }
-   if (b > 0xFF)
-   {
-      b >>= 8;
-      result += 8;
-   }
-   return result + MsbTable[b];
-}
 
 namespace {
 
@@ -410,39 +382,46 @@ namespace {
   // be necessary to touch any of them.
 
   void init_masks() {
+
     SetMaskBB[SQ_NONE] = 0ULL;
     ClearMaskBB[SQ_NONE] = ~SetMaskBB[SQ_NONE];
-    for(Square s = SQ_A1; s <= SQ_H8; s++) {
-      SetMaskBB[s] = (1ULL << s);
-      ClearMaskBB[s] = ~SetMaskBB[s];
+
+    for (Square s = SQ_A1; s <= SQ_H8; s++)
+    {
+        SetMaskBB[s] = (1ULL << s);
+        ClearMaskBB[s] = ~SetMaskBB[s];
     }
-    for(Color c = WHITE; c <= BLACK; c++)
-      for(Square s = SQ_A1; s <= SQ_H8; s++) {
-        PassedPawnMask[c][s] =
-          in_front_bb(c, s) & this_and_neighboring_files_bb(s);
-        OutpostMask[c][s] = in_front_bb(c, s) & neighboring_files_bb(s);
-      }
+
+    for (Color c = WHITE; c <= BLACK; c++)
+        for (Square s = SQ_A1; s <= SQ_H8; s++)
+        {
+            SquaresInFrontMask[c][s] = in_front_bb(c, s) & file_bb(s);
+            PassedPawnMask[c][s] = in_front_bb(c, s) & this_and_neighboring_files_bb(s);
+            AttackSpanMask[c][s] = in_front_bb(c, s) & neighboring_files_bb(s);
+        }
 
     for (Bitboard b = 0ULL; b < 256ULL; b++)
         BitCount8Bit[b] = (uint8_t)count_1s(b);
   }
 
+  int remove_bit_8(int i) { return ((i & ~15) >> 1) | (i & 7); }
 
   void init_ray_bitboards() {
+
     int d[8] = {1, -1, 16, -16, 17, -17, 15, -15};
-    for(int i = 0; i < 128; i = (i + 9) & ~8) {
-      for(int j = 0; j < 8; j++) {
-        RayBB[(i&7)|((i>>4)<<3)][j] = EmptyBoardBB;
-        for(int k = i + d[j]; (k & 0x88) == 0; k += d[j])
-          set_bit(&(RayBB[(i&7)|((i>>4)<<3)][j]), Square((k&7)|((k>>4)<<3)));
-      }
-    }
+
+    for (int i = 0; i < 128; i = (i + 9) & ~8)
+        for (int j = 0; j < 8; j++)
+        {
+            RayBB[remove_bit_8(i)][j] = EmptyBoardBB;
+            for (int k = i + d[j]; (k & 0x88) == 0; k += d[j])
+                set_bit(&(RayBB[remove_bit_8(i)][j]), Square(remove_bit_8(k)));
+        }
   }
 
-
   void init_attacks() {
-    int i, j, k, l;
-    int step[16][8] =  {
+
+    const int step[16][8] =  {
       {0},
       {7,9,0}, {17,15,10,6,-6,-10,-15,-17}, {9,7,-7,-9,0}, {8,1,-1,-8,0},
       {9,7,-7,-9,8,1,-1,-8}, {9,7,-7,-9,8,1,-1,-8}, {0}, {0},
@@ -450,105 +429,115 @@ namespace {
       {9,7,-7,-9,8,1,-1,-8}, {9,7,-7,-9,8,1,-1,-8}
     };
 
-    for(i = 0; i < 64; i++) {
-      for(j = 0; j <= int(BK); j++) {
-        StepAttackBB[j][i] = EmptyBoardBB;
-        for(k = 0; k < 8 && step[j][k] != 0; k++) {
-          l = i + step[j][k];
-          if(l >= 0 && l < 64 && abs((i&7) - (l&7)) < 3)
-            StepAttackBB[j][i] |= (1ULL << l);
+    for (int i = 0; i < 64; i++)
+        for (int j = 0; j <= int(BK); j++)
+        {
+            StepAttackBB[j][i] = EmptyBoardBB;
+            for (int k = 0; k < 8 && step[j][k] != 0; k++)
+            {
+                int l = i + step[j][k];
+                if (l >= 0 && l < 64 && abs((i & 7) - (l & 7)) < 3)
+                    StepAttackBB[j][i] |= (1ULL << l);
+           }
         }
-      }
-    }
   }
 
-
   Bitboard sliding_attacks(int sq, Bitboard block, int dirs, int deltas[][2],
                            int fmin=0, int fmax=7, int rmin=0, int rmax=7) {
     Bitboard result = 0ULL;
-    int rk = sq / 8, fl = sq % 8, r, f, i;
-    for(i = 0; i < dirs; i++) {
-      int dx = deltas[i][0], dy = deltas[i][1];
-      for(f = fl+dx, r = rk+dy;
-          (dx==0 || (f>=fmin && f<=fmax)) && (dy==0 || (r>=rmin && r<=rmax));
-          f += dx, r += dy) {
-        result |= (1ULL << (f + r*8));
-        if(block & (1ULL << (f + r*8))) break;
-      }
+    int rk = sq / 8;
+    int fl = sq % 8;
+
+    for (int i = 0; i < dirs; i++)
+    {
+        int dx = deltas[i][0];
+        int dy = deltas[i][1];
+        int f = fl + dx;
+        int r = rk + dy;
+
+        while (   (dx == 0 || (f >= fmin && f <= fmax))
+               && (dy == 0 || (r >= rmin && r <= rmax)))
+        {
+            result |= (1ULL << (f + r*8));
+            if (block & (1ULL << (f + r*8)))
+                break;
+
+            f += dx;
+            r += dy;
+        }
     }
     return result;
   }
 
-
   void init_between_bitboards() {
-    SquareDelta step[8] = {
-      DELTA_E, DELTA_W, DELTA_N, DELTA_S, DELTA_NE, DELTA_SW, DELTA_NW, DELTA_SE
-    };
-    SignedDirection d;
-    for(Square s1 = SQ_A1; s1 <= SQ_H8; s1++)
-      for(Square s2 = SQ_A1; s2 <= SQ_H8; s2++) {
-        BetweenBB[s1][s2] = EmptyBoardBB;
-        d = signed_direction_between_squares(s1, s2);
-        if(d != SIGNED_DIR_NONE)
-          for(Square s3 = s1 + step[d]; s3 != s2; s3 += step[d])
-            set_bit(&(BetweenBB[s1][s2]), s3);
+
+    const SquareDelta step[8] = { DELTA_E, DELTA_W, DELTA_N, DELTA_S,
+                                  DELTA_NE, DELTA_SW, DELTA_NW, DELTA_SE };
+
+    for (Square s1 = SQ_A1; s1 <= SQ_H8; s1++)
+        for (Square s2 = SQ_A1; s2 <= SQ_H8; s2++)
+        {
+            BetweenBB[s1][s2] = EmptyBoardBB;
+            SignedDirection d = signed_direction_between_squares(s1, s2);
+
+            if (d != SIGNED_DIR_NONE)
+            {
+                for (Square s3 = s1 + step[d]; s3 != s2; s3 += step[d])
+                    set_bit(&(BetweenBB[s1][s2]), s3);
+            }
       }
   }
 
-
   Bitboard index_to_bitboard(int index, Bitboard mask) {
-    int i, j, bits = count_1s(mask);
+
     Bitboard result = 0ULL;
-    for(i = 0; i < bits; i++) {
-      j = pop_1st_bit(&mask);
-      if(index & (1 << i)) result |= (1ULL << j);
+    int bits = count_1s(mask);
+
+    for (int i = 0; i < bits; i++)
+    {
+        int j = pop_1st_bit(&mask);
+        if (index & (1 << i))
+            result |= (1ULL << j);
     }
     return result;
   }
 
+  void init_sliding_attacks(Bitboard attacks[], int attackIndex[], Bitboard mask[],
+                            const int shift[], const Bitboard mult[], int deltas[][2]) {
 
-  void init_sliding_attacks(Bitboard attacks[],
-                            int attackIndex[], Bitboard mask[],
-                            const int shift[2], const Bitboard mult[],
-                            int deltas[][2]) {
-    int i, j, k, index = 0;
-    Bitboard b;
-    for(i = 0; i < 64; i++) {
-      attackIndex[i] = index;
-      mask[i] = sliding_attacks(i, 0ULL, 4, deltas, 1, 6, 1, 6);
+    for (int i = 0, index = 0; i < 64; i++)
+    {
+        attackIndex[i] = index;
+        mask[i] = sliding_attacks(i, 0ULL, 4, deltas, 1, 6, 1, 6);
 
 #if defined(IS_64BIT)
-      j = (1 << (64 - shift[i]));
+        int j = (1 << (64 - shift[i]));
 #else
-      j = (1 << (32 - shift[i]));
+        int j = (1 << (32 - shift[i]));
 #endif
 
-      for(k = 0; k < j; k++) {
-
+        for (int k = 0; k < j; k++)
+        {
 #if defined(IS_64BIT)
-        b = index_to_bitboard(k, mask[i]);
-        attacks[index + ((b * mult[i]) >> shift[i])] =
-          sliding_attacks(i, b, 4, deltas);
+            Bitboard b = index_to_bitboard(k, mask[i]);
+            attacks[index + ((b * mult[i]) >> shift[i])] = sliding_attacks(i, b, 4, deltas);
 #else
-        b = index_to_bitboard(k, mask[i]);
-        attacks[index +
-                 (unsigned(int(b) * int(mult[i]) ^
-                           int(b >> 32) * int(mult[i] >> 32))
-                  >> shift[i])] =
-          sliding_attacks(i, b, 4, deltas);
+            Bitboard b = index_to_bitboard(k, mask[i]);
+            unsigned v = int(b) * int(mult[i]) ^ int(b >> 32) * int(mult[i] >> 32);
+            attacks[index + (v >> shift[i])] = sliding_attacks(i, b, 4, deltas);
 #endif
-      }
-      index += j;
+        }
+        index += j;
     }
   }
 
-
   void init_pseudo_attacks() {
-    Square s;
-    for(s = SQ_A1; s <= SQ_H8; s++) {
-      BishopPseudoAttacks[s] = bishop_attacks_bb(s, EmptyBoardBB);
-      RookPseudoAttacks[s] = rook_attacks_bb(s, EmptyBoardBB);
-      QueenPseudoAttacks[s] = queen_attacks_bb(s, EmptyBoardBB);
+
+    for (Square s = SQ_A1; s <= SQ_H8; s++)
+    {
+        BishopPseudoAttacks[s] = bishop_attacks_bb(s, EmptyBoardBB);
+        RookPseudoAttacks[s]   = rook_attacks_bb(s, EmptyBoardBB);
+        QueenPseudoAttacks[s]  = queen_attacks_bb(s, EmptyBoardBB);
     }
   }
 

src/bitboard.h

@@ -74,8 +74,9 @@ extern Bitboard StepAttackBB[16][64];
 extern Bitboard RayBB[64][8];
 extern Bitboard BetweenBB[64][64];
 
+extern Bitboard SquaresInFrontMask[2][64];
 extern Bitboard PassedPawnMask[2][64];
-extern Bitboard OutpostMask[2][64];
+extern Bitboard AttackSpanMask[2][64];
 
 extern const uint64_t RMult[64];
 extern const int RShift[64];
@@ -127,9 +128,8 @@ inline void do_move_bb(Bitboard *b, Bitboard move_bb) {
   *b ^= move_bb;
 }
 
-/// rank_bb() and file_bb() gives a bitboard containing all squares on a given
-/// file or rank.  It is also possible to pass a square as input to these
-/// functions.
+/// 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.
 
 inline Bitboard rank_bb(Rank r) {
   return RankBB[r];
@@ -156,7 +156,7 @@ inline Bitboard neighboring_files_bb(File f) {
 }
 
 inline Bitboard neighboring_files_bb(Square s) {
-  return neighboring_files_bb(square_file(s));
+  return NeighboringFilesBB[square_file(s)];
 }
 
 
@@ -169,7 +169,7 @@ inline Bitboard this_and_neighboring_files_bb(File f) {
 }
 
 inline Bitboard this_and_neighboring_files_bb(Square s) {
-  return this_and_neighboring_files_bb(square_file(s));
+  return ThisAndNeighboringFilesBB[square_file(s)];
 }
 
 
@@ -195,7 +195,7 @@ inline Bitboard in_front_bb(Color c, Rank r) {
 }
 
 inline Bitboard in_front_bb(Color c, Square s) {
-  return in_front_bb(c, square_rank(s));
+  return InFrontBB[c][square_rank(s)];
 }
 
 
@@ -208,7 +208,7 @@ inline Bitboard behind_bb(Color c, Rank r) {
 }
 
 inline Bitboard behind_bb(Color c, Square s) {
-  return in_front_bb(opposite_color(c), square_rank(s));
+  return InFrontBB[opposite_color(c)][square_rank(s)];
 }
 
 
@@ -274,12 +274,11 @@ inline Bitboard squares_between(Square s1, Square s2) {
 
 /// squares_in_front_of 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.  For instance,
-/// squares_in_front_of(BLACK, SQ_E4) returns a bitboard with the squares
-/// e3, e2 and e1 set.
+/// from the point of view of the given color. Definition of the table is:
+/// SquaresInFrontOf[c][s] = in_front_bb(c, s) & file_bb(s)
 
 inline Bitboard squares_in_front_of(Color c, Square s) {
-  return in_front_bb(c, s) & file_bb(s);
+  return SquaresInFrontMask[c][s];
 }
 
 
@@ -287,33 +286,27 @@ inline Bitboard squares_in_front_of(Color c, Square s) {
 /// behind the square instead of in front of the square.
 
 inline Bitboard squares_behind(Color c, Square s) {
-  return in_front_bb(opposite_color(c), s) & file_bb(s);
+  return SquaresInFrontMask[opposite_color(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.
+/// the given square is a passed pawn. Definition of the table is:
+/// PassedPawnMask[c][s] = in_front_bb(c, s) & this_and_neighboring_files_bb(s)
 
 inline Bitboard passed_pawn_mask(Color c, Square s) {
   return PassedPawnMask[c][s];
 }
 
 
-/// outpost_mask takes a color and a square as input, and returns a bitboard
-/// mask which can be used to test whether a piece on the square can possibly
-/// be driven away by an enemy pawn.
+/// 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) & neighboring_files_bb(s);
 
-inline Bitboard outpost_mask(Color c, Square s) {
-  return OutpostMask[c][s];
-}
-
-
-/// isolated_pawn_mask takes a square as input, and returns a bitboard mask
-/// which can be used to test whether a pawn on the given square is isolated.
-
-inline Bitboard isolated_pawn_mask(Square s) {
-  return neighboring_files_bb(s);
+inline Bitboard attack_span_mask(Color c, Square s) {
+  return AttackSpanMask[c][s];
 }
 
 
@@ -349,7 +342,6 @@ extern Square pop_1st_bit(Bitboard* b);
 
 extern void print_bitboard(Bitboard b);
 extern void init_bitboards();
-extern int bitScanReverse32(uint32_t b);
 
 
 #endif // !defined(BITBOARD_H_INCLUDED)

src/book.cpp

@@ -399,14 +399,15 @@ const string Book::file_name() { // Not const to compile on HP-UX 11.X
 /// Book::get_move() gets a book move for a given position. Returns
 /// MOVE_NONE if no book move is found.
 
-Move Book::get_move(const Position& pos) {
+Move Book::get_move(const Position& pos, bool findBestMove) {
 
   if (!is_open() || bookSize == 0)
       return MOVE_NONE;
 
-  int bookMove = 0, scoresSum = 0;
-  uint64_t key = book_key(pos);
   BookEntry entry;
+  int bookMove = MOVE_NONE;
+  int scoresSum = 0, bestScore = 0;
+  uint64_t key = book_key(pos);
 
   // Choose a book move among the possible moves for the given position
   for (int idx = find_key(key); idx < bookSize; idx++)
@@ -419,6 +420,17 @@ Move Book::get_move(const Position& pos) {
 
       assert(score > 0);
 
+      // If findBestMove is true choose highest rated book move
+      if (findBestMove)
+      {
+          if (score > bestScore)
+          {
+              bestScore = score;
+              bookMove = entry.move;
+          }
+          continue;
+      }
+
       // Choose book move according to its score. If a move has a very
       // high score it has more probability to be choosen then a one with
       // lower score. Note that first entry is always chosen.

src/book.h

@@ -61,7 +61,7 @@ public:
   void open(const std::string& fName);
   void close();
   const std::string file_name();
-  Move get_move(const Position& pos);
+  Move get_move(const Position& pos, bool findBestMove);
 
 private:
   Book& operator>>(uint64_t& n) { n = read_integer(8); return *this; }

src/endgame.cpp

@@ -104,7 +104,7 @@ namespace {
 /// attacking side a bonus for driving the defending king towards the edge
 /// of the board, and for keeping the distance between the two kings small.
 template<>
-Value EvaluationFunction<KXK>::apply(const Position& pos) {
+Value EvaluationFunction<KXK>::apply(const Position& pos) const {
 
   assert(pos.non_pawn_material(weakerSide) == Value(0));
   assert(pos.piece_count(weakerSide, PAWN) == Value(0));
@@ -130,7 +130,7 @@ Value EvaluationFunction<KXK>::apply(const Position& pos) {
 /// Mate with KBN vs K. This is similar to KX vs K, but we have to drive the
 /// defending king towards a corner square of the right color.
 template<>
-Value EvaluationFunction<KBNK>::apply(const Position& pos) {
+Value EvaluationFunction<KBNK>::apply(const Position& pos) const {
 
   assert(pos.non_pawn_material(weakerSide) == Value(0));
   assert(pos.piece_count(weakerSide, PAWN) == Value(0));
@@ -159,7 +159,7 @@ Value EvaluationFunction<KBNK>::apply(const Position& pos) {
 
 /// KP vs K. This endgame is evaluated with the help of a bitbase.
 template<>
-Value EvaluationFunction<KPK>::apply(const Position& pos) {
+Value EvaluationFunction<KPK>::apply(const Position& pos) const {
 
   assert(pos.non_pawn_material(strongerSide) == Value(0));
   assert(pos.non_pawn_material(weakerSide) == Value(0));
@@ -207,7 +207,7 @@ Value EvaluationFunction<KPK>::apply(const Position& pos) {
 /// far advanced with support of the king, while the attacking king is far
 /// away.
 template<>
-Value EvaluationFunction<KRKP>::apply(const Position& pos) {
+Value EvaluationFunction<KRKP>::apply(const Position& pos) const {
 
   assert(pos.non_pawn_material(strongerSide) == RookValueMidgame);
   assert(pos.piece_count(strongerSide, PAWN) == 0);
@@ -264,7 +264,7 @@ Value EvaluationFunction<KRKP>::apply(const Position& pos) {
 /// KR vs KB. This is very simple, and always returns drawish scores.  The
 /// score is slightly bigger when the defending king is close to the edge.
 template<>
-Value EvaluationFunction<KRKB>::apply(const Position& pos) {
+Value EvaluationFunction<KRKB>::apply(const Position& pos) const {
 
   assert(pos.non_pawn_material(strongerSide) == RookValueMidgame);
   assert(pos.piece_count(strongerSide, PAWN) == 0);
@@ -280,7 +280,7 @@ Value EvaluationFunction<KRKB>::apply(const Position& pos) {
 /// KR vs KN.  The attacking side has slightly better winning chances than
 /// in KR vs KB, particularly if the king and the knight are far apart.
 template<>
-Value EvaluationFunction<KRKN>::apply(const Position& pos) {
+Value EvaluationFunction<KRKN>::apply(const Position& pos) const {
 
   assert(pos.non_pawn_material(strongerSide) == RookValueMidgame);
   assert(pos.piece_count(strongerSide, PAWN) == 0);
@@ -304,7 +304,7 @@ Value EvaluationFunction<KRKN>::apply(const Position& pos) {
 /// for the defending side in the search, this is usually sufficient to be
 /// able to win KQ vs KR.
 template<>
-Value EvaluationFunction<KQKR>::apply(const Position& pos) {
+Value EvaluationFunction<KQKR>::apply(const Position& pos) const {
 
   assert(pos.non_pawn_material(strongerSide) == QueenValueMidgame);
   assert(pos.piece_count(strongerSide, PAWN) == 0);
@@ -323,7 +323,7 @@ Value EvaluationFunction<KQKR>::apply(const Position& pos) {
 }
 
 template<>
-Value EvaluationFunction<KBBKN>::apply(const Position& pos) {
+Value EvaluationFunction<KBBKN>::apply(const Position& pos) const {
 
   assert(pos.piece_count(strongerSide, BISHOP) == 2);
   assert(pos.non_pawn_material(strongerSide) == 2*BishopValueMidgame);
@@ -352,12 +352,12 @@ Value EvaluationFunction<KBBKN>::apply(const Position& pos) {
 /// K and two minors vs K and one or two minors or K and two knights against
 /// king alone are always draw.
 template<>
-Value EvaluationFunction<KmmKm>::apply(const Position&) {
+Value EvaluationFunction<KmmKm>::apply(const Position&) const {
   return Value(0);
 }
 
 template<>
-Value EvaluationFunction<KNNK>::apply(const Position&) {
+Value EvaluationFunction<KNNK>::apply(const Position&) const {
   return Value(0);
 }
 
@@ -367,7 +367,7 @@ Value EvaluationFunction<KNNK>::apply(const Position&) {
 /// returned. If not, the return value is SCALE_FACTOR_NONE, i.e. no scaling
 /// will be used.
 template<>
-ScaleFactor ScalingFunction<KBPsK>::apply(const Position& pos) {
+ScaleFactor ScalingFunction<KBPsK>::apply(const Position& pos) const {
 
   assert(pos.non_pawn_material(strongerSide) == BishopValueMidgame);
   assert(pos.piece_count(strongerSide, BISHOP) == 1);
@@ -421,7 +421,7 @@ ScaleFactor ScalingFunction<KBPsK>::apply(const Position& pos) {
 /// It tests for fortress draws with a rook on the third rank defended by
 /// a pawn.
 template<>
-ScaleFactor ScalingFunction<KQKRPs>::apply(const Position& pos) {
+ScaleFactor ScalingFunction<KQKRPs>::apply(const Position& pos) const {
 
   assert(pos.non_pawn_material(strongerSide) == QueenValueMidgame);
   assert(pos.piece_count(strongerSide, QUEEN) == 1);
@@ -452,7 +452,7 @@ ScaleFactor ScalingFunction<KQKRPs>::apply(const Position& pos) {
 /// It would also be nice to rewrite the actual code for this function,
 /// which is mostly copied from Glaurung 1.x, and not very pretty.
 template<>
-ScaleFactor ScalingFunction<KRPKR>::apply(const Position &pos) {
+ScaleFactor ScalingFunction<KRPKR>::apply(const Position& pos) const {
 
   assert(pos.non_pawn_material(strongerSide) == RookValueMidgame);
   assert(pos.piece_count(strongerSide, PAWN) == 1);
@@ -570,7 +570,7 @@ ScaleFactor ScalingFunction<KRPKR>::apply(const Position &pos) {
 /// single pattern: If the stronger side has no pawns and the defending king
 /// is actively placed, the position is drawish.
 template<>
-ScaleFactor ScalingFunction<KRPPKRP>::apply(const Position &pos) {
+ScaleFactor ScalingFunction<KRPPKRP>::apply(const Position& pos) const {
 
   assert(pos.non_pawn_material(strongerSide) == RookValueMidgame);
   assert(pos.piece_count(strongerSide, PAWN) == 2);
@@ -609,7 +609,7 @@ ScaleFactor ScalingFunction<KRPPKRP>::apply(const Position &pos) {
 /// against king. There is just a single rule here: If all pawns are on
 /// the same rook file and are blocked by the defending king, it's a draw.
 template<>
-ScaleFactor ScalingFunction<KPsK>::apply(const Position &pos) {
+ScaleFactor ScalingFunction<KPsK>::apply(const Position& pos) const {
 
   assert(pos.non_pawn_material(strongerSide) == Value(0));
   assert(pos.piece_count(strongerSide, PAWN) >= 2);
@@ -655,7 +655,7 @@ ScaleFactor ScalingFunction<KPsK>::apply(const Position &pos) {
 /// it's a draw. If the two bishops have opposite color, it's almost always
 /// a draw.
 template<>
-ScaleFactor ScalingFunction<KBPKB>::apply(const Position &pos) {
+ScaleFactor ScalingFunction<KBPKB>::apply(const Position& pos) const {
 
   assert(pos.non_pawn_material(strongerSide) == BishopValueMidgame);
   assert(pos.piece_count(strongerSide, BISHOP) == 1);
@@ -708,7 +708,7 @@ ScaleFactor ScalingFunction<KBPKB>::apply(const Position &pos) {
 /// KBPPKBScalingFunction scales KBPP vs KB endgames. It detects a few basic
 /// draws with opposite-colored bishops.
 template<>
-ScaleFactor ScalingFunction<KBPPKB>::apply(const Position& pos) {
+ScaleFactor ScalingFunction<KBPPKB>::apply(const Position& pos) const {
 
   assert(pos.non_pawn_material(strongerSide) == BishopValueMidgame);
   assert(pos.piece_count(strongerSide, BISHOP) == 1);
@@ -784,7 +784,7 @@ ScaleFactor ScalingFunction<KBPPKB>::apply(const Position& pos) {
 /// square of the king is not of the same color as the stronger side's bishop,
 /// it's a draw.
 template<>
-ScaleFactor ScalingFunction<KBPKN>::apply(const Position &pos) {
+ScaleFactor ScalingFunction<KBPKN>::apply(const Position& pos) const {
 
   assert(pos.non_pawn_material(strongerSide) == BishopValueMidgame);
   assert(pos.piece_count(strongerSide, BISHOP) == 1);
@@ -811,7 +811,7 @@ ScaleFactor ScalingFunction<KBPKN>::apply(const Position &pos) {
 /// If the pawn is a rook pawn on the 7th rank and the defending king prevents
 /// the pawn from advancing, the position is drawn.
 template<>
-ScaleFactor ScalingFunction<KNPK>::apply(const Position &pos) {
+ScaleFactor ScalingFunction<KNPK>::apply(const Position& pos) const {
 
   assert(pos.non_pawn_material(strongerSide) == KnightValueMidgame);
   assert(pos.piece_count(strongerSide, KNIGHT) == 1);
@@ -841,7 +841,7 @@ ScaleFactor ScalingFunction<KNPK>::apply(const Position &pos) {
 /// advanced and not on a rook file; in this case it is often possible to win
 /// (e.g. 8/4k3/3p4/3P4/6K1/8/8/8 w - - 0 1).
 template<>
-ScaleFactor ScalingFunction<KPKP>::apply(const Position &pos) {
+ScaleFactor ScalingFunction<KPKP>::apply(const Position& pos) const {
 
   assert(pos.non_pawn_material(strongerSide) == Value(0));
   assert(pos.non_pawn_material(weakerSide) == Value(0));

src/endgame.h

@@ -68,7 +68,7 @@ class EndgameFunctionBase {
 public:
   EndgameFunctionBase(Color c) : strongerSide(c), weakerSide(opposite_color(c)) {}
   virtual ~EndgameFunctionBase() {}
-  virtual T apply(const Position&) = 0;
+  virtual T apply(const Position&) const = 0;
   Color color() const { return strongerSide; }
 
 protected:
@@ -85,14 +85,14 @@ template<EndgameType>
 struct EvaluationFunction : public EndgameEvaluationFunctionBase {
   typedef EndgameEvaluationFunctionBase Base;
   explicit EvaluationFunction(Color c): EndgameEvaluationFunctionBase(c) {}
-  Value apply(const Position&);
+  Value apply(const Position&) const;
 };
 
 template<EndgameType>
 struct ScalingFunction : public EndgameScalingFunctionBase {
   typedef EndgameScalingFunctionBase Base;
   explicit ScalingFunction(Color c) : EndgameScalingFunctionBase(c) {}
-  ScaleFactor apply(const Position&);
+  ScaleFactor apply(const Position&) const;
 };
 
 

src/evaluate.cpp

@@ -46,9 +46,11 @@ namespace {
   const int GrainSize = 8;
 
   // Evaluation weights, initialized from UCI options
-  Score WeightMobility, WeightPawnStructure;
-  Score WeightPassedPawns, WeightSpace;
-  Score WeightKingSafety[2];
+  enum { Mobility, PawnStructure, PassedPawns, Space, KingDangerUs, KingDangerThem };
+  Score Weights[6];
+
+  typedef Value V;
+  #define S(mg, eg) make_score(mg, eg)
 
   // Internal evaluation weights. These are applied on top of the evaluation
   // weights read from UCI parameters. The purpose is to be able to change
@@ -56,19 +58,9 @@ namespace {
   // parameters at 100, which looks prettier.
   //
   // Values modified by Joona Kiiski
-  const Score WeightMobilityInternal      = make_score(248, 271);
-  const Score WeightPawnStructureInternal = make_score(233, 201);
-  const Score WeightPassedPawnsInternal   = make_score(252, 259);
-  const Score WeightSpaceInternal         = make_score( 46,   0);
-  const Score WeightKingSafetyInternal    = make_score(247,   0);
-  const Score WeightKingOppSafetyInternal = make_score(259,   0);
-
-  // Mobility and outposts bonus modified by Joona Kiiski
-
-  typedef Value V;
-  #define S(mg, eg) make_score(mg, eg)
-
-  CACHE_LINE_ALIGNMENT
+  const Score WeightsInternal[] = {
+      S(248, 271), S(233, 201), S(252, 259), S(46, 0), S(247, 0), S(259, 0)
+  };
 
   // Knight mobility bonus in middle game and endgame, indexed by the number
   // of attacked squares not occupied by friendly piecess.
@@ -138,28 +130,22 @@ namespace {
     V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0)  // 8
   };
 
-  // ThreatBonus[][] contains bonus according to which piece type
-  // attacks which one.
-  #define Z S(0, 0)
-
+  // ThreatBonus[attacking][attacked] contains bonus according to which
+  // piece type attacks which one.
   const Score ThreatBonus[8][8] = {
-      { Z, Z, Z, Z, Z, Z, Z, Z }, // not used
-      { Z, S(18,37),       Z, S(37,47), S(55,97), S(55,97), Z, Z }, // KNIGHT attacks
-      { Z, S(18,37), S(37,47),       Z, S(55,97), S(55,97), Z, Z }, // BISHOP attacks
-      { Z, S( 9,27), S(27,47), S(27,47),       Z, S(37,47), Z, Z }, // ROOK attacks
-      { Z, S(27,37), S(27,37), S(27,37), S(27,37),       Z, Z, Z }, // QUEEN attacks
-      { Z, Z, Z, Z, Z, Z, Z, Z }, // not used
-      { Z, Z, Z, Z, Z, Z, Z, Z }, // not used
-      { Z, Z, Z, Z, Z, Z, Z, Z }  // not used
+    {}, {},
+    { S(0, 0), S( 7, 39), S( 0,  0), S(24, 49), S(41,100), S(41,100) }, // KNIGHT
+    { S(0, 0), S( 7, 39), S(24, 49), S( 0,  0), S(41,100), S(41,100) }, // BISHOP
+    { S(0, 0), S(-1, 29), S(15, 49), S(15, 49), S( 0,  0), S(24, 49) }, // ROOK
+    { S(0, 0), S(15, 39), S(15, 39), S(15, 39), S(15, 39), S( 0,  0) }  // QUEEN
   };
 
   // ThreatedByPawnPenalty[] contains a penalty according to which piece
   // type is attacked by an enemy pawn.
   const Score ThreatedByPawnPenalty[8] = {
-    Z, Z, S(56, 70), S(56, 70), S(76, 99), S(86, 118), Z, Z
+    S(0, 0), S(0, 0), S(56, 70), S(56, 70), S(76, 99), S(86, 118)
   };
 
-  #undef Z
   #undef S
 
   // Bonus for unstoppable passed pawns
@@ -211,33 +197,22 @@ namespace {
     (1ULL<<SQ_C5) | (1ULL<<SQ_D5) | (1ULL<<SQ_E5) | (1ULL<<SQ_F5)
   };
 
-  /// King safety constants and variables. The king safety scores are taken
-  /// from the array SafetyTable[]. Various little "meta-bonuses" measuring
-  /// the strength of the attack are added up into an integer, which is used
-  /// as an index to SafetyTable[].
+  /// King danger constants and variables. The king danger scores are taken
+  /// from the KingDangerTable[]. Various little "meta-bonuses" measuring
+  /// the strength of the enemy attack are added up into an integer, which
+  /// is used as an index to KingDangerTable[].
 
-  // Attack weights for each piece type and table indexed on piece type
-  const int QueenAttackWeight  = 5;
-  const int RookAttackWeight   = 3;
-  const int BishopAttackWeight = 2;
-  const int KnightAttackWeight = 2;
+  // KingAttackWeights[] contains king attack weights by piece type
+  const int KingAttackWeights[8] = { 0, 0, 2, 2, 3, 5 };
 
-  const int AttackWeight[] = { 0, 0, KnightAttackWeight, BishopAttackWeight, RookAttackWeight, QueenAttackWeight };
-
-  // Bonuses for safe checks
+  // Bonuses for enemy's safe checks
   const int QueenContactCheckBonus = 3;
   const int DiscoveredCheckBonus   = 3;
-  const int QueenCheckBonus        = 2; 
+  const int QueenCheckBonus        = 2;
   const int RookCheckBonus         = 1;
-  const int BishopCheckBonus       = 1; 
+  const int BishopCheckBonus       = 1;
   const int KnightCheckBonus       = 1;
 
-  // Scan for queen contact mates?
-  const bool QueenContactMates = true;
-
-  // Bonus for having a mate threat
-  const int MateThreatBonus = 3;
-
   // InitKingDanger[] contains bonuses based on the position of the defending
   // king.
   const int InitKingDanger[64] = {
@@ -251,9 +226,8 @@ namespace {
     15, 15, 15, 15, 15, 15, 15, 15
   };
 
-  // SafetyTable[] contains the actual king safety scores. It is initialized
-  // in init_safety().
-  Value SafetyTable[100];
+  // KingDangerTable[color][] contains the actual king danger weighted scores
+  Score KingDangerTable[2][128];
 
   // Pawn and material hash tables, indexed by the current thread id.
   // Note that they will be initialized at 0 being global variables.
@@ -266,7 +240,10 @@ namespace {
 
   // Function prototypes
   template<bool HasPopCnt>
-  Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID);
+  Value do_evaluate(const Position& pos, EvalInfo& ei);
+
+  template<Color Us, bool HasPopCnt>
+  void init_attack_tables(const Position& pos, EvalInfo& ei);
 
   template<Color Us, bool HasPopCnt>
   void evaluate_pieces_of_color(const Position& pos, EvalInfo& ei);
@@ -278,9 +255,12 @@ namespace {
   void evaluate_threats(const Position& pos, EvalInfo& ei);
 
   template<Color Us, bool HasPopCnt>
-  void evaluate_space(const Position& pos, EvalInfo& ei);
+  int evaluate_space(const Position& pos, EvalInfo& ei);
 
+  template<Color Us>
   void evaluate_passed_pawns(const Position& pos, EvalInfo& ei);
+
+  void evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei);
   void evaluate_trapped_bishop_a7h7(const Position& pos, Square s, Color us, EvalInfo& ei);
   void evaluate_trapped_bishop_a1h1(const Position& pos, Square s, Color us, EvalInfo& ei);
   inline Score apply_weight(Score v, Score weight);
@@ -297,19 +277,21 @@ namespace {
 /// evaluate() is the main evaluation function. It always computes two
 /// values, an endgame score and a middle game score, and interpolates
 /// between them based on the remaining material.
-Value evaluate(const Position& pos, EvalInfo& ei, int threadID) {
+Value evaluate(const Position& pos, EvalInfo& ei) {
 
-    return CpuHasPOPCNT ? do_evaluate<true>(pos, ei, threadID)
-                        : do_evaluate<false>(pos, ei, threadID);
+    return CpuHasPOPCNT ? do_evaluate<true>(pos, ei)
+                        : do_evaluate<false>(pos, ei);
 }
 
 namespace {
 
 template<bool HasPopCnt>
-Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) {
+Value do_evaluate(const Position& pos, EvalInfo& ei) {
+
+  ScaleFactor factor[2];
 
   assert(pos.is_ok());
-  assert(threadID >= 0 && threadID < MAX_THREADS);
+  assert(pos.thread() >= 0 && pos.thread() < MAX_THREADS);
   assert(!pos.is_check());
 
   memset(&ei, 0, sizeof(EvalInfo));
@@ -319,7 +301,7 @@ Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) {
   ei.value = pos.value();
 
   // Probe the material hash table
-  ei.mi = MaterialTable[threadID]->get_material_info(pos);
+  ei.mi = MaterialTable[pos.thread()]->get_material_info(pos);
   ei.value += ei.mi->material_value();
 
   // If we have a specialized evaluation function for the current material
@@ -328,30 +310,16 @@ Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) {
       return ei.mi->evaluate(pos);
 
   // After get_material_info() call that modifies them
-  ScaleFactor factor[2];
   factor[WHITE] = ei.mi->scale_factor(pos, WHITE);
   factor[BLACK] = ei.mi->scale_factor(pos, BLACK);
 
   // Probe the pawn hash table
-  ei.pi = PawnTable[threadID]->get_pawn_info(pos);
-  ei.value += apply_weight(ei.pi->pawns_value(), WeightPawnStructure);
+  ei.pi = PawnTable[pos.thread()]->get_pawn_info(pos);
+  ei.value += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]);
 
-  // Initialize king attack bitboards and king attack zones for both sides
-  ei.attackedBy[WHITE][KING] = pos.attacks_from<KING>(pos.king_square(WHITE));
-  ei.attackedBy[BLACK][KING] = pos.attacks_from<KING>(pos.king_square(BLACK));
-  ei.kingZone[WHITE] = ei.attackedBy[BLACK][KING] | (ei.attackedBy[BLACK][KING] >> 8);
-  ei.kingZone[BLACK] = ei.attackedBy[WHITE][KING] | (ei.attackedBy[WHITE][KING] << 8);
-
-  // Initialize pawn attack bitboards for both sides
-  ei.attackedBy[WHITE][PAWN] = ei.pi->pawn_attacks(WHITE);
-  ei.attackedBy[BLACK][PAWN] = ei.pi->pawn_attacks(BLACK);
-  Bitboard b1 = ei.attackedBy[WHITE][PAWN] & ei.attackedBy[BLACK][KING];
-  Bitboard b2 = ei.attackedBy[BLACK][PAWN] & ei.attackedBy[WHITE][KING];
-  if (b1)
-      ei.kingAttackersCount[WHITE] = count_1s_max_15<HasPopCnt>(b1)/2;
-
-  if (b2)
-      ei.kingAttackersCount[BLACK] = count_1s_max_15<HasPopCnt>(b2)/2;
+  // Initialize attack bitboards with pawns evaluation
+  init_attack_tables<WHITE, HasPopCnt>(pos, ei);
+  init_attack_tables<BLACK, HasPopCnt>(pos, ei);
 
   // Evaluate pieces
   evaluate_pieces_of_color<WHITE, HasPopCnt>(pos, ei);
@@ -363,43 +331,44 @@ Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) {
   evaluate_king<WHITE, HasPopCnt>(pos, ei);
   evaluate_king<BLACK, HasPopCnt>(pos, ei);
 
-  // Evaluate tactical threats, we need full attack info
+  // Evaluate tactical threats, we need full attack info including king
   evaluate_threats<WHITE>(pos, ei);
   evaluate_threats<BLACK>(pos, ei);
 
-  // Evaluate passed pawns. We evaluate passed pawns for both sides at once,
-  // because we need to know which side promotes first in positions where
-  // both sides have an unstoppable passed pawn. To be called after all attacks
-  // are computed, included king.
-  if (ei.pi->passed_pawns())
-      evaluate_passed_pawns(pos, ei);
+  // Evaluate passed pawns, we need full attack info including king
+  evaluate_passed_pawns<WHITE>(pos, ei);
+  evaluate_passed_pawns<BLACK>(pos, ei);
+
+  // If one side has only a king, check whether exsists any unstoppable passed pawn
+  if (!pos.non_pawn_material(WHITE) || !pos.non_pawn_material(BLACK))
+      evaluate_unstoppable_pawns(pos, ei);
 
   Phase phase = ei.mi->game_phase();
 
   // Middle-game specific evaluation terms
   if (phase > PHASE_ENDGAME)
   {
-    // Pawn storms in positions with opposite castling.
-    if (   square_file(pos.king_square(WHITE)) >= FILE_E
-        && square_file(pos.king_square(BLACK)) <= FILE_D)
+      // Pawn storms in positions with opposite castling
+      if (   square_file(pos.king_square(WHITE)) >= FILE_E
+          && square_file(pos.king_square(BLACK)) <= FILE_D)
 
-        ei.value += make_score(ei.pi->queenside_storm_value(WHITE) - ei.pi->kingside_storm_value(BLACK), 0);
+          ei.value += make_score(ei.pi->queenside_storm_value(WHITE) - ei.pi->kingside_storm_value(BLACK), 0);
 
-    else if (   square_file(pos.king_square(WHITE)) <= FILE_D
-             && square_file(pos.king_square(BLACK)) >= FILE_E)
+      else if (   square_file(pos.king_square(WHITE)) <= FILE_D
+               && square_file(pos.king_square(BLACK)) >= FILE_E)
 
-        ei.value += make_score(ei.pi->kingside_storm_value(WHITE) - ei.pi->queenside_storm_value(BLACK), 0);
+          ei.value += make_score(ei.pi->kingside_storm_value(WHITE) - ei.pi->queenside_storm_value(BLACK), 0);
 
-    // Evaluate space for both sides
-    if (ei.mi->space_weight() > 0)
-    {
-        evaluate_space<WHITE, HasPopCnt>(pos, ei);
-        evaluate_space<BLACK, HasPopCnt>(pos, ei);
-    }
+      // Evaluate space for both sides
+      if (ei.mi->space_weight() > 0)
+      {
+          int s = evaluate_space<WHITE, HasPopCnt>(pos, ei) - evaluate_space<BLACK, HasPopCnt>(pos, ei);
+          ei.value += apply_weight(make_score(s * ei.mi->space_weight(), 0), Weights[Space]);
+      }
   }
 
   // Mobility
-  ei.value += apply_weight(ei.mobility, WeightMobility);
+  ei.value += apply_weight(ei.mobility, Weights[Mobility]);
 
   // If we don't already have an unusual scale factor, check for opposite
   // colored bishop endgames, and use a lower scale for those
@@ -431,11 +400,7 @@ Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) {
   }
 
   // Interpolate between the middle game and the endgame score
-  Color stm = pos.side_to_move();
-
-  Value v = Sign[stm] * scale_by_game_phase(ei.value, phase, factor);
-
-  return (ei.mateThreat[stm] == MOVE_NONE ? v : 8 * QueenValueMidgame - v);
+  return Sign[pos.side_to_move()] * scale_by_game_phase(ei.value, phase, factor);
 }
 
 } // namespace
@@ -482,28 +447,46 @@ void quit_eval() {
 
 void read_weights(Color us) {
 
-  Color them = opposite_color(us);
+  // King safety is asymmetrical. Our king danger level is weighted by
+  // "Cowardice" UCI parameter, instead the opponent one by "Aggressiveness".
+  const int kingDangerUs   = (us == WHITE ? KingDangerUs   : KingDangerThem);
+  const int kingDangerThem = (us == WHITE ? KingDangerThem : KingDangerUs);
 
-  WeightMobility         = weight_option("Mobility (Middle Game)", "Mobility (Endgame)", WeightMobilityInternal);
-  WeightPawnStructure    = weight_option("Pawn Structure (Middle Game)", "Pawn Structure (Endgame)", WeightPawnStructureInternal);
-  WeightPassedPawns      = weight_option("Passed Pawns (Middle Game)", "Passed Pawns (Endgame)", WeightPassedPawnsInternal);
-  WeightSpace            = weight_option("Space", "Space", WeightSpaceInternal);
-  WeightKingSafety[us]   = weight_option("Cowardice", "Cowardice", WeightKingSafetyInternal);
-  WeightKingSafety[them] = weight_option("Aggressiveness", "Aggressiveness", WeightKingOppSafetyInternal);
+  Weights[Mobility]       = weight_option("Mobility (Middle Game)", "Mobility (Endgame)", WeightsInternal[Mobility]);
+  Weights[PawnStructure]  = weight_option("Pawn Structure (Middle Game)", "Pawn Structure (Endgame)", WeightsInternal[PawnStructure]);
+  Weights[PassedPawns]    = weight_option("Passed Pawns (Middle Game)", "Passed Pawns (Endgame)", WeightsInternal[PassedPawns]);
+  Weights[Space]          = weight_option("Space", "Space", WeightsInternal[Space]);
+  Weights[kingDangerUs]   = weight_option("Cowardice", "Cowardice", WeightsInternal[KingDangerUs]);
+  Weights[kingDangerThem] = weight_option("Aggressiveness", "Aggressiveness", WeightsInternal[KingDangerThem]);
 
   // If running in analysis mode, make sure we use symmetrical king safety. We do this
-  // by replacing both WeightKingSafety[us] and WeightKingSafety[them] by their average.
+  // by replacing both Weights[kingDangerUs] and Weights[kingDangerThem] by their average.
   if (get_option_value_bool("UCI_AnalyseMode"))
-  {
-      WeightKingSafety[us] = (WeightKingSafety[us] + WeightKingSafety[them]) / 2;
-      WeightKingSafety[them] = WeightKingSafety[us];
-  }
+      Weights[kingDangerUs] = Weights[kingDangerThem] = (Weights[kingDangerUs] + Weights[kingDangerThem]) / 2;
+
   init_safety();
 }
 
 
 namespace {
 
+  // init_attack_tables() initializes king bitboards for both sides adding
+  // pawn attacks. To be done before other evaluations.
+
+  template<Color Us, bool HasPopCnt>
+  void init_attack_tables(const Position& pos, EvalInfo& ei) {
+
+    const Color Them = (Us == WHITE ? BLACK : WHITE);
+
+    Bitboard b = ei.attackedBy[Them][KING] = pos.attacks_from<KING>(pos.king_square(Them));
+    ei.kingZone[Us] = (b | (Us == WHITE ? b >> 8 : b << 8));
+    ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(Us);
+    b &= ei.attackedBy[Us][PAWN];
+    if (b)
+        ei.kingAttackersCount[Us] = count_1s_max_15<HasPopCnt>(b) / 2;
+  }
+
+
   // evaluate_outposts() evaluates bishop and knight outposts squares
 
   template<PieceType Piece, Color Us>
@@ -561,7 +544,7 @@ namespace {
         if (b & ei.kingZone[Us])
         {
             ei.kingAttackersCount[Us]++;
-            ei.kingAttackersWeight[Us] += AttackWeight[Piece];
+            ei.kingAttackersWeight[Us] += KingAttackWeights[Piece];
             Bitboard bb = (b & ei.attackedBy[Them][KING]);
             if (bb)
                 ei.kingAdjacentZoneAttacksCount[Us] += count_1s_max_15<HasPopCnt>(bb);
@@ -579,7 +562,7 @@ namespace {
             ei.value -= Sign[Us] * ThreatedByPawnPenalty[Piece];
 
         // Bishop and knight outposts squares
-        if ((Piece == BISHOP || Piece == KNIGHT) && pos.square_is_weak(s, Them))
+        if ((Piece == BISHOP || Piece == KNIGHT) && pos.square_is_weak(s, Us))
             evaluate_outposts<Piece, Us>(pos, ei, s);
 
         // Special patterns: trapped bishops on a7/h7/a2/h2
@@ -707,276 +690,170 @@ namespace {
 
     const Color Them = (Us == WHITE ? BLACK : WHITE);
 
-    Bitboard undefended, attackedByOthers, escapeSquares, occ, b, b2, safe;
-    Square from, to;
+    Bitboard undefended, b, b1, b2, safe;
     bool sente;
-    int attackUnits, count, shelter = 0;
-    const Square s = pos.king_square(Us);
+    int attackUnits, shelter = 0;
+    const Square ksq = pos.king_square(Us);
 
     // King shelter
-    if (relative_rank(Us, s) <= RANK_4)
+    if (relative_rank(Us, ksq) <= RANK_4)
     {
-        shelter = ei.pi->get_king_shelter(pos, Us, s);
+        shelter = ei.pi->get_king_shelter(pos, Us, ksq);
         ei.value += Sign[Us] * make_score(shelter, 0);
     }
 
     // King safety. This is quite complicated, and is almost certainly far
     // from optimally tuned.
     if (   pos.piece_count(Them, QUEEN) >= 1
-        && ei.kingAttackersCount[Them] >= 2
-        && pos.non_pawn_material(Them) >= QueenValueMidgame + RookValueMidgame
+        && ei.kingAttackersCount[Them]  >= 2
+        && pos.non_pawn_material(Them)  >= QueenValueMidgame + RookValueMidgame
         && ei.kingAdjacentZoneAttacksCount[Them])
     {
-      // Is it the attackers turn to move?
-      sente = (Them == pos.side_to_move());
+        // Is it the attackers turn to move?
+        sente = (Them == pos.side_to_move());
 
-      // Find the attacked squares around the king which has no defenders
-      // apart from the king itself
-      undefended = ei.attacked_by(Them) & ei.attacked_by(Us, KING);
-      undefended &= ~(  ei.attacked_by(Us, PAWN)   | ei.attacked_by(Us, KNIGHT)
-                      | ei.attacked_by(Us, BISHOP) | ei.attacked_by(Us, ROOK)
-                      | ei.attacked_by(Us, QUEEN));
+        // Find the attacked squares around the king which has no defenders
+        // apart from the king itself
+        undefended = ei.attacked_by(Them) & ei.attacked_by(Us, KING);
+        undefended &= ~(  ei.attacked_by(Us, PAWN)   | ei.attacked_by(Us, KNIGHT)
+                        | ei.attacked_by(Us, BISHOP) | ei.attacked_by(Us, ROOK)
+                        | ei.attacked_by(Us, QUEEN));
 
-      // Initialize the 'attackUnits' variable, which is used later on as an
-      // index to the SafetyTable[] array. The initial value is based on the
-      // number and types of the attacking pieces, the number of attacked and
-      // undefended squares around the king, the square of the king, and the
-      // quality of the pawn shelter.
-      attackUnits =  Min(25, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2)
-                   + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + count_1s_max_15<HasPopCnt>(undefended))
-                   + InitKingDanger[relative_square(Us, s)]
-                   - (shelter >> 5);
+        // Initialize the 'attackUnits' variable, which is used later on as an
+        // index to the KingDangerTable[] array. The initial value is based on
+        // the number and types of the enemy's attacking pieces, the number of
+        // attacked and undefended squares around our king, the square of the
+        // king, and the quality of the pawn shelter.
+        attackUnits =  Min(25, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2)
+                     + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + count_1s_max_15<HasPopCnt>(undefended))
+                     + InitKingDanger[relative_square(Us, ksq)]
+                     - shelter / 32;
 
-      // Analyse safe queen contact checks
-      b = undefended & ei.attacked_by(Them, QUEEN) & ~pos.pieces_of_color(Them);
-      if (b)
-      {
-        attackedByOthers =  ei.attacked_by(Them, PAWN)   | ei.attacked_by(Them, KNIGHT)
-                          | ei.attacked_by(Them, BISHOP) | ei.attacked_by(Them, ROOK);
-
-        b &= attackedByOthers;
-
-        // Squares attacked by the queen and supported by another enemy piece and
-        // not defended by other pieces but our king.
+        // Analyse enemy's safe queen contact checks. First find undefended
+        // squares around the king attacked by enemy queen...
+        b = undefended & ei.attacked_by(Them, QUEEN) & ~pos.pieces_of_color(Them);
         if (b)
         {
-            // The bitboard b now contains the squares available for safe queen
-            // contact checks.
-            count = count_1s_max_15<HasPopCnt>(b);
-            attackUnits += QueenContactCheckBonus * count * (sente ? 2 : 1);
-
-            // Is there a mate threat?
-            if (QueenContactMates && !pos.is_check())
-            {
-                escapeSquares = pos.attacks_from<KING>(s) & ~pos.pieces_of_color(Us) & ~attackedByOthers;
-                occ = pos.occupied_squares();
-                while (b)
-                {
-                    to = pop_1st_bit(&b);
-
-                    // Do we have escape squares from queen contact check attack ?
-                    if (!(escapeSquares & ~queen_attacks_bb(to, occ & ClearMaskBB[s])))
-                    {
-                        // We have a mate, unless the queen is pinned or there
-                        // is an X-ray attack through the queen.
-                        for (int i = 0; i < pos.piece_count(Them, QUEEN); i++)
-                        {
-                            from = pos.piece_list(Them, QUEEN, i);
-                            if (    bit_is_set(pos.attacks_from<QUEEN>(from), to)
-                                && !bit_is_set(pos.pinned_pieces(Them), from)
-                                && !(rook_attacks_bb(to, occ & ClearMaskBB[from]) & pos.pieces(ROOK, QUEEN, Us))
-                                && !(bishop_attacks_bb(to, occ & ClearMaskBB[from]) & pos.pieces(BISHOP, QUEEN, Us)))
-
-                                // Set the mate threat move
-                                ei.mateThreat[Them] = make_move(from, to);
-                        }
-                    }
-                }
-            }
+            // ...then remove squares not supported by another enemy piece
+            b &= (  ei.attacked_by(Them, PAWN)   | ei.attacked_by(Them, KNIGHT)
+                  | ei.attacked_by(Them, BISHOP) | ei.attacked_by(Them, ROOK));
+            if (b)
+                attackUnits += QueenContactCheckBonus * count_1s_max_15<HasPopCnt>(b) * (sente ? 2 : 1);
         }
-      }
 
-      // Analyse safe distance checks
-      safe = ~(pos.pieces_of_color(Them) | ei.attacked_by(Us));
+        // Analyse enemy's safe distance checks for sliders and knights
+        safe = ~(pos.pieces_of_color(Them) | ei.attacked_by(Us));
 
-      if (QueenCheckBonus > 0 || RookCheckBonus > 0)
-      {
-          b = pos.attacks_from<ROOK>(s) & safe;
+        b1 = pos.attacks_from<ROOK>(ksq) & safe;
+        b2 = pos.attacks_from<BISHOP>(ksq) & safe;
 
-          // Queen checks
-          b2 = b & ei.attacked_by(Them, QUEEN);
-          if (b2)
-              attackUnits += QueenCheckBonus * count_1s_max_15<HasPopCnt>(b2);
+        // Enemy queen safe checks
+        b = (b1 | b2) & ei.attacked_by(Them, QUEEN);
+        if (b)
+            attackUnits += QueenCheckBonus * count_1s_max_15<HasPopCnt>(b);
 
-          // Rook checks
-          b2 = b & ei.attacked_by(Them, ROOK);
-          if (b2)
-              attackUnits += RookCheckBonus * count_1s_max_15<HasPopCnt>(b2);
-      }
-      if (QueenCheckBonus > 0 || BishopCheckBonus > 0)
-      {
-          b = pos.attacks_from<BISHOP>(s) & safe;
+        // Enemy rooks safe checks
+        b = b1 & ei.attacked_by(Them, ROOK);
+        if (b)
+            attackUnits += RookCheckBonus * count_1s_max_15<HasPopCnt>(b);
 
-          // Queen checks
-          b2 = b & ei.attacked_by(Them, QUEEN);
-          if (b2)
-              attackUnits += QueenCheckBonus * count_1s_max_15<HasPopCnt>(b2);
+        // Enemy bishops safe checks
+        b = b2 & ei.attacked_by(Them, BISHOP);
+        if (b)
+            attackUnits += BishopCheckBonus * count_1s_max_15<HasPopCnt>(b);
 
-          // Bishop checks
-          b2 = b & ei.attacked_by(Them, BISHOP);
-          if (b2)
-              attackUnits += BishopCheckBonus * count_1s_max_15<HasPopCnt>(b2);
-      }
-      if (KnightCheckBonus > 0)
-      {
-          b = pos.attacks_from<KNIGHT>(s) & safe;
+        // Enemy knights safe checks
+        b = pos.attacks_from<KNIGHT>(ksq) & ei.attacked_by(Them, KNIGHT) & safe;
+        if (b)
+            attackUnits += KnightCheckBonus * count_1s_max_15<HasPopCnt>(b);
 
-          // Knight checks
-          b2 = b & ei.attacked_by(Them, KNIGHT);
-          if (b2)
-              attackUnits += KnightCheckBonus * count_1s_max_15<HasPopCnt>(b2);
-      }
+        // To index KingDangerTable[] attackUnits must be in [0, 99] range
+        attackUnits = Min(99, Max(0, attackUnits));
 
-      // Analyse discovered checks (only for non-pawns right now, consider
-      // adding pawns later).
-      if (DiscoveredCheckBonus)
-      {
-          b = pos.discovered_check_candidates(Them) & ~pos.pieces(PAWN);
-          if (b)
-              attackUnits += DiscoveredCheckBonus * count_1s_max_15<HasPopCnt>(b) * (sente ? 2 : 1);
-      }
-
-      // Has a mate threat been found? We don't do anything here if the
-      // side with the mating move is the side to move, because in that
-      // case the mating side will get a huge bonus at the end of the main
-      // evaluation function instead.
-      if (ei.mateThreat[Them] != MOVE_NONE)
-          attackUnits += MateThreatBonus;
-
-      // Ensure that attackUnits is between 0 and 99, in order to avoid array
-      // out of bounds errors.
-      attackUnits = Min(99, Max(0, attackUnits));
-
-      // Finally, extract the king safety score from the SafetyTable[] array.
-      // Add the score to the evaluation, and also to ei.futilityMargin. The
-      // reason for adding the king safety score to the futility margin is
-      // that the king safety scores can sometimes be very big, and that
-      // capturing a single attacking piece can therefore result in a score
-      // change far bigger than the value of the captured piece.
-      Score v = apply_weight(make_score(SafetyTable[attackUnits], 0), WeightKingSafety[Us]);
-      ei.value -= Sign[Us] * v;
-      ei.futilityMargin[Us] += mg_value(v);
+        // Finally, extract the king danger score from the KingDangerTable[]
+        // array and subtract the score from evaluation. Set also ei.kingDanger[]
+        // value that will be used for pruning because this value can sometimes
+        // be very big, and so capturing a single attacking piece can therefore
+        // result in a score change far bigger than the value of the captured piece.
+        ei.value -= Sign[Us] * KingDangerTable[Us][attackUnits];
+        ei.kingDanger[Us] = mg_value(KingDangerTable[Us][attackUnits]);
     }
   }
 
 
-  // evaluate_passed_pawns_of_color() evaluates the passed pawns of the given color
+  // evaluate_passed_pawns<>() evaluates the passed pawns of the given color
 
   template<Color Us>
-  void evaluate_passed_pawns_of_color(const Position& pos, int movesToGo[], Square pawnToGo[], EvalInfo& ei) {
+  void evaluate_passed_pawns(const Position& pos, EvalInfo& ei) {
 
     const Color Them = (Us == WHITE ? BLACK : WHITE);
 
-    Bitboard b2, b3, b4;
-    Square ourKingSq = pos.king_square(Us);
-    Square theirKingSq = pos.king_square(Them);
-    Bitboard b = ei.pi->passed_pawns() & pos.pieces(PAWN, Us);
+    Bitboard squaresToQueen, defendedSquares, unsafeSquares, supportingPawns;
+    Bitboard b = ei.pi->passed_pawns() & pos.pieces_of_color(Us);
 
     while (b)
     {
         Square s = pop_1st_bit(&b);
 
-        assert(pos.piece_on(s) == piece_of_color_and_type(Us, PAWN));
         assert(pos.pawn_is_passed(Us, s));
 
         int r = int(relative_rank(Us, s) - RANK_2);
-        int tr = Max(0, r * (r - 1));
+        int tr = r * (r - 1);
 
         // Base bonus based on rank
         Value mbonus = Value(20 * tr);
         Value ebonus = Value(10 + r * r * 10);
 
-        // Adjust bonus based on king proximity
         if (tr)
         {
             Square blockSq = s + pawn_push(Us);
 
-            ebonus -= Value(square_distance(ourKingSq, blockSq) * 3 * tr);
-            ebonus -= Value(square_distance(ourKingSq, blockSq + pawn_push(Us)) * 1 * tr);
-            ebonus += Value(square_distance(theirKingSq, blockSq) * 6 * tr);
+            // Adjust bonus based on kings proximity
+            ebonus -= Value(square_distance(pos.king_square(Us), blockSq) * 3 * tr);
+            ebonus -= Value(square_distance(pos.king_square(Us), blockSq + pawn_push(Us)) * 1 * tr);
+            ebonus += Value(square_distance(pos.king_square(Them), blockSq) * 6 * tr);
 
             // If the pawn is free to advance, increase bonus
             if (pos.square_is_empty(blockSq))
             {
-                // There are no enemy pawns in the pawn's path
-                b2 = squares_in_front_of(Us, s);
-
-                assert((b2 & pos.pieces(PAWN, Them)) == EmptyBoardBB);
-
-                // Squares attacked by us
-                b4 = b2 & ei.attacked_by(Us);
-
-                // Squares attacked or occupied by enemy pieces
-                b3 = b2 & (ei.attacked_by(Them) | pos.pieces_of_color(Them));
+                squaresToQueen = squares_in_front_of(Us, s);
+                defendedSquares = squaresToQueen & ei.attacked_by(Us);
 
                 // If there is an enemy rook or queen attacking the pawn from behind,
-                // add all X-ray attacks by the rook or queen.
+                // add all X-ray attacks by the rook or queen. Otherwise consider only
+                // the squares in the pawn's path attacked or occupied by the enemy.
                 if (   (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them))
                     && (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them) & pos.attacks_from<QUEEN>(s)))
-                    b3 = b2;
+                    unsafeSquares = squaresToQueen;
+                else
+                    unsafeSquares = squaresToQueen & (ei.attacked_by(Them) | pos.pieces_of_color(Them));
 
-                // Are any of the squares in the pawn's path attacked or occupied by the enemy?
-                if (b3 == EmptyBoardBB)
-                    // No enemy attacks or pieces, huge bonus!
-                    // Even bigger if we protect the pawn's path
-                    ebonus += Value(tr * (b2 == b4 ? 17 : 15));
+                // If there aren't enemy attacks or pieces along the path to queen give
+                // huge bonus. Even bigger if we protect the pawn's path.
+                if (!unsafeSquares)
+                    ebonus += Value(tr * (squaresToQueen == defendedSquares ? 17 : 15));
                 else
                     // OK, there are enemy attacks or pieces (but not pawns). Are those
                     // squares which are attacked by the enemy also attacked by us ?
                     // If yes, big bonus (but smaller than when there are no enemy attacks),
                     // if no, somewhat smaller bonus.
-                    ebonus += Value(tr * ((b3 & b4) == b3 ? 13 : 8));
+                    ebonus += Value(tr * ((unsafeSquares & defendedSquares) == unsafeSquares ? 13 : 8));
 
                 // At last, add a small bonus when there are no *friendly* pieces
                 // in the pawn's path.
-                if ((b2 & pos.pieces_of_color(Us)) == EmptyBoardBB)
+                if (!(squaresToQueen & pos.pieces_of_color(Us)))
                     ebonus += Value(tr);
             }
         } // tr != 0
 
-        // If the pawn is supported by a friendly pawn, increase bonus
-        b2 = pos.pieces(PAWN, Us) & neighboring_files_bb(s);
-        if (b2 & rank_bb(s))
+        // Increase the bonus if the passed pawn is supported by a friendly pawn
+        // on the same rank and a bit smaller if it's on the previous rank.
+        supportingPawns = pos.pieces(PAWN, Us) & neighboring_files_bb(s);
+        if (supportingPawns & rank_bb(s))
             ebonus += Value(r * 20);
-        else if (pos.attacks_from<PAWN>(s, Them) & b2)
+        else if (supportingPawns & rank_bb(s - pawn_push(Us)))
             ebonus += Value(r * 12);
 
-        // If the other side has only a king, check whether the pawn is
-        // unstoppable
-        if (pos.non_pawn_material(Them) == Value(0))
-        {
-            Square qsq;
-            int d;
-
-            qsq = relative_square(Us, make_square(square_file(s), RANK_8));
-            d =  square_distance(s, qsq)
-               - square_distance(theirKingSq, qsq)
-               + (Us != pos.side_to_move());
-
-            if (d < 0)
-            {
-                int mtg = RANK_8 - relative_rank(Us, s);
-                int blockerCount = count_1s_max_15(squares_in_front_of(Us,s) & pos.occupied_squares());
-                mtg += blockerCount;
-                d += blockerCount;
-                if (d < 0 && (!movesToGo[Us] || movesToGo[Us] > mtg))
-                {
-                    movesToGo[Us] = mtg;
-                    pawnToGo[Us] = s;
-                }
-            }
-        }
-
         // Rook pawns are a special case: They are sometimes worse, and
         // sometimes better than other passed pawns. It is difficult to find
         // good rules for determining whether they are good or bad. For now,
@@ -992,23 +869,54 @@ namespace {
                 ebonus -= ebonus / 4;
         }
 
-        // Add the scores for this pawn to the middle game and endgame eval.
-        ei.value += Sign[Us] * apply_weight(make_score(mbonus, ebonus), WeightPassedPawns);
+        // Add the scores for this pawn to the middle game and endgame eval
+        ei.value += Sign[Us] * apply_weight(make_score(mbonus, ebonus), Weights[PassedPawns]);
 
     } // while
   }
 
 
-  // evaluate_passed_pawns() evaluates the passed pawns for both sides
+  // evaluate_unstoppable_pawns() evaluates the unstoppable passed pawns for both sides
 
-  void evaluate_passed_pawns(const Position& pos, EvalInfo& ei) {
+  void evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei) {
 
     int movesToGo[2] = {0, 0};
     Square pawnToGo[2] = {SQ_NONE, SQ_NONE};
 
-    // Evaluate pawns for each color
-    evaluate_passed_pawns_of_color<WHITE>(pos, movesToGo, pawnToGo, ei);
-    evaluate_passed_pawns_of_color<BLACK>(pos, movesToGo, pawnToGo, ei);
+    for (Color c = WHITE; c <= BLACK; c++)
+    {
+        // Skip evaluation if other side has non-pawn pieces
+        if (pos.non_pawn_material(opposite_color(c)))
+            continue;
+
+        Bitboard b = ei.pi->passed_pawns() & pos.pieces_of_color(c);
+
+        while (b)
+        {
+            Square s = pop_1st_bit(&b);
+            Square queeningSquare = relative_square(c, make_square(square_file(s), RANK_8));
+            int d =  square_distance(s, queeningSquare)
+                   - (relative_rank(c, s) == RANK_2) // Double pawn push
+                   - square_distance(pos.king_square(opposite_color(c)), queeningSquare)
+                   + int(c != pos.side_to_move());
+
+            // Do we protect the path to queening ?
+            bool pathDefended = (ei.attacked_by(c) & squares_in_front_of(c, s)) == squares_in_front_of(c, s);
+
+            if (d < 0 || pathDefended)
+            {
+                int mtg = RANK_8 - relative_rank(c, s);
+                int blockerCount = count_1s_max_15(squares_in_front_of(c, s) & pos.occupied_squares());
+                mtg += blockerCount;
+                d += blockerCount;
+                if ((d < 0 || pathDefended) && (!movesToGo[c] || movesToGo[c] > mtg))
+                {
+                    movesToGo[c] = mtg;
+                    pawnToGo[c] = s;
+                }
+            }
+        }
+    }
 
     // Neither side has an unstoppable passed pawn?
     if (!(movesToGo[WHITE] | movesToGo[BLACK]))
@@ -1131,29 +1039,24 @@ namespace {
   // twice. Finally, the space bonus is scaled by a weight taken from the
   // material hash table.
   template<Color Us, bool HasPopCnt>
-  void evaluate_space(const Position& pos, EvalInfo& ei) {
+  int evaluate_space(const Position& pos, EvalInfo& ei) {
 
     const Color Them = (Us == WHITE ? BLACK : WHITE);
 
     // Find the safe squares for our pieces inside the area defined by
     // SpaceMask[us]. A square is unsafe if it is attacked by an enemy
     // pawn, or if it is undefended and attacked by an enemy piece.
+    Bitboard safe =   SpaceMask[Us]
+                   & ~pos.pieces(PAWN, Us)
+                   & ~ei.attacked_by(Them, PAWN)
+                   & (ei.attacked_by(Us) | ~ei.attacked_by(Them));
 
-    Bitboard safeSquares =   SpaceMask[Us]
-                          & ~pos.pieces(PAWN, Us)
-                          & ~ei.attacked_by(Them, PAWN)
-                          & ~(~ei.attacked_by(Us) & ei.attacked_by(Them));
+    // Find all squares which are at most three squares behind some friendly pawn
+    Bitboard behind = pos.pieces(PAWN, Us);
+    behind |= (Us == WHITE ? behind >>  8 : behind <<  8);
+    behind |= (Us == WHITE ? behind >> 16 : behind << 16);
 
-    // Find all squares which are at most three squares behind some friendly
-    // pawn.
-    Bitboard behindFriendlyPawns = pos.pieces(PAWN, Us);
-    behindFriendlyPawns |= (Us == WHITE ? behindFriendlyPawns >>  8 : behindFriendlyPawns <<  8);
-    behindFriendlyPawns |= (Us == WHITE ? behindFriendlyPawns >> 16 : behindFriendlyPawns << 16);
-
-    int space =  count_1s_max_15<HasPopCnt>(safeSquares)
-               + count_1s_max_15<HasPopCnt>(behindFriendlyPawns & safeSquares);
-
-    ei.value += Sign[Us] * apply_weight(make_score(space * ei.mi->space_weight(), 0), WeightSpace);
+    return count_1s_max_15<HasPopCnt>(safe) + count_1s_max_15<HasPopCnt>(behind & safe);
   }
 
 
@@ -1186,45 +1089,36 @@ namespace {
 
   Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight) {
 
-    Score uciWeight = make_score(get_option_value_int(mgOpt), get_option_value_int(egOpt));
+    // Scale option value from 100 to 256
+    int mg = get_option_value_int(mgOpt) * 256 / 100;
+    int eg = get_option_value_int(egOpt) * 256 / 100;
 
-    // Convert to integer to prevent overflow
-    int mg = mg_value(uciWeight);
-    int eg = eg_value(uciWeight);
-
-    mg = (mg * 0x100) / 100;
-    eg = (eg * 0x100) / 100;
-    mg = (mg * mg_value(internalWeight)) / 0x100;
-    eg = (eg * eg_value(internalWeight)) / 0x100;
-    return make_score(mg, eg);
+    return apply_weight(make_score(mg, eg), internalWeight);
   }
 
   // init_safety() initizes the king safety evaluation, based on UCI
-  // parameters.  It is called from read_weights().
+  // parameters. It is called from read_weights().
 
   void init_safety() {
 
-    int maxSlope = 30;
-    int peak     = 0x500;
-    double a     = 0.4;
-    double b     = 0.0;
+    const Value MaxSlope = Value(30);
+    const Value Peak = Value(1280);
+    Value t[100];
 
+    // First setup the base table
     for (int i = 0; i < 100; i++)
     {
-        if (i < b)
-            SafetyTable[i] = Value(0);
-        else
-            SafetyTable[i] = Value((int)(a * (i - b) * (i - b)));
+        t[i] = Value(int(0.4 * i * i));
+
+        if (i > 0)
+            t[i] = Min(t[i], t[i - 1] + MaxSlope);
+
+        t[i] = Min(t[i], Peak);
     }
 
-    for (int i = 0; i < 100; i++)
-    {
-        if (SafetyTable[i+1] - SafetyTable[i] > maxSlope)
-            for (int j = i + 1; j < 100; j++)
-                SafetyTable[j] = SafetyTable[j-1] + Value(maxSlope);
-
-        if (SafetyTable[i]  > Value(peak))
-            SafetyTable[i] = Value(peak);
-    }
+    // Then apply the weights and get the final KingDangerTable[] array
+    for (Color c = WHITE; c <= BLACK; c++)
+        for (int i = 0; i < 100; i++)
+            KingDangerTable[c][i] = apply_weight(make_score(t[i], 0), Weights[KingDangerUs + c]);
   }
 }

src/evaluate.h

@@ -47,7 +47,7 @@ class Position;
 
 struct EvalInfo {
 
-  EvalInfo() { futilityMargin[0] = futilityMargin[1] = Value(0); }
+  EvalInfo() { kingDanger[0] = kingDanger[1] = Value(0); }
 
   // Middle game and endgame evaluations
   Score value;
@@ -89,15 +89,11 @@ struct EvalInfo {
   // 2 to kingAdjacentZoneAttacksCount[BLACK].
   int kingAdjacentZoneAttacksCount[2];
 
-  // mateThreat[color] is a move for the given side which gives a direct mate.
-  Move mateThreat[2];
-
-  // Middle game and endgame mobility scores.
+  // Middle game and endgame mobility scores
   Score mobility;
 
-  // Extra futility margin. This is added to the standard futility margin
-  // in the quiescence search. One for each color.
-  Value futilityMargin[2];
+  // Value of the danger for the king of the given color
+  Value kingDanger[2];
 };
 
 
@@ -105,7 +101,7 @@ struct EvalInfo {
 //// Prototypes
 ////
 
-extern Value evaluate(const Position& pos, EvalInfo& ei, int threadID);
+extern Value evaluate(const Position& pos, EvalInfo& ei);
 extern void init_eval(int threads);
 extern void quit_eval();
 extern void read_weights(Color sideToMove);

src/main.cpp

@@ -57,8 +57,19 @@ int main(int argc, char *argv[]) {
   CALLGRIND_START_INSTRUMENTATION;
 #endif
 
-  // Process command line arguments if any
-  if (argc > 1)
+  if (argc <= 1)
+  {
+      // Print copyright notice
+      cout << engine_name()
+           << " by Tord Romstad, Marco Costalba, Joona Kiiski" << endl;
+
+      if (CpuHasPOPCNT)
+          cout << "Good! CPU has hardware POPCNT." << endl;
+
+      // Enter UCI mode
+      uci_main_loop();
+  }
+  else // Process command line arguments
   {
       if (string(argv[1]) != "bench" || argc < 4 || argc > 8)
           cout << "Usage: stockfish bench <hash size> <threads> "
@@ -68,22 +79,13 @@ int main(int argc, char *argv[]) {
       else
       {
           string time = argc > 4 ? argv[4] : "60";
-          string fen = argc > 5 ? argv[5] : "default";
-          string lim = argc > 6 ? argv[6] : "time";
-          string tim = argc > 7 ? argv[7] : "";
+          string fen  = argc > 5 ? argv[5] : "default";
+          string lim  = argc > 6 ? argv[6] : "time";
+          string tim  = argc > 7 ? argv[7] : "";
           benchmark(string(argv[2]) + " " + string(argv[3]) + " " + time + " " + fen + " " + lim + " " + tim);
       }
-      return 0;
   }
 
-  // Print copyright notice
-  cout << engine_name()
-       << ". By Tord Romstad, Marco Costalba, Joona Kiiski." << endl;
-
-  if (CpuHasPOPCNT)
-      cout << "Good! CPU has hardware POPCNT. We will use it." << endl;
-
-  // Enter UCI mode
-  uci_main_loop();
+  Application::free_resources();
   return 0;
 }

src/material.cpp

@@ -55,17 +55,40 @@ namespace {
   { 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 } };
 
-  // Named endgame evaluation and scaling functions, these
-  // are accessed direcly and not through the function maps.
-  EvaluationFunction<KmmKm> EvaluateKmmKm(WHITE);
-  EvaluationFunction<KXK>   EvaluateKXK(WHITE), EvaluateKKX(BLACK);
-  ScalingFunction<KBPsK>    ScaleKBPsK(WHITE),  ScaleKKBPs(BLACK);
-  ScalingFunction<KQKRPs>   ScaleKQKRPs(WHITE), ScaleKRPsKQ(BLACK);
-  ScalingFunction<KPsK>     ScaleKPsK(WHITE),   ScaleKKPs(BLACK);
-  ScalingFunction<KPKP>     ScaleKPKPw(WHITE),  ScaleKPKPb(BLACK);
-
   typedef EndgameEvaluationFunctionBase EF;
   typedef EndgameScalingFunctionBase SF;
+
+  // Endgame evaluation and scaling functions accessed direcly and not through
+  // the function maps because correspond to more then one material hash key.
+  EvaluationFunction<KmmKm> EvaluateKmmKm[] = { EvaluationFunction<KmmKm>(WHITE), EvaluationFunction<KmmKm>(BLACK) };
+  EvaluationFunction<KXK>   EvaluateKXK[]   = { EvaluationFunction<KXK>(WHITE),   EvaluationFunction<KXK>(BLACK) };
+  ScalingFunction<KBPsK>    ScaleKBPsK[]    = { ScalingFunction<KBPsK>(WHITE),    ScalingFunction<KBPsK>(BLACK) };
+  ScalingFunction<KQKRPs>   ScaleKQKRPs[]   = { ScalingFunction<KQKRPs>(WHITE),   ScalingFunction<KQKRPs>(BLACK) };
+  ScalingFunction<KPsK>     ScaleKPsK[]     = { ScalingFunction<KPsK>(WHITE),     ScalingFunction<KPsK>(BLACK) };
+  ScalingFunction<KPKP>     ScaleKPKP[]     = { ScalingFunction<KPKP>(WHITE),     ScalingFunction<KPKP>(BLACK) };
+
+  // Helper templates used to detect a given material distribution
+  template<Color Us> bool is_KXK(const Position& pos) {
+    const Color Them = (Us == WHITE ? BLACK : WHITE);
+    return   pos.non_pawn_material(Them) == Value(0)
+          && pos.piece_count(Them, PAWN) == 0
+          && pos.non_pawn_material(Us)   >= RookValueMidgame;
+  }
+
+  template<Color Us> bool is_KBPsK(const Position& pos) {
+    return   pos.non_pawn_material(Us)   == BishopValueMidgame
+          && pos.piece_count(Us, BISHOP) == 1
+          && pos.piece_count(Us, PAWN)   >= 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)    == QueenValueMidgame
+          && pos.piece_count(Us, QUEEN)   == 1
+          && pos.piece_count(Them, ROOK)  == 1
+          && pos.piece_count(Them, PAWN)  >= 1;
+  }
 }
 
 
@@ -181,22 +204,13 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) {
   if ((mi->evaluationFunction = funcs->get<EF>(key)) != NULL)
       return mi;
 
-  else if (   pos.non_pawn_material(BLACK) == Value(0)
-           && pos.piece_count(BLACK, PAWN) == 0
-           && pos.non_pawn_material(WHITE) >= RookValueMidgame)
+  else if (is_KXK<WHITE>(pos) || is_KXK<BLACK>(pos))
   {
-      mi->evaluationFunction = &EvaluateKXK;
+      mi->evaluationFunction = is_KXK<WHITE>(pos) ? &EvaluateKXK[WHITE] : &EvaluateKXK[BLACK];
       return mi;
   }
-  else if (   pos.non_pawn_material(WHITE) == Value(0)
-           && pos.piece_count(WHITE, PAWN) == 0
-           && pos.non_pawn_material(BLACK) >= RookValueMidgame)
-  {
-      mi->evaluationFunction = &EvaluateKKX;
-      return mi;
-  }
-  else if (   pos.pieces(PAWN) == EmptyBoardBB
-           && pos.pieces(ROOK) == EmptyBoardBB
+  else if (   pos.pieces(PAWN)  == EmptyBoardBB
+           && pos.pieces(ROOK)  == EmptyBoardBB
            && pos.pieces(QUEEN) == EmptyBoardBB)
   {
       // Minor piece endgame with at least one minor piece per side and
@@ -207,7 +221,7 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) {
       if (   pos.piece_count(WHITE, BISHOP) + pos.piece_count(WHITE, KNIGHT) <= 2
           && pos.piece_count(BLACK, BISHOP) + pos.piece_count(BLACK, KNIGHT) <= 2)
       {
-          mi->evaluationFunction = &EvaluateKmmKm;
+          mi->evaluationFunction = &EvaluateKmmKm[WHITE];
           return mi;
       }
   }
@@ -215,10 +229,8 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) {
   // OK, we didn't find any special evaluation function for the current
   // material configuration. Is there a suitable scaling function?
   //
-  // The code below is rather messy, and it could easily get worse later,
-  // if we decide to add more special cases. We face problems when there
-  // are several conflicting applicable scaling functions and we need to
-  // decide which one to use.
+  // We face problems when there are several conflicting applicable
+  // scaling functions and we need to decide which one to use.
   SF* sf;
 
   if ((sf = funcs->get<SF>(key)) != NULL)
@@ -230,48 +242,36 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) {
   // 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.
-  if (   pos.non_pawn_material(WHITE) == BishopValueMidgame
-      && pos.piece_count(WHITE, BISHOP) == 1
-      && pos.piece_count(WHITE, PAWN) >= 1)
-      mi->scalingFunction[WHITE] = &ScaleKBPsK;
+  if (is_KBPsK<WHITE>(pos))
+      mi->scalingFunction[WHITE] = &ScaleKBPsK[WHITE];
 
-  if (   pos.non_pawn_material(BLACK) == BishopValueMidgame
-      && pos.piece_count(BLACK, BISHOP) == 1
-      && pos.piece_count(BLACK, PAWN) >= 1)
-      mi->scalingFunction[BLACK] = &ScaleKKBPs;
+  if (is_KBPsK<BLACK>(pos))
+      mi->scalingFunction[BLACK] = &ScaleKBPsK[BLACK];
 
-  if (   pos.piece_count(WHITE, PAWN) == 0
-      && pos.non_pawn_material(WHITE) == QueenValueMidgame
-      && pos.piece_count(WHITE, QUEEN) == 1
-      && pos.piece_count(BLACK, ROOK) == 1
-      && pos.piece_count(BLACK, PAWN) >= 1)
-      mi->scalingFunction[WHITE] = &ScaleKQKRPs;
+  if (is_KQKRPs<WHITE>(pos))
+      mi->scalingFunction[WHITE] = &ScaleKQKRPs[WHITE];
 
-  else if (   pos.piece_count(BLACK, PAWN) == 0
-           && pos.non_pawn_material(BLACK) == QueenValueMidgame
-           && pos.piece_count(BLACK, QUEEN) == 1
-           && pos.piece_count(WHITE, ROOK) == 1
-           && pos.piece_count(WHITE, PAWN) >= 1)
-      mi->scalingFunction[BLACK] = &ScaleKRPsKQ;
+  else if (is_KQKRPs<BLACK>(pos))
+      mi->scalingFunction[BLACK] = &ScaleKQKRPs[BLACK];
 
   if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) == Value(0))
   {
       if (pos.piece_count(BLACK, PAWN) == 0)
       {
           assert(pos.piece_count(WHITE, PAWN) >= 2);
-          mi->scalingFunction[WHITE] = &ScaleKPsK;
+          mi->scalingFunction[WHITE] = &ScaleKPsK[WHITE];
       }
       else if (pos.piece_count(WHITE, PAWN) == 0)
       {
           assert(pos.piece_count(BLACK, PAWN) >= 2);
-          mi->scalingFunction[BLACK] = &ScaleKKPs;
+          mi->scalingFunction[BLACK] = &ScaleKPsK[BLACK];
       }
       else if (pos.piece_count(WHITE, PAWN) == 1 && pos.piece_count(BLACK, PAWN) == 1)
       {
           // This is a special case because we set scaling functions
           // for both colors instead of only one.
-          mi->scalingFunction[WHITE] = &ScaleKPKPw;
-          mi->scalingFunction[BLACK] = &ScaleKPKPb;
+          mi->scalingFunction[WHITE] = &ScaleKPKP[WHITE];
+          mi->scalingFunction[BLACK] = &ScaleKPKP[BLACK];
       }
   }
 
@@ -403,7 +403,7 @@ Key EndgameFunctions::buildKey(const string& keyCode) {
         s << char(upcase? toupper(keyCode[i]) : tolower(keyCode[i]));
     }
     s << 8 - keyCode.length() << "/8/8/8/8/8/8/8 w -";
-    return Position(s.str()).get_material_key();
+    return Position(s.str(), 0).get_material_key();
 }
 
 const string EndgameFunctions::swapColors(const string& keyCode) {

src/mersenne.cpp

@@ -41,109 +41,131 @@
    email: m-mat @ math.sci.hiroshima-u.ac.jp (remove space)
 */
 
-#include "types.h"
 #include "mersenne.h"
 
-/* Period parameters */
-#define N 624
-#define M 397
-#define MATRIX_A 0x9908b0dfUL   /* constant vector a */
-#define UPPER_MASK 0x80000000UL /* most significant w-r bits */
-#define LOWER_MASK 0x7fffffffUL /* least significant r bits */
+namespace {
 
-static unsigned long mt[N]; /* the array for the state vector  */
-static int mti=N+1; /* mti==N+1 means mt[N] is not initialized */
+  // Period parameters
+  const int N = 624;
+  const int M = 397;
+  const unsigned long MATRIX_A   = 0x9908b0dfUL; // Constant vector a
+  const unsigned long UPPER_MASK = 0x80000000UL; // Most significant w-r bits
+  const unsigned long LOWER_MASK = 0x7fffffffUL; // Least significant r bits
 
-/* initializes mt[N] with a seed */
-static void init_genrand(unsigned long s)
-{
-    mt[0]= s & 0xffffffffUL;
-    for (mti=1; mti<N; mti++) {
-        mt[mti] =
-            (1812433253UL * (mt[mti-1] ^ (mt[mti-1] >> 30)) + mti);
-        /* See Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier. */
-        /* In the previous versions, MSBs of the seed affect   */
-        /* only MSBs of the array mt[].                        */
-        /* 2002/01/09 modified by Makoto Matsumoto             */
-        mt[mti] &= 0xffffffffUL;
-        /* for >32 bit machines */
-    }
-}
+  unsigned long mt[N]; // The array for the state vector
+  int mti = N + 1;     // mti == N+1 means mt[N] is not initialized
 
-/* initialize by an array with array-length */
-/* init_key is the array for initializing keys */
-/* key_length is its length */
-/* slight change for C++, 2004/2/26 */
-static void init_by_array(unsigned long init_key[], int key_length)
-{
-    int i, j, k;
-    init_genrand(19650218UL);
-    i=1; j=0;
-    k = (N>key_length ? N : key_length);
-    for (; k; k--) {
-        mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 30)) * 1664525UL))
-          + init_key[j] + j; /* non linear */
-        mt[i] &= 0xffffffffUL; /* for WORDSIZE > 32 machines */
-        i++; j++;
-        if (i>=N) { mt[0] = mt[N-1]; i=1; }
-        if (j>=key_length) j=0;
-    }
-    for (k=N-1; k; k--) {
-        mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 30)) * 1566083941UL))
-          - i; /* non linear */
-        mt[i] &= 0xffffffffUL; /* for WORDSIZE > 32 machines */
-        i++;
-        if (i>=N) { mt[0] = mt[N-1]; i=1; }
-    }
+  // Initializes mt[N] with a seed
+  void init_genrand(unsigned long s) {
 
-    mt[0] = 0x80000000UL; /* MSB is 1; assuring non-zero initial array */
-}
+      mt[0]= s & 0xffffffffUL;
+      for (mti = 1; mti < N; mti++)
+      {
+          // See Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier.
+          // In the previous versions, MSBs of the seed affect
+          // only MSBs of the array mt[].
+          // 2002/01/09 modified by Makoto Matsumoto
+          mt[mti] = 1812433253UL * (mt[mti-1] ^ (mt[mti-1] >> 30)) + mti;
+          mt[mti] &= 0xffffffffUL; // For > 32 bit machines
+      }
+  }
+
+  // Initialize by an array with array-length
+  // init_key is the array for initializing keys
+  // key_length is its length
+  // slight change for C++, 2004/2/26
+  void init_by_array(unsigned long init_key[], int key_length) {
+
+      int i = 1;
+      int j = 0;
+      int k = (N > key_length ? N : key_length);
+
+      init_genrand(19650218UL);
+
+      for ( ; k; k--)
+      {
+          mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 30)) * 1664525UL)) + init_key[j] + j; // Non linear
+          mt[i] &= 0xffffffffUL; // For WORDSIZE > 32 machines
+          i++; j++;
+          if (i >= N)
+          {
+              mt[0] = mt[N-1];
+              i = 1;
+          }
+          if (j >= key_length)
+              j = 0;
+      }
+      for (k = N-1; k; k--)
+      {
+          mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 30)) * 1566083941UL)) - i; // Non linear
+          mt[i] &= 0xffffffffUL; // For WORDSIZE > 32 machines
+          i++;
+          if (i >= N)
+          {
+              mt[0] = mt[N-1];
+              i = 1;
+          }
+      }
+      mt[0] = 0x80000000UL; // MSB is 1; assuring non-zero initial array
+  }
+
+} // namespace
+
+
+// Generates a random number on [0,0xffffffff]-interval
+uint32_t genrand_int32() {
 
-/* generates a random number on [0,0xffffffff]-interval */
-uint32_t genrand_int32(void) {
   unsigned long y;
-  static unsigned long mag01[2]={0x0UL, MATRIX_A};
+  static unsigned long mag01[2] = {0x0UL, MATRIX_A};
   /* mag01[x] = x * MATRIX_A  for x=0,1 */
 
-  if (mti >= N) { /* generate N words at one time */
-    int kk;
+  // Generate N words at one time
+  if (mti >= N)
+  {
+      int kk;
 
-    if (mti == N+1)   /* if init_genrand() has not been called, */
-      init_genrand(5489UL); /* a default initial seed is used */
+      if (mti == N+1)           // If init_genrand() has not been called,
+          init_genrand(5489UL); // a default initial seed is used.
 
-    for (kk=0;kk<N-M;kk++) {
-      y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK);
-      mt[kk] = mt[kk+M] ^ (y >> 1) ^ mag01[y & 0x1UL];
-    }
-    for (;kk<N-1;kk++) {
-      y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK);
-      mt[kk] = mt[kk+(M-N)] ^ (y >> 1) ^ mag01[y & 0x1UL];
-    }
-    y = (mt[N-1]&UPPER_MASK)|(mt[0]&LOWER_MASK);
-    mt[N-1] = mt[M-1] ^ (y >> 1) ^ mag01[y & 0x1UL];
-
-    mti = 0;
+      for (kk = 0; kk < N-M; kk++)
+      {
+          y = (mt[kk] & UPPER_MASK) | (mt[kk+1] & LOWER_MASK);
+          mt[kk] = mt[kk+M] ^ (y >> 1) ^ mag01[y & 0x1UL];
+      }
+      for ( ; kk < N-1; kk++)
+      {
+          y = (mt[kk] & UPPER_MASK) | (mt[kk+1] & LOWER_MASK);
+          mt[kk] = mt[kk+(M-N)] ^ (y >> 1) ^ mag01[y & 0x1UL];
+      }
+      y = (mt[N-1] & UPPER_MASK) | (mt[0] & LOWER_MASK);
+      mt[N-1] = mt[M-1] ^ (y >> 1) ^ mag01[y & 0x1UL];
+      mti = 0;
   }
 
   y = mt[mti++];
 
-  /* Tempering */
+  // Tempering
   y ^= (y >> 11);
-  y ^= (y << 7) & 0x9d2c5680UL;
+  y ^= (y <<  7) & 0x9d2c5680UL;
   y ^= (y << 15) & 0xefc60000UL;
   y ^= (y >> 18);
 
   return y;
 }
 
-uint64_t genrand_int64(void) {
+uint64_t genrand_int64() {
+
   uint64_t x, y;
 
-  x = genrand_int32(); y = genrand_int32();
-  return (x<<32)|y;
+  x = genrand_int32();
+  y = genrand_int32();
+  return (x << 32) | y;
 }
 
-void init_mersenne(void) {
-  unsigned long init[4]={0x123, 0x234, 0x345, 0x456}, length=4;
+void init_mersenne() {
+
+  unsigned long init[4] = {0x123, 0x234, 0x345, 0x456};
+  unsigned long length = 4;
+
   init_by_array(init, length);
 }

src/mersenne.h

@@ -32,9 +32,9 @@
 //// Prototypes
 ////
 
-extern uint32_t genrand_int32(void);
-extern uint64_t genrand_int64(void);
-extern void init_mersenne(void);
+extern uint32_t genrand_int32();
+extern uint64_t genrand_int64();
+extern void init_mersenne();
 
 
 #endif // !defined(MERSENNE_H_INCLUDED)

src/misc.cpp

@@ -39,6 +39,10 @@
 
 #endif
 
+#if !defined(NO_PREFETCH)
+#  include <xmmintrin.h>
+#endif
+
 #include <cassert>
 #include <cstdio>
 #include <iomanip>
@@ -54,7 +58,7 @@ using namespace std;
 /// Version number. If this is left empty, the current date (in the format
 /// YYMMDD) is used as a version number.
 
-static const string EngineVersion = "1.7.1";
+static const string EngineVersion = "1.8 beta 2";
 static const string AppName = "Stockfish";
 static const string AppTag  = "";
 
@@ -147,7 +151,7 @@ const string engine_name() {
   const string cpu64(CpuHas64BitPath ? " 64bit" : "");
 
   if (!EngineVersion.empty())
-      return AppName+ " " + EngineVersion + cpu64;
+      return AppName + " " + EngineVersion + cpu64;
 
   string date(__DATE__); // From compiler, format is "Sep 21 2008"
   string months("Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec");
@@ -287,4 +291,27 @@ int Bioskey()
         return 0;
     }
 }
+
 #endif
+
+/// 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 RAM, that can be very slow.
+#if defined(NO_PREFETCH)
+void prefetch(char*) {}
+#else
+
+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.
+   __asm__ ("");
+#endif
+
+  _mm_prefetch(addr, _MM_HINT_T2);
+  _mm_prefetch(addr+64, _MM_HINT_T2); // 64 bytes ahead
+}
+
+#endif
+

src/misc.h

@@ -55,6 +55,7 @@ extern const std::string engine_name();
 extern int get_system_time();
 extern int cpu_count();
 extern int Bioskey();
+extern void prefetch(char* addr);
 
 
 ////

src/move.h

@@ -101,11 +101,11 @@ inline void sort_moves(T* firstMove, T* lastMove, T** lastPositive)
 
     // Split positives vs non-positives
     do {
-        while ((++p)->score > 0);
+        while ((++p)->score > 0) {}
 
         if (p != d)
         {
-            while (--d != p && d->score <= 0);
+            while (--d != p && d->score <= 0) {}
 
             tmp = *p;
             *p = *d;

src/movegen.cpp

@@ -338,6 +338,10 @@ bool move_is_legal(const Position& pos, const Move m, Bitboard pinned) {
            ||(square_rank(to) == RANK_1 && us != WHITE)) != bool(move_is_promotion(m)))
           return false;
 
+      // The promotion piece, if any, must be valid
+      if (move_promotion_piece(m) > QUEEN || move_promotion_piece(m) == PAWN)
+          return false;
+
       // Proceed according to the square delta between the origin and
       // destination squares.
       switch (direction)

src/movepick.cpp

@@ -70,18 +70,18 @@ namespace {
 /// search captures, promotions and some checks) and about how important good
 /// move ordering is at the current node.
 
-MovePicker::MovePicker(const Position& p, Move ttm, Depth d,
-                       const History& h, SearchStack* ss, Value beta) : pos(p), H(h) {
+MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h,
+                       SearchStack* ss, Value beta) : pos(p), H(h) {
   int searchTT = ttm;
   ttMoves[0].move = ttm;
-  lastBadCapture = badCaptures;
   badCaptureThreshold = 0;
+  lastBadCapture = badCaptures;
 
   pinned = p.pinned_pieces(pos.side_to_move());
 
   if (ss && !p.is_check())
   {
-      ttMoves[1].move = (ss->mateKiller == ttm)? MOVE_NONE : ss->mateKiller;
+      ttMoves[1].move = (ss->mateKiller == ttm) ? MOVE_NONE : ss->mateKiller;
       searchTT |= ttMoves[1].move;
       killers[0].move = ss->killers[0];
       killers[1].move = ss->killers[1];
@@ -98,7 +98,8 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d,
           badCaptureThreshold = -PawnValueMidgame;
 
       phasePtr = MainSearchPhaseTable;
-  } else if (d == Depth(0))
+  }
+  else if (d == Depth(0))
       phasePtr = QsearchWithChecksPhaseTable;
   else
   {
@@ -111,7 +112,7 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d,
           searchTT = ttMoves[0].move = MOVE_NONE;
   }
 
-  phasePtr += !searchTT - 1;
+  phasePtr += int(!searchTT) - 1;
   go_next_phase();
 }
 
@@ -312,9 +313,9 @@ Move MovePicker::get_next_move() {
           case PH_KILLERS:
               move = (curMove++)->move;
               if (   move != MOVE_NONE
+                  && move_is_legal(pos, move, pinned)
                   && move != ttMoves[0].move
                   && move != ttMoves[1].move
-                  && move_is_legal(pos, move, pinned)
                   && !pos.move_is_capture(move))
                   return move;
               break;

src/movepick.h

@@ -61,11 +61,11 @@ private:
 
   const Position& pos;
   const History& H;
+  Bitboard pinned;
   MoveStack ttMoves[2], killers[2];
   int badCaptureThreshold, phase;
   const uint8_t* phasePtr;
   MoveStack *curMove, *lastMove, *lastGoodNonCapture, *lastBadCapture;
-  Bitboard pinned;
   MoveStack moves[256], badCaptures[64];
 };
 

src/pawns.cpp

@@ -94,12 +94,13 @@ namespace {
   };
 
   // Pawn storm open file bonuses by file
-  const int16_t KStormOpenFileBonus[8] = { 31, 31, 18, 0, 0, 0, 0, 0 };
-  const int16_t QStormOpenFileBonus[8] = { 0, 0, 0, 0, 0, 26, 42, 26 };
+  const int16_t QStormOpenFileBonus[8] = { 31, 31, 18, 0, 0, 0, 0, 0 };
+  const int16_t KStormOpenFileBonus[8] = { 0, 0, 0, 0, 0, 26, 42, 26 };
 
   // Pawn storm lever bonuses by file
   const int StormLeverBonus[8] = { -8, -8, -13, 0, 0, -13, -8, -8 };
 
+  #undef S
 }
 
 
@@ -107,11 +108,10 @@ namespace {
 //// Functions
 ////
 
-/// Constructor
+/// PawnInfoTable c'tor and d'tor instantiated one each thread
 
-PawnInfoTable::PawnInfoTable(unsigned numOfEntries) {
+PawnInfoTable::PawnInfoTable(unsigned numOfEntries) : size(numOfEntries) {
 
-  size = numOfEntries;
   entries = new PawnInfo[size];
   if (!entries)
   {
@@ -122,9 +122,8 @@ PawnInfoTable::PawnInfoTable(unsigned numOfEntries) {
 }
 
 
-/// Destructor
-
 PawnInfoTable::~PawnInfoTable() {
+
   delete [] entries;
 }
 
@@ -140,11 +139,11 @@ void PawnInfo::clear() {
 
 
 /// PawnInfoTable::get_pawn_info() takes a position object as input, computes
-/// a PawnInfo 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.
+/// a PawnInfo 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.
 
-PawnInfo* PawnInfoTable::get_pawn_info(const Position& pos) {
+PawnInfo* PawnInfoTable::get_pawn_info(const Position& pos) const {
 
   assert(pos.is_ok());
 
@@ -179,12 +178,13 @@ PawnInfo* PawnInfoTable::get_pawn_info(const Position& pos) {
 
 template<Color Us>
 Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns,
-                                    Bitboard theirPawns, PawnInfo* pi) {
+                                    Bitboard theirPawns, PawnInfo* pi) const {
+  Bitboard b;
   Square s;
   File f;
   Rank r;
-  bool passed, isolated, doubled, chain, backward, candidate;
   int bonus;
+  bool passed, isolated, doubled, opposed, chain, backward, candidate;
   Score value = make_score(0, 0);
   const Square* ptr = pos.piece_list_begin(Us, PAWN);
 
@@ -205,69 +205,24 @@ Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns,
 
       assert(pos.piece_on(s) == piece_of_color_and_type(Us, PAWN));
 
-      // Passed, isolated or doubled pawn?
-      passed   = Position::pawn_is_passed(theirPawns, Us, s);
-      isolated = Position::pawn_is_isolated(ourPawns, s);
-      doubled  = Position::pawn_is_doubled(ourPawns, Us, s);
+      // Calculate kingside and queenside pawn storm scores for both colors to be
+      // used when evaluating middle game positions with opposite side castling.
+      bonus = (f >= FILE_F ? evaluate_pawn_storm<Us, KingSide>(s, r, f, theirPawns) : 0);
+      pi->ksStormValue[Us] += KStormTable[relative_square(Us, s)] + bonus;
 
-      // We calculate kingside and queenside pawn storm
-      // scores for both colors. These are used when evaluating
-      // middle game positions with opposite side castling.
-      //
-      // Each pawn is given a base score given by a piece square table
-      // (KStormTable[] or QStormTable[]). Pawns which seem to have good
-      // chances of creating an open file by exchanging itself against an
-      // enemy pawn on an adjacent file gets an additional bonus.
+      bonus = (f <= FILE_C ? evaluate_pawn_storm<Us, QueenSide>(s, r, f, theirPawns) : 0);
+      pi->qsStormValue[Us] += QStormTable[relative_square(Us, s)] + bonus;
 
-      // Kingside pawn storms
-      bonus = KStormTable[relative_square(Us, s)];
-      if (f >= FILE_F)
-      {
-          Bitboard b = outpost_mask(Us, s) & theirPawns & (FileFBB | FileGBB | FileHBB);
-          while (b)
-          {
-              // Give a bonus according to the distance of the nearest enemy pawn
-              Square s2 = pop_1st_bit(&b);
-              int v = StormLeverBonus[f] - 2 * square_distance(s, s2);
+      // Our rank plus previous one. Used for chain detection.
+      b = rank_bb(r) | rank_bb(r + (Us == WHITE ? -1 : 1));
 
-              // If enemy pawn has no pawn beside itself is particularly vulnerable.
-              // Big bonus, especially against a weakness on the rook file
-              if (!(theirPawns & neighboring_files_bb(s2) & rank_bb(s2)))
-                  v *= (square_file(s2) == FILE_H ? 4 : 2);
-
-              bonus += v;
-          }
-      }
-      pi->ksStormValue[Us] += bonus;
-
-      // Queenside pawn storms
-      bonus = QStormTable[relative_square(Us, s)];
-      if (f <= FILE_C)
-      {
-          Bitboard b = outpost_mask(Us, s) & theirPawns & (FileABB | FileBBB | FileCBB);
-          while (b)
-          {
-              // Give a bonus according to the distance of the nearest enemy pawn
-              Square s2 = pop_1st_bit(&b);
-              int v = StormLeverBonus[f] - 4 * square_distance(s, s2);
-
-              // If enemy pawn has no pawn beside itself is particularly vulnerable.
-              // Big bonus, especially against a weakness on the rook file
-              if (!(theirPawns & neighboring_files_bb(s2) & rank_bb(s2)))
-                  v *= (square_file(s2) == FILE_A ? 4 : 2);
-
-              bonus += v;
-          }
-      }
-      pi->qsStormValue[Us] += bonus;
-
-      // Member of a pawn chain (but not the backward one)? We could speed up
-      // the test a little by introducing an array of masks indexed by color
-      // and square for doing the test, but because everything is hashed,
-      // it probably won't make any noticable difference.
-      chain =  ourPawns
-             & neighboring_files_bb(f)
-             & (rank_bb(r) | rank_bb(r - (Us == WHITE ? 1 : -1)));
+      // Passed, isolated, doubled or member of a pawn
+      // chain (but not the backward one) ?
+      passed   = !(theirPawns & passed_pawn_mask(Us, s));
+      doubled  =   ourPawns   & squares_behind(Us, s);
+      opposed  =   theirPawns & squares_in_front_of(Us, s);
+      isolated = !(ourPawns   & neighboring_files_bb(f));
+      chain    =   ourPawns   & neighboring_files_bb(f) & b;
 
       // Test for backward pawn
       //
@@ -276,7 +231,7 @@ Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns,
       // there are friendly pawns behind on neighboring files it cannot
       // be backward either.
       if (   (passed | isolated | chain)
-          || (ourPawns & behind_bb(Us, r) & neighboring_files_bb(f))
+          || (ourPawns & attack_span_mask(opposite_color(Us), s))
           || (pos.attacks_from<PAWN>(s, Us) & theirPawns))
           backward = false;
       else
@@ -285,7 +240,7 @@ Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns,
           // pawn on neighboring files. We now check whether the pawn is
           // backward by looking in the forward direction on the neighboring
           // files, and seeing whether we meet a friendly or an enemy pawn first.
-          Bitboard b = pos.attacks_from<PAWN>(s, Us);
+          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.
@@ -297,12 +252,12 @@ Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns,
           backward = (b | (Us == WHITE ? b << 8 : b >> 8)) & theirPawns;
       }
 
+      assert(passed | opposed | (attack_span_mask(Us, s) & theirPawns));
+
       // Test for candidate passed pawn
-      candidate =   !passed
-                 && !(theirPawns & file_bb(f))
-                 && (  count_1s_max_15(neighboring_files_bb(f) & (behind_bb(Us, r) | rank_bb(r)) & ourPawns)
-                     - count_1s_max_15(neighboring_files_bb(f) & in_front_bb(Us, r)              & theirPawns)
-                     >= 0);
+      candidate =   !(opposed | passed)
+                 && (b = attack_span_mask(opposite_color(Us), s + pawn_push(Us)) & ourPawns) != EmptyBoardBB
+                 &&  count_1s_max_15(b) >= count_1s_max_15(attack_span_mask(Us, s) & theirPawns);
 
       // In order to prevent doubled passed pawns from receiving a too big
       // bonus, only the frontmost passed pawn on each file is considered as
@@ -310,10 +265,12 @@ Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns,
       if (passed && (ourPawns & squares_in_front_of(Us, s)))
           passed = false;
 
-      // Score this pawn
+      // Mark the pawn as passed. Pawn will be properly scored in evaluation
+      // because we need full attack info to evaluate passed pawns.
       if (passed)
           set_bit(&(pi->passedPawns), s);
 
+      // Score this pawn
       if (isolated)
       {
           value -= IsolatedPawnPenalty[f];
@@ -340,13 +297,47 @@ Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns,
 }
 
 
+/// PawnInfoTable::evaluate_pawn_storm() evaluates each pawn which seems
+/// to have good chances of creating an open file by exchanging itself
+/// against an enemy pawn on an adjacent file.
+
+template<Color Us, PawnInfoTable::SideType Side>
+int PawnInfoTable::evaluate_pawn_storm(Square s, Rank r, File f, Bitboard theirPawns) const {
+
+  const Bitboard StormFilesBB = (Side == KingSide ? FileFBB | FileGBB | FileHBB
+                                                  : FileABB | FileBBB | FileCBB);
+  const int K = (Side == KingSide ? 2 : 4);
+  const File RookFile = (Side == KingSide ? FILE_H : FILE_A);
+
+  Bitboard b = attack_span_mask(Us, s) & theirPawns & StormFilesBB;
+  int bonus = 0;
+
+  while (b)
+  {
+      // Give a bonus according to the distance of the nearest enemy pawn
+      Square s2 = pop_1st_bit(&b);
+      Rank r2 = square_rank(s2);
+      int v = StormLeverBonus[f] - K * rank_distance(r, r2);
+
+      // If enemy pawn has no pawn beside itself is particularly vulnerable.
+      // Big bonus, especially against a weakness on the rook file
+      if (!(theirPawns & neighboring_files_bb(s2) & rank_bb(s2)))
+          v *= (square_file(s2) == RookFile ? 4 : 2);
+
+      bonus += v;
+  }
+  return bonus;
+}
+
+
 /// PawnInfo::updateShelter calculates and caches king shelter. It is called
 /// only when king square changes, about 20% of total get_king_shelter() calls.
 int PawnInfo::updateShelter(const Position& pos, Color c, Square ksq) {
 
-  unsigned shelter = 0;
   Bitboard pawns = pos.pieces(PAWN, c) & this_and_neighboring_files_bb(ksq);
+  unsigned shelter = 0;
   unsigned r = ksq & (7 << 3);
+
   for (int i = 1, k = (c ? -8 : 8); i < 4; i++)
   {
       r += k;

src/pawns.h

@@ -64,10 +64,10 @@ private:
   Key key;
   Bitboard passedPawns;
   Bitboard pawnAttacks[2];
+  Square kingSquares[2];
   Score value;
   int16_t ksStormValue[2], qsStormValue[2];
   uint8_t halfOpenFiles[2];
-  Square kingSquares[2];
   uint8_t kingShelters[2];
 };
 
@@ -78,14 +78,19 @@ private:
 
 class PawnInfoTable {
 
+  enum SideType { KingSide, QueenSide };
+
 public:
   PawnInfoTable(unsigned numOfEntries);
   ~PawnInfoTable();
-  PawnInfo* get_pawn_info(const Position& pos);
+  PawnInfo* get_pawn_info(const Position& pos) const;
 
 private:
   template<Color Us>
-  Score evaluate_pawns(const Position& pos, Bitboard ourPawns, Bitboard theirPawns, PawnInfo* pi);
+  Score evaluate_pawns(const Position& pos, Bitboard ourPawns, Bitboard theirPawns, PawnInfo* pi) const;
+
+  template<Color Us, SideType Side>
+  int evaluate_pawn_storm(Square s, Rank r, File f, Bitboard theirPawns) const;
 
   unsigned size;
   PawnInfo* entries;

src/piece.cpp

@@ -38,7 +38,7 @@ static const string PieceChars(" pnbrqk PNBRQK");
 
 char piece_type_to_char(PieceType pt, bool upcase) {
 
-  return PieceChars[pt + upcase * 7];
+  return PieceChars[pt + int(upcase) * 7];
 }
 
 PieceType piece_type_from_char(char c) {

src/position.cpp

@@ -47,7 +47,6 @@ using std::string;
 Key Position::zobrist[2][8][64];
 Key Position::zobEp[64];
 Key Position::zobCastle[16];
-Key Position::zobMaterial[2][8][16];
 Key Position::zobSideToMove;
 Key Position::zobExclusion;
 
@@ -75,23 +74,23 @@ CheckInfo::CheckInfo(const Position& pos) {
 }
 
 
-/// Position c'tors. Here we always create a slower but safer copy of
-/// the original position or the FEN string, we want the new born Position
-/// object do not depend on any external data. Instead if we know what we
-/// are doing and we need speed we can create a position with default
-/// c'tor Position() and then use just fast_copy().
+/// Position c'tors. Here we always create a copy of the original position
+/// or the FEN string, we want the new born Position object do not depend
+/// on any external data so we detach state pointer from the source one.
 
-Position::Position() {}
+Position::Position(int th) : threadID(th) {}
 
-Position::Position(const Position& pos) {
+Position::Position(const Position& pos, int th) {
 
   memcpy(this, &pos, sizeof(Position));
   detach(); // Always detach() in copy c'tor to avoid surprises
+  threadID = th;
 }
 
-Position::Position(const string& fen) {
+Position::Position(const string& fen, int th) {
 
   from_fen(fen);
+  threadID = th;
 }
 
 
@@ -341,7 +340,7 @@ void Position::print(Move m) const {
   std::cout << std::endl;
   if (m != MOVE_NONE)
   {
-      Position p(*this);
+      Position p(*this, thread());
       string col = (color_of_piece_on(move_from(m)) == BLACK ? ".." : "");
       std::cout << "Move is: " << col << move_to_san(p, m) << std::endl;
   }
@@ -697,14 +696,14 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
   assert(is_ok());
   assert(move_is_ok(m));
 
-  Bitboard key = st->key;
+  Key key = st->key;
 
   // Copy some fields of old state to our new StateInfo object except the
   // ones which are recalculated from scratch anyway, then switch our state
   // pointer to point to the new, ready to be updated, state.
   struct ReducedStateInfo {
     Key pawnKey, materialKey;
-    int castleRights, rule50, pliesFromNull;
+    int castleRights, rule50, gamePly, pliesFromNull;
     Square epSquare;
     Score value;
     Value npMaterial[2];
@@ -716,8 +715,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
 
   // Save the current key to the history[] array, in order to be able to
   // detect repetition draws.
-  history[gamePly] = key;
-  gamePly++;
+  history[st->gamePly++] = key;
 
   // Update side to move
   key ^= zobSideToMove;
@@ -774,7 +772,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
   }
 
   // Prefetch TT access as soon as we know key is updated
-  TT.prefetch(key);
+  prefetch((char*)TT.first_entry(key));
 
   // Move the piece
   Bitboard move_bb = make_move_bb(from, to);
@@ -809,6 +807,46 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
               key ^= zobEp[st->epSquare];
           }
       }
+
+      if (pm) // promotion ?
+      {
+          PieceType promotion = move_promotion_piece(m);
+
+          assert(promotion >= KNIGHT && promotion <= QUEEN);
+
+          // Insert promoted piece instead of pawn
+          clear_bit(&(byTypeBB[PAWN]), to);
+          set_bit(&(byTypeBB[promotion]), to);
+          board[to] = piece_of_color_and_type(us, promotion);
+
+          // Update piece counts
+          pieceCount[us][promotion]++;
+          pieceCount[us][PAWN]--;
+
+          // Update material key
+          st->materialKey ^= zobrist[us][PAWN][pieceCount[us][PAWN]];
+          st->materialKey ^= zobrist[us][promotion][pieceCount[us][promotion]-1];
+
+          // Update piece lists, move the last pawn at index[to] position
+          // and shrink the list. Add a new promotion piece to the list.
+          Square lastPawnSquare = pieceList[us][PAWN][pieceCount[us][PAWN]];
+          index[lastPawnSquare] = index[to];
+          pieceList[us][PAWN][index[lastPawnSquare]] = lastPawnSquare;
+          pieceList[us][PAWN][pieceCount[us][PAWN]] = SQ_NONE;
+          index[to] = pieceCount[us][promotion] - 1;
+          pieceList[us][promotion][index[to]] = to;
+
+          // Partially revert hash keys update
+          key ^= zobrist[us][PAWN][to] ^ zobrist[us][promotion][to];
+          st->pawnKey ^= zobrist[us][PAWN][to];
+
+          // Partially revert and update incremental scores
+          st->value -= pst(us, PAWN, to);
+          st->value += pst(us, promotion, to);
+
+          // Update material
+          st->npMaterial[us] += piece_value_midgame(promotion);
+      }
   }
 
   // Update incremental scores
@@ -817,46 +855,6 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
   // Set capture piece
   st->capture = capture;
 
-  if (pm) // promotion ?
-  {
-      PieceType promotion = move_promotion_piece(m);
-
-      assert(promotion >= KNIGHT && promotion <= QUEEN);
-
-      // Insert promoted piece instead of pawn
-      clear_bit(&(byTypeBB[PAWN]), to);
-      set_bit(&(byTypeBB[promotion]), to);
-      board[to] = piece_of_color_and_type(us, promotion);
-
-      // Update material key
-      st->materialKey ^= zobMaterial[us][PAWN][pieceCount[us][PAWN]];
-      st->materialKey ^= zobMaterial[us][promotion][pieceCount[us][promotion]+1];
-
-      // Update piece counts
-      pieceCount[us][PAWN]--;
-      pieceCount[us][promotion]++;
-
-      // Update piece lists, move the last pawn at index[to] position
-      // and shrink the list. Add a new promotion piece to the list.
-      Square lastPawnSquare = pieceList[us][PAWN][pieceCount[us][PAWN]];
-      index[lastPawnSquare] = index[to];
-      pieceList[us][PAWN][index[lastPawnSquare]] = lastPawnSquare;
-      pieceList[us][PAWN][pieceCount[us][PAWN]] = SQ_NONE;
-      index[to] = pieceCount[us][promotion] - 1;
-      pieceList[us][promotion][index[to]] = to;
-
-      // Partially revert hash keys update
-      key ^= zobrist[us][PAWN][to] ^ zobrist[us][promotion][to];
-      st->pawnKey ^= zobrist[us][PAWN][to];
-
-      // Partially revert and update incremental scores
-      st->value -= pst(us, PAWN, to);
-      st->value += pst(us, promotion, to);
-
-      // Update material
-      st->npMaterial[us] += piece_value_midgame(promotion);
-  }
-
   // Update the key with the final value
   st->key = key;
 
@@ -896,23 +894,31 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
 /// Position::do_capture_move() is a private method used to update captured
 /// piece info. It is called from the main Position::do_move function.
 
-void Position::do_capture_move(Bitboard& key, PieceType capture, Color them, Square to, bool ep) {
+void Position::do_capture_move(Key& key, PieceType capture, Color them, Square to, bool ep) {
 
     assert(capture != KING);
 
     Square capsq = to;
 
-    if (ep) // en passant ?
+    // If the captured piece was a pawn, update pawn hash key,
+    // otherwise update non-pawn material.
+    if (capture == PAWN)
     {
-        capsq = (them == BLACK)? (to - DELTA_N) : (to - DELTA_S);
+        if (ep) // en passant ?
+        {
+            capsq = (them == BLACK)? (to - DELTA_N) : (to - DELTA_S);
 
-        assert(to == st->epSquare);
-        assert(relative_rank(opposite_color(them), to) == RANK_6);
-        assert(piece_on(to) == EMPTY);
-        assert(piece_on(capsq) == piece_of_color_and_type(them, PAWN));
+            assert(to == st->epSquare);
+            assert(relative_rank(opposite_color(them), to) == RANK_6);
+            assert(piece_on(to) == EMPTY);
+            assert(piece_on(capsq) == piece_of_color_and_type(them, PAWN));
 
-        board[capsq] = EMPTY;
+            board[capsq] = EMPTY;
+        }
+        st->pawnKey ^= zobrist[them][PAWN][capsq];
     }
+    else
+        st->npMaterial[them] -= piece_value_midgame(capture);
 
     // Remove captured piece
     clear_bit(&(byColorBB[them]), capsq);
@@ -925,19 +931,12 @@ void Position::do_capture_move(Bitboard& key, PieceType capture, Color them, Squ
     // Update incremental scores
     st->value -= pst(them, capture, capsq);
 
-    // If the captured piece was a pawn, update pawn hash key,
-    // otherwise update non-pawn material.
-    if (capture == PAWN)
-        st->pawnKey ^= zobrist[them][PAWN][capsq];
-    else
-        st->npMaterial[them] -= piece_value_midgame(capture);
-
-    // Update material hash key
-    st->materialKey ^= zobMaterial[them][capture][pieceCount[them][capture]];
-
     // Update piece count
     pieceCount[them][capture]--;
 
+    // Update material hash key
+    st->materialKey ^= zobrist[them][capture][pieceCount[them][capture]];
+
     // Update piece list, move the last piece at index[capsq] position
     //
     // WARNING: This is a not perfectly revresible operation. When we
@@ -1061,7 +1060,6 @@ void Position::undo_move(Move m) {
   assert(is_ok());
   assert(move_is_ok(m));
 
-  gamePly--;
   sideToMove = opposite_color(sideToMove);
 
   if (move_is_castle(m))
@@ -1111,7 +1109,6 @@ void Position::undo_move(Move m) {
       pieceList[us][PAWN][index[to]] = to;
   }
 
-
   // Put the piece back at the source square
   Bitboard move_bb = make_move_bb(to, from);
   do_move_bb(&(byColorBB[us]), move_bb);
@@ -1246,21 +1243,20 @@ void Position::do_null_move(StateInfo& backupSt) {
 
   // Save the current key to the history[] array, in order to be able to
   // detect repetition draws.
-  history[gamePly] = st->key;
+  history[st->gamePly++] = st->key;
 
   // Update the necessary information
   if (st->epSquare != SQ_NONE)
       st->key ^= zobEp[st->epSquare];
 
   st->key ^= zobSideToMove;
-  TT.prefetch(st->key);
+  prefetch((char*)TT.first_entry(st->key));
 
   sideToMove = opposite_color(sideToMove);
   st->epSquare = SQ_NONE;
   st->rule50++;
   st->pliesFromNull = 0;
   st->value += (sideToMove == WHITE) ?  TempoValue : -TempoValue;
-  gamePly++;
 }
 
 
@@ -1282,7 +1278,7 @@ void Position::undo_null_move() {
   // Update the necessary information
   sideToMove = opposite_color(sideToMove);
   st->rule50--;
-  gamePly--;
+  st->gamePly--;
 }
 
 
@@ -1311,11 +1307,11 @@ int Position::see_sign(Move m) const {
   Square from = move_from(m);
   Square to = move_to(m);
 
-  // Early return if SEE cannot be negative because capturing piece value
-  // is not bigger then captured one.
-  if (   midgame_value_of_piece_on(from) <= midgame_value_of_piece_on(to)
-      && type_of_piece_on(from) != KING)
-         return 1;
+  // Early return if SEE cannot be negative because captured piece value
+  // is not less then capturing one. Note that king moves always return
+  // here because king midgame value is set to 0.
+  if (midgame_value_of_piece_on(to) >= midgame_value_of_piece_on(from))
+      return 1;
 
   return see(from, to);
 }
@@ -1479,7 +1475,6 @@ void Position::clear() {
           pieceList[0][i][j] = pieceList[1][i][j] = SQ_NONE;
 
   sideToMove = WHITE;
-  gamePly = 0;
   initialKFile = FILE_E;
   initialKRFile = FILE_H;
   initialQRFile = FILE_A;
@@ -1494,7 +1489,7 @@ void Position::clear() {
 
 void Position::reset_game_ply() {
 
-  gamePly = 0;
+  st->gamePly = 0;
 }
 
 
@@ -1598,8 +1593,8 @@ Key Position::compute_material_key() const {
       for (PieceType pt = PAWN; pt <= QUEEN; pt++)
       {
           int count = piece_count(c, pt);
-          for (int i = 0; i <= count; i++)
-              result ^= zobMaterial[c][pt][i];
+          for (int i = 0; i < count; i++)
+              result ^= zobrist[c][pt][i];
       }
   return result;
 }
@@ -1672,8 +1667,8 @@ bool Position::is_draw() const {
       return true;
 
   // Draw by repetition?
-  for (int i = 4; i <= Min(Min(gamePly, st->rule50), st->pliesFromNull); i += 2)
-      if (history[gamePly - i] == st->key)
+  for (int i = 4, e = Min(Min(st->gamePly, st->rule50), st->pliesFromNull); i <= e; i += 2)
+      if (history[st->gamePly - i] == st->key)
           return true;
 
   return false;
@@ -1752,15 +1747,6 @@ void Position::init_zobrist() {
       zobCastle[i] = genrand_int64();
 
   zobSideToMove = genrand_int64();
-
-  for (int i = 0; i < 2; i++)
-      for (int j = 0; j < 8; j++)
-          for (int k = 0; k < 16; k++)
-              zobMaterial[i][j][k] = (k > 0)? Key(genrand_int64()) : Key(0LL);
-
-  for (int i = 0; i < 16; i++)
-      zobMaterial[0][KING][i] = zobMaterial[1][KING][i] = Key(0ULL);
-
   zobExclusion = genrand_int64();
 }
 
@@ -1797,6 +1783,7 @@ void Position::flipped_copy(const Position& pos) {
   assert(pos.is_ok());
 
   clear();
+  threadID = pos.thread();
 
   // Board
   for (Square s = SQ_A1; s <= SQ_H8; s++)

src/position.h

@@ -70,9 +70,9 @@ struct CheckInfo {
 
     CheckInfo(const Position&);
 
-    Square ksq;
     Bitboard dcCandidates;
     Bitboard checkSq[8];
+    Square ksq;
 };
 
 /// Castle rights, encoded as bit fields
@@ -100,13 +100,13 @@ enum Phase {
 
 struct StateInfo {
   Key pawnKey, materialKey;
-  int castleRights, rule50, pliesFromNull;
+  int castleRights, rule50, gamePly, pliesFromNull;
   Square epSquare;
   Score value;
   Value npMaterial[2];
 
-  Key key;
   PieceType capture;
+  Key key;
   Bitboard checkersBB;
   StateInfo* previous;
 };
@@ -139,6 +139,9 @@ class Position {
   friend class MaterialInfo;
   friend class EndgameFunctions;
 
+  Position(); // No default or copy c'tor allowed
+  Position(const Position& pos);
+
 public:
   enum GamePhase {
       MidGame,
@@ -146,9 +149,9 @@ public:
   };
 
   // Constructors
-  Position();
-  explicit Position(const Position& pos);
-  explicit Position(const std::string& fen);
+  explicit Position(int threadID);
+  Position(const Position& pos, int threadID);
+  Position(const std::string& fen, int threadID);
 
   // Text input/output
   void from_fen(const std::string& fen);
@@ -228,9 +231,6 @@ public:
 
   // Information about pawns
   bool pawn_is_passed(Color c, Square s) const;
-  static bool pawn_is_passed(Bitboard theirPawns, Color c, Square s);
-  static bool pawn_is_isolated(Bitboard ourPawns, Square s);
-  static bool pawn_is_doubled(Bitboard ourPawns, Color c, Square s);
 
   // Weak squares
   bool square_is_weak(Square s, Color c) const;
@@ -274,6 +274,9 @@ public:
   bool opposite_colored_bishops() const;
   bool has_pawn_on_7th(Color c) const;
 
+  // Current thread ID searching on the position
+  int thread() const;
+
   // Reset the gamePly variable to 0
   void reset_game_ply();
 
@@ -293,7 +296,7 @@ private:
   void allow_ooo(Color c);
 
   // Helper functions for doing and undoing moves
-  void do_capture_move(Bitboard& key, PieceType capture, Color them, Square to, bool ep);
+  void do_capture_move(Key& key, PieceType capture, Color them, Square to, bool ep);
   void do_castle_move(Move m);
   void undo_castle_move(Move m);
   void find_checkers();
@@ -326,18 +329,17 @@ private:
 
   // Other info
   Color sideToMove;
-  int gamePly;
   Key history[MaxGameLength];
   int castleRightsMask[64];
-  File initialKFile, initialKRFile, initialQRFile;
   StateInfo startState;
+  File initialKFile, initialKRFile, initialQRFile;
+  int threadID;
   StateInfo* st;
 
   // Static variables
   static Key zobrist[2][8][64];
   static Key zobEp[64];
   static Key zobCastle[16];
-  static Key zobMaterial[2][8][16];
   static Key zobSideToMove;
   static Score PieceSquareTable[16][64];
   static Key zobExclusion;
@@ -412,8 +414,8 @@ inline int Position::piece_count(Color c, PieceType pt) const {
   return pieceCount[c][pt];
 }
 
-inline Square Position::piece_list(Color c, PieceType pt, int index) const {
-  return pieceList[c][pt][index];
+inline Square Position::piece_list(Color c, PieceType pt, int idx) const {
+  return pieceList[c][pt][idx];
 }
 
 inline const Square* Position::piece_list_begin(Color c, PieceType pt) const {
@@ -485,20 +487,8 @@ inline bool Position::pawn_is_passed(Color c, Square s) const {
   return !(pieces(PAWN, opposite_color(c)) & passed_pawn_mask(c, s));
 }
 
-inline bool Position::pawn_is_passed(Bitboard theirPawns, Color c, Square s) {
-  return !(theirPawns & passed_pawn_mask(c, s));
-}
-
-inline bool Position::pawn_is_isolated(Bitboard ourPawns, Square s) {
-  return !(ourPawns & neighboring_files_bb(s));
-}
-
-inline bool Position::pawn_is_doubled(Bitboard ourPawns, Color c, Square s) {
-  return ourPawns & squares_behind(c, s);
-}
-
 inline bool Position::square_is_weak(Square s, Color c) const {
-  return !(pieces(PAWN, c) & outpost_mask(opposite_color(c), s));
+  return !(pieces(PAWN, opposite_color(c)) & attack_span_mask(c, s));
 }
 
 inline Key Position::get_key() const {
@@ -573,4 +563,8 @@ inline PieceType Position::captured_piece() const {
   return st->capture;
 }
 
+inline int Position::thread() const {
+  return threadID;
+}
+
 #endif // !defined(POSITION_H_INCLUDED)

src/san.cpp

@@ -299,7 +299,7 @@ const string line_to_san(const Position& pos, Move line[], int startColumn, bool
   string moveStr;
   size_t length = 0;
   size_t maxLength = 80 - startColumn;
-  Position p(pos);
+  Position p(pos, pos.thread());
 
   for (int i = 0; line[i] != MOVE_NONE; i++)
   {

src/search.h

@@ -54,11 +54,13 @@ struct SearchStack {
   Move currentMove;
   Move mateKiller;
   Move threatMove;
+  Move excludedMove;
   Move killers[KILLER_MAX];
   Depth reduction;
   Value eval;
+  bool skipNullMove;
 
-  void init(int ply);
+  void init();
   void initKillers();
 };
 

src/thread.h

@@ -51,11 +51,10 @@ struct SplitPoint {
   // Const data after splitPoint has been setup
   SplitPoint* parent;
   const Position* pos;
-  bool pvNode;
   Depth depth;
-  bool mateThreat;
+  bool pvNode, mateThreat;
   Value beta;
-  int ply, master, slaves[MAX_THREADS];
+  int ply;
   SearchStack sstack[MAX_THREADS][PLY_MAX_PLUS_2];
 
   // Const pointers to shared data
@@ -66,9 +65,9 @@ struct SplitPoint {
   Lock lock;
   volatile Value alpha;
   volatile Value bestValue;
-  volatile int moves;
-  volatile int cpus;
+  volatile int moveCount;
   volatile bool stopRequest;
+  volatile int slaves[MAX_THREADS];
 };
 
 // ThreadState type is used to represent thread's current state
@@ -84,7 +83,7 @@ enum ThreadState
 };
 
 struct Thread {
-  SplitPoint* splitPoint;
+  SplitPoint* volatile splitPoint;
   volatile int activeSplitPoints;
   uint64_t nodes;
   uint64_t betaCutOffs[2];

src/tt.cpp

@@ -25,9 +25,6 @@
 #include <cassert>
 #include <cmath>
 #include <cstring>
-#if !(defined(__hpux) || defined(__ppc__) || defined(__ppc64__) || defined(__arm__))
-#  include <xmmintrin.h>
-#endif
 
 #include "movegen.h"
 #include "tt.h"
@@ -91,16 +88,6 @@ void TranspositionTable::clear() {
 }
 
 
-/// TranspositionTable::first_entry returns a pointer to the first
-/// entry of a cluster given a position. The low 32 bits of the key
-/// are used to get the index in the table.
-
-inline TTEntry* TranspositionTable::first_entry(const Key posKey) const {
-
-  return entries[uint32_t(posKey) & (size - 1)].data;
-}
-
-
 /// TranspositionTable::store writes a new entry containing a position,
 /// a value, a value type, a search depth, and a best move to the
 /// transposition table. Transposition table is organized in clusters of
@@ -111,7 +98,7 @@ inline TTEntry* TranspositionTable::first_entry(const Key posKey) const {
 /// is bigger than the depth of t2. A TTEntry of type VALUE_TYPE_EVAL
 /// never replaces another entry for the same position.
 
-void TranspositionTable::store(const Key posKey, Value v, ValueType t, Depth d, Move m) {
+void TranspositionTable::store(const Key posKey, Value v, ValueType t, Depth d, Move m, Value statV, Value kingD) {
 
   TTEntry *tte, *replace;
   uint32_t posKey32 = posKey >> 32; // Use the high 32 bits as key
@@ -121,15 +108,11 @@ void TranspositionTable::store(const Key posKey, Value v, ValueType t, Depth d,
   {
       if (!tte->key() || tte->key() == posKey32) // empty or overwrite old
       {
-          // Do not overwrite when new type is VALUE_TYPE_EV_LO
-          if (tte->key() && t == VALUE_TYPE_EV_LO)
-              return;
-
           // Preserve any exsisting ttMove
           if (m == MOVE_NONE)
               m = tte->move();
 
-          *tte = TTEntry(posKey32, v, t, d, m, generation);
+          tte->save(posKey32, v, t, d, m, generation, statV, kingD);
           return;
       }
       else if (i == 0)  // replace would be a no-op in this common case
@@ -142,7 +125,7 @@ void TranspositionTable::store(const Key posKey, Value v, ValueType t, Depth d,
       if (c1 + c2 + c3 > 0)
           replace = tte;
   }
-  *replace = TTEntry(posKey32, v, t, d, m, generation);
+  replace->save(posKey32, v, t, d, m, generation, statV, kingD);
   writes++;
 }
 
@@ -164,31 +147,6 @@ TTEntry* TranspositionTable::retrieve(const Key posKey) const {
 }
 
 
-/// TranspositionTable::prefetch looks up the current position in the
-/// transposition table and load it in L1/L2 cache. This is a non
-/// blocking function and do not stalls the CPU waiting for data
-/// to be loaded from RAM, that can be very slow. When we will
-/// subsequently call retrieve() the TT data will be already
-/// quickly accessible in L1/L2 CPU cache.
-#if defined(__hpux) || defined(__ppc__) || defined(__ppc64__) || defined(__arm__)
-void TranspositionTable::prefetch(const Key) const {} // Not supported on HP UX
-#else
-
-void TranspositionTable::prefetch(const Key posKey) const {
-
-#if defined(__INTEL_COMPILER) || defined(__ICL)
-   // This hack prevents prefetches to be optimized away by
-   // Intel compiler. Both MSVC and gcc seems not affected.
-   __asm__ ("");
-#endif
-
-   char const* addr = (char*)first_entry(posKey);
-  _mm_prefetch(addr, _MM_HINT_T2);
-  _mm_prefetch(addr+64, _MM_HINT_T2); // 64 bytes ahead
-}
-
-#endif
-
 /// 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
@@ -209,13 +167,13 @@ void TranspositionTable::new_search() {
 void TranspositionTable::insert_pv(const Position& pos, Move pv[]) {
 
   StateInfo st;
-  Position p(pos);
+  Position p(pos, pos.thread());
 
   for (int i = 0; pv[i] != MOVE_NONE; i++)
   {
       TTEntry *tte = retrieve(p.get_key());
       if (!tte || tte->move() != pv[i])
-          store(p.get_key(), VALUE_NONE, VALUE_TYPE_NONE, Depth(-127*OnePly), pv[i]);
+          store(p.get_key(), VALUE_NONE, VALUE_TYPE_NONE, Depth(-127*OnePly), pv[i], VALUE_NONE, VALUE_NONE);
       p.do_move(pv[i], st);
   }
 }
@@ -231,7 +189,7 @@ void TranspositionTable::extract_pv(const Position& pos, Move pv[], const int PL
 
   const TTEntry* tte;
   StateInfo st;
-  Position p(pos);
+  Position p(pos, pos.thread());
   int ply = 0;
 
   // Update position to the end of current PV

src/tt.h

@@ -46,43 +46,52 @@
 /// the 32 bits of the data field are so defined
 ///
 /// bit  0-16: move
-/// bit 17-18: not used
-/// bit 19-22: value type
+/// bit 17-19: not used
+/// bit 20-22: value type
 /// bit 23-31: generation
 
 class TTEntry {
 
 public:
-  TTEntry() {}
-  TTEntry(uint32_t k, Value v, ValueType t, Depth d, Move m, int generation)
-        : key_ (k), data((m & 0x1FFFF) | (t << 19) | (generation << 23)),
-          value_(int16_t(v)), depth_(int16_t(d)) {}
+  void save(uint32_t k, Value v, ValueType t, Depth d, Move m, int g, Value statV, Value kd) {
 
-  uint32_t key() const { return key_; }
-  Depth depth() const { return Depth(depth_); }
+      key32 = k;
+      data = (m & 0x1FFFF) | (t << 20) | (g << 23);
+      value16     = int16_t(v);
+      depth16     = int16_t(d);
+      staticValue = int16_t(statV);
+      kingDanger  = int16_t(kd);
+  }
+
+  uint32_t key() const { return key32; }
+  Depth depth() const { return Depth(depth16); }
   Move move() const { return Move(data & 0x1FFFF); }
-  Value value() const { return Value(value_); }
-  ValueType type() const { return ValueType((data >> 19) & 0xF); }
-  int generation() const { return (data >> 23); }
+  Value value() const { return Value(value16); }
+  ValueType type() const { return ValueType((data >> 20) & 7); }
+  int generation() const { return data >> 23; }
+  Value static_value() const { return Value(staticValue); }
+  Value king_danger() const { return Value(kingDanger); }
 
 private:
-  uint32_t key_;
+  uint32_t key32;
   uint32_t data;
-  int16_t value_;
-  int16_t depth_;
+  int16_t value16;
+  int16_t depth16;
+  int16_t staticValue;
+  int16_t kingDanger;
 };
 
 
 /// This is the number of TTEntry slots for each position
-const int ClusterSize = 5;
+const int ClusterSize = 4;
 
 /// Each group of ClusterSize number of TTEntry form a TTCluster
-/// that is indexed by a single position key. Cluster is padded
-/// to a cache line size so to guarantee always aligned accesses.
+/// that is indexed by a single position key. TTCluster size must
+///  be not bigger then a cache line size, in case it is less then
+/// it should be padded to guarantee always aligned accesses.
 
 struct TTCluster {
   TTEntry data[ClusterSize];
-  char cache_line_padding[64 - sizeof(TTEntry[ClusterSize])];
 };
 
 
@@ -97,17 +106,15 @@ public:
   ~TranspositionTable();
   void set_size(size_t mbSize);
   void clear();
-  void store(const Key posKey, Value v, ValueType type, Depth d, Move m);
+  void store(const Key posKey, Value v, ValueType type, Depth d, Move m, Value statV, Value kingD);
   TTEntry* retrieve(const Key posKey) const;
-  void prefetch(const Key posKey) const;
   void new_search();
   void insert_pv(const Position& pos, Move pv[]);
   void extract_pv(const Position& pos, Move pv[], const int PLY_MAX);
   int full() const;
+  TTEntry* first_entry(const Key posKey) const;
 
 private:
-  inline TTEntry* first_entry(const Key posKey) const;
-
   // Be sure 'writes' is at least one cache line away
   // from read only variables.
   unsigned char pad_before[64 - sizeof(unsigned)];
@@ -121,4 +128,14 @@ private:
 
 extern TranspositionTable TT;
 
+
+/// TranspositionTable::first_entry returns a pointer to the first
+/// entry of a cluster given a position. The low 32 bits of the key
+/// are used to get the index in the table.
+
+inline TTEntry* TranspositionTable::first_entry(const Key posKey) const {
+
+  return entries[uint32_t(posKey) & (size - 1)].data;
+}
+
 #endif // !defined(TT_H_INCLUDED)

src/types.h

@@ -49,20 +49,32 @@ typedef uint64_t Bitboard;
 
 
 ////
-//// Compiler specific defines
+//// Configuration
 ////
 
-// Quiet a warning on Intel compiler
-#if !defined(__SIZEOF_INT__ )
-#define __SIZEOF_INT__ 0
-#endif
+//// For Linux and OSX configuration is done automatically using Makefile.
+//// To get started type "make help".
+////
+//// For windows part of the configuration is detected automatically, but
+//// some switches need to be set manually:
+////
+//// -DNDEBUG       | Disable debugging mode. Use always.
+////
+//// -DNO_PREFETCH  | Disable use of prefetch asm-instruction. A must if you want the
+////                | executable 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. Around 4% speed-up.
 
-// Check for 64 bits for different compilers: Intel, MSVC and gcc
-#if defined(__x86_64) || defined(_M_X64) || defined(_WIN64) || (__SIZEOF_INT__ > 4)
+// Automatic detection for 64-bit under Windows
+#if defined(_WIN64)
 #define IS_64BIT
 #endif
 
-#if defined(IS_64BIT) && (defined(__GNUC__) || defined(__INTEL_COMPILER))
+// Automatic detection for use of bsfq asm-instruction under Windows.
+// Works only in 64-bit mode. Does not work with MSVC.
+#if defined(_WIN64) && defined(__INTEL_COMPILER)
 #define USE_BSFQ
 #endif
 

src/uci.cpp

@@ -54,7 +54,7 @@ namespace {
   // The root position. This is set up when the user (or in practice, the GUI)
   // sends the "position" UCI command. The root position is sent to the think()
   // function when the program receives the "go" command.
-  Position RootPosition;
+  Position RootPosition(0);
 
   // Local functions
   bool handle_command(const string& command);
@@ -143,7 +143,7 @@ namespace {
         RootPosition.print();
     else if (token == "flip")
     {
-        Position p(RootPosition);
+        Position p(RootPosition, RootPosition.thread());
         RootPosition.flipped_copy(p);
     }
     else if (token == "eval")
@@ -151,7 +151,7 @@ namespace {
         EvalInfo ei;
         cout << "Incremental mg: " << mg_value(RootPosition.value())
              << "\nIncremental eg: " << eg_value(RootPosition.value())
-             << "\nFull eval: " << evaluate(RootPosition, ei, 0) << endl;
+             << "\nFull eval: " << evaluate(RootPosition, ei) << endl;
     }
     else if (token == "key")
         cout << "key: " << hex << RootPosition.get_key()
@@ -308,7 +308,7 @@ namespace {
 
     string token;
     int depth, tm, n;
-    Position pos(RootPosition);
+    Position pos(RootPosition, RootPosition.thread());
 
     if (!(uip >> depth))
         return;

src/ucioption.cpp

@@ -79,6 +79,7 @@ namespace {
     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);
     o["Mobility (Endgame)"] = Option(100, 0, 200);
     o["Pawn Structure (Middle Game)"] = Option(100, 0, 200);
@@ -92,8 +93,8 @@ namespace {
     o["Check Extension (non-PV nodes)"] = Option(1, 0, 2);
     o["Single Evasion Extension (PV nodes)"] = Option(2, 0, 2);
     o["Single Evasion Extension (non-PV nodes)"] = Option(2, 0, 2);
-    o["Mate Threat Extension (PV nodes)"] = Option(0, 0, 2);
-    o["Mate Threat Extension (non-PV nodes)"] = Option(0, 0, 2);
+    o["Mate Threat Extension (PV nodes)"] = Option(2, 0, 2);
+    o["Mate Threat Extension (non-PV nodes)"] = Option(2, 0, 2);
     o["Pawn Push to 7th Extension (PV nodes)"] = Option(1, 0, 2);
     o["Pawn Push to 7th Extension (non-PV nodes)"] = Option(1, 0, 2);
     o["Passed Pawn Extension (PV nodes)"] = Option(1, 0, 2);
@@ -113,9 +114,6 @@ namespace {
     o["UCI_Chess960"] = Option(false);
     o["UCI_AnalyseMode"] = Option(false);
 
-    // Temporary hack for 1.7.1 to be removed in next release
-    o["Zugzwang detection"] = Option(false);
-
     // Any option should know its name so to be easily printed
     for (Options::iterator it = o.begin(); it != o.end(); ++it)
         it->second.name = it->first;

src/value.h

@@ -33,16 +33,10 @@
 ////
 
 enum ValueType {
-  VALUE_TYPE_NONE =  0,
+  VALUE_TYPE_NONE  = 0,
   VALUE_TYPE_UPPER = 1,  // Upper bound
   VALUE_TYPE_LOWER = 2,  // Lower bound
-  VALUE_TYPE_EXACT = 3,  // Exact score
-  VALUE_TYPE_EVAL  = 4,  // Static evaluation value
-  VALUE_TYPE_NULL  = 8,  // Null search value
-
-  VALUE_TYPE_EV_UP = VALUE_TYPE_EVAL | VALUE_TYPE_UPPER,
-  VALUE_TYPE_EV_LO = VALUE_TYPE_EVAL | VALUE_TYPE_LOWER,
-  VALUE_TYPE_NS_LO = VALUE_TYPE_NULL | VALUE_TYPE_LOWER,
+  VALUE_TYPE_EXACT = VALUE_TYPE_UPPER | VALUE_TYPE_LOWER
 };