- echo "Reference bench:" $benchref
#
# Verify bench number against various builds
- - export CXXFLAGS=-Werror
+ - export CXXFLAGS="-Werror -D_GLIBCXX_DEBUG"
- make clean && make -j2 ARCH=x86-64 optimize=no debug=yes build && ../tests/signature.sh $benchref
- make clean && make -j2 ARCH=x86-32 optimize=no debug=yes build && ../tests/signature.sh $benchref
- make clean && make -j2 ARCH=x86-32 build && ../tests/signature.sh $benchref
-# List of authors for Stockfish, as of January 7, 2020
+# List of authors for Stockfish, as of March 30, 2020
Tord Romstad (romstad)
Marco Costalba (mcostalba)
Elvin Liu (solarlight2)
erbsenzaehler
Ernesto Gatti
+Linmiao Xu (linrock)
Fabian Beuke (madnight)
Fabian Fichter (ianfab)
fanon
Fauzi Akram Dabat (FauziAkram)
Felix Wittmann
gamander
+Gary Heckman (gheckman)
gguliash
Gian-Carlo Pascutto (gcp)
Gontran Lemaire (gonlem)
Nicklas Persson (NicklasPersson)
Niklas Fiekas (niklasf)
Nikolay Kostov (NikolayIT)
+Nguyen Pham
Ondrej Mosnáček (WOnder93)
Oskar Werkelin Ahlin
Pablo Vazquez
Patrick Jansen (mibere)
pellanda
Peter Zsifkovits (CoffeeOne)
+Praveen Kumar Tummala (praveentml)
+Rahul Dsilva (silversolver1)
Ralph Stößer (Ralph Stoesser)
Raminder Singh
renouve
theo77186
Tom Truscott
Tom Vijlbrief (tomtor)
+Tomasz Sobczyk (Sopel97)
Torsten Franz (torfranz, tfranzer)
Tracey Emery (basepr1me)
+Unai Corzo (unaiic)
Uri Blass (uriblass)
Vince Negri (cuddlestmonkey)
# an amazing and essential framework for the development of Stockfish!
#
# https://github.com/glinscott/fishtest/blob/master/AUTHORS
-
-
-
-
this equal to the number of CPU cores available.
* #### Hash
- The size of the hash table in MB.
+ The size of the hash table in MB. It is recommended to set Hash after setting Threads.
* #### Clear Hash
Clear the hash table.
If enabled by UCI_LimitStrength, aim for an engine strength of the given Elo.
This Elo rating has been calibrated at a time control of 60s+0.6s and anchored to CCRL 40/4.
+ * #### UCI_ShowWDL
+ If enabled, show approximate WDL statistics as part of the engine output.
+ These WDL numbers model expected game outcomes for a given evaluation and
+ game ply for engine self-play at fishtest LTC conditions (60+0.6s per game).
+
* #### Move Overhead
Assume a time delay of x ms due to network and GUI overheads. This is useful to
avoid losses on time in those cases.
- * #### Minimum Thinking Time
- Search for at least x ms per move.
-
* #### Slow Mover
Lower values will make Stockfish take less time in games, higher values will
make it think longer.
needed for optimal play and in addition being able to take into account
the 50-move rule.
+## Large Pages
+
+Stockfish supports large pages on Linux and Windows. Large pages make
+the hash access more efficient, improving the engine speed, especially
+on large hash sizes. Typical increases are 5..10% in terms of nps, but
+speed increases up to 30% have been measured. The support is
+automatic. Stockfish attempts to use large pages when available and
+will fall back to regular memory allocation when this is not the case.
+
+### Support on Linux
+
+Large page support on Linux is obtained by the Linux kernel
+transparent huge pages functionality. Typically, transparent huge pages
+are already enabled and no configuration is needed.
+
+### Support on Windows
+
+The use of large pages requires "Lock Pages in Memory" privilege. See
+[Enable the Lock Pages in Memory Option (Windows)](https://docs.microsoft.com/en-us/sql/database-engine/configure-windows/enable-the-lock-pages-in-memory-option-windows)
+on how to enable this privilege. Logout/login may be needed
+afterwards. Due to memory fragmentation, it may not always be
+possible to allocate large pages even when enabled. A reboot
+might alleviate this problem. To determine whether large pages
+are in use, see the engine log.
## Compiling Stockfish yourself from the sources
-On Unix-like systems, it should be possible to compile Stockfish
-directly from the source code with the included Makefile.
+Stockfish has support for 32 or 64-bit CPUs, certain hardware
+instructions, big-endian machines such as Power PC, and other platforms.
+
+On Unix-like systems, it should be easy to compile Stockfish
+directly from the source code with the included Makefile in the folder
+`src`. In general it is recommended to run `make help` to see a list of make
+targets with corresponding descriptions.
-Stockfish has support for 32 or 64-bit CPUs, the hardware POPCNT
-instruction, big-endian machines such as Power PC, and other platforms.
+```
+ cd src
+ make help
+ make build ARCH=x86-64-modern
+```
-In general it is recommended to run `make help` to see a list of make
-targets with corresponding descriptions. When not using the Makefile to
-compile (for instance with Microsoft MSVC) you need to manually
-set/unset some switches in the compiler command line; see file *types.h*
-for a quick reference.
+When not using the Makefile to compile (for instance with Microsoft MSVC) you
+need to manually set/unset some switches in the compiler command line; see
+file *types.h* for a quick reference.
When reporting an issue or a bug, please tell us which version and
compiler you used to create your executable. These informations can
### Built-in benchmark for pgo-builds
PGOBENCH = ./$(EXE) bench
-### Object files
-OBJS = benchmark.o bitbase.o bitboard.o endgame.o evaluate.o main.o \
- material.o misc.o movegen.o movepick.o pawns.o position.o psqt.o \
- search.o thread.o timeman.o tt.o uci.o ucioption.o syzygy/tbprobe.o \
- hashprobe.grpc.pb.o hashprobe.pb.o
-CLIOBJS = client.o hashprobe.grpc.pb.o hashprobe.pb.o uci.o
+### Source and object files
+SRCS = benchmark.cpp bitbase.cpp bitboard.cpp endgame.cpp evaluate.cpp main.cpp \
+ material.cpp misc.cpp movegen.cpp movepick.cpp pawns.cpp position.cpp psqt.cpp \
+ search.cpp thread.cpp timeman.cpp tt.cpp uci.cpp ucioption.cpp tune.cpp syzygy/tbprobe.cpp \
+ hashprobe.grpc.pb.cc hashprobe.pb.cc
+CLISRCS = client.cpp hashprobe.grpc.pb.cc hashprobe.pb.cc uci.cpp
+
+OBJS = $(notdir $(SRCS:.cpp=.o))
+CLIOBJS = $(notdir $(CLISRCS:.cpp=.o))
+
+VPATH = syzygy
### Establish the operating system name
KERNEL = $(shell uname -s)
### Section 2. High-level Configuration
### ==========================================================================
#
-# flag --- Comp switch --- Description
+# flag --- Comp switch --- Description
# ----------------------------------------------------------------------------
#
# debug = yes/no --- -DNDEBUG --- Enable/Disable debug mode
optimize = yes
debug = no
sanitize = no
-bits = 32
+bits = 64
prefetch = no
popcnt = no
sse = no
pext = no
### 2.2 Architecture specific
-
ifeq ($(ARCH),general-32)
arch = any
+ bits = 32
endif
ifeq ($(ARCH),x86-32-old)
arch = i386
+ bits = 32
endif
ifeq ($(ARCH),x86-32)
arch = i386
+ bits = 32
prefetch = yes
sse = yes
endif
ifeq ($(ARCH),general-64)
arch = any
- bits = 64
endif
ifeq ($(ARCH),x86-64)
arch = x86_64
- bits = 64
prefetch = yes
sse = yes
endif
ifeq ($(ARCH),x86-64-modern)
arch = x86_64
- bits = 64
prefetch = yes
popcnt = yes
sse = yes
ifeq ($(ARCH),x86-64-bmi2)
arch = x86_64
- bits = 64
prefetch = yes
popcnt = yes
sse = yes
ifeq ($(ARCH),armv7)
arch = armv7
prefetch = yes
+ bits = 32
+endif
+
+ifeq ($(ARCH),armv8)
+ arch = armv8-a
+ prefetch = yes
+ popcnt = yes
endif
ifeq ($(ARCH),ppc-32)
arch = ppc
+ bits = 32
endif
ifeq ($(ARCH),ppc-64)
arch = ppc64
- bits = 64
popcnt = yes
prefetch = yes
endif
-
### ==========================================================================
-### Section 3. Low-level configuration
+### Section 3. Low-level Configuration
### ==========================================================================
### 3.1 Selecting compiler (default = gcc)
-
CXXFLAGS += -Wall -Wcast-qual -fno-exceptions -std=c++11 $(EXTRACXXFLAGS)
DEPENDFLAGS += -std=c++11
LDFLAGS += $(EXTRALDFLAGS)
CXX=g++
CXXFLAGS += -pedantic -Wextra
- ifeq ($(ARCH),armv7)
+ ifeq ($(ARCH),$(filter $(ARCH),armv7 armv8))
ifeq ($(OS),Android)
CXXFLAGS += -m$(bits)
LDFLAGS += -m$(bits)
endif
endif
- ifeq ($(ARCH),armv7)
+ ifeq ($(ARCH),$(filter $(ARCH),armv7 armv8))
ifeq ($(OS),Android)
CXXFLAGS += -m$(bits)
LDFLAGS += -m$(bits)
### 3.6 popcnt
ifeq ($(popcnt),yes)
- ifeq ($(arch),ppc64)
+ ifeq ($(arch),$(filter $(arch),ppc64 armv8-a))
CXXFLAGS += -DUSE_POPCNT
else ifeq ($(comp),icc)
CXXFLAGS += -msse3 -DUSE_POPCNT
endif
endif
-### 3.8 Link Time Optimization, it works since gcc 4.5 but not on mingw under Windows.
+### 3.8 Link Time Optimization
### This is a mix of compile and link time options because the lto link phase
### needs access to the optimization flags.
ifeq ($(optimize),yes)
LDFLAGS += $(CXXFLAGS)
endif
+# To use LTO and static linking on windows, the tool chain requires a recent gcc:
+# gcc version 10.1 in msys2 or TDM-GCC version 9.2 are know to work, older might not.
+# So, only enable it for a cross from Linux by default.
ifeq ($(comp),mingw)
ifeq ($(KERNEL),Linux)
CXXFLAGS += -flto
LDFLAGS += -fPIE -pie
endif
-
### ==========================================================================
-### Section 4. Public targets
+### Section 4. Public Targets
### ==========================================================================
help:
@echo "ppc-64 > PPC 64-bit"
@echo "ppc-32 > PPC 32-bit"
@echo "armv7 > ARMv7 32-bit"
+ @echo "armv8 > ARMv8 64-bit"
@echo "general-64 > unspecified 64-bit"
@echo "general-32 > unspecified 32-bit"
@echo ""
@echo ""
-.PHONY: help build profile-build strip install clean objclean profileclean help \
+.PHONY: help build profile-build strip install clean objclean profileclean \
config-sanity icc-profile-use icc-profile-make gcc-profile-use gcc-profile-make \
clang-profile-use clang-profile-make
# clean auxiliary profiling files
profileclean:
@rm -rf profdir
- @rm -f bench.txt *.gcda ./syzygy/*.gcda *.gcno ./syzygy/*.gcno
+ @rm -f bench.txt *.gcda *.gcno
@rm -f stockfish.profdata *.profraw
default:
help
### ==========================================================================
-### Section 5. Private targets
+### Section 5. Private Targets
### ==========================================================================
all: $(EXE) client .depend
@test "$(sanitize)" = "undefined" || test "$(sanitize)" = "thread" || test "$(sanitize)" = "address" || test "$(sanitize)" = "no"
@test "$(optimize)" = "yes" || test "$(optimize)" = "no"
@test "$(arch)" = "any" || test "$(arch)" = "x86_64" || test "$(arch)" = "i386" || \
- test "$(arch)" = "ppc64" || test "$(arch)" = "ppc" || test "$(arch)" = "armv7"
+ test "$(arch)" = "ppc64" || test "$(arch)" = "ppc" || \
+ test "$(arch)" = "armv7" || test "$(arch)" = "armv8-a"
@test "$(bits)" = "32" || test "$(bits)" = "64"
@test "$(prefetch)" = "yes" || test "$(prefetch)" = "no"
@test "$(popcnt)" = "yes" || test "$(popcnt)" = "no"
# Other stuff
.depend:
- -@$(CXX) $(DEPENDFLAGS) -MM $(OBJS:.o=.cpp) $(OBJS:.o=.cc) > $@ 2> /dev/null
+ -@$(CXX) $(DEPENDFLAGS) -MM $(SRCS) > $@ 2> /dev/null
-include .depend
-
"4rrk1/1p1nq3/p7/2p1P1pp/3P2bp/3Q1Bn1/PPPB4/1K2R1NR w - - 40 21",
"r3k2r/3nnpbp/q2pp1p1/p7/Pp1PPPP1/4BNN1/1P5P/R2Q1RK1 w kq - 0 16",
"3Qb1k1/1r2ppb1/pN1n2q1/Pp1Pp1Pr/4P2p/4BP2/4B1R1/1R5K b - - 11 40",
+ "4k3/3q1r2/1N2r1b1/3ppN2/2nPP3/1B1R2n1/2R1Q3/3K4 w - - 5 1",
// 5-man positions
"8/8/8/8/5kp1/P7/8/1K1N4 w - - 0 1", // Kc2 - mate
// Chess 960
"setoption name UCI_Chess960 value true",
- "bbqnnrkr/pppppppp/8/8/8/8/PPPPPPPP/BBQNNRKR w KQkq - 0 1 moves g2g3 d7d5 d2d4 c8h3 c1g5 e8d6 g5e7 f7f6",
+ "bbqnnrkr/pppppppp/8/8/8/8/PPPPPPPP/BBQNNRKR w HFhf - 0 1 moves g2g3 d7d5 d2d4 c8h3 c1g5 e8d6 g5e7 f7f6",
"setoption name UCI_Chess960 value false"
};
*/
#include <cassert>
-#include <numeric>
#include <vector>
+#include <bitset>
#include "bitboard.h"
#include "types.h"
// Positions with the pawn on files E to H will be mirrored before probing.
constexpr unsigned MAX_INDEX = 2*24*64*64; // stm * psq * wksq * bksq = 196608
- // Each uint32_t stores results of 32 positions, one per bit
- uint32_t KPKBitbase[MAX_INDEX / 32];
+ std::bitset<MAX_INDEX> KPKBitbase;
// A KPK bitbase index is an integer in [0, IndexMax] range
//
// bit 12: side to move (WHITE or BLACK)
// bit 13-14: white pawn file (from FILE_A to FILE_D)
// bit 15-17: white pawn RANK_7 - rank (from RANK_7 - RANK_7 to RANK_7 - RANK_2)
- unsigned index(Color us, Square bksq, Square wksq, Square psq) {
- return int(wksq) | (bksq << 6) | (us << 12) | (file_of(psq) << 13) | ((RANK_7 - rank_of(psq)) << 15);
+ unsigned index(Color stm, Square bksq, Square wksq, Square psq) {
+ return int(wksq) | (bksq << 6) | (stm << 12) | (file_of(psq) << 13) | ((RANK_7 - rank_of(psq)) << 15);
}
enum Result {
KPKPosition() = default;
explicit KPKPosition(unsigned idx);
operator Result() const { return result; }
- Result classify(const std::vector<KPKPosition>& db)
- { return us == WHITE ? classify<WHITE>(db) : classify<BLACK>(db); }
+ Result classify(const std::vector<KPKPosition>& db);
- template<Color Us> Result classify(const std::vector<KPKPosition>& db);
-
- Color us;
+ Color stm;
Square ksq[COLOR_NB], psq;
Result result;
};
} // namespace
-bool Bitbases::probe(Square wksq, Square wpsq, Square bksq, Color us) {
+bool Bitbases::probe(Square wksq, Square wpsq, Square bksq, Color stm) {
assert(file_of(wpsq) <= FILE_D);
- unsigned idx = index(us, bksq, wksq, wpsq);
- return KPKBitbase[idx / 32] & (1 << (idx & 0x1F));
+ return KPKBitbase[index(stm, bksq, wksq, wpsq)];
}
for (repeat = idx = 0; idx < MAX_INDEX; ++idx)
repeat |= (db[idx] == UNKNOWN && db[idx].classify(db) != UNKNOWN);
- // Map 32 results into one KPKBitbase[] entry
+ // Fill the bitbase with the decisive results
for (idx = 0; idx < MAX_INDEX; ++idx)
if (db[idx] == WIN)
- KPKBitbase[idx / 32] |= 1 << (idx & 0x1F);
+ KPKBitbase.set(idx);
}
ksq[WHITE] = Square((idx >> 0) & 0x3F);
ksq[BLACK] = Square((idx >> 6) & 0x3F);
- us = Color ((idx >> 12) & 0x01);
+ stm = Color ((idx >> 12) & 0x01);
psq = make_square(File((idx >> 13) & 0x3), Rank(RANK_7 - ((idx >> 15) & 0x7)));
- // Check if two pieces are on the same square or if a king can be captured
+ // Invalid if two pieces are on the same square or if a king can be captured
if ( distance(ksq[WHITE], ksq[BLACK]) <= 1
|| ksq[WHITE] == psq
|| ksq[BLACK] == psq
- || (us == WHITE && (PawnAttacks[WHITE][psq] & ksq[BLACK])))
+ || (stm == WHITE && (pawn_attacks_bb(WHITE, psq) & ksq[BLACK])))
result = INVALID;
- // Immediate win if a pawn can be promoted without getting captured
- else if ( us == WHITE
+ // Win if the pawn can be promoted without getting captured
+ else if ( stm == WHITE
&& rank_of(psq) == RANK_7
- && ksq[us] != psq + NORTH
- && ( distance(ksq[~us], psq + NORTH) > 1
- || (PseudoAttacks[KING][ksq[us]] & (psq + NORTH))))
+ && ksq[WHITE] != psq + NORTH
+ && ( distance(ksq[BLACK], psq + NORTH) > 1
+ || (distance(ksq[WHITE], psq + NORTH) == 1)))
result = WIN;
- // Immediate draw if it is a stalemate or a king captures undefended pawn
- else if ( us == BLACK
- && ( !(PseudoAttacks[KING][ksq[us]] & ~(PseudoAttacks[KING][ksq[~us]] | PawnAttacks[~us][psq]))
- || (PseudoAttacks[KING][ksq[us]] & psq & ~PseudoAttacks[KING][ksq[~us]])))
+ // Draw if it is stalemate or the black king can capture the pawn
+ else if ( stm == BLACK
+ && ( !(attacks_bb<KING>(ksq[BLACK]) & ~(attacks_bb<KING>(ksq[WHITE]) | pawn_attacks_bb(WHITE, psq)))
+ || (attacks_bb<KING>(ksq[BLACK]) & ~attacks_bb<KING>(ksq[WHITE]) & psq)))
result = DRAW;
// Position will be classified later
result = UNKNOWN;
}
- template<Color Us>
Result KPKPosition::classify(const std::vector<KPKPosition>& db) {
// White to move: If one move leads to a position classified as WIN, the result
// of the current position is DRAW. If all moves lead to positions classified
// as WIN, the position is classified as WIN, otherwise the current position is
// classified as UNKNOWN.
-
- constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
- constexpr Result Good = (Us == WHITE ? WIN : DRAW);
- constexpr Result Bad = (Us == WHITE ? DRAW : WIN);
+ const Result Good = (stm == WHITE ? WIN : DRAW);
+ const Result Bad = (stm == WHITE ? DRAW : WIN);
Result r = INVALID;
- Bitboard b = PseudoAttacks[KING][ksq[Us]];
+ Bitboard b = attacks_bb<KING>(ksq[stm]);
while (b)
- r |= Us == WHITE ? db[index(Them, ksq[Them] , pop_lsb(&b), psq)]
- : db[index(Them, pop_lsb(&b), ksq[Them] , psq)];
+ r |= stm == WHITE ? db[index(BLACK, ksq[BLACK] , pop_lsb(&b), psq)]
+ : db[index(WHITE, pop_lsb(&b), ksq[WHITE], psq)];
- if (Us == WHITE)
+ if (stm == WHITE)
{
if (rank_of(psq) < RANK_7) // Single push
- r |= db[index(Them, ksq[Them], ksq[Us], psq + NORTH)];
+ r |= db[index(BLACK, ksq[BLACK], ksq[WHITE], psq + NORTH)];
if ( rank_of(psq) == RANK_2 // Double push
- && psq + NORTH != ksq[Us]
- && psq + NORTH != ksq[Them])
- r |= db[index(Them, ksq[Them], ksq[Us], psq + NORTH + NORTH)];
+ && psq + NORTH != ksq[WHITE]
+ && psq + NORTH != ksq[BLACK])
+ r |= db[index(BLACK, ksq[BLACK], ksq[WHITE], psq + NORTH + NORTH)];
}
return result = r & Good ? Good : r & UNKNOWN ? UNKNOWN : Bad;
Bitboard RookTable[0x19000]; // To store rook attacks
Bitboard BishopTable[0x1480]; // To store bishop attacks
- void init_magics(Bitboard table[], Magic magics[], Direction directions[]);
+ void init_magics(PieceType pt, Bitboard table[], Magic magics[]);
}
for (File f = FILE_A; f <= FILE_H; ++f)
s += b & make_square(f, r) ? "| X " : "| ";
- s += "|\n+---+---+---+---+---+---+---+---+\n";
+ s += "| " + std::to_string(1 + r) + "\n+---+---+---+---+---+---+---+---+\n";
}
+ s += " a b c d e f g h\n";
return s;
}
void Bitboards::init() {
for (unsigned i = 0; i < (1 << 16); ++i)
- PopCnt16[i] = std::bitset<16>(i).count();
+ PopCnt16[i] = uint8_t(std::bitset<16>(i).count());
for (Square s = SQ_A1; s <= SQ_H8; ++s)
SquareBB[s] = (1ULL << s);
for (Square s2 = SQ_A1; s2 <= SQ_H8; ++s2)
SquareDistance[s1][s2] = std::max(distance<File>(s1, s2), distance<Rank>(s1, s2));
- for (Square s = SQ_A1; s <= SQ_H8; ++s)
- {
- PawnAttacks[WHITE][s] = pawn_attacks_bb<WHITE>(square_bb(s));
- PawnAttacks[BLACK][s] = pawn_attacks_bb<BLACK>(square_bb(s));
- }
+ init_magics(ROOK, RookTable, RookMagics);
+ init_magics(BISHOP, BishopTable, BishopMagics);
- // Helper returning the target bitboard of a step from a square
- auto landing_square_bb = [&](Square s, int step)
+ for (Square s1 = SQ_A1; s1 <= SQ_H8; ++s1)
{
- Square to = Square(s + step);
- return is_ok(to) && distance(s, to) <= 2 ? square_bb(to) : Bitboard(0);
- };
+ PawnAttacks[WHITE][s1] = pawn_attacks_bb<WHITE>(square_bb(s1));
+ PawnAttacks[BLACK][s1] = pawn_attacks_bb<BLACK>(square_bb(s1));
- for (Square s = SQ_A1; s <= SQ_H8; ++s)
- {
for (int step : {-9, -8, -7, -1, 1, 7, 8, 9} )
- PseudoAttacks[KING][s] |= landing_square_bb(s, step);
+ PseudoAttacks[KING][s1] |= safe_destination(s1, step);
for (int step : {-17, -15, -10, -6, 6, 10, 15, 17} )
- PseudoAttacks[KNIGHT][s] |= landing_square_bb(s, step);
- }
-
- Direction RookDirections[] = { NORTH, EAST, SOUTH, WEST };
- Direction BishopDirections[] = { NORTH_EAST, SOUTH_EAST, SOUTH_WEST, NORTH_WEST };
+ PseudoAttacks[KNIGHT][s1] |= safe_destination(s1, step);
- init_magics(RookTable, RookMagics, RookDirections);
- init_magics(BishopTable, BishopMagics, BishopDirections);
-
- for (Square s1 = SQ_A1; s1 <= SQ_H8; ++s1)
- {
PseudoAttacks[QUEEN][s1] = PseudoAttacks[BISHOP][s1] = attacks_bb<BISHOP>(s1, 0);
PseudoAttacks[QUEEN][s1] |= PseudoAttacks[ ROOK][s1] = attacks_bb< ROOK>(s1, 0);
namespace {
- Bitboard sliding_attack(Direction directions[], Square sq, Bitboard occupied) {
-
- Bitboard attack = 0;
+ Bitboard sliding_attack(PieceType pt, Square sq, Bitboard occupied) {
- for (int i = 0; i < 4; ++i)
- for (Square s = sq + directions[i];
- is_ok(s) && distance(s, s - directions[i]) == 1;
- s += directions[i])
- {
- attack |= s;
+ Bitboard attacks = 0;
+ Direction RookDirections[4] = {NORTH, SOUTH, EAST, WEST};
+ Direction BishopDirections[4] = {NORTH_EAST, SOUTH_EAST, SOUTH_WEST, NORTH_WEST};
- if (occupied & s)
- break;
- }
+ for(Direction d : (pt == ROOK ? RookDirections : BishopDirections))
+ {
+ Square s = sq;
+ while(safe_destination(s, d) && !(occupied & s))
+ attacks |= (s += d);
+ }
- return attack;
+ return attacks;
}
// www.chessprogramming.org/Magic_Bitboards. In particular, here we use the so
// called "fancy" approach.
- void init_magics(Bitboard table[], Magic magics[], Direction directions[]) {
+ void init_magics(PieceType pt, Bitboard table[], Magic magics[]) {
// Optimal PRNG seeds to pick the correct magics in the shortest time
int seeds[][RANK_NB] = { { 8977, 44560, 54343, 38998, 5731, 95205, 104912, 17020 },
// the number of 1s of the mask. Hence we deduce the size of the shift to
// apply to the 64 or 32 bits word to get the index.
Magic& m = magics[s];
- m.mask = sliding_attack(directions, s, 0) & ~edges;
+ m.mask = sliding_attack(pt, s, 0) & ~edges;
m.shift = (Is64Bit ? 64 : 32) - popcount(m.mask);
// Set the offset for the attacks table of the square. We have individual
b = size = 0;
do {
occupancy[size] = b;
- reference[size] = sliding_attack(directions, s, b);
+ reference[size] = sliding_attack(pt, s, b);
if (HasPext)
m.attacks[pext(b, m.mask)] = reference[size];
extern Magic BishopMagics[SQUARE_NB];
inline Bitboard square_bb(Square s) {
- assert(s >= SQ_A1 && s <= SQ_H8);
+ assert(is_ok(s));
return SquareBB[s];
}
+
/// Overloads of bitwise operators between a Bitboard and a Square for testing
/// whether a given bit is set in a bitboard, and for setting and clearing bits.
inline Bitboard operator|(Square s, Bitboard b) { return b | s; }
inline Bitboard operator^(Square s, Bitboard b) { return b ^ s; }
-inline Bitboard operator|(Square s, Square s2) { return square_bb(s) | square_bb(s2); }
+inline Bitboard operator|(Square s1, Square s2) { return square_bb(s1) | s2; }
constexpr bool more_than_one(Bitboard b) {
return b & (b - 1);
}
-inline bool opposite_colors(Square s1, Square s2) {
- return bool(DarkSquares & s1) != bool(DarkSquares & s2);
+
+constexpr bool opposite_colors(Square s1, Square s2) {
+ return (s1 + rank_of(s1) + s2 + rank_of(s2)) & 1;
}
/// rank_bb() and file_bb() return a bitboard representing all the squares on
/// the given file or rank.
-inline Bitboard rank_bb(Rank r) {
+constexpr Bitboard rank_bb(Rank r) {
return Rank1BB << (8 * r);
}
-inline Bitboard rank_bb(Square s) {
+constexpr Bitboard rank_bb(Square s) {
return rank_bb(rank_of(s));
}
-inline Bitboard file_bb(File f) {
+constexpr Bitboard file_bb(File f) {
return FileABB << f;
}
-inline Bitboard file_bb(Square s) {
+constexpr Bitboard file_bb(Square s) {
return file_bb(file_of(s));
}
-/// shift() moves a bitboard one step along direction D
+/// shift() moves a bitboard one or two steps as specified by the direction D
template<Direction D>
constexpr Bitboard shift(Bitboard b) {
: shift<SOUTH_WEST>(b) | shift<SOUTH_EAST>(b);
}
+inline Bitboard pawn_attacks_bb(Color c, Square s) {
+
+ assert(is_ok(s));
+ return PawnAttacks[c][s];
+}
+
/// pawn_double_attacks_bb() returns the squares doubly attacked by pawns of the
/// given color from the squares in the given bitboard.
/// adjacent_files_bb() returns a bitboard representing all the squares on the
-/// adjacent files of the given one.
+/// adjacent files of a given square.
-inline Bitboard adjacent_files_bb(Square s) {
+constexpr Bitboard adjacent_files_bb(Square s) {
return shift<EAST>(file_bb(s)) | shift<WEST>(file_bb(s));
}
-/// between_bb() returns squares that are linearly between the given squares
-/// If the given squares are not on a same file/rank/diagonal, return 0.
+/// line_bb() returns a bitboard representing an entire line (from board edge
+/// to board edge) that intersects the two given squares. If the given squares
+/// are not on a same file/rank/diagonal, the function returns 0. For instance,
+/// line_bb(SQ_C4, SQ_F7) will return a bitboard with the A2-G8 diagonal.
+
+inline Bitboard line_bb(Square s1, Square s2) {
+
+ assert(is_ok(s1) && is_ok(s2));
+ return LineBB[s1][s2];
+}
+
+
+/// between_bb() returns a bitboard representing squares that are linearly
+/// between the two given squares (excluding the given squares). If the given
+/// squares are not on a same file/rank/diagonal, we return 0. For instance,
+/// between_bb(SQ_C4, SQ_F7) will return a bitboard with squares D5 and E6.
inline Bitboard between_bb(Square s1, Square s2) {
- return LineBB[s1][s2] & ( (AllSquares << (s1 + (s1 < s2)))
- ^(AllSquares << (s2 + !(s1 < s2))));
+ Bitboard b = line_bb(s1, s2) & ((AllSquares << s1) ^ (AllSquares << s2));
+ return b & (b - 1); //exclude lsb
}
/// in front of the given one, from the point of view of the given color. For instance,
/// forward_ranks_bb(BLACK, SQ_D3) will return the 16 squares on ranks 1 and 2.
-inline Bitboard forward_ranks_bb(Color c, Square s) {
- return c == WHITE ? ~Rank1BB << 8 * (rank_of(s) - RANK_1)
- : ~Rank8BB >> 8 * (RANK_8 - rank_of(s));
+constexpr Bitboard forward_ranks_bb(Color c, Square s) {
+ return c == WHITE ? ~Rank1BB << 8 * relative_rank(WHITE, s)
+ : ~Rank8BB >> 8 * relative_rank(BLACK, s);
}
/// forward_file_bb() returns a bitboard representing all the squares along the
/// line in front of the given one, from the point of view of the given color.
-inline Bitboard forward_file_bb(Color c, Square s) {
+constexpr Bitboard forward_file_bb(Color c, Square s) {
return forward_ranks_bb(c, s) & file_bb(s);
}
/// pawn_attack_span() returns a bitboard representing all the squares that can
-/// be attacked by a pawn of the given color when it moves along its file,
-/// starting from the given square.
+/// be attacked by a pawn of the given color when it moves along its file, starting
+/// from the given square.
-inline Bitboard pawn_attack_span(Color c, Square s) {
+constexpr Bitboard pawn_attack_span(Color c, Square s) {
return forward_ranks_bb(c, s) & adjacent_files_bb(s);
}
/// passed_pawn_span() returns a bitboard which can be used to test if a pawn of
/// the given color and on the given square is a passed pawn.
-inline Bitboard passed_pawn_span(Color c, Square s) {
- return forward_ranks_bb(c, s) & (adjacent_files_bb(s) | file_bb(s));
+constexpr Bitboard passed_pawn_span(Color c, Square s) {
+ return pawn_attack_span(c, s) | forward_file_bb(c, s);
}
/// straight or on a diagonal line.
inline bool aligned(Square s1, Square s2, Square s3) {
- return LineBB[s1][s2] & s3;
+ return line_bb(s1, s2) & s3;
}
template<> inline int distance<Rank>(Square x, Square y) { return std::abs(rank_of(x) - rank_of(y)); }
template<> inline int distance<Square>(Square x, Square y) { return SquareDistance[x][y]; }
-template<class T> constexpr const T& clamp(const T& v, const T& lo, const T& hi) {
- return v < lo ? lo : v > hi ? hi : v;
+inline int edge_distance(File f) { return std::min(f, File(FILE_H - f)); }
+inline int edge_distance(Rank r) { return std::min(r, Rank(RANK_8 - r)); }
+
+
+/// safe_destination() returns the bitboard of target square for the given step
+/// from the given square. If the step is off the board, returns empty bitboard.
+
+inline Bitboard safe_destination(Square s, int step)
+{
+ Square to = Square(s + step);
+ return is_ok(to) && distance(s, to) <= 2 ? square_bb(to) : Bitboard(0);
}
-/// attacks_bb() returns a bitboard representing all the squares attacked by a
-/// piece of type Pt (bishop or rook) placed on 's'.
+
+/// attacks_bb(Square) returns the pseudo attacks of the give piece type
+/// assuming an empty board.
+
+template<PieceType Pt>
+inline Bitboard attacks_bb(Square s) {
+
+ assert((Pt != PAWN) && (is_ok(s)));
+
+ return PseudoAttacks[Pt][s];
+}
+
+
+/// attacks_bb(Square, Bitboard) returns the attacks by the given piece
+/// assuming the board is occupied according to the passed Bitboard.
+/// Sliding piece attacks do not continue passed an occupied square.
template<PieceType Pt>
inline Bitboard attacks_bb(Square s, Bitboard occupied) {
- const Magic& m = Pt == ROOK ? RookMagics[s] : BishopMagics[s];
- return m.attacks[m.index(occupied)];
+ assert((Pt != PAWN) && (is_ok(s)));
+
+ switch (Pt)
+ {
+ case BISHOP: return BishopMagics[s].attacks[BishopMagics[s].index(occupied)];
+ case ROOK : return RookMagics[s].attacks[ RookMagics[s].index(occupied)];
+ case QUEEN : return attacks_bb<BISHOP>(s, occupied) | attacks_bb<ROOK>(s, occupied);
+ default : return PseudoAttacks[Pt][s];
+ }
}
inline Bitboard attacks_bb(PieceType pt, Square s, Bitboard occupied) {
- assert(pt != PAWN);
+ assert((pt != PAWN) && (is_ok(s)));
switch (pt)
{
/// pop_lsb() finds and clears the least significant bit in a non-zero bitboard
inline Square pop_lsb(Bitboard* b) {
+ assert(*b);
const Square s = lsb(*b);
*b &= *b - 1;
return s;
}
-/// frontmost_sq() returns the most advanced square for the given color
+/// frontmost_sq() returns the most advanced square for the given color,
+/// requires a non-zero bitboard.
inline Square frontmost_sq(Color c, Bitboard b) {
+ assert(b);
return c == WHITE ? msb(b) : lsb(b);
}
#include "endgame.h"
#include "movegen.h"
-using std::string;
-
namespace {
- // Table used to drive the king towards the edge of the board
+ // Used to drive the king towards the edge of the board
// in KX vs K and KQ vs KR endgames.
- constexpr int PushToEdges[SQUARE_NB] = {
- 100, 90, 80, 70, 70, 80, 90, 100,
- 90, 70, 60, 50, 50, 60, 70, 90,
- 80, 60, 40, 30, 30, 40, 60, 80,
- 70, 50, 30, 20, 20, 30, 50, 70,
- 70, 50, 30, 20, 20, 30, 50, 70,
- 80, 60, 40, 30, 30, 40, 60, 80,
- 90, 70, 60, 50, 50, 60, 70, 90,
- 100, 90, 80, 70, 70, 80, 90, 100
- };
-
- // Table used to drive the king towards a corner square of the
- // right color in KBN vs K endgames.
- constexpr int PushToCorners[SQUARE_NB] = {
- 6400, 6080, 5760, 5440, 5120, 4800, 4480, 4160,
- 6080, 5760, 5440, 5120, 4800, 4480, 4160, 4480,
- 5760, 5440, 4960, 4480, 4480, 4000, 4480, 4800,
- 5440, 5120, 4480, 3840, 3520, 4480, 4800, 5120,
- 5120, 4800, 4480, 3520, 3840, 4480, 5120, 5440,
- 4800, 4480, 4000, 4480, 4480, 4960, 5440, 5760,
- 4480, 4160, 4480, 4800, 5120, 5440, 5760, 6080,
- 4160, 4480, 4800, 5120, 5440, 5760, 6080, 6400
- };
-
- // Tables used to drive a piece towards or away from another piece
- constexpr int PushClose[8] = { 0, 0, 100, 80, 60, 40, 20, 10 };
- constexpr int PushAway [8] = { 0, 5, 20, 40, 60, 80, 90, 100 };
-
- // Pawn Rank based scaling factors used in KRPPKRP endgame
- constexpr int KRPPKRPScaleFactors[RANK_NB] = { 0, 9, 10, 14, 21, 44, 0, 0 };
+ // Values range from 27 (center squares) to 90 (in the corners)
+ inline int push_to_edge(Square s) {
+ int rd = edge_distance(rank_of(s)), fd = edge_distance(file_of(s));
+ return 90 - (7 * fd * fd / 2 + 7 * rd * rd / 2);
+ }
+
+ // Used to drive the king towards A1H8 corners in KBN vs K endgames.
+ // Values range from 0 on A8H1 diagonal to 7 in A1H8 corners
+ inline int push_to_corner(Square s) {
+ return abs(7 - rank_of(s) - file_of(s));
+ }
+
+ // Drive a piece close to or away from another piece
+ inline int push_close(Square s1, Square s2) { return 140 - 20 * distance(s1, s2); }
+ inline int push_away(Square s1, Square s2) { return 120 - push_close(s1, s2); }
#ifndef NDEBUG
bool verify_material(const Position& pos, Color c, Value npm, int pawnsCnt) {
assert(pos.count<PAWN>(strongSide) == 1);
if (file_of(pos.square<PAWN>(strongSide)) >= FILE_E)
- sq = Square(int(sq) ^ 7); // Mirror SQ_H1 -> SQ_A1
+ sq = flip_file(sq);
- return strongSide == WHITE ? sq : ~sq;
+ return strongSide == WHITE ? sq : flip_rank(sq);
}
} // namespace
add<KQKR>("KQKR");
add<KNNKP>("KNNKP");
- add<KNPK>("KNPK");
- add<KNPKB>("KNPKB");
add<KRPKR>("KRPKR");
add<KRPKB>("KRPKB");
add<KBPKB>("KBPKB");
if (pos.side_to_move() == weakSide && !MoveList<LEGAL>(pos).size())
return VALUE_DRAW;
- Square winnerKSq = pos.square<KING>(strongSide);
- Square loserKSq = pos.square<KING>(weakSide);
+ Square strongKing = pos.square<KING>(strongSide);
+ Square weakKing = pos.square<KING>(weakSide);
Value result = pos.non_pawn_material(strongSide)
+ pos.count<PAWN>(strongSide) * PawnValueEg
- + PushToEdges[loserKSq]
- + PushClose[distance(winnerKSq, loserKSq)];
+ + push_to_edge(weakKing)
+ + push_close(strongKing, weakKing);
if ( pos.count<QUEEN>(strongSide)
|| pos.count<ROOK>(strongSide)
||(pos.count<BISHOP>(strongSide) && pos.count<KNIGHT>(strongSide))
|| ( (pos.pieces(strongSide, BISHOP) & ~DarkSquares)
&& (pos.pieces(strongSide, BISHOP) & DarkSquares)))
- result = std::min(result + VALUE_KNOWN_WIN, VALUE_MATE_IN_MAX_PLY - 1);
+ result = std::min(result + VALUE_KNOWN_WIN, VALUE_TB_WIN_IN_MAX_PLY - 1);
return strongSide == pos.side_to_move() ? result : -result;
}
assert(verify_material(pos, strongSide, KnightValueMg + BishopValueMg, 0));
assert(verify_material(pos, weakSide, VALUE_ZERO, 0));
- Square winnerKSq = pos.square<KING>(strongSide);
- Square loserKSq = pos.square<KING>(weakSide);
- Square bishopSq = pos.square<BISHOP>(strongSide);
+ Square strongKing = pos.square<KING>(strongSide);
+ Square strongBishop = pos.square<BISHOP>(strongSide);
+ Square weakKing = pos.square<KING>(weakSide);
// If our bishop does not attack A1/H8, we flip the enemy king square
// to drive to opposite corners (A8/H1).
- Value result = VALUE_KNOWN_WIN
- + PushClose[distance(winnerKSq, loserKSq)]
- + PushToCorners[opposite_colors(bishopSq, SQ_A1) ? ~loserKSq : loserKSq];
+ Value result = (VALUE_KNOWN_WIN + 3520)
+ + push_close(strongKing, weakKing)
+ + 420 * push_to_corner(opposite_colors(strongBishop, SQ_A1) ? flip_file(weakKing) : weakKing);
- assert(abs(result) < VALUE_MATE_IN_MAX_PLY);
+ assert(abs(result) < VALUE_TB_WIN_IN_MAX_PLY);
return strongSide == pos.side_to_move() ? result : -result;
}
assert(verify_material(pos, weakSide, VALUE_ZERO, 0));
// Assume strongSide is white and the pawn is on files A-D
- Square wksq = normalize(pos, strongSide, pos.square<KING>(strongSide));
- Square bksq = normalize(pos, strongSide, pos.square<KING>(weakSide));
- Square psq = normalize(pos, strongSide, pos.square<PAWN>(strongSide));
+ Square strongKing = normalize(pos, strongSide, pos.square<KING>(strongSide));
+ Square strongPawn = normalize(pos, strongSide, pos.square<PAWN>(strongSide));
+ Square weakKing = normalize(pos, strongSide, pos.square<KING>(weakSide));
Color us = strongSide == pos.side_to_move() ? WHITE : BLACK;
- if (!Bitbases::probe(wksq, psq, bksq, us))
+ if (!Bitbases::probe(strongKing, strongPawn, weakKing, us))
return VALUE_DRAW;
- Value result = VALUE_KNOWN_WIN + PawnValueEg + Value(rank_of(psq));
+ Value result = VALUE_KNOWN_WIN + PawnValueEg + Value(rank_of(strongPawn));
return strongSide == pos.side_to_move() ? result : -result;
}
assert(verify_material(pos, strongSide, RookValueMg, 0));
assert(verify_material(pos, weakSide, VALUE_ZERO, 1));
- Square wksq = relative_square(strongSide, pos.square<KING>(strongSide));
- Square bksq = relative_square(strongSide, pos.square<KING>(weakSide));
- Square rsq = relative_square(strongSide, pos.square<ROOK>(strongSide));
- Square psq = relative_square(strongSide, pos.square<PAWN>(weakSide));
-
- Square queeningSq = make_square(file_of(psq), RANK_1);
+ Square strongKing = pos.square<KING>(strongSide);
+ Square weakKing = pos.square<KING>(weakSide);
+ Square strongRook = pos.square<ROOK>(strongSide);
+ Square weakPawn = pos.square<PAWN>(weakSide);
+ Square queeningSquare = make_square(file_of(weakPawn), relative_rank(weakSide, RANK_8));
Value result;
// If the stronger side's king is in front of the pawn, it's a win
- if (forward_file_bb(WHITE, wksq) & psq)
- result = RookValueEg - distance(wksq, psq);
+ if (forward_file_bb(strongSide, strongKing) & weakPawn)
+ result = RookValueEg - distance(strongKing, weakPawn);
// If the weaker side's king is too far from the pawn and the rook,
// it's a win.
- else if ( distance(bksq, psq) >= 3 + (pos.side_to_move() == weakSide)
- && distance(bksq, rsq) >= 3)
- result = RookValueEg - distance(wksq, psq);
+ else if ( distance(weakKing, weakPawn) >= 3 + (pos.side_to_move() == weakSide)
+ && distance(weakKing, strongRook) >= 3)
+ result = RookValueEg - distance(strongKing, weakPawn);
// If the pawn is far advanced and supported by the defending king,
// the position is drawish
- else if ( rank_of(bksq) <= RANK_3
- && distance(bksq, psq) == 1
- && rank_of(wksq) >= RANK_4
- && distance(wksq, psq) > 2 + (pos.side_to_move() == strongSide))
- result = Value(80) - 8 * distance(wksq, psq);
+ else if ( relative_rank(strongSide, weakKing) <= RANK_3
+ && distance(weakKing, weakPawn) == 1
+ && relative_rank(strongSide, strongKing) >= RANK_4
+ && distance(strongKing, weakPawn) > 2 + (pos.side_to_move() == strongSide))
+ result = Value(80) - 8 * distance(strongKing, weakPawn);
else
- result = Value(200) - 8 * ( distance(wksq, psq + SOUTH)
- - distance(bksq, psq + SOUTH)
- - distance(psq, queeningSq));
+ result = Value(200) - 8 * ( distance(strongKing, weakPawn + pawn_push(weakSide))
+ - distance(weakKing, weakPawn + pawn_push(weakSide))
+ - distance(weakPawn, queeningSquare));
return strongSide == pos.side_to_move() ? result : -result;
}
assert(verify_material(pos, strongSide, RookValueMg, 0));
assert(verify_material(pos, weakSide, BishopValueMg, 0));
- Value result = Value(PushToEdges[pos.square<KING>(weakSide)]);
+ Value result = Value(push_to_edge(pos.square<KING>(weakSide)));
return strongSide == pos.side_to_move() ? result : -result;
}
assert(verify_material(pos, strongSide, RookValueMg, 0));
assert(verify_material(pos, weakSide, KnightValueMg, 0));
- Square bksq = pos.square<KING>(weakSide);
- Square bnsq = pos.square<KNIGHT>(weakSide);
- Value result = Value(PushToEdges[bksq] + PushAway[distance(bksq, bnsq)]);
+ Square weakKing = pos.square<KING>(weakSide);
+ Square weakKnight = pos.square<KNIGHT>(weakSide);
+ Value result = Value(push_to_edge(weakKing) + push_away(weakKing, weakKnight));
return strongSide == pos.side_to_move() ? result : -result;
}
assert(verify_material(pos, strongSide, QueenValueMg, 0));
assert(verify_material(pos, weakSide, VALUE_ZERO, 1));
- Square winnerKSq = pos.square<KING>(strongSide);
- Square loserKSq = pos.square<KING>(weakSide);
- Square
pawnSq = pos.square<PAWN>(weakSide);
+ Square strongKing = pos.square<KING>(strongSide);
+ Square weakKing = pos.square<KING>(weakSide);
+ Square
weakPawn = pos.square<PAWN>(weakSide);
- Value result = Value(PushClose[distance(winnerKSq, loserKSq)]);
+ Value result = Value(push_close(strongKing, weakKing));
- if ( relative_rank(weakSide, pawnSq) != RANK_7
- || distance(loserKSq, pawnSq) != 1
- || !((FileABB | FileCBB | FileFBB | FileHBB) & pawnSq))
+ if ( relative_rank(weakSide, weakPawn) != RANK_7
+ || distance(weakKing, weakPawn) != 1
+ || ((FileBBB | FileDBB | FileEBB | FileGBB) & weakPawn))
result += QueenValueEg - PawnValueEg;
return strongSide == pos.side_to_move() ? result : -result;
}
-/// KQ vs KR. This is almost identical to KX vs K: We give the attacking
+/// KQ vs KR. This is almost identical to KX vs K: we give the attacking
/// king a bonus for having the kings close together, and for forcing the
/// defending king towards the edge. If we also take care to avoid null move for
/// the defending side in the search, this is usually sufficient to win KQ vs KR.
assert(verify_material(pos, strongSide, QueenValueMg, 0));
assert(verify_material(pos, weakSide, RookValueMg, 0));
- Square winnerKSq = pos.square<KING>(strongSide);
- Square loserKSq = pos.square<KING>(weakSide);
+ Square strongKing = pos.square<KING>(strongSide);
+ Square weakKing = pos.square<KING>(weakSide);
Value result = QueenValueEg
- RookValueEg
- + PushToEdges[loserKSq]
- + PushClose[distance(winnerKSq, loserKSq)];
+ + push_to_edge(weakKing)
+ + push_close(strongKing, weakKing);
return strongSide == pos.side_to_move() ? result : -result;
}
-/// KNN vs KP. Simply push the opposing king to the corner
+/// KNN vs KP. Very drawish, but there are some mate opportunities if we can
+/// press the weakSide King to a corner before the pawn advances too much.
template<>
Value Endgame<KNNKP>::operator()(const Position& pos) const {
assert(verify_material(pos, strongSide, 2 * KnightValueMg, 0));
assert(verify_material(pos, weakSide, VALUE_ZERO, 1));
- Value result = 2 * KnightValueEg
- - PawnValueEg
- + PushToEdges[pos.square<KING>(weakSide)];
+ Square weakKing = pos.square<KING>(weakSide);
+ Square weakPawn = pos.square<PAWN>(weakSide);
+
+ Value result = PawnValueEg
+ + 2 * push_to_edge(weakKing)
+ - 10 * relative_rank(weakSide, weakPawn);
return strongSide == pos.side_to_move() ? result : -result;
}
// No assertions about the material of weakSide, because we want draws to
// be detected even when the weaker side has some pawns.
- Bitboard pawns = pos.pieces(strongSide, PAWN);
- File pawnsFile = file_of(lsb(pawns));
+ Bitboard strongPawns = pos.pieces(strongSide, PAWN);
+ Bitboard allPawns = pos.pieces(PAWN);
+
+ Square strongBishop = pos.square<BISHOP>(strongSide);
+ Square weakKing = pos.square<KING>(weakSide);
+ Square strongKing = pos.square<KING>(strongSide);
- // All pawns are on a single rook file?
- if ( (pawnsFile == FILE_A || pawnsFile == FILE_H)
- && !(pawns & ~file_bb(pawnsFile)))
+ // All strongSide pawns are on a single rook file?
+ if (!(strongPawns & ~FileABB) || !(strongPawns & ~FileHBB))
{
- Square bishopSq = pos.square<BISHOP>(strongSide);
- Square queeningSq = relative_square(strongSide, make_square(pawnsFile, RANK_8));
- Square kingSq = pos.square<KING>(weakSide);
+ Square queeningSquare = relative_square(strongSide, make_square(file_of(lsb(strongPawns)), RANK_8));
- if ( opposite_colors(queeningSq, bishopSq)
- && distance(queeningSq, kingSq) <= 1)
+ if ( opposite_colors(queeningSquare, strongBishop)
+ && distance(queeningSquare, weakKing) <= 1)
return SCALE_FACTOR_DRAW;
}
// If all the pawns are on the same B or G file, then it's potentially a draw
- if ( (pawnsFile == FILE_B || pawnsFile == FILE_G)
- && !(pos.pieces(PAWN) & ~file_bb(pawnsFile))
+ if ((!(allPawns & ~FileBBB) || !(allPawns & ~FileGBB))
&& pos.non_pawn_material(weakSide) == 0
&& pos.count<PAWN>(weakSide) >= 1)
{
- // Get weakSide pawn that is closest to the home rank
- Square weakPawnSq = frontmost_sq(strongSide, pos.pieces(weakSide, PAWN));
-
- Square strongKingSq = pos.square<KING>(strongSide);
- Square weakKingSq = pos.square<KING>(weakSide);
- Square bishopSq = pos.square<BISHOP>(strongSide);
+ // Get the least advanced weakSide pawn
+ Square weakPawn = frontmost_sq(strongSide, pos.pieces(weakSide, PAWN));
// There's potential for a draw if our pawn is blocked on the 7th rank,
- // the bishop cannot attack it or they only have one pawn left
- if ( relative_rank(strongSide, weakPawnSq) == RANK_7
- && (pos.pieces(strongSide, PAWN) & (weakPawnSq + pawn_push(weakSide)))
- && (opposite_colors(bishopSq, weakPawnSq) || pos.count<PAWN>(strongSide) == 1))
+ // the bishop cannot attack it or they only have one pawn left.
+ if ( relative_rank(strongSide, weakPawn) == RANK_7
+ && (strongPawns & (weakPawn + pawn_push(weakSide)))
+ && (opposite_colors(strongBishop, weakPawn) || !more_than_one(strongPawns)))
{
- int strongKingDist = distance(weakPawnSq, strongKingSq);
- int weakKingDist = distance(weakPawnSq, weakKingSq);
+ int strongKingDist = distance(weakPawn, strongKing);
+ int weakKingDist = distance(weakPawn, weakKing);
// It's a draw if the weak king is on its back two ranks, within 2
// squares of the blocking pawn and the strong king is not
// closer. (I think this rule only fails in practically
// unreachable positions such as 5k1K/6p1/6P1/8/8/3B4/8/8 w
// and positions where qsearch will immediately correct the
- // problem such as 8/4k1p1/6P1/1K6/3B4/8/8/8 w)
- if ( relative_rank(strongSide, weakKingSq) >= RANK_7
+ // problem such as 8/4k1p1/6P1/1K6/3B4/8/8/8 w).
+ if ( relative_rank(strongSide, weakKing) >= RANK_7
&& weakKingDist <= 2
&& weakKingDist <= strongKingDist)
return SCALE_FACTOR_DRAW;
assert(pos.count<ROOK>(weakSide) == 1);
assert(pos.count<PAWN>(weakSide) >= 1);
- Square kingSq = pos.square<KING>(weakSide);
- Square rsq = pos.square<ROOK>(weakSide);
+ Square strongKing = pos.square<KING>(strongSide);
+ Square weakKing = pos.square<KING>(weakSide);
+ Square weakRook = pos.square<ROOK>(weakSide);
- if ( relative_rank(weakSide, kingSq) <= RANK_2
- && relative_rank(weakSide, pos.square<KING>(strongSide)) >= RANK_4
- && relative_rank(weakSide, rsq) == RANK_3
+ if ( relative_rank(weakSide, weakKing) <= RANK_2
+ && relative_rank(weakSide, strongKing) >= RANK_4
+ && relative_rank(weakSide, weakRook) == RANK_3
&& ( pos.pieces(weakSide, PAWN)
- & pos.attacks_from<KING>(kingSq)
- & pos.attacks_from<PAWN>(rsq, strongSide)))
+ & attacks_bb<KING>(weakKing)
+ & pawn_attacks_bb(strongSide, weakRook)))
return SCALE_FACTOR_DRAW;
return SCALE_FACTOR_NONE;
assert(verify_material(pos, weakSide, RookValueMg, 0));
// Assume strongSide is white and the pawn is on files A-D
- Square wksq = normalize(pos, strongSide, pos.square<KING>(strongSide));
- Square bksq = normalize(pos, strongSide, pos.square<KING>(weakSide));
- Square wrsq = normalize(pos, strongSide, pos.square<ROOK>(strongSide));
- Square wpsq = normalize(pos, strongSide, pos.square<PAWN>(strongSide));
- Square brsq = normalize(pos, strongSide, pos.square<ROOK>(weakSide));
-
- File f = file_of(wpsq);
- Rank r = rank_of(wpsq);
- Square queeningSq = make_square(f, RANK_8);
+ Square strongKing = normalize(pos, strongSide, pos.square<KING>(strongSide));
+ Square strongRook = normalize(pos, strongSide, pos.square<ROOK>(strongSide));
+ Square strongPawn = normalize(pos, strongSide, pos.square<PAWN>(strongSide));
+ Square weakKing = normalize(pos, strongSide, pos.square<KING>(weakSide));
+ Square weakRook = normalize(pos, strongSide, pos.square<ROOK>(weakSide));
+
+ File pawnFile = file_of(strongPawn);
+ Rank pawnRank = rank_of(strongPawn);
+ Square queeningSquare = make_square(pawnFile, RANK_8);
int tempo = (pos.side_to_move() == strongSide);
// If the pawn is not too far advanced and the defending king defends the
// queening square, use the third-rank defence.
- if ( r <= RANK_5
- && distance(bksq, queeningSq) <= 1
- && wksq <= SQ_H5
- && (rank_of(brsq) == RANK_6 || (r <= RANK_3 && rank_of(wrsq) != RANK_6)))
+ if ( pawnRank <= RANK_5
+ && distance(weakKing, queeningSquare) <= 1
+ && strongKing <= SQ_H5
+ && (rank_of(weakRook) == RANK_6 || (pawnRank <= RANK_3 && rank_of(strongRook) != RANK_6)))
return SCALE_FACTOR_DRAW;
// The defending side saves a draw by checking from behind in case the pawn
// has advanced to the 6th rank with the king behind.
- if ( r == RANK_6
- && distance(bksq, queeningSq) <= 1
- && rank_of(wksq) + tempo <= RANK_6
- && (rank_of(brsq) == RANK_1 || (!tempo && distance<File>(brsq, wpsq) >= 3)))
+ if ( pawnRank == RANK_6
+ && distance(weakKing, queeningSquare) <= 1
+ && rank_of(strongKing) + tempo <= RANK_6
+ && (rank_of(weakRook) == RANK_1 || (!tempo && distance<File>(weakRook, strongPawn) >= 3)))
return SCALE_FACTOR_DRAW;
- if ( r >= RANK_6
- && bksq == queeningSq
- && rank_of(brsq) == RANK_1
- && (!tempo || distance(wksq, wpsq) >= 2))
+ if ( pawnRank >= RANK_6
+ && weakKing == queeningSquare
+ && rank_of(weakRook) == RANK_1
+ && (!tempo || distance(strongKing, strongPawn) >= 2))
return SCALE_FACTOR_DRAW;
// White pawn on a7 and rook on a8 is a draw if black's king is on g7 or h7
// and the black rook is behind the pawn.
- if ( wpsq == SQ_A7
- && wrsq == SQ_A8
- && (bksq == SQ_H7 || bksq == SQ_G7)
- && file_of(brsq) == FILE_A
- && (rank_of(brsq) <= RANK_3 || file_of(wksq) >= FILE_D || rank_of(wksq) <= RANK_5))
+ if ( strongPawn == SQ_A7
+ && strongRook == SQ_A8
+ && (weakKing == SQ_H7 || weakKing == SQ_G7)
+ && file_of(weakRook) == FILE_A
+ && (rank_of(weakRook) <= RANK_3 || file_of(strongKing) >= FILE_D || rank_of(strongKing) <= RANK_5))
return SCALE_FACTOR_DRAW;
// If the defending king blocks the pawn and the attacking king is too far
// away, it's a draw.
- if ( r <= RANK_5
- && bksq == wpsq + NORTH
- && distance(wksq, wpsq) - tempo >= 2
- && distance(wksq, brsq) - tempo >= 2)
+ if ( pawnRank <= RANK_5
+ && weakKing == strongPawn + NORTH
+ && distance(strongKing, strongPawn) - tempo >= 2
+ && distance(strongKing, weakRook) - tempo >= 2)
return SCALE_FACTOR_DRAW;
// Pawn on the 7th rank supported by the rook from behind usually wins if the
// attacking king is closer to the queening square than the defending king,
// and the defending king cannot gain tempi by threatening the attacking rook.
- if ( r == RANK_7
- && f != FILE_A
- && file_of(wrsq) == f
- && wrsq != queeningSq
- && (distance(wksq, queeningSq) < distance(bksq, queeningSq) - 2 + tempo)
- && (distance(wksq, queeningSq) < distance(bksq, wrsq) + tempo))
- return ScaleFactor(SCALE_FACTOR_MAX - 2 * distance(wksq, queeningSq));
+ if ( pawnRank == RANK_7
+ && pawnFile != FILE_A
+ && file_of(strongRook) == pawnFile
+ && strongRook != queeningSquare
+ && (distance(strongKing, queeningSquare) < distance(weakKing, queeningSquare) - 2 + tempo)
+ && (distance(strongKing, queeningSquare) < distance(weakKing, strongRook) + tempo))
+ return ScaleFactor(SCALE_FACTOR_MAX - 2 * distance(strongKing, queeningSquare));
// Similar to the above, but with the pawn further back
- if ( f != FILE_A
- && file_of(wrsq) == f
- && wrsq < wpsq
- && (distance(wksq, queeningSq) < distance(bksq, queeningSq) - 2 + tempo)
- && (distance(wksq, wpsq + NORTH) < distance(bksq, wpsq + NORTH) - 2 + tempo)
- && ( distance(bksq, wrsq) + tempo >= 3
- || ( distance(wksq, queeningSq) < distance(bksq, wrsq) + tempo
- && (distance(wksq, wpsq + NORTH) < distance(bksq, wrsq) + tempo))))
+ if ( pawnFile != FILE_A
+ && file_of(strongRook) == pawnFile
+ && strongRook < strongPawn
+ && (distance(strongKing, queeningSquare) < distance(weakKing, queeningSquare) - 2 + tempo)
+ && (distance(strongKing, strongPawn + NORTH) < distance(weakKing, strongPawn + NORTH) - 2 + tempo)
+ && ( distance(weakKing, strongRook) + tempo >= 3
+ || ( distance(strongKing, queeningSquare) < distance(weakKing, strongRook) + tempo
+ && (distance(strongKing, strongPawn + NORTH) < distance(weakKing, strongPawn) + tempo))))
return ScaleFactor( SCALE_FACTOR_MAX
- - 8 * distance(wpsq, queeningSq)
- - 2 * distance(wksq, queeningSq));
+ - 8 * distance(strongPawn, queeningSquare)
+ - 2 * distance(strongKing, queeningSquare));
// If the pawn is not far advanced and the defending king is somewhere in
// the pawn's path, it's probably a draw.
- if (r <= RANK_4 && bksq > wpsq)
+ if (pawnRank <= RANK_4 && weakKing > strongPawn)
{
- if (file_of(bksq) == file_of(wpsq))
+ if (file_of(weakKing) == file_of(strongPawn))
return ScaleFactor(10);
- if ( distance<File>(bksq, wpsq) == 1
- && distance(wksq, bksq) > 2)
- return ScaleFactor(24 - 2 * distance(wksq, bksq));
+ if ( distance<File>(weakKing, strongPawn) == 1
+ && distance(strongKing, weakKing) > 2)
+ return ScaleFactor(24 - 2 * distance(strongKing, weakKing));
}
return SCALE_FACTOR_NONE;
}
// Test for a rook pawn
if (pos.pieces(PAWN) & (FileABB | FileHBB))
{
- Square ksq = pos.square<KING>(weakSide);
- Square bsq = pos.square<BISHOP>(weakSide);
- Square psq = pos.square<PAWN>(strongSide);
- Rank rk = relative_rank(strongSide, psq);
+ Square weakKing = pos.square<KING>(weakSide);
+ Square weakBishop = pos.square<BISHOP>(weakSide);
+ Square strongKing = pos.square<KING>(strongSide);
+ Square strongPawn = pos.square<PAWN>(strongSide);
+ Rank pawnRank = relative_rank(strongSide, strongPawn);
Direction push = pawn_push(strongSide);
// If the pawn is on the 5th rank and the pawn (currently) is on
// a fortress. Depending on the king position give a moderate
// reduction or a stronger one if the defending king is near the
// corner but not trapped there.
- if (rk == RANK_5 && !opposite_colors(bsq, psq))
+ if (pawnRank == RANK_5 && !opposite_colors(weakBishop, strongPawn))
{
- int d = distance(psq + 3 * push, ksq);
+ int d = distance(strongPawn + 3 * push, weakKing);
- if (d <= 2 && !(d == 0 && ksq == pos.square<KING>(strongSide) + 2 * push))
+ if (d <= 2 && !(d == 0 && weakKing == strongKing + 2 * push))
return ScaleFactor(24);
else
return ScaleFactor(48);
// it's drawn if the bishop attacks the square in front of the
// pawn from a reasonable distance and the defending king is near
// the corner
- if ( rk == RANK_6
- && distance(psq + 2 * push, ksq) <= 1
- && (PseudoAttacks[BISHOP][bsq] & (psq + push))
- && distance<File>(bsq, psq) >= 2)
+ if ( pawnRank == RANK_6
+ && distance(strongPawn + 2 * push, weakKing) <= 1
+ && (attacks_bb<BISHOP>(weakBishop) & (strongPawn + push))
+ && distance<File>(weakBishop, strongPawn) >= 2)
return ScaleFactor(8);
}
assert(verify_material(pos, strongSide, RookValueMg, 2));
assert(verify_material(pos, weakSide, RookValueMg, 1));
- Square
wpsq1 = pos.squares<PAWN>(strongSide)[0];
- Square
wpsq2 = pos.squares<PAWN>(strongSide)[1];
- Square bksq = pos.square<KING>(weakSide);
+ Square
strongPawn1 = pos.squares<PAWN>(strongSide)[0];
+ Square
strongPawn2 = pos.squares<PAWN>(strongSide)[1];
+ Square weakKing = pos.square<KING>(weakSide);
// Does the stronger side have a passed pawn?
- if (pos.pawn_passed(strongSide, wpsq1) || pos.pawn_passed(strongSide, wpsq2))
+ if (pos.pawn_passed(strongSide, strongPawn1) || pos.pawn_passed(strongSide, strongPawn2))
return SCALE_FACTOR_NONE;
- Rank r = std::max(relative_rank(strongSide, wpsq1), relative_rank(strongSide, wpsq2));
+ Rank pawnRank = std::max(relative_rank(strongSide, strongPawn1), relative_rank(strongSide, strongPawn2));
- if ( distance<File>(bksq, wpsq1) <= 1
- && distance<File>(bksq, wpsq2) <= 1
- && relative_rank(strongSide, bksq) > r)
+ if ( distance<File>(weakKing, strongPawn1) <= 1
+ && distance<File>(weakKing, strongPawn2) <= 1
+ && relative_rank(strongSide, weakKing) > pawnRank)
{
- assert(r > RANK_1 && r < RANK_7);
- return ScaleFactor(KRPPKRPScaleFactors[r]);
+ assert(pawnRank > RANK_1 && pawnRank < RANK_7);
+ return ScaleFactor(7 * pawnRank);
}
return SCALE_FACTOR_NONE;
}
-/// K and two or more pawns vs K. There is just a single rule here: If all pawns
+/// K and two or more pawns vs K. There is just a single rule here: if all pawns
/// are on the same rook file and are blocked by the defending king, it's a draw.
template<>
ScaleFactor Endgame<KPsK>::operator()(const Position& pos) const {
assert(pos.count<PAWN>(strongSide) >= 2);
assert(verify_material(pos, weakSide, VALUE_ZERO, 0));
- Square ksq = pos.square<KING>(weakSide);
- Bitboard pawns = pos.pieces(strongSide, PAWN);
+ Square weakKing = pos.square<KING>(weakSide);
+ Bitboard strongPawns = pos.pieces(strongSide, PAWN);
- // If all pawns are ahead of the king, on a single rook file and
- // the king is within one file of the pawns, it's a draw.
- if ( !(pawns & ~forward_ranks_bb(weakSide, ksq))
- && !((pawns & ~FileABB) && (pawns & ~FileHBB))
- && distance<File>(ksq, lsb(pawns)) <= 1)
+ // If all pawns are ahead of the king on a single rook file, it's a draw.
+ if ( !(strongPawns & ~(FileABB | FileHBB))
+ && !(strongPawns & ~passed_pawn_span(weakSide, weakKing)))
return SCALE_FACTOR_DRAW;
return SCALE_FACTOR_NONE;
assert(verify_material(pos, strongSide, BishopValueMg, 1));
assert(verify_material(pos, weakSide, BishopValueMg, 0));
- Square
pawnSq = pos.square<PAWN>(strongSide);
- Square strongBishopSq = pos.square<BISHOP>(strongSide);
- Square weakBishopSq = pos.square<BISHOP>(weakSide);
- Square weakKingSq = pos.square<KING>(weakSide);
+ Square
strongPawn = pos.square<PAWN>(strongSide);
+ Square strongBishop = pos.square<BISHOP>(strongSide);
+ Square weakBishop = pos.square<BISHOP>(weakSide);
+ Square weakKing = pos.square<KING>(weakSide);
// Case 1: Defending king blocks the pawn, and cannot be driven away
- if ( file_of(weakKingSq) == file_of(pawnSq)
- && relative_rank(strongSide, pawnSq) < relative_rank(strongSide, weakKingSq)
- && ( opposite_colors(weakKingSq, strongBishopSq)
- || relative_rank(strongSide, weakKingSq) <= RANK_6))
+ if ( (forward_file_bb(strongSide, strongPawn) & weakKing)
+ && ( opposite_colors(weakKing, strongBishop)
+ || relative_rank(strongSide, weakKing) <= RANK_6))
return SCALE_FACTOR_DRAW;
// Case 2: Opposite colored bishops
- if (opposite_colors(strongBishopSq, weakBishopSq))
+ if (opposite_colors(strongBishop, weakBishop))
return SCALE_FACTOR_DRAW;
return SCALE_FACTOR_NONE;
assert(verify_material(pos, strongSide, BishopValueMg, 2));
assert(verify_material(pos, weakSide, BishopValueMg, 0));
- Square wbsq = pos.square<BISHOP>(strongSide);
- Square bbsq = pos.square<BISHOP>(weakSide);
+ Square strongBishop = pos.square<BISHOP>(strongSide);
+ Square weakBishop = pos.square<BISHOP>(weakSide);
- if (!opposite_colors(wbsq, bbsq))
+ if (!opposite_colors(strongBishop, weakBishop))
return SCALE_FACTOR_NONE;
- Square ksq = pos.square<KING>(weakSide);
- Square
psq1 = pos.squares<PAWN>(strongSide)[0];
- Square
psq2 = pos.squares<PAWN>(strongSide)[1];
+ Square weakKing = pos.square<KING>(weakSide);
+ Square
strongPawn1 = pos.squares<PAWN>(strongSide)[0];
+ Square
strongPawn2 = pos.squares<PAWN>(strongSide)[1];
Square blockSq1, blockSq2;
- if (relative_rank(strongSide, psq1) > relative_rank(strongSide, psq2))
+ if (relative_rank(strongSide, strongPawn1) > relative_rank(strongSide, strongPawn2))
{
- blockSq1 = psq1 + pawn_push(strongSide);
- blockSq2 = make_square(file_of(psq2), rank_of(psq1));
+ blockSq1 = strongPawn1 + pawn_push(strongSide);
+ blockSq2 = make_square(file_of(strongPawn2), rank_of(strongPawn1));
}
else
{
- blockSq1 = psq2 + pawn_push(strongSide);
- blockSq2 = make_square(file_of(psq1), rank_of(psq2));
+ blockSq1 = strongPawn2 + pawn_push(strongSide);
+ blockSq2 = make_square(file_of(strongPawn1), rank_of(strongPawn2));
}
- switch (distance<File>(psq1, psq2))
+ switch (distance<File>(strongPawn1, strongPawn2))
{
case 0:
// Both pawns are on the same file. It's an easy draw if the defender firmly
// controls some square in the frontmost pawn's path.
- if ( file_of(ksq) == file_of(blockSq1)
- && relative_rank(strongSide, ksq) >= relative_rank(strongSide, blockSq1)
- && opposite_colors(ksq, wbsq))
+ if ( file_of(weakKing) == file_of(blockSq1)
+ && relative_rank(strongSide, weakKing) >= relative_rank(strongSide, blockSq1)
+ && opposite_colors(weakKing, strongBishop))
return SCALE_FACTOR_DRAW;
else
return SCALE_FACTOR_NONE;
// Pawns on adjacent files. It's a draw if the defender firmly controls the
// square in front of the frontmost pawn's path, and the square diagonally
// behind this square on the file of the other pawn.
- if ( ksq == blockSq1
- && opposite_colors(ksq, wbsq)
- && ( bbsq == blockSq2
- || (pos.attacks_from<BISHOP>(blockSq2) & pos.pieces(weakSide, BISHOP))
- || distance<Rank>(psq1, psq2) >= 2))
+ if ( weakKing == blockSq1
+ && opposite_colors(weakKing, strongBishop)
+ && ( weakBishop == blockSq2
+ || (attacks_bb<BISHOP>(blockSq2, pos.pieces()) & pos.pieces(weakSide, BISHOP))
+ || distance<Rank>(strongPawn1, strongPawn2) >= 2))
return SCALE_FACTOR_DRAW;
- else if ( ksq == blockSq2
- && opposite_colors(ksq, wbsq)
- && ( bbsq == blockSq1
- || (pos.attacks_from<BISHOP>(blockSq1) & pos.pieces(weakSide, BISHOP))))
+ else if ( weakKing == blockSq2
+ && opposite_colors(weakKing, strongBishop)
+ && ( weakBishop == blockSq1
+ || (attacks_bb<BISHOP>(blockSq1, pos.pieces()) & pos.pieces(weakSide, BISHOP))))
return SCALE_FACTOR_DRAW;
else
return SCALE_FACTOR_NONE;
}
-/// KBP vs KN. There is a single rule: If the defending king is somewhere along
+/// KBP vs KN. There is a single rule: if the defending king is somewhere along
/// the path of the pawn, and the square of the king is not of the same color as
/// the stronger side's bishop, it's a draw.
template<>
assert(verify_material(pos, strongSide, BishopValueMg, 1));
assert(verify_material(pos, weakSide, KnightValueMg, 0));
- Square
pawnSq = pos.square<PAWN>(strongSide);
- Square strongBishopSq = pos.square<BISHOP>(strongSide);
- Square weakKingSq = pos.square<KING>(weakSide);
+ Square
strongPawn = pos.square<PAWN>(strongSide);
+ Square strongBishop = pos.square<BISHOP>(strongSide);
+ Square weakKing = pos.square<KING>(weakSide);
- if ( file_of(weakKingSq) == file_of(pawnSq)
- && relative_rank(strongSide, pawnSq) < relative_rank(strongSide, weakKingSq)
- && ( opposite_colors(weakKingSq, strongBishopSq)
- || relative_rank(strongSide, weakKingSq) <= RANK_6))
+ if ( file_of(weakKing) == file_of(strongPawn)
+ && relative_rank(strongSide, strongPawn) < relative_rank(strongSide, weakKing)
+ && ( opposite_colors(weakKing, strongBishop)
+ || relative_rank(strongSide, weakKing) <= RANK_6))
return SCALE_FACTOR_DRAW;
return SCALE_FACTOR_NONE;
}
-/// KNP vs K. There is a single rule: 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 Endgame<KNPK>::operator()(const Position& pos) const {
-
- assert(verify_material(pos, strongSide, KnightValueMg, 1));
- assert(verify_material(pos, weakSide, VALUE_ZERO, 0));
-
- // Assume strongSide is white and the pawn is on files A-D
- Square pawnSq = normalize(pos, strongSide, pos.square<PAWN>(strongSide));
- Square weakKingSq = normalize(pos, strongSide, pos.square<KING>(weakSide));
-
- if (pawnSq == SQ_A7 && distance(SQ_A8, weakKingSq) <= 1)
- return SCALE_FACTOR_DRAW;
-
- return SCALE_FACTOR_NONE;
-}
-
-
-/// KNP vs KB. If knight can block bishop from taking pawn, it's a win.
-/// Otherwise the position is drawn.
-template<>
-ScaleFactor Endgame<KNPKB>::operator()(const Position& pos) const {
-
- assert(verify_material(pos, strongSide, KnightValueMg, 1));
- assert(verify_material(pos, weakSide, BishopValueMg, 0));
-
- Square pawnSq = pos.square<PAWN>(strongSide);
- Square bishopSq = pos.square<BISHOP>(weakSide);
- Square weakKingSq = pos.square<KING>(weakSide);
-
- // King needs to get close to promoting pawn to prevent knight from blocking.
- // Rules for this are very tricky, so just approximate.
- if (forward_file_bb(strongSide, pawnSq) & pos.attacks_from<BISHOP>(bishopSq))
- return ScaleFactor(distance(weakKingSq, pawnSq));
-
- return SCALE_FACTOR_NONE;
-}
-
-
/// KP vs KP. This is done by removing the weakest side's pawn and probing the
-/// KP vs K bitbase: If the weakest side has a draw without the pawn, it probably
+/// KP vs K bitbase: if the weakest side has a draw without the pawn, it probably
/// has at least a draw with the pawn as well. The exception is when the stronger
/// side's pawn is far advanced and not on a rook file; in this case it is often
/// possible to win (e.g. 8/4k3/3p4/3P4/6K1/8/8/8 w - - 0 1).
assert(verify_material(pos, weakSide, VALUE_ZERO, 1));
// Assume strongSide is white and the pawn is on files A-D
- Square wksq = normalize(pos, strongSide, pos.square<KING>(strongSide));
- Square bksq = normalize(pos, strongSide, pos.square<KING>(weakSide));
- Square
psq = normalize(pos, strongSide, pos.square<PAWN>(strongSide));
+ Square strongKing = normalize(pos, strongSide, pos.square<KING>(strongSide));
+ Square weakKing = normalize(pos, strongSide, pos.square<KING>(weakSide));
+ Square
strongPawn = normalize(pos, strongSide, pos.square<PAWN>(strongSide));
Color us = strongSide == pos.side_to_move() ? WHITE : BLACK;
// If the pawn has advanced to the fifth rank or further, and is not a
// rook pawn, it's too dangerous to assume that it's at least a draw.
- if (rank_of(psq) >= RANK_5 && file_of(psq) != FILE_A)
+ if (rank_of(strongPawn) >= RANK_5 && file_of(strongPawn) != FILE_A)
return SCALE_FACTOR_NONE;
// Probe the KPK bitbase with the weakest side's pawn removed. If it's a draw,
// it's probably at least a draw even with the pawn.
- return Bitbases::probe(wksq, psq, bksq, us) ? SCALE_FACTOR_NONE : SCALE_FACTOR_DRAW;
+ return Bitbases::probe(strongKing, strongPawn, weakKing, us) ? SCALE_FACTOR_NONE : SCALE_FACTOR_DRAW;
}
#ifndef ENDGAME_H_INCLUDED
#define ENDGAME_H_INCLUDED
-#include <unordered_map>
#include <memory>
#include <string>
#include <type_traits>
+#include <unordered_map>
#include <utility>
#include "position.h"
KBPKB, // KBP vs KB
KBPPKB, // KBPP vs KB
KBPKN, // KBP vs KN
- KNPK, // KNP vs K
- KNPKB, // KNP vs KB
KPKP // KP vs KP
};
enum Tracing { NO_TRACE, TRACE };
enum Term { // The first 8 entries are reserved for PieceType
- MATERIAL = 8, IMBALANCE, MOBILITY, THREAT, PASSED, SPACE, INITIATIVE, TOTAL, TERM_NB
+ MATERIAL = 8, IMBALANCE, MOBILITY, THREAT, PASSED, SPACE, WINNABLE, TOTAL, TERM_NB
};
Score scores[TERM_NB][COLOR_NB];
std::ostream& operator<<(std::ostream& os, Term t) {
- if (t == MATERIAL || t == IMBALANCE || t == INITIATIVE || t == TOTAL)
+ if (t == MATERIAL || t == IMBALANCE || t == WINNABLE || t == TOTAL)
os << " ---- ----" << " | " << " ---- ----";
else
os << scores[t][WHITE] << " | " << scores[t][BLACK];
namespace {
// Threshold for lazy and space evaluation
- constexpr Value LazyThreshold = Value(1400);
+ constexpr Value LazyThreshold1 = Value(1400);
+ constexpr Value LazyThreshold2 = Value(1300);
constexpr Value SpaceThreshold = Value(12222);
// KingAttackWeights[PieceType] contains king attack weights by piece type
constexpr int KingAttackWeights[PIECE_TYPE_NB] = { 0, 0, 81, 52, 44, 10 };
- // Penalties for enemy's safe checks
- constexpr int QueenSafeCheck = 780;
- constexpr int RookSafeCheck = 1080;
- constexpr int BishopSafeCheck = 635;
- constexpr int KnightSafeCheck = 790;
+ // SafeCheck[PieceType][single/multiple] contains safe check bonus by piece type,
+ // higher if multiple safe checks are possible for that piece type.
+ constexpr int SafeCheck[][2] = {
+ {}, {}, {792, 1283}, {645, 967}, {1084, 1897}, {772, 1119}
+ };
#define S(mg, eg) make_score(mg, eg)
// MobilityBonus[PieceType-2][attacked] contains bonuses for middle and end game,
// indexed by piece type and number of attacked squares in the mobility area.
constexpr Score MobilityBonus[][32] = {
- { S(-62,-81), S(-53,-56), S(-12,-30), S( -4,-14), S( 3, 8), S( 13, 15), // Knights
- S( 22, 23), S( 28, 27), S( 33, 33) },
- { S(-48,-59), S(-20,-23), S( 16, -3), S( 26, 13), S( 38, 24), S( 51, 42), // Bishops
+ { S(-62,-81), S(-53,-56), S(-12,-31), S( -4,-16), S( 3, 5), S( 13, 11), // Knight
+ S( 22, 17), S( 28, 20), S( 33, 25) },
+ { S(-48,-59), S(-20,-23), S( 16, -3), S( 26, 13), S( 38, 24), S( 51, 42), // Bishop
S( 55, 54), S( 63, 57), S( 63, 65), S( 68, 73), S( 81, 78), S( 81, 86),
S( 91, 88), S( 98, 97) },
- { S(-58,-76), S(-27,-18), S(-15, 28), S(-10, 55), S( -5, 69), S( -2, 82), // Rooks
- S( 9,112), S( 16,118), S( 30,132), S( 29,142), S( 32,155), S( 38,165),
- S( 46,166), S( 48,169), S( 58,171) },
- { S(-39,-36), S(-21,-15), S( 3, 8), S( 3, 18), S( 14, 34), S( 22, 54), // Queens
- S( 28, 61), S( 41, 73), S( 43, 79), S( 48, 92), S( 56, 94), S( 60,104),
- S( 60,113), S( 66,120), S( 67,123), S( 70,126), S( 71,133), S( 73,136),
- S( 79,140), S( 88,143), S( 88,148), S( 99,166), S(102,170), S(102,175),
- S(106,184), S(109,191), S(113,206), S(116,212) }
+ { S(-60,-78), S(-20,-17), S( 2, 23), S( 3, 39), S( 3, 70), S( 11, 99), // Rook
+ S( 22,103), S( 31,121), S( 40,134), S( 40,139), S( 41,158), S( 48,164),
+ S( 57,168), S( 57,169), S( 62,172) },
+ { S(-30,-48), S(-12,-30), S( -8, -7), S( -9, 19), S( 20, 40), S( 23, 55), // Queen
+ S( 23, 59), S( 35, 75), S( 38, 78), S( 53, 96), S( 64, 96), S( 65,100),
+ S( 65,121), S( 66,127), S( 67,131), S( 67,133), S( 72,136), S( 72,141),
+ S( 77,147), S( 79,150), S( 93,151), S(108,168), S(108,168), S(108,171),
+ S(110,182), S(114,182), S(114,192), S(116,219) }
+ };
+
+ // KingProtector[knight/bishop] contains penalty for each distance unit to own king
+ constexpr Score KingProtector[] = { S(8, 9), S(6, 9) };
+
+ // Outpost[knight/bishop] contains bonuses for each knight or bishop occupying a
+ // pawn protected square on rank 4 to 6 which is also safe from a pawn attack.
+ constexpr Score Outpost[] = { S(56, 36), S(30, 23) };
+
+ // PassedRank[Rank] contains a bonus according to the rank of a passed pawn
+ constexpr Score PassedRank[RANK_NB] = {
+ S(0, 0), S(10, 28), S(17, 33), S(15, 41), S(62, 72), S(168, 177), S(276, 260)
};
// RookOnFile[semiopen/open] contains bonuses for each rook when there is
// no (friendly) pawn on the rook file.
- constexpr Score RookOnFile[] = { S(21, 4), S(47, 25) };
+ constexpr Score RookOnFile[] = { S(19, 7), S(48, 29) };
// ThreatByMinor/ByRook[attacked PieceType] contains bonuses according to
// which piece type attacks which one. Attacks on lesser pieces which are
// pawn-defended are not considered.
constexpr Score ThreatByMinor[PIECE_TYPE_NB] = {
- S(0, 0), S(6, 32), S(59, 41), S(79, 56), S(90, 119), S(79, 161)
+ S(0, 0), S(5, 32), S(57, 41), S(77, 56), S(88, 119), S(79, 161)
};
constexpr Score ThreatByRook[PIECE_TYPE_NB] = {
- S(0, 0), S(3, 44), S(38, 71), S(38, 61), S(0, 38), S(51, 38)
- };
-
- // PassedRank[Rank] contains a bonus according to the rank of a passed pawn
- constexpr Score PassedRank[RANK_NB] = {
- S(0, 0), S(10, 28), S(17, 33), S(15, 41), S(62, 72), S(168, 177), S(276, 260)
+ S(0, 0), S(3, 46), S(37, 68), S(42, 60), S(0, 38), S(58, 41)
};
// Assorted bonuses and penalties
- constexpr Score BishopPawns = S( 3, 7);
- constexpr Score CorneredBishop = S( 50, 50);
- constexpr Score FlankAttacks = S( 8, 0);
- constexpr Score Hanging = S( 69, 36);
- constexpr Score KingProtector = S( 7, 8);
- constexpr Score KnightOnQueen = S( 16, 12);
- constexpr Score LongDiagonalBishop = S( 45, 0);
- constexpr Score MinorBehindPawn = S( 18, 3);
- constexpr Score Outpost = S( 30, 21);
- constexpr Score PassedFile = S( 11, 8);
- constexpr Score PawnlessFlank = S( 17, 95);
- constexpr Score RestrictedPiece = S( 7, 7);
- constexpr Score ReachableOutpost = S( 32, 10);
- constexpr Score RookOnQueenFile = S( 7, 6);
- constexpr Score SliderOnQueen = S( 59, 18);
- constexpr Score ThreatByKing = S( 24, 89);
- constexpr Score ThreatByPawnPush = S( 48, 39);
- constexpr Score ThreatBySafePawn = S(173, 94);
- constexpr Score TrappedRook = S( 52, 10);
- constexpr Score WeakQueen = S( 49, 15);
+ constexpr Score BadOutpost = S( -7, 36);
+ constexpr Score BishopOnKingRing = S( 24, 0);
+ constexpr Score BishopPawns = S( 3, 7);
+ constexpr Score BishopXRayPawns = S( 4, 5);
+ constexpr Score CorneredBishop = S( 50, 50);
+ constexpr Score FlankAttacks = S( 8, 0);
+ constexpr Score Hanging = S( 69, 36);
+ constexpr Score KnightOnQueen = S( 16, 11);
+ constexpr Score LongDiagonalBishop = S( 45, 0);
+ constexpr Score MinorBehindPawn = S( 18, 3);
+ constexpr Score PassedFile = S( 11, 8);
+ constexpr Score PawnlessFlank = S( 17, 95);
+ constexpr Score QueenInfiltration = S( -2, 14);
+ constexpr Score ReachableOutpost = S( 31, 22);
+ constexpr Score RestrictedPiece = S( 7, 7);
+ constexpr Score RookOnKingRing = S( 16, 0);
+ constexpr Score RookOnQueenFile = S( 6, 11);
+ constexpr Score SliderOnQueen = S( 60, 18);
+ constexpr Score ThreatByKing = S( 24, 89);
+ constexpr Score ThreatByPawnPush = S( 48, 39);
+ constexpr Score ThreatBySafePawn = S(173, 94);
+ constexpr Score TrappedRook = S( 55, 13);
+ constexpr Score WeakQueenProtection = S( 14, 0);
+ constexpr Score WeakQueen = S( 56, 15);
+
#undef S
template<Color Us> Score threats() const;
template<Color Us> Score passed() const;
template<Color Us> Score space() const;
- ScaleFactor scale_factor(Value eg) const;
- Score initiative(Score score) const;
+ Value winnable(Score score) const;
const Position& pos;
Material::Entry* me;
// Evaluation::initialize() computes king and pawn attacks, and the king ring
// bitboard for a given color. This is done at the beginning of the evaluation.
+
template<Tracing T> template<Color Us>
void Evaluation<T>::initialize() {
- constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
+ constexpr Color Them = ~Us;
constexpr Direction Up = pawn_push(Us);
constexpr Direction Down = -Up;
constexpr Bitboard LowRanks = (Us == WHITE ? Rank2BB | Rank3BB : Rank7BB | Rank6BB);
mobilityArea[Us] = ~(b | pos.pieces(Us, KING, QUEEN) | pos.blockers_for_king(Us) | pe->pawn_attacks(Them));
// Initialize attackedBy[] for king and pawns
- attackedBy[Us][KING] = pos.attacks_from<KING>(ksq);
+ attackedBy[Us][KING] = attacks_bb<KING>(ksq);
attackedBy[Us][PAWN] = pe->pawn_attacks(Us);
attackedBy[Us][ALL_PIECES] = attackedBy[Us][KING] | attackedBy[Us][PAWN];
attackedBy2[Us] = dblAttackByPawn | (attackedBy[Us][KING] & attackedBy[Us][PAWN]);
// Init our king safety tables
- Square s = make_square(clamp(file_of(ksq), FILE_B, FILE_G),
- clamp(rank_of(ksq), RANK_2, RANK_7));
- kingRing[Us] = PseudoAttacks[KING][s] | s;
+ Square s = make_square(Utility::clamp(file_of(ksq), FILE_B, FILE_G),
+ Utility::clamp(rank_of(ksq), RANK_2, RANK_7));
+ kingRing[Us] = attacks_bb<KING>(s) | s;
kingAttackersCount[Them] = popcount(kingRing[Us] & pe->pawn_attacks(Them));
kingAttacksCount[Them] = kingAttackersWeight[Them] = 0;
// Evaluation::pieces() scores pieces of a given color and type
+
template<Tracing T> template<Color Us, PieceType Pt>
Score Evaluation<T>::pieces() {
- constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
+ constexpr Color Them = ~Us;
constexpr Direction Down = -pawn_push(Us);
constexpr Bitboard OutpostRanks = (Us == WHITE ? Rank4BB | Rank5BB | Rank6BB
: Rank5BB | Rank4BB | Rank3BB);
// Find attacked squares, including x-ray attacks for bishops and rooks
b = Pt == BISHOP ? attacks_bb<BISHOP>(s, pos.pieces() ^ pos.pieces(QUEEN))
: Pt == ROOK ? attacks_bb< ROOK>(s, pos.pieces() ^ pos.pieces(QUEEN) ^ pos.pieces(Us, ROOK))
- : pos.attacks_from<Pt>(s);
+ : attacks_bb<Pt>(s, pos.pieces());
if (pos.blockers_for_king(Us) & s)
- b &= LineBB[pos.square<KING>(Us)][s];
+ b &= line_bb(pos.square<KING>(Us), s);
attackedBy2[Us] |= attackedBy[Us][ALL_PIECES] & b;
attackedBy[Us][Pt] |= b;
kingAttacksCount[Us] += popcount(b & attackedBy[Them][KING]);
}
+ else if (Pt == ROOK && (file_bb(s) & kingRing[Them]))
+ score += RookOnKingRing;
+
+ else if (Pt == BISHOP && (attacks_bb<BISHOP>(s, pos.pieces(PAWN)) & kingRing[Them]))
+ score += BishopOnKingRing;
+
int mob = popcount(b & mobilityArea[Us]);
mobility[Us] += MobilityBonus[Pt - 2][mob];
if (Pt == BISHOP || Pt == KNIGHT)
{
- // Bonus if piece is on an outpost square or can reach one
+ // Bonus if the piece is on an outpost square or can reach one
+ // Reduced bonus for knights (BadOutpost) if few relevant targets
bb = OutpostRanks & attackedBy[Us][PAWN] & ~pe->pawn_attacks_span(Them);
- if (bb & s)
- score += Outpost * (Pt == KNIGHT ? 2 : 1);
-
+ Bitboard targets = pos.pieces(Them) & ~pos.pieces(PAWN);
+
+ if ( Pt == KNIGHT
+ && bb & s & ~CenterFiles // on a side outpost
+ && !(b & targets) // no relevant attacks
+ && (!more_than_one(targets & (s & QueenSide ? QueenSide : KingSide))))
+ score += BadOutpost;
+ else if (bb & s)
+ score += Outpost[Pt == BISHOP];
else if (Pt == KNIGHT && bb & b & ~pos.pieces(Us))
score += ReachableOutpost;
- // Knight and Bishop bonus for being right behind a pawn
+ // Bonus for a knight or bishop shielded by pawn
if (shift<Down>(pos.pieces(PAWN)) & s)
score += MinorBehindPawn;
// Penalty if the piece is far from the king
- score -= KingProtector * distance(s, pos.square<KING>(Us));
+ score -= KingProtector[Pt == BISHOP] * distance(pos.square<KING>(Us), s);
if (Pt == BISHOP)
{
- // Penalty according to number of pawns on the same color square as the
- // bishop, bigger when the center files are blocked with pawns.
+ // Penalty according to the number of our pawns on the same color square as the
+ // bishop, bigger when the center files are blocked with pawns and smaller
+ // when the bishop is outside the pawn chain.
Bitboard blocked = pos.pieces(Us, PAWN) & shift<Down>(pos.pieces());
score -= BishopPawns * pos.pawns_on_same_color_squares(Us, s)
- * (1 + popcount(blocked & CenterFiles));
+ * (!(attackedBy[Us][PAWN] & s) + popcount(blocked & CenterFiles));
+
+ // Penalty for all enemy pawns x-rayed
+ score -= BishopXRayPawns * popcount(attacks_bb<BISHOP>(s) & pos.pieces(Them, PAWN));
// Bonus for bishop on a long diagonal which can "see" both center squares
if (more_than_one(attacks_bb<BISHOP>(s, pos.pieces(PAWN)) & Center))
Bitboard queenPinners;
if (pos.slider_blockers(pos.pieces(Them, ROOK, BISHOP), s, queenPinners))
score -= WeakQueen;
+
+ // Bonus for queen on weak square in enemy camp
+ if (relative_rank(Us, s) > RANK_4 && (~pe->pawn_attacks_span(Them) & s))
+ score += QueenInfiltration;
}
}
if (T)
// Evaluation::king() assigns bonuses and penalties to a king of a given color
+
template<Tracing T> template<Color Us>
Score Evaluation<T>::king() const {
- constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
+ constexpr Color Them = ~Us;
constexpr Bitboard Camp = (Us == WHITE ? AllSquares ^ Rank6BB ^ Rank7BB ^ Rank8BB
: AllSquares ^ Rank1BB ^ Rank2BB ^ Rank3BB);
b2 = attacks_bb<BISHOP>(ksq, pos.pieces() ^ pos.pieces(Us, QUEEN));
// Enemy rooks checks
- rookChecks = b1 & safe & attackedBy[Them][ROOK];
-
+ rookChecks = b1 & attackedBy[Them][ROOK] & safe;
if (rookChecks)
- kingDanger += RookSafeCheck;
+ kingDanger += SafeCheck[ROOK][more_than_one(rookChecks)];
else
unsafeChecks |= b1 & attackedBy[Them][ROOK];
- // Enemy queen safe checks: we count them only if they are from squares from
- // which we can't give a rook check, because rook checks are more valuable.
- queenChecks = (b1 | b2)
- & attackedBy[Them][QUEEN]
- & safe
- & ~attackedBy[Us][QUEEN]
- & ~rookChecks;
-
+ // Enemy queen safe checks: count them only if the checks are from squares from
+ // which opponent cannot give a rook check, because rook checks are more valuable.
+ queenChecks = (b1 | b2) & attackedBy[Them][QUEEN] & safe
+ & ~(attackedBy[Us][QUEEN] | rookChecks);
if (queenChecks)
- kingDanger += QueenSafeCheck;
+ kingDanger += SafeCheck[QUEEN][more_than_one(queenChecks)];
- // Enemy bishops checks: we count them only if they are from squares from
- // which we can't give a queen check, because queen checks are more valuable.
- bishopChecks = b2
- & attackedBy[Them][BISHOP]
- & safe
+ // Enemy bishops checks: count them only if they are from squares from which
+ // opponent cannot give a queen check, because queen checks are more valuable.
+ bishopChecks = b2 & attackedBy[Them][BISHOP] & safe
& ~queenChecks;
-
if (bishopChecks)
- kingDanger += BishopSafeCheck;
+ kingDanger += SafeCheck[BISHOP][more_than_one(bishopChecks)];
+
else
unsafeChecks |= b2 & attackedBy[Them][BISHOP];
// Enemy knights checks
- knightChecks = pos.attacks_from<KNIGHT>(ksq) & attackedBy[Them][KNIGHT];
-
+ knightChecks = attacks_bb<KNIGHT>(ksq) & attackedBy[Them][KNIGHT];
if (knightChecks & safe)
- kingDanger += KnightSafeCheck;
+ kingDanger += SafeCheck[KNIGHT][more_than_one(knightChecks & safe)];
else
unsafeChecks |= knightChecks;
b2 = b1 & attackedBy2[Them];
b3 = attackedBy[Us][ALL_PIECES] & KingFlank[file_of(ksq)] & Camp;
- int kingFlankAttack = popcount(b1) + popcount(b2);
+ int kingFlankAttack = popcount(b1) + popcount(b2);
int kingFlankDefense = popcount(b3);
kingDanger += kingAttackersCount[Them] * kingAttackersWeight[Them]
// Evaluation::threats() assigns bonuses according to the types of the
// attacking and the attacked pieces.
+
template<Tracing T> template<Color Us>
Score Evaluation<T>::threats() const {
- constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
+ constexpr Color Them = ~Us;
constexpr Direction Up = pawn_push(Us);
constexpr Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
b = ~attackedBy[Them][ALL_PIECES]
| (nonPawnEnemies & attackedBy2[Us]);
score += Hanging * popcount(weak & b);
+
+ // Additional bonus if weak piece is only protected by a queen
+ score += WeakQueenProtection * popcount(weak & attackedBy[Them][QUEEN]);
}
// Bonus for restricting their piece moves
b = attackedBy[Them][ALL_PIECES]
& ~stronglyProtected
& attackedBy[Us][ALL_PIECES];
-
score += RestrictedPiece * popcount(b);
// Protected or unattacked squares
// Bonus for threats on the next moves against enemy queen
if (pos.count<QUEEN>(Them) == 1)
{
+ bool queenImbalance = pos.count<QUEEN>() == 1;
+
Square s = pos.square<QUEEN>(Them);
- safe = mobilityArea[Us] & ~stronglyProtected;
+ safe = mobilityArea[Us]
+ & ~pos.pieces(Us, PAWN)
+ & ~stronglyProtected;
- b = attackedBy[Us][KNIGHT] & pos.attacks_from<KNIGHT>(s);
+ b = attackedBy[Us][KNIGHT] & attacks_bb<KNIGHT>(s);
- score += KnightOnQueen * popcount(b & safe);
+ score += KnightOnQueen * popcount(b & safe) * (1 + queenImbalance);
- b = (attackedBy[Us][BISHOP] & pos.attacks_from<BISHOP>(s))
- | (attackedBy[Us][ROOK ] & pos.attacks_from<ROOK >(s));
+ b = (attackedBy[Us][BISHOP] & attacks_bb<BISHOP>(s, pos.pieces()))
+ | (attackedBy[Us][ROOK ] & attacks_bb<ROOK >(s, pos.pieces()));
- score += SliderOnQueen * popcount(b & safe & attackedBy2[Us]);
+ score += SliderOnQueen * popcount(b & safe & attackedBy2[Us]) * (1 + queenImbalance);
}
if (T)
template<Tracing T> template<Color Us>
Score Evaluation<T>::passed() const {
- constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
+ constexpr Color Them = ~Us;
constexpr Direction Up = pawn_push(Us);
+ constexpr Direction Down = -Up;
auto king_proximity = [&](Color c, Square s) {
return std::min(distance(pos.square<KING>(c), s), 5);
};
- Bitboard b, bb, squaresToQueen, unsafeSquares;
+ Bitboard b, bb, squaresToQueen, unsafeSquares, blockedPassers, helpers;
Score score = SCORE_ZERO;
b = pe->passed_pawns(Us);
+ blockedPassers = b & shift<Down>(pos.pieces(Them, PAWN));
+ if (blockedPassers)
+ {
+ helpers = shift<Up>(pos.pieces(Us, PAWN))
+ & ~pos.pieces(Them)
+ & (~attackedBy2[Them] | attackedBy[Us][ALL_PIECES]);
+
+ // Remove blocked candidate passers that don't have help to pass
+ b &= ~blockedPassers
+ | shift<WEST>(helpers)
+ | shift<EAST>(helpers);
+ }
+
while (b)
{
Square s = pop_lsb(&b);
}
} // r > RANK_3
- // Scale down bonus for candidate passers which need more than one
- // pawn push to become passed, or have a pawn in front of them.
- if ( !pos.pawn_passed(Us, s + Up)
- || (pos.pieces(PAWN) & (s + Up)))
- bonus = bonus / 2;
-
- score += bonus - PassedFile * map_to_queenside(file_of(s));
+ score += bonus - PassedFile * edge_distance(file_of(s));
}
if (T)
}
- // Evaluation::space() computes the space evaluation for a given side. The
- // space evaluation is a simple bonus based on the number of safe squares
- // available for minor pieces on the central four files on ranks 2--4. Safe
- // squares one, two or three squares behind a friendly pawn are counted
- // twice. Finally, the space bonus is multiplied by a weight. The aim is to
- // improve play on game opening.
+ // Evaluation::space() computes a space evaluation for a given side, aiming to improve game
+ // play in the opening. It is based on the number of safe squares on the 4 central files
+ // on ranks 2 to 4. Completely safe squares behind a friendly pawn are counted twice.
+ // Finally, the space bonus is multiplied by a weight which decreases according to occupancy.
template<Tracing T> template<Color Us>
Score Evaluation<T>::space() const {
+ // Early exit if, for example, both queens or 6 minor pieces have been exchanged
if (pos.non_pawn_material() < SpaceThreshold)
return SCORE_ZERO;
- constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
+ constexpr Color Them = ~Us;
constexpr Direction Down = -pawn_push(Us);
constexpr Bitboard SpaceMask =
Us == WHITE ? CenterFiles & (Rank2BB | Rank3BB | Rank4BB)
behind |= shift<Down+Down>(behind);
int bonus = popcount(safe) + popcount(behind & safe & ~attackedBy[Them][ALL_PIECES]);
- int weight = pos.count<ALL_PIECES>(Us) - 1;
+ int weight = pos.count<ALL_PIECES>(Us) - 3 + std::min(pe->blocked_count(), 9);
Score score = make_score(bonus * weight * weight / 16, 0);
if (T)
}
- // Evaluation::initiative() computes the initiative correction value
- // for the position. It is a second order bonus/malus based on the
- // known attacking/defending status of the players.
+ // Evaluation::winnable() adjusts the midgame and endgame score components, based on
+ // the known attacking/defending status of the players. The final value is derived
+ // by interpolation from the midgame and endgame values.
template<Tracing T>
- Score Evaluation<T>::initiative(Score score) const {
-
- Value mg = mg_value(score);
- Value eg = eg_value(score);
+ Value Evaluation<T>::winnable(Score score) const {
int outflanking = distance<File>(pos.square<KING>(WHITE), pos.square<KING>(BLACK))
- distance<Rank>(pos.square<KING>(WHITE), pos.square<KING>(BLACK));
- bool infiltration = rank_of(pos.square<KING>(WHITE)) > RANK_4
- || rank_of(pos.square<KING>(BLACK)) < RANK_5;
-
bool pawnsOnBothFlanks = (pos.pieces(PAWN) & QueenSide)
&& (pos.pieces(PAWN) & KingSide);
- bool almostUnwinnable = !pe->passed_count()
- && outflanking < 0
+ bool almostUnwinnable = outflanking < 0
&& !pawnsOnBothFlanks;
+ bool infiltration = rank_of(pos.square<KING>(WHITE)) > RANK_4
+ || rank_of(pos.square<KING>(BLACK)) < RANK_5;
+
// Compute the initiative bonus for the attacking side
int complexity = 9 * pe->passed_count()
- + 1
1 * pos.count<PAWN>()
+ + 1
2 * pos.count<PAWN>()
+ 9 * outflanking
- + 12 * infiltration
+ 21 * pawnsOnBothFlanks
+ + 24 * infiltration
+ 51 * !pos.non_pawn_material()
- 43 * almostUnwinnable
- - 100 ;
+ -110 ;
+
+ Value mg = mg_value(score);
+ Value eg = eg_value(score);
// Now apply the bonus: note that we find the attacking side by extracting the
// sign of the midgame or endgame values, and that we carefully cap the bonus
// so that the midgame and endgame scores do not change sign after the bonus.
- int u = ((mg > 0) - (mg < 0)) * std::max(std::min(complexity + 50, 0), -abs(mg));
+ int u = ((mg > 0) - (mg < 0)) * Utility::clamp(complexity + 50, -abs(mg), 0);
int v = ((eg > 0) - (eg < 0)) * std::max(complexity, -abs(eg));
- if (T)
- Trace::add(INITIATIVE, make_score(u, v));
-
- return make_score(u, v);
- }
-
-
- // Evaluation::scale_factor() computes the scale factor for the winning side
-
- template<Tracing T>
- ScaleFactor Evaluation<T>::scale_factor(Value eg) const {
+ mg += u;
+ eg += v;
+ // Compute the scale factor for the winning side
Color strongSide = eg > VALUE_DRAW ? WHITE : BLACK;
int sf = me->scale_factor(pos, strongSide);
- // If scale is not already specific, scale down the endgame via general heuristics
+ // If scale factor is not already specific, scale down via general heuristics
if (sf == SCALE_FACTOR_NORMAL)
{
- if ( pos.opposite_bishops()
- && pos.non_pawn_material() == 2 * BishopValueMg)
- sf = 22 ;
+ if (pos.opposite_bishops())
+ {
+ if ( pos.non_pawn_material(WHITE) == BishopValueMg
+ && pos.non_pawn_material(BLACK) == BishopValueMg)
+ sf = 18 + 4 * popcount(pe->passed_pawns(strongSide));
+ else
+ sf = 22 + 3 * pos.count<ALL_PIECES>(strongSide);
+ }
+ else if ( pos.non_pawn_material(WHITE) == RookValueMg
+ && pos.non_pawn_material(BLACK) == RookValueMg
+ && pos.count<PAWN>(strongSide) - pos.count<PAWN>(~strongSide) <= 1
+ && bool(KingSide & pos.pieces(strongSide, PAWN)) != bool(QueenSide & pos.pieces(strongSide, PAWN))
+ && (attacks_bb<KING>(pos.square<KING>(~strongSide)) & pos.pieces(~strongSide, PAWN)))
+ sf = 36;
+ else if (pos.count<QUEEN>() == 1)
+ sf = 37 + 3 * (pos.count<QUEEN>(WHITE) == 1 ? pos.count<BISHOP>(BLACK) + pos.count<KNIGHT>(BLACK)
+ : pos.count<BISHOP>(WHITE) + pos.count<KNIGHT>(WHITE));
else
- sf = std::min(sf, 36 + (pos.opposite_bishops() ? 2 : 7) * pos.count<PAWN>(strongSide));
+ sf = std::min(sf, 36 + 7 * pos.count<PAWN>(strongSide));
+ }
- sf = std::max(0, sf - (pos.rule50_count() - 12) / 4);
+ // Interpolate between the middlegame and (scaled by 'sf') endgame score
+ v = mg * int(me->game_phase())
+ + eg * int(PHASE_MIDGAME - me->game_phase()) * ScaleFactor(sf) / SCALE_FACTOR_NORMAL;
+ v /= PHASE_MIDGAME;
+
+ if (T)
+ {
+ Trace::add(WINNABLE, make_score(u, eg * ScaleFactor(sf) / SCALE_FACTOR_NORMAL - eg_value(score)));
+ Trace::add(TOTAL, make_score(mg, eg * ScaleFactor(sf) / SCALE_FACTOR_NORMAL));
}
- return ScaleFactor(sf);
+ return Value(v);
}
score += pe->pawn_score(WHITE) - pe->pawn_score(BLACK);
// Early exit if score is high
- Value v = (mg_value(score) + eg_value(score)) / 2;
- if (abs(v) > LazyThreshold + pos.non_pawn_material() / 64)
- return pos.side_to_move() == WHITE ? v : -v;
+ auto lazy_skip = [&](Value lazyThreshold) {
+ return abs(mg_value(score) + eg_value(score)) / 2 > lazyThreshold + pos.non_pawn_material() / 64;
+ };
- // Main evaluation begins here
+ if (lazy_skip(LazyThreshold1))
+ goto make_v;
+ // Main evaluation begins here
initialize<WHITE>();
initialize<BLACK>();
- // Pieces should be evaluated first (populate attack tables)
+ // Pieces evaluated first (also populates attackedBy, attackedBy2).
+ // Note that the order of evaluation of the terms is left unspecified.
score += pieces<WHITE, KNIGHT>() - pieces<BLACK, KNIGHT>()
+ pieces<WHITE, BISHOP>() - pieces<BLACK, BISHOP>()
+ pieces<WHITE, ROOK >() - pieces<BLACK, ROOK >()
score += mobility[WHITE] - mobility[BLACK];
+ // More complex interactions that require fully populated attack bitboards
score += king< WHITE>() - king< BLACK>()
- + threats<WHITE>() - threats<BLACK>()
- + passed< WHITE>() - passed< BLACK>()
- + space< WHITE>() - space< BLACK>();
+ + passed< WHITE>() - passed< BLACK>();
- score += initiative(score);
+ if (lazy_skip(LazyThreshold2))
+ goto make_v;
- // Interpolate between a middlegame and a (scaled by 'sf') endgame score
- ScaleFactor sf = scale_factor(eg_value(score));
- v = mg_value(score) * int(me->game_phase())
- + eg_value(score) * int(PHASE_MIDGAME - me->game_phase()) * sf / SCALE_FACTOR_NORMAL;
+ score += threats<WHITE>() - threats<BLACK>()
+ + space< WHITE>() - space< BLACK>();
- v /= PHASE_MIDGAME;
+make_v:
+ // Derive single value from mg and eg parts of score
+ Value v = winnable(score);
// In case of tracing add all remaining individual evaluation terms
if (T)
Trace::add(IMBALANCE, me->imbalance());
Trace::add(PAWN, pe->pawn_score(WHITE), pe->pawn_score(BLACK));
Trace::add(MOBILITY, mobility[WHITE], mobility[BLACK]);
- Trace::add(TOTAL, score);
}
- return (pos.side_to_move() == WHITE ? v : -v) // Side to move point of view
- + Eval::Tempo;
+ // Evaluation grain
+ v = (v / 16) * 16;
+
+ // Side to move point of view
+ v = (pos.side_to_move() == WHITE ? v : -v) + Tempo;
+
+ // Damp down the evaluation linearly when shuffling
+ v = v * (100 - pos.rule50_count()) / 100;
+
+ return v;
}
} // namespace
<< " Threats | " << Term(THREAT)
<< " Passed | " << Term(PASSED)
<< " Space | " << Term(SPACE)
- << " Initiative | " << Term(INITIATIVE)
+ << " Winnable | " << Term(WINNABLE)
<< " ------------+-------------+-------------+------------\n"
<< " Total | " << Term(TOTAL);
- ss << "\nTotal evaluation: " << to_cp(v) << " (white side)\n";
+ ss << "\nFinal evaluation: " << to_cp(v) << " (white side)\n";
return ss.str();
}
namespace Eval {
-constexpr Value Tempo = Value(28); // Must be visible to search
-
std::string trace(const Position& pos);
Value evaluate(const Position& pos);
#include <thread>
#include "bitboard.h"
+#include "endgame.h"
#include "position.h"
#include "search.h"
#include "thread.h"
#include "tt.h"
#include "uci.h"
-#include "endgame.h"
#include "syzygy/tbprobe.h"
#include <grpc/grpc.h>
std::cout << engine_info() << std::endl;
UCI::init(Options);
+ Tune::init();
PSQT::init();
Bitboards::init();
Position::init();
Bitbases::init();
Endgames::init();
- Threads.set(Options["Threads"]);
+ Threads.set(size_t(Options["Threads"]));
Search::clear(); // After threads are up
UCI::loop(argc, argv);
constexpr int QuadraticTheirs[][PIECE_TYPE_NB] = {
// THEIR PIECES
// pair pawn knight bishop rook queen
- { 0 }, // Bishop pair
- { 36, 0 }, // Pawn
- { 9, 63, 0 }, // Knight OUR PIECES
- { 59, 65, 42, 0 }, // Bishop
- { 46, 39, 24, -24, 0 }, // Rook
- { 97, 100, -42, 137, 268, 0 } // Queen
+ { }, // Bishop pair
+ { 36, }, // Pawn
+ { 9, 63, }, // Knight OUR PIECES
+ { 59, 65, 42, }, // Bishop
+ { 46, 39, 24, -24, }, // Rook
+ { 97, 100, -42, 137, 268, } // Queen
};
// Endgame evaluation and scaling functions are accessed directly and not through
&& pos.count<PAWN>(~us) >= 1;
}
+
/// imbalance() calculates the imbalance by comparing the piece count of each
/// piece type for both colors.
+
template<Color Us>
int imbalance(const int pieceCount[][PIECE_TYPE_NB]) {
- constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
+ constexpr Color Them = ~Us;
int bonus = 0;
if (!pieceCount[Us][pt1])
continue;
- int v = 0;
+ int v = QuadraticOurs[pt1][pt1] * pieceCount[Us][pt1];
- for (int pt2 = NO_PIECE_TYPE; pt2 <= pt1; ++pt2)
+ for (int pt2 = NO_PIECE_TYPE; pt2 < pt1; ++pt2)
v += QuadraticOurs[pt1][pt2] * pieceCount[Us][pt2]
+ QuadraticTheirs[pt1][pt2] * pieceCount[Them][pt2];
namespace Material {
+
/// Material::probe() looks up the current position's material configuration in
/// the material hash table. It returns a pointer to the Entry if the position
/// is found. Otherwise a new Entry is computed and stored there, so we don't
Value npm_w = pos.non_pawn_material(WHITE);
Value npm_b = pos.non_pawn_material(BLACK);
- Value npm = clamp(npm_w + npm_b, EndgameLimit, MidgameLimit);
+ Value npm = Utility::clamp(npm_w + npm_b, EndgameLimit, MidgameLimit);
// Map total non-pawn material into [PHASE_ENDGAME, PHASE_MIDGAME]
e->gamePhase = Phase(((npm - EndgameLimit) * PHASE_MIDGAME) / (MidgameLimit - EndgameLimit));
bool specialized_eval_exists() const { return evaluationFunction != nullptr; }
Value evaluate(const Position& pos) const { return (*evaluationFunction)(pos); }
- // scale_factor takes a position and a color as input and returns a scale factor
+ // scale_factor() takes a position and a color as input and returns a scale factor
// for the given color. We have to provide the position in addition to the color
// because the scale factor may also be a function which should be applied to
// the position. For instance, in KBP vs K endgames, the scaling function looks
#include <sstream>
#include <vector>
+#if defined(__linux__) && !defined(__ANDROID__)
+#include <stdlib.h>
+#include <sys/mman.h>
+#endif
+
#include "misc.h"
#include "thread.h"
/// Version number. If Version is left empty, then compile date in the format
/// DD-MM-YY and show in engine_info.
-const string Version = "11";
+const string Version = "";
/// Our fancy logging facility. The trick here is to replace cin.rdbuf() and
/// cout.rdbuf() with two Tie objects that tie cin and cout to a file stream. We
const std::string compiler_info() {
- #define STRINGIFY2(x) #x
- #define STRINGIFY(x) STRINGIFY2(x)
- #define VER_STRING(major, minor, patch) STRINGIFY(major) "." STRINGIFY(minor) "." STRINGIFY(patch)
+ #define stringify2(x) #x
+ #define stringify(x) stringify2(x)
+ #define make_version_string(major, minor, patch) stringify(major) "." stringify(minor) "." stringify(patch)
/// Predefined macros hell:
///
#ifdef __clang__
compiler += "clang++ ";
- compiler += VER_STRING(__clang_major__, __clang_minor__, __clang_patchlevel__);
+ compiler += make_version_string(__clang_major__, __clang_minor__, __clang_patchlevel__);
#elif __INTEL_COMPILER
compiler += "Intel compiler ";
compiler += "(version ";
- compiler += STRINGIFY(__INTEL_COMPILER) " update " STRINGIFY(__INTEL_COMPILER_UPDATE);
+ compiler += stringify(__INTEL_COMPILER) " update " stringify(__INTEL_COMPILER_UPDATE);
compiler += ")";
#elif _MSC_VER
compiler += "MSVC ";
compiler += "(version ";
- compiler += STRINGIFY(_MSC_FULL_VER) "." STRINGIFY(_MSC_BUILD);
+ compiler += stringify(_MSC_FULL_VER) "." stringify(_MSC_BUILD);
compiler += ")";
#elif __GNUC__
compiler += "g++ (GNUC) ";
- compiler += VER_STRING(__GNUC__, __GNUC_MINOR__, __GNUC_PATCHLEVEL__);
+ compiler += make_version_string(__GNUC__, __GNUC_MINOR__, __GNUC_PATCHLEVEL__);
#else
compiler += "Unknown compiler ";
compiler += "(unknown version)";
#endif
- #if defined(__APPLE__)
+ #if defined(__APPLE__)
compiler += " on Apple";
#elif defined(__CYGWIN__)
compiler += " on Cygwin";
#endif
+
+/// aligned_ttmem_alloc() will return suitably aligned memory, and if possible use large pages.
+/// The returned pointer is the aligned one, while the mem argument is the one that needs
+/// to be passed to free. With c++17 some of this functionality could be simplified.
+
+#if defined(__linux__) && !defined(__ANDROID__)
+
+void* aligned_ttmem_alloc(size_t allocSize, void*& mem) {
+
+ constexpr size_t alignment = 2 * 1024 * 1024; // assumed 2MB page sizes
+ size_t size = ((allocSize + alignment - 1) / alignment) * alignment; // multiple of alignment
+ if (posix_memalign(&mem, alignment, size))
+ mem = nullptr;
+ madvise(mem, allocSize, MADV_HUGEPAGE);
+ return mem;
+}
+
+#elif defined(_WIN64)
+
+static void* aligned_ttmem_alloc_large_pages(size_t allocSize) {
+
+ HANDLE hProcessToken { };
+ LUID luid { };
+ void* mem = nullptr;
+
+ const size_t largePageSize = GetLargePageMinimum();
+ if (!largePageSize)
+ return nullptr;
+
+ // We need SeLockMemoryPrivilege, so try to enable it for the process
+ if (!OpenProcessToken(GetCurrentProcess(), TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY, &hProcessToken))
+ return nullptr;
+
+ if (LookupPrivilegeValue(NULL, SE_LOCK_MEMORY_NAME, &luid))
+ {
+ TOKEN_PRIVILEGES tp { };
+ TOKEN_PRIVILEGES prevTp { };
+ DWORD prevTpLen = 0;
+
+ tp.PrivilegeCount = 1;
+ tp.Privileges[0].Luid = luid;
+ tp.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;
+
+ // Try to enable SeLockMemoryPrivilege. Note that even if AdjustTokenPrivileges() succeeds,
+ // we still need to query GetLastError() to ensure that the privileges were actually obtained.
+ if (AdjustTokenPrivileges(
+ hProcessToken, FALSE, &tp, sizeof(TOKEN_PRIVILEGES), &prevTp, &prevTpLen) &&
+ GetLastError() == ERROR_SUCCESS)
+ {
+ // Round up size to full pages and allocate
+ allocSize = (allocSize + largePageSize - 1) & ~size_t(largePageSize - 1);
+ mem = VirtualAlloc(
+ NULL, allocSize, MEM_RESERVE | MEM_COMMIT | MEM_LARGE_PAGES, PAGE_READWRITE);
+
+ // Privilege no longer needed, restore previous state
+ AdjustTokenPrivileges(hProcessToken, FALSE, &prevTp, 0, NULL, NULL);
+ }
+ }
+
+ CloseHandle(hProcessToken);
+
+ return mem;
+}
+
+void* aligned_ttmem_alloc(size_t allocSize, void*& mem) {
+
+ static bool firstCall = true;
+
+ // Try to allocate large pages
+ mem = aligned_ttmem_alloc_large_pages(allocSize);
+
+ // Suppress info strings on the first call. The first call occurs before 'uci'
+ // is received and in that case this output confuses some GUIs.
+ if (!firstCall)
+ {
+ if (mem)
+ sync_cout << "info string Hash table allocation: Windows large pages used." << sync_endl;
+ else
+ sync_cout << "info string Hash table allocation: Windows large pages not used." << sync_endl;
+ }
+ firstCall = false;
+
+ // Fall back to regular, page aligned, allocation if necessary
+ if (!mem)
+ mem = VirtualAlloc(NULL, allocSize, MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);
+
+ return mem;
+}
+
+#else
+
+void* aligned_ttmem_alloc(size_t allocSize, void*& mem) {
+
+ constexpr size_t alignment = 64; // assumed cache line size
+ size_t size = allocSize + alignment - 1; // allocate some extra space
+ mem = malloc(size);
+ void* ret = reinterpret_cast<void*>((uintptr_t(mem) + alignment - 1) & ~uintptr_t(alignment - 1));
+ return ret;
+}
+
+#endif
+
+
+/// aligned_ttmem_free() will free the previously allocated ttmem
+
+#if defined(_WIN64)
+
+void aligned_ttmem_free(void* mem) {
+
+ if (mem && !VirtualFree(mem, 0, MEM_RELEASE))
+ {
+ DWORD err = GetLastError();
+ std::cerr << "Failed to free transposition table. Error code: 0x" <<
+ std::hex << err << std::dec << std::endl;
+ exit(EXIT_FAILURE);
+ }
+}
+
+#else
+
+void aligned_ttmem_free(void *mem) {
+ free(mem);
+}
+
+#endif
+
+
namespace WinProcGroup {
#ifndef _WIN32
const std::string compiler_info();
void prefetch(void* addr);
void start_logger(const std::string& fname);
+void* aligned_ttmem_alloc(size_t size, void*& mem);
+void aligned_ttmem_free(void* mem); // nop if mem == nullptr
void dbg_hit_on(bool b);
void dbg_hit_on(bool c, bool b);
#define sync_cout std::cout << IO_LOCK
#define sync_endl std::endl << IO_UNLOCK
+namespace Utility {
+
+/// Clamp a value between lo and hi. Available in c++17.
+template<class T> constexpr const T& clamp(const T& v, const T& lo, const T& hi) {
+ return v < lo ? lo : v > hi ? hi : v;
+}
+
+}
/// xorshift64star Pseudo-Random Number Generator
/// This class is based on original code written and dedicated
{ return T(rand64() & rand64() & rand64()); }
};
+inline uint64_t mul_hi64(uint64_t a, uint64_t b) {
+#if defined(__GNUC__) && defined(IS_64BIT)
+ __extension__ typedef unsigned __int128 uint128;
+ return ((uint128)a * (uint128)b) >> 64;
+#else
+ uint64_t aL = (uint32_t)a, aH = a >> 32;
+ uint64_t bL = (uint32_t)b, bH = b >> 32;
+ uint64_t c1 = (aL * bL) >> 32;
+ uint64_t c2 = aH * bL + c1;
+ uint64_t c3 = aL * bH + (uint32_t)c2;
+ return aH * bH + (c2 >> 32) + (c3 >> 32);
+#endif
+}
/// Under Windows it is not possible for a process to run on more than one
/// logical processor group. This usually means to be limited to use max 64
ExtMove* make_promotions(ExtMove* moveList, Square to, Square ksq) {
if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS)
+ {
*moveList++ = make<PROMOTION>(to - D, to, QUEEN);
+ if (attacks_bb<KNIGHT>(to) & ksq)
+ *moveList++ = make<PROMOTION>(to - D, to, KNIGHT);
+ }
if (Type == QUIETS || Type == EVASIONS || Type == NON_EVASIONS)
{
*moveList++ = make<PROMOTION>(to - D, to, ROOK);
*moveList++ = make<PROMOTION>(to - D, to, BISHOP);
- *moveList++ = make<PROMOTION>(to - D, to, KNIGHT);
+ if (!(attacks_bb<KNIGHT>(to) & ksq))
+ *moveList++ = make<PROMOTION>(to - D, to, KNIGHT);
}
- // Knight promotion is the only promotion that can give a direct check
- // that's not already included in the queen promotion.
- if (Type == QUIET_CHECKS && (PseudoAttacks[KNIGHT][to] & ksq))
- *moveList++ = make<PROMOTION>(to - D, to, KNIGHT);
- else
- (void)ksq; // Silence a warning under MSVC
-
return moveList;
}
template<Color Us, GenType Type>
ExtMove* generate_pawn_moves(const Position& pos, ExtMove* moveList, Bitboard target) {
- // Compute some compile time parameters relative to the white side
- constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
+ constexpr Color Them = ~Us;
constexpr Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB);
constexpr Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
constexpr Direction Up = pawn_push(Us);
if (Type == QUIET_CHECKS)
{
- b1 &= pos.attacks_from<PAWN>(ksq, Them);
- b2 &= pos.attacks_from<PAWN>(ksq, Them);
+ b1 &= pawn_attacks_bb(Them, ksq);
+ b2 &= pawn_attacks_bb(Them, ksq);
// Add pawn pushes which give discovered check. This is possible only
// if the pawn is not on the same file as the enemy king, because we
if (Type == EVASIONS && !(target & (pos.ep_square() - Up)))
return moveList;
- b1 = pawnsNotOn7 & pos.attacks_from<PAWN>(pos.ep_square(), Them);
+ b1 = pawnsNotOn7 & pawn_attacks_bb(Them, pos.ep_square());
assert(b1);
}
- template<PieceType Pt, bool Checks>
- ExtMove* generate_moves(const Position& pos, ExtMove* moveList, Color us,
- Bitboard target) {
+ template<Color Us, PieceType Pt, bool Checks>
+ ExtMove* generate_moves(const Position& pos, ExtMove* moveList, Bitboard target) {
static_assert(Pt != KING && Pt != PAWN, "Unsupported piece type in generate_moves()");
- const Square* pl = pos.squares<Pt>(us);
+ const Square* pl = pos.squares<Pt>(Us);
for (Square from = *pl; from != SQ_NONE; from = *++pl)
{
if (Checks)
{
if ( (Pt == BISHOP || Pt == ROOK || Pt == QUEEN)
- && !(PseudoAttacks[Pt][from] & target & pos.check_squares(Pt)))
+ && !(attacks_bb<Pt>(from) & target & pos.check_squares(Pt)))
continue;
- if (pos.blockers_for_king(~us) & from)
+ if (pos.blockers_for_king(~Us) & from)
continue;
}
- Bitboard b = pos.attacks_from<Pt>(from) & target;
+ Bitboard b = attacks_bb<Pt>(from, pos.pieces()) & target;
if (Checks)
b &= pos.check_squares(Pt);
template<Color Us, GenType Type>
- ExtMove* generate_all(const Position& pos, ExtMove* moveList, Bitboard target) {
-
- constexpr CastlingRights OO = Us & KING_SIDE;
- constexpr CastlingRights OOO = Us & QUEEN_SIDE;
+ ExtMove* generate_all(const Position& pos, ExtMove* moveList) {
constexpr bool Checks = Type == QUIET_CHECKS; // Reduce template instantations
+ Bitboard target;
+
+ switch (Type)
+ {
+ case CAPTURES:
+ target = pos.pieces(~Us);
+ break;
+ case QUIETS:
+ case QUIET_CHECKS:
+ target = ~pos.pieces();
+ break;
+ case EVASIONS:
+ {
+ Square checksq = lsb(pos.checkers());
+ target = between_bb(pos.square<KING>(Us), checksq) | checksq;
+ break;
+ }
+ case NON_EVASIONS:
+ target = ~pos.pieces(Us);
+ break;
+ default:
+ static_assert(true, "Unsupported type in generate_all()");
+ }
moveList = generate_pawn_moves<Us, Type>(pos, moveList, target);
- moveList = generate_moves<KNIGHT, Checks>(pos, moveList, Us, target);
- moveList = generate_moves<BISHOP, Checks>(pos, moveList, Us, target);
- moveList = generate_moves< ROOK, Checks>(pos, moveList, Us, target);
- moveList = generate_moves< QUEEN, Checks>(pos, moveList, Us, target);
+ moveList = generate_moves<Us, KNIGHT, Checks>(pos, moveList, target);
+ moveList = generate_moves<Us, BISHOP, Checks>(pos, moveList, target);
+ moveList = generate_moves<Us, ROOK, Checks>(pos, moveList, target);
+ moveList = generate_moves<Us, QUEEN, Checks>(pos, moveList, target);
if (Type != QUIET_CHECKS && Type != EVASIONS)
{
Square ksq = pos.square<KING>(Us);
- Bitboard b = pos.attacks_from<KING>(ksq) & target;
+ Bitboard b = attacks_bb<KING>(ksq) & target;
while (b)
*moveList++ = make_move(ksq, pop_lsb(&b));
- if (Type != CAPTURES && pos.can_castle(CastlingRights(OO | OOO)))
- {
- if (!pos.castling_impeded(OO) && pos.can_castle(OO))
- *moveList++ = make<CASTLING>(ksq, pos.castling_rook_square(OO));
-
- if (!pos.castling_impeded(OOO) && pos.can_castle(OOO))
- *moveList++ = make<CASTLING>(ksq, pos.castling_rook_square(OOO));
- }
+ if ((Type != CAPTURES) && pos.can_castle(Us & ANY_CASTLING))
+ for(CastlingRights cr : { Us & KING_SIDE, Us & QUEEN_SIDE } )
+ if (!pos.castling_impeded(cr) && pos.can_castle(cr))
+ *moveList++ = make<CASTLING>(ksq, pos.castling_rook_square(cr));
}
return moveList;
} // namespace
-/// <CAPTURES> Generates all pseudo-legal captures and queen promotions
-/// <QUIETS> Generates all pseudo-legal non-captures and underpromotions
+/// <CAPTURES> Generates all pseudo-legal captures plus queen and checking knight promotions
+/// <QUIETS> Generates all pseudo-legal non-captures and underpromotions(except checking knight)
/// <NON_EVASIONS> Generates all pseudo-legal captures and non-captures
///
/// Returns a pointer to the end of the move list.
Color us = pos.side_to_move();
- Bitboard target = Type == CAPTURES ? pos.pieces(~us)
- : Type == QUIETS ? ~pos.pieces()
- : Type == NON_EVASIONS ? ~pos.pieces(us) : 0;
-
- return us == WHITE ? generate_all<WHITE, Type>(pos, moveList, target)
- : generate_all<BLACK, Type>(pos, moveList, target);
+ return us == WHITE ? generate_all<WHITE, Type>(pos, moveList)
+ : generate_all<BLACK, Type>(pos, moveList);
}
// Explicit template instantiations
template ExtMove* generate<NON_EVASIONS>(const Position&, ExtMove*);
-/// generate<QUIET_CHECKS> generates all pseudo-legal non-captures and knight
-/// underpromotions that give check. Returns a pointer to the end of the move list.
+/// generate<QUIET_CHECKS> generates all pseudo-legal non-captures.
+/// Returns a pointer to the end of the move list.
template<>
ExtMove* generate<QUIET_CHECKS>(const Position& pos, ExtMove* moveList) {
assert(!pos.checkers());
Color us = pos.side_to_move();
- Bitboard dc = pos.blockers_for_king(~us) & pos.pieces(us);
+ Bitboard dc = pos.blockers_for_king(~us) & pos.pieces(us) & ~pos.pieces(PAWN);
while (dc)
{
Square from = pop_lsb(&dc);
PieceType pt = type_of(pos.piece_on(from));
- if (pt == PAWN)
- continue; // Will be generated together with direct checks
-
- Bitboard b = pos.attacks_from(pt, from) & ~pos.pieces();
+ Bitboard b = attacks_bb(pt, from, pos.pieces()) & ~pos.pieces();
if (pt == KING)
- b &= ~PseudoAttacks[QUEEN][pos.square<KING>(~us)];
+ b &= ~attacks_bb<QUEEN>(pos.square<KING>(~us));
while (b)
*moveList++ = make_move(from, pop_lsb(&b));
}
- return us == WHITE ? generate_all<WHITE, QUIET_CHECKS>(pos, moveList, ~pos.pieces())
- : generate_all<BLACK, QUIET_CHECKS>(pos, moveList, ~pos.pieces());
+ return us == WHITE ? generate_all<WHITE, QUIET_CHECKS>(pos, moveList)
+ : generate_all<BLACK, QUIET_CHECKS>(pos, moveList);
}
// the king evasions in order to skip known illegal moves, which avoids any
// useless legality checks later on.
while (sliders)
- {
- Square checksq = pop_lsb(&sliders);
- sliderAttacks |= LineBB[checksq][ksq] ^ checksq;
- }
+ sliderAttacks |= line_bb(ksq, pop_lsb(&sliders)) & ~pos.checkers();
// Generate evasions for king, capture and non capture moves
- Bitboard b = pos.attacks_from<KING>(ksq) & ~pos.pieces(us) & ~sliderAttacks;
+ Bitboard b = attacks_bb<KING>(ksq) & ~pos.pieces(us) & ~sliderAttacks;
while (b)
*moveList++ = make_move(ksq, pop_lsb(&b));
return moveList; // Double check, only a king move can save the day
// Generate blocking evasions or captures of the checking piece
- Square checksq = lsb(pos.checkers());
- Bitboard target = between_bb(checksq, ksq) | checksq;
-
- return us == WHITE ? generate_all<WHITE, EVASIONS>(pos, moveList, target)
- : generate_all<BLACK, EVASIONS>(pos, moveList, target);
+ return us == WHITE ? generate_all<WHITE, EVASIONS>(pos, moveList)
+ : generate_all<BLACK, EVASIONS>(pos, moveList);
}
/// ordering is at the current node.
/// MovePicker constructor for the main search
-MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh,
- const CapturePieceToHistory* cph, const PieceToHistory** ch, Move cm, Move* killers)
- : pos(p), mainHistory(mh), captureHistory(cph), continuationHistory(ch),
- refutations{{killers[0], 0}, {killers[1], 0}, {cm, 0}}, depth(d) {
+MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh, const LowPlyHistory* lp,
+ const CapturePieceToHistory* cph, const PieceToHistory** ch, Move cm, const Move* killers, int pl)
+ : pos(p), mainHistory(mh), lowPlyHistory(lp), captureHistory(cph), continuationHistory(ch),
+ ttMove(ttm), refutations{{killers[0], 0}, {killers[1], 0}, {cm, 0}}, depth(d), ply(pl) {
assert(d > 0);
- stage = pos.checkers() ? EVASION_TT : MAIN_TT;
- ttMove = ttm && pos.pseudo_legal(ttm) ? ttm : MOVE_NONE;
- stage += (ttMove == MOVE_NONE);
+ stage = (pos.checkers() ? EVASION_TT : MAIN_TT) +
+ !(ttm && pos.pseudo_legal(ttm));
}
/// MovePicker constructor for quiescence search
MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh,
const CapturePieceToHistory* cph, const PieceToHistory** ch, Square rs)
- : pos(p), mainHistory(mh), captureHistory(cph), continuationHistory(ch), recaptureSquare(rs), depth(d) {
+ : pos(p), mainHistory(mh), captureHistory(cph), continuationHistory(ch), ttMove(ttm), recaptureSquare(rs), depth(d) {
assert(d <= 0);
- stage = pos.checkers() ? EVASION_TT : QSEARCH_TT;
- ttMove = ttm
- && (depth > DEPTH_QS_RECAPTURES || to_sq(ttm) == recaptureSquare)
- && pos.pseudo_legal(ttm) ? ttm : MOVE_NONE;
- stage += (ttMove == MOVE_NONE);
+ stage = (pos.checkers() ? EVASION_TT : QSEARCH_TT) +
+ !(ttm && (depth > DEPTH_QS_RECAPTURES || to_sq(ttm) == recaptureSquare)
+ && pos.pseudo_legal(ttm));
}
/// MovePicker constructor for ProbCut: we generate captures with SEE greater
/// than or equal to the given threshold.
MovePicker::MovePicker(const Position& p, Move ttm, Value th, const CapturePieceToHistory* cph)
- : pos(p), captureHistory(cph), threshold(th) {
+ : pos(p), captureHistory(cph), ttMove(ttm), threshold(th) {
assert(!pos.checkers());
- stage = PROBCUT_TT;
- ttMove = ttm
- && pos.capture(ttm)
- && pos.pseudo_legal(ttm)
- && pos.see_ge(ttm, threshold) ? ttm : MOVE_NONE;
- stage += (ttMove == MOVE_NONE);
+ stage = PROBCUT_TT + !(ttm && pos.capture(ttm)
+ && pos.pseudo_legal(ttm)
+ && pos.see_ge(ttm, threshold));
}
/// MovePicker::score() assigns a numerical value to each move in a list, used
+ 2 * (*continuationHistory[0])[pos.moved_piece(m)][to_sq(m)]
+ 2 * (*continuationHistory[1])[pos.moved_piece(m)][to_sq(m)]
+ 2 * (*continuationHistory[3])[pos.moved_piece(m)][to_sq(m)]
- + (*continuationHistory[5])[pos.moved_piece(m)][to_sq(m)];
+ + (*continuationHistory[5])[pos.moved_piece(m)][to_sq(m)]
+ + (ply < MAX_LPH ? std::min(4, depth / 3) * (*lowPlyHistory)[ply][from_to(m)] : 0);
else // Type == EVASIONS
{
case GOOD_CAPTURE:
if (select<Best>([&](){
- return pos.see_ge(*cur, Value(-55 * cur->value / 1024)) ?
+ return pos.see_ge(*cur, Value(-69 * cur->value / 1024)) ?
// Move losing capture to endBadCaptures to be tried later
true : (*endBadCaptures++ = *cur, false); }))
return *(cur - 1);
/// the move's from and to squares, see www.chessprogramming.org/Butterfly_Boards
typedef Stats<int16_t, 10692, COLOR_NB, int(SQUARE_NB) * int(SQUARE_NB)> ButterflyHistory;
+/// At higher depths LowPlyHistory records successful quiet moves near the root and quiet
+/// moves which are/were in the PV (ttPv)
+/// It is cleared with each new search and filled during iterative deepening
+constexpr int MAX_LPH = 4;
+typedef Stats<int16_t, 10692, MAX_LPH, int(SQUARE_NB) * int(SQUARE_NB)> LowPlyHistory;
+
/// CounterMoveHistory stores counter moves indexed by [piece][to] of the previous
/// move, see www.chessprogramming.org/Countermove_Heuristic
typedef Stats<Move, NOT_USED, PIECE_NB, SQUARE_NB> CounterMoveHistory;
const PieceToHistory**,
Square);
MovePicker(const Position&, Move, Depth, const ButterflyHistory*,
+ const LowPlyHistory*,
const CapturePieceToHistory*,
const PieceToHistory**,
Move,
- Move*);
+ const Move*,
+ int);
Move next_move(bool skipQuiets = false);
private:
const Position& pos;
const ButterflyHistory* mainHistory;
+ const LowPlyHistory* lowPlyHistory;
const CapturePieceToHistory* captureHistory;
const PieceToHistory** continuationHistory;
Move ttMove;
Square recaptureSquare;
Value threshold;
Depth depth;
+ int ply;
ExtMove moves[MAX_MOVES];
};
// Pawn penalties
constexpr Score Backward = S( 9, 24);
- constexpr Score BlockedStorm = S(82, 82);
constexpr Score Doubled = S(11, 56);
constexpr Score Isolated = S( 5, 15);
constexpr Score WeakLever = S( 0, 56);
constexpr Score WeakUnopposed = S(13, 27);
+ // Bonus for blocked pawns at 5th or 6th rank
+ constexpr Score BlockedPawn[2] = { S(-11, -4), S(-3, 4) };
+
+ constexpr Score BlockedStorm[RANK_NB] = {
+ S(0, 0), S(0, 0), S(76, 78), S(-10, 15), S(-7, 10), S(-4, 6), S(-1, 2)
+ };
+
// Connected pawn bonus
constexpr int Connected[RANK_NB] = { 0, 7, 8, 12, 29, 48, 86 };
#undef S
#undef V
+
+ /// evaluate() calculates a score for the static pawn structure of the given position.
+ /// We cannot use the location of pieces or king in this function, as the evaluation
+ /// of the pawn structure will be stored in a small cache for speed reasons, and will
+ /// be re-used even when the pieces have moved.
+
template<Color Us>
Score evaluate(const Position& pos, Pawns::Entry* e) {
- constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
+ constexpr Color Them = ~Us;
constexpr Direction Up = pawn_push(Us);
Bitboard neighbours, stoppers, support, phalanx, opposed;
e->passedPawns[Us] = 0;
e->kingSquares[Us] = SQ_NONE;
e->pawnAttacks[Us] = e->pawnAttacksSpan[Us] = pawn_attacks_bb<Us>(ourPawns);
+ e->blockedCount += popcount(shift<Up>(ourPawns) & (theirPawns | doubleAttackThem));
// Loop through all pawns of the current color and score each pawn
while ((s = *pl++) != SQ_NONE)
opposed = theirPawns & forward_file_bb(Us, s);
blocked = theirPawns & (s + Up);
stoppers = theirPawns & passed_pawn_span(Us, s);
- lever = theirPawns & PawnAttacks[Us][s];
- leverPush = theirPawns & PawnAttacks[Us][s + Up];
+ lever = theirPawns & pawn_attacks_bb(Us, s);
+ leverPush = theirPawns & pawn_attacks_bb(Us, s + Up);
doubled = ourPawns & (s - Up);
neighbours = ourPawns & adjacent_files_bb(s);
phalanx = neighbours & rank_bb(s);
// (a) there is no stoppers except some levers
// (b) the only stoppers are the leverPush, but we outnumber them
// (c) there is only one front stopper which can be levered.
+ // (Refined in Evaluation::passed)
passed = !(stoppers ^ lever)
|| ( !(stoppers ^ leverPush)
&& popcount(phalanx) >= popcount(leverPush))
|| ( stoppers == blocked && r >= RANK_5
&& (shift<Up>(support) & ~(theirPawns | doubleAttackThem)));
+ passed &= !(forward_file_bb(Us, s) & ourPawns);
+
// Passed pawns will be properly scored later in evaluation when we have
// full attack info.
if (passed)
}
else if (!neighbours)
- score -= Isolated
- + WeakUnopposed * !opposed;
+ {
+ if ( opposed
+ && (ourPawns & forward_file_bb(Them, s))
+ && !(theirPawns & adjacent_files_bb(s)))
+ score -= Doubled;
+ else
+ score -= Isolated
+ + WeakUnopposed * !opposed;
+ }
else if (backward)
- score -= Backward
- + WeakUnopposed * !opposed;
+ score -= Backward
+ + WeakUnopposed * !opposed;
if (!support)
- score -= Doubled * doubled
- + WeakLever * more_than_one(lever);
+ score -= Doubled * doubled
+ + WeakLever * more_than_one(lever);
+
+ if (blocked && r > RANK_4)
+ score += BlockedPawn[r-4];
}
return score;
namespace Pawns {
+
/// Pawns::probe() looks up the current position's pawns configuration in
/// the pawns hash table. It returns a pointer to the Entry if the position
/// is found. Otherwise a new Entry is computed and stored there, so we don't
return e;
e->key = key;
+ e->blockedCount = 0;
e->scores[WHITE] = evaluate<WHITE>(pos, e);
e->scores[BLACK] = evaluate<BLACK>(pos, e);
/// penalty for a king, looking at the king file and the two closest files.
template<Color Us>
-Score Entry::evaluate_shelter(const Position& pos, Square ksq) {
+Score Entry::evaluate_shelter(const Position& pos, Square ksq) const {
- constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
+ constexpr Color Them = ~Us;
Bitboard b = pos.pieces(PAWN) & ~forward_ranks_bb(Them, ksq);
- Bitboard ourPawns = b & pos.pieces(Us);
+ Bitboard ourPawns = b & pos.pieces(Us) & ~pawnAttacks[Them];
Bitboard theirPawns = b & pos.pieces(Them);
Score bonus = make_score(5, 5);
- File center = clamp(file_of(ksq), FILE_B, FILE_G);
+ File center = Utility::clamp(file_of(ksq), FILE_B, FILE_G);
for (File f = File(center - 1); f <= File(center + 1); ++f)
{
b = ourPawns & file_bb(f);
b = theirPawns & file_bb(f);
int theirRank = b ? relative_rank(Us, frontmost_sq(Them, b)) : 0;
- File d = map_to_queenside(f);
+ int d = edge_distance(f);
bonus += make_score(ShelterStrength[d][ourRank], 0);
if (ourRank && (ourRank == theirRank - 1))
- bonus -= BlockedStorm * int(theirRank == RANK_3);
+ bonus -= BlockedStorm[theirRank];
else
bonus -= make_score(UnblockedStorm[d][theirRank], 0);
}
// In endgame we like to bring our king near our closest pawn
Bitboard pawns = pos.pieces(Us, PAWN);
- int minPawnDist = pawns ? 8 : 0;
+ int minPawnDist = 6;
- if (pawns & PseudoAttacks[KING][ksq])
+ if (pawns & attacks_bb<KING>(ksq))
minPawnDist = 1;
else while (pawns)
minPawnDist = std::min(minPawnDist, distance(ksq, pop_lsb(&pawns)));
Bitboard passed_pawns(Color c) const { return passedPawns[c]; }
Bitboard pawn_attacks_span(Color c) const { return pawnAttacksSpan[c]; }
int passed_count() const { return popcount(passedPawns[WHITE] | passedPawns[BLACK]); }
+ int blocked_count() const { return blockedCount; }
template<Color Us>
Score king_safety(const Position& pos) {
Score do_king_safety(const Position& pos);
template<Color Us>
- Score evaluate_shelter(const Position& pos, Square ksq);
+ Score evaluate_shelter(const Position& pos, Square ksq) const;
Key key;
Score scores[COLOR_NB];
Square kingSquares[COLOR_NB];
Score kingSafety[COLOR_NB];
int castlingRights[COLOR_NB];
+ int blockedCount;
};
typedef HashTable<Entry, 131072> Table;
for (File f = FILE_A; f <= FILE_H; ++f)
os << " | " << PieceToChar[pos.piece_on(make_square(f, r))];
- os << " |\n +---+---+---+---+---+---+---+---+\n";
+ os << " | " << (1 + r) << "\n +---+---+---+---+---+---+---+---+\n";
}
- os << "\nFen: " << pos.fen() << "\nKey: " << std::hex << std::uppercase
+ os << " a b c d e f g h\n"
+ << "\nFen: " << pos.fen() << "\nKey: " << std::hex << std::uppercase
<< std::setfill('0') << std::setw(16) << pos.key()
<< std::setfill(' ') << std::dec << "\nCheckers: ";
Move cuckooMove[8192];
-/// Position::init() initializes at startup the various arrays used to compute
-/// hash keys.
+/// Position::init() initializes at startup the various arrays used to compute hash keys
void Position::init() {
Zobrist::enpassant[f] = rng.rand<Key>();
for (int cr = NO_CASTLING; cr <= ANY_CASTLING; ++cr)
- {
- Zobrist::castling[cr] = 0;
- Bitboard b = cr;
- while (b)
- {
- Key k = Zobrist::castling[1ULL << pop_lsb(&b)];
- Zobrist::castling[cr] ^= k ? k : rng.rand<Key>();
- }
- }
+ Zobrist::castling[cr] = rng.rand<Key>();
Zobrist::side = rng.rand<Key>();
Zobrist::noPawns = rng.rand<Key>();
for (Piece pc : Pieces)
for (Square s1 = SQ_A1; s1 <= SQ_H8; ++s1)
for (Square s2 = Square(s1 + 1); s2 <= SQ_H8; ++s2)
- if (PseudoAttacks[type_of(pc)][s1] & s2)
+ if ((type_of(pc) != PAWN) && (attacks_bb(type_of(pc), s1, 0) & s2))
{
Move move = make_move(s1, s2);
Key key = Zobrist::psq[pc][s1] ^ Zobrist::psq[pc][s2] ^ Zobrist::side;
4) En passant target square (in algebraic notation). If there's no en passant
target square, this is "-". If a pawn has just made a 2-square move, this
- is the position "behind" the pawn. This is recorded only if there is a pawn
- in position to make an en passant capture, and if there really is a pawn
- that might have advanced two squares.
+ is the position "behind" the pawn. Following X-FEN standard, this is recorded only
+ if there is a pawn in position to make an en passant capture, and if there really
+ is a pawn that might have advanced two squares.
5) Halfmove clock. This is the number of halfmoves since the last pawn advance
or capture. This is used to determine if a draw can be claimed under the
set_castling_right(c, rsq);
}
- // 4. En passant square. Ignore if no pawn capture is possible
+ // 4. En passant square.
+ // Ignore if square is invalid or not on side to move relative rank 6.
+ bool enpassant = false;
+
if ( ((ss >> col) && (col >= 'a' && col <= 'h'))
- && ((ss >> row) && (row == '3' || row == '6')))
+ && ((ss >> row) && (row == (sideToMove == WHITE ? '6' : '3'))))
{
st->epSquare = make_square(File(col - 'a'), Rank(row - '1'));
- if ( !(attackers_to(st->epSquare) & pieces(sideToMove, PAWN))
- || !(pieces(~sideToMove, PAWN) & (st->epSquare + pawn_push(~sideToMove))))
- st->epSquare = SQ_NONE;
+ // En passant square will be considered only if
+ // a) side to move have a pawn threatening epSquare
+ // b) there is an enemy pawn in front of epSquare
+ // c) there is no piece on epSquare or behind epSquare
+ enpassant = pawn_attacks_bb(~sideToMove, st->epSquare) & pieces(sideToMove, PAWN)
+ && (pieces(~sideToMove, PAWN) & (st->epSquare + pawn_push(~sideToMove)))
+ && !(pieces() & (st->epSquare | (st->epSquare + pawn_push(sideToMove))));
}
- else
+
+ if (!enpassant)
st->epSquare = SQ_NONE;
// 5-6. Halfmove clock and fullmove number
Square rto = relative_square(c, cr & KING_SIDE ? SQ_F1 : SQ_D1);
castlingPath[cr] = (between_bb(rfrom, rto) | between_bb(kfrom, kto) | rto | kto)
- & ~(square_bb(kfrom) | rfrom);
+ & ~(kfrom | rfrom);
}
Square ksq = square<KING>(~sideToMove);
- si->checkSquares[PAWN] = attacks_from<PAWN>(ksq, ~sideToMove);
- si->checkSquares[KNIGHT] = attacks_from<KNIGHT>(ksq);
- si->checkSquares[BISHOP] = attacks_from<BISHOP>(ksq);
- si->checkSquares[ROOK] = attacks_from<ROOK>(ksq);
+ si->checkSquares[PAWN] = pawn_attacks_bb(~sideToMove, ksq);
+ si->checkSquares[KNIGHT] = attacks_bb<KNIGHT>(ksq);
+ si->checkSquares[BISHOP] = attacks_bb<BISHOP>(ksq, pieces());
+ si->checkSquares[ROOK] = attacks_bb<ROOK>(ksq, pieces());
si->checkSquares[QUEEN] = si->checkSquares[BISHOP] | si->checkSquares[ROOK];
si->checkSquares[KING] = 0;
}
Position& Position::set(const string& code, Color c, StateInfo* si) {
- assert(code.length() > 0 && code.length() < 8);
assert(code[0] == 'K');
string sides[] = { code.substr(code.find('K', 1)), // Weak
- code.substr(0, code.find('K', 1)) }; // Strong
+ code.substr(0, std::min(code.find('v'), code.find('K', 1))) }; // Strong
+
+ assert(sides[0].length() > 0 && sides[0].length() < 8);
+ assert(sides[1].length() > 0 && sides[1].length() < 8);
std::transform(sides[c].begin(), sides[c].end(), sides[c].begin(), tolower);
pinners = 0;
// Snipers are sliders that attack 's' when a piece and other snipers are removed
- Bitboard snipers = ( (PseudoAttacks[ ROOK][s] & pieces(QUEEN, ROOK))
- | (PseudoAttacks[BISHOP][s] & pieces(QUEEN, BISHOP))) & sliders;
+ Bitboard snipers = ( (attacks_bb< ROOK>(s) & pieces(QUEEN, ROOK))
+ | (attacks_bb<BISHOP>(s) & pieces(QUEEN, BISHOP))) & sliders;
Bitboard occupancy = pieces() ^ snipers;
while (snipers)
Bitboard Position::attackers_to(Square s, Bitboard occupied) const {
- return (attacks_from<PAWN>(s, BLACK) & pieces(WHITE, PAWN))
- | (attacks_from<PAWN>(s, WHITE) & pieces(BLACK, PAWN))
- | (attacks_from<KNIGHT>(s) & pieces(KNIGHT))
+ return (pawn_attacks_bb(BLACK, s) & pieces(WHITE, PAWN))
+ | (pawn_attacks_bb(WHITE, s) & pieces(BLACK, PAWN))
+ | (attacks_bb<KNIGHT>(s) & pieces(KNIGHT))
| (attacks_bb< ROOK>(s, occupied) & pieces( ROOK, QUEEN))
| (attacks_bb<BISHOP>(s, occupied) & pieces(BISHOP, QUEEN))
- | (attacks_from<KING>(s) & pieces(KING));
+ | (attacks_bb<KING>(s) & pieces(KING));
}
if ((Rank8BB | Rank1BB) & to)
return false;
- if ( !(attacks_from<PAWN>(from, us) & pieces(~us) & to) // Not a capture
+ if ( !(pawn_attacks_bb(us, from) & pieces(~us) & to) // Not a capture
&& !((from + pawn_push(us) == to) && empty(to)) // Not a single push
&& !( (from + 2 * pawn_push(us) == to) // Not a double push
- && (rank_of(from) == relative_rank(us, RANK_2))
+ && (relative_rank(us, from) == RANK_2)
&& empty(to)
&& empty(to - pawn_push(us))))
return false;
}
- else if (!(attacks_from(type_of(pc), from) & to))
+ else if (!(attacks_bb(type_of(pc), from, pieces()) & to))
return false;
// Evasions generator already takes care to avoid some kind of illegal moves
Square to = to_sq(m);
// Is there a direct check?
- if (st->checkSquares[type_of(piece_on(from))] & to)
+ if (check_squares(type_of(piece_on(from))) & to)
return true;
// Is there a discovered check?
- if ( (st->blockersForKing[~sideToMove] & from)
+ if ( (blockers_for_king(~sideToMove) & from)
&& !aligned(from, to, square<KING>(~sideToMove)))
return true;
case CASTLING:
{
Square kfrom = from;
- Square rfrom = to; // Castling is encoded as 'King captures the rook'
+ Square rfrom = to; // Castling is encoded as 'king captures the rook'
Square kto = relative_square(sideToMove, rfrom > kfrom ? SQ_G1 : SQ_C1);
Square rto = relative_square(sideToMove, rfrom > kfrom ? SQ_F1 : SQ_D1);
- return (PseudoAttacks[ROOK][rto] & square<KING>(~sideToMove))
+ return (attacks_bb<ROOK>(rto) & square<KING>(~sideToMove))
&& (attacks_bb<ROOK>(rto, (pieces() ^ kfrom ^ rfrom) | rto | kto) & square<KING>(~sideToMove));
}
default:
assert(relative_rank(us, to) == RANK_6);
assert(piece_on(to) == NO_PIECE);
assert(piece_on(capsq) == make_piece(them, PAWN));
-
- board[capsq] = NO_PIECE; // Not done by remove_piece()
}
st->pawnKey ^= Zobrist::psq[captured][capsq];
st->nonPawnMaterial[them] -= PieceValue[MG][captured];
// Update board and piece lists
- remove_piece(captured, capsq);
+ remove_piece(capsq);
+
+ if (type_of(m) == ENPASSANT)
+ board[capsq] = NO_PIECE;
// Update material hash key and prefetch access to materialTable
k ^= Zobrist::psq[captured][capsq];
// Update castling rights if needed
if (st->castlingRights && (castlingRightsMask[from] | castlingRightsMask[to]))
{
- int cr = castlingRightsMask[from] | castlingRightsMask[to];
- k ^= Zobrist::castling[st->castlingRights & cr];
- st->castlingRights &= ~cr;
+ k ^= Zobrist::castling[st->castlingRights];
+ st->castlingRights &= ~(castlingRightsMask[from] | castlingRightsMask[to]);
+ k ^= Zobrist::castling[st->castlingRights];
}
// Move the piece. The tricky Chess960 castling is handled earlier
if (type_of(m) != CASTLING)
- move_piece(pc, from, to);
+ move_piece(from, to);
// If the moving piece is a pawn do some special extra work
if (type_of(pc) == PAWN)
{
// Set en-passant square if the moved pawn can be captured
if ( (int(to) ^ int(from)) == 16
- && (attacks_from<PAWN>(to - pawn_push(us), us) & pieces(them, PAWN)))
+ && (pawn_attacks_bb(us, to - pawn_push(us)) & pieces(them, PAWN)))
{
st->epSquare = to - pawn_push(us);
k ^= Zobrist::enpassant[file_of(st->epSquare)];
assert(relative_rank(us, to) == RANK_8);
assert(type_of(promotion) >= KNIGHT && type_of(promotion) <= QUEEN);
- remove_piece(pc, to);
+ remove_piece(to);
put_piece(promotion, to);
// Update hash keys
assert(type_of(pc) == promotion_type(m));
assert(type_of(pc) >= KNIGHT && type_of(pc) <= QUEEN);
- remove_piece(pc, to);
+ remove_piece(to);
pc = make_piece(us, PAWN);
put_piece(pc, to);
}
}
else
{
- move_piece(pc, to, from); // Put the piece back at the source square
+ move_piece(to, from); // Put the piece back at the source square
if (st->capturedPiece)
{
to = relative_square(us, kingSide ? SQ_G1 : SQ_C1);
// Remove both pieces first since squares could overlap in Chess960
- remove_piece(make_piece(us, KING), Do ? from : to);
- remove_piece(make_piece(us, ROOK), Do ? rfrom : rto);
- board[Do ? from : to] = board[Do ? rfrom : rto] = NO_PIECE; // Since remove_piece doesn't do it for us
+ remove_piece(Do ? from : to);
+ remove_piece(Do ? rfrom : rto);
+ board[Do ? from : to] = board[Do ? rfrom : rto] = NO_PIECE; // Since remove_piece doesn't do this for us
put_piece(make_piece(us, KING), Do ? to : from);
put_piece(make_piece(us, ROOK), Do ? rto : rfrom);
}
return bool(res);
}
+
/// Position::is_draw() tests whether the position is drawn by 50-move rule
/// or by repetition. It does not detect stalemates.
// Return a draw score if a position repeats once earlier but strictly
// after the root, or repeats twice before or at the root.
- if (st->repetition && st->repetition < ply)
- return true;
-
- return false;
+ return st->repetition && st->repetition < ply;
}
int repetition;
};
+
/// A list to keep track of the position states along the setup moves (from the
/// start position to the position just before the search starts). Needed by
/// 'draw by repetition' detection. Use a std::deque because pointers to
const std::string fen() const;
// Position representation
- Bitboard pieces() const;
Bitboard pieces(PieceType pt) const;
Bitboard pieces(PieceType pt1, PieceType pt2) const;
Bitboard pieces(Color c) const;
bool is_on_semiopen_file(Color c, Square s) const;
// Castling
- int castling_rights(Color c) const;
+ CastlingRights castling_rights(Color c) const;
bool can_castle(CastlingRights cr) const;
bool castling_impeded(CastlingRights cr) const;
Square castling_rook_square(CastlingRights cr) const;
// Attacks to/from a given square
Bitboard attackers_to(Square s) const;
Bitboard attackers_to(Square s, Bitboard occupied) const;
- Bitboard attacks_from(PieceType pt, Square s) const;
- template<PieceType> Bitboard attacks_from(Square s) const;
- template<PieceType> Bitboard attacks_from(Square s, Color c) const;
Bitboard slider_blockers(Bitboard sliders, Square s, Bitboard& pinners) const;
// Properties of moves
// Other helpers
void put_piece(Piece pc, Square s);
- void remove_piece(Piece pc, Square s);
- void move_piece(Piece pc, Square from, Square to);
+ void remove_piece(Square s);
+ void move_piece(Square from, Square to);
template<bool Do>
void do_castling(Color us, Square from, Square& to, Square& rfrom, Square& rto);
return sideToMove;
}
-inline bool Position::empty(Square s) const {
- return board[s] == NO_PIECE;
-}
-
inline Piece Position::piece_on(Square s) const {
+ assert(is_ok(s));
return board[s];
}
-inline Piece Position::moved_piece(Move m) const {
- return board[from_sq(m)];
+inline bool Position::empty(Square s) const {
+ return piece_on(s) == NO_PIECE;
}
-inline Bitboard Position::pieces() const {
- return byTypeBB[ALL_PIECES];
+inline Piece Position::moved_piece(Move m) const {
+ return piece_on(from_sq(m));
}
-inline Bitboard Position::pieces(PieceType pt) const {
+inline Bitboard Position::pieces(PieceType pt = ALL_PIECES) const {
return byTypeBB[pt];
}
inline Bitboard Position::pieces(PieceType pt1, PieceType pt2) const {
- return byTypeBB[pt1] | byTypeBB[pt2];
+ return pieces(pt1) | pieces(pt2);
}
inline Bitboard Position::pieces(Color c) const {
}
inline Bitboard Position::pieces(Color c, PieceType pt) const {
- return byColorBB[c] & byTypeBB[pt];
+ return pieces(c) & pieces(pt);
}
inline Bitboard Position::pieces(Color c, PieceType pt1, PieceType pt2) const {
- return byColorBB[c] & (byTypeBB[pt1] | byTypeBB[pt2]);
+ return pieces(c) & (pieces(pt1) | pieces(pt2));
}
template<PieceType Pt> inline int Position::count(Color c) const {
}
template<PieceType Pt> inline int Position::count() const {
- return pieceCount[make_piece(WHITE, Pt)] + pieceCount[make_piece(BLACK, Pt)];
+ return count<Pt>(WHITE) + count<Pt>(BLACK);
}
template<PieceType Pt> inline const Square* Position::squares(Color c) const {
template<PieceType Pt> inline Square Position::square(Color c) const {
assert(pieceCount[make_piece(c, Pt)] == 1);
- return pieceList[make_piece(c, Pt)][0];
+ return squares<Pt>(c)[0];
}
inline Square Position::ep_square() const {
return st->castlingRights & cr;
}
-inline int Position::castling_rights(Color c) const {
- return st->castlingRights & (c == WHITE ? WHITE_CASTLING : BLACK_CASTLING);
+inline CastlingRights Position::castling_rights(Color c) const {
+ return c & CastlingRights(st->castlingRights);
}
inline bool Position::castling_impeded(CastlingRights cr) const {
assert(cr == WHITE_OO || cr == WHITE_OOO || cr == BLACK_OO || cr == BLACK_OOO);
- return byTypeBB[ALL_PIECES] & castlingPath[cr];
+ return pieces() & castlingPath[cr];
}
inline Square Position::castling_rook_square(CastlingRights cr) const {
return castlingRookSquare[cr];
}
-template<PieceType Pt>
-inline Bitboard Position::attacks_from(Square s) const {
- static_assert(Pt != PAWN, "Pawn attacks need color");
-
- return Pt == BISHOP || Pt == ROOK ? attacks_bb<Pt>(s, byTypeBB[ALL_PIECES])
- : Pt == QUEEN ? attacks_from<ROOK>(s) | attacks_from<BISHOP>(s)
- : PseudoAttacks[Pt][s];
-}
-
-template<>
-inline Bitboard Position::attacks_from<PAWN>(Square s, Color c) const {
- return PawnAttacks[c][s];
-}
-
-inline Bitboard Position::attacks_from(PieceType pt, Square s) const {
- return attacks_bb(pt, s, byTypeBB[ALL_PIECES]);
-}
-
inline Bitboard Position::attackers_to(Square s) const {
- return attackers_to(s, byTypeBB[ALL_PIECES]);
+ return attackers_to(s, pieces());
}
inline Bitboard Position::checkers() const {
}
inline Value Position::non_pawn_material() const {
- return st->nonPawnMaterial[WHITE] + st->nonPawnMaterial[BLACK];
+ return non_pawn_material(WHITE) + non_pawn_material(BLACK);
}
inline int Position::game_ply() const {
}
inline bool Position::opposite_bishops() const {
- return pieceCount[W_BISHOP] == 1
- && pieceCount[B_BISHOP] == 1
+ return count<BISHOP>(WHITE) == 1
+ && count<BISHOP>(BLACK) == 1
&& opposite_colors(square<BISHOP>(WHITE), square<BISHOP>(BLACK));
}
inline void Position::put_piece(Piece pc, Square s) {
board[s] = pc;
- byTypeBB[ALL_PIECES] |= s;
- byTypeBB[type_of(pc)] |= s;
+ byTypeBB[ALL_PIECES] |= byTypeBB[type_of(pc)] |= s;
byColorBB[color_of(pc)] |= s;
index[s] = pieceCount[pc]++;
pieceList[pc][index[s]] = s;
psq += PSQT::psq[pc][s];
}
-inline void Position::remove_piece(Piece pc, Square s) {
+inline void Position::remove_piece(Square s) {
// WARNING: This is not a reversible operation. If we remove a piece in
// do_move() and then replace it in undo_move() we will put it at the end of
// the list and not in its original place, it means index[] and pieceList[]
// are not invariant to a do_move() + undo_move() sequence.
+ Piece pc = board[s];
byTypeBB[ALL_PIECES] ^= s;
byTypeBB[type_of(pc)] ^= s;
byColorBB[color_of(pc)] ^= s;
psq -= PSQT::psq[pc][s];
}
-inline void Position::move_piece(Piece pc, Square from, Square to) {
+inline void Position::move_piece(Square from, Square to) {
// index[from] is not updated and becomes stale. This works as long as index[]
// is accessed just by known occupied squares.
+ Piece pc = board[from];
Bitboard fromTo = from | to;
byTypeBB[ALL_PIECES] ^= fromTo;
byTypeBB[type_of(pc)] ^= fromTo;
#include <algorithm>
#include "types.h"
-
-Value PieceValue[PHASE_NB][PIECE_NB] = {
- { VALUE_ZERO, PawnValueMg, KnightValueMg, BishopValueMg, RookValueMg, QueenValueMg },
- { VALUE_ZERO, PawnValueEg, KnightValueEg, BishopValueEg, RookValueEg, QueenValueEg }
-};
+#include "bitboard.h"
namespace PSQT {
{ },
{ S( 3,-10), S( 3, -6), S( 10, 10), S( 19, 0), S( 16, 14), S( 19, 7), S( 7, -5), S( -5,-19) },
{ S( -9,-10), S(-15,-10), S( 11,-10), S( 15, 4), S( 32, 4), S( 22, 3), S( 5, -6), S(-22, -4) },
- { S( -8, 6), S(-23, -2), S( 6, -8), S( 20, -4), S( 40,-13), S( 17,-12), S( 4,-10), S(-12, -9) },
- { S( 13, 9), S( 0, 4), S(-13, 3), S( 1,-12), S( 11,-12), S( -2, -6), S(-13, 13), S( 5, 8) },
- { S( -5, 28), S(-12, 20), S( -7, 21), S( 22, 28), S( -8, 30), S( -5, 7), S(-15, 6), S(-18, 13) },
+ { S( -4, 6), S(-23, -2), S( 6, -8), S( 20, -4), S( 40,-13), S( 17,-12), S( 4,-10), S( -8, -9) },
+ { S( 13, 10), S( 0, 5), S(-13, 4), S( 1, -5), S( 11, -5), S( -2, -5), S(-13, 14), S( 5, 9) },
+ { S( 5, 28), S(-12, 20), S( -7, 21), S( 22, 28), S( -8, 30), S( -5, 7), S(-15, 6), S( -8, 13) },
{ S( -7, 0), S( 7,-11), S( -3, 12), S(-13, 21), S( 5, 25), S(-16, 19), S( 10, 4), S( -8, 7) }
};
Score psq[PIECE_NB][SQUARE_NB];
-// init() initializes piece-square tables: the white halves of the tables are
-// copied from Bonus[] adding the piece value, then the black halves of the
-// tables are initialized by flipping and changing the sign of the white scores.
+
+// PSQT::init() initializes piece-square tables: the white halves of the tables are
+// copied from Bonus[] and PBonus[], adding the piece value, then the black halves of
+// the tables are initialized by flipping and changing the sign of the white scores.
void init() {
- for (Piece pc = W_PAWN; pc <= W_KING; ++pc)
+ for (Piece pc : {W_PAWN, W_KNIGHT, W_BISHOP, W_ROOK, W_QUEEN, W_KING})
{
- PieceValue[MG][~pc] = PieceValue[MG][pc];
- PieceValue[EG][~pc] = PieceValue[EG][pc];
-
Score score = make_score(PieceValue[MG][pc], PieceValue[EG][pc]);
for (Square s = SQ_A1; s <= SQ_H8; ++s)
{
- File f = map_to_queenside(file_of(s));
- psq[ pc][ s] = score + (type_of(pc) == PAWN ? PBonus[rank_of(s)][file_of(s)]
- : Bonus[pc][rank_of(s)][f]);
- psq[~pc][~s] = -psq[pc][s];
+ File f = File(edge_distance(file_of(s)));
+ psq[ pc][s] = score + (type_of(pc) == PAWN ? PBonus[rank_of(s)][file_of(s)]
+ : Bonus[pc][rank_of(s)][f]);
+ psq[~pc][flip_rank(s)] = -psq[pc][s];
}
}
}
// Different node types, used as a template parameter
enum NodeType { NonPV, PV };
- constexpr uint64_t ttHitAverageWindow = 4096;
- constexpr uint64_t ttHitAverageResolution = 1024;
+ constexpr uint64_t TtHitAverageWindow = 4096;
+ constexpr uint64_t TtHitAverageResolution = 1024;
// Razor and futility margins
- constexpr int RazorMargin = 531;
+ constexpr int RazorMargin = 527;
Value futility_margin(Depth d, bool improving) {
- return Value(217 * (d - improving));
+ return Value(227 * (d - improving));
}
// Reductions lookup table, initialized at startup
Depth reduction(bool i, Depth d, int mn) {
int r = Reductions[d] * Reductions[mn];
- return (r + 511) / 1024 + (!i && r > 1007);
+ return (r + 570) / 1024 + (!i && r > 1018);
}
constexpr int futility_move_count(bool improving, Depth depth) {
- return (5 + depth * depth) * (1 + improving) / 2 - 1;
+ return (3 + depth * depth) / (2 - improving);
}
// History and stats update bonus, based on depth
int stat_bonus(Depth d) {
- return d > 15 ? -8 : 19 * d * d + 155 * d - 132;
+ return d > 15 ? 27 : 17 * d * d + 133 * d - 134;
}
// Add a small random component to draw evaluations to avoid 3fold-blindness
Value value_from_tt(Value v, int ply, int r50c);
void update_pv(Move* pv, Move move, Move* childPv);
void update_continuation_histories(Stack* ss, Piece pc, Square to, int bonus);
- void update_quiet_stats(const Position& pos, Stack* ss, Move move, int bonus);
+ void update_quiet_stats(const Position& pos, Stack* ss, Move move, int bonus, int depth);
void update_all_stats(const Position& pos, Stack* ss, Move bestMove, Value bestValue, Value beta, Square prevSq,
Move* quietsSearched, int quietCount, Move* capturesSearched, int captureCount, Depth depth);
void Search::init() {
for (int i = 1; i < MAX_MOVES; ++i)
- Reductions[i] = int((24.8 + std::log(Threads.size()) / 2) * std::log(i));
+ Reductions[i] = int((24.8 + std::log(Threads.size())) * std::log(i));
}
}
else
{
- for (Thread* th : Threads)
- {
- th->bestMoveChanges = 0;
- if (th != this)
- th->start_searching();
- }
-
- Thread::search(); // Let's start searching!
+ Threads.start_searching(); // start non-main threads
+ Thread::search(); // main thread start searching
}
// When we reach the maximum depth, we can arrive here without a raise of
Threads.stop = true;
// Wait until all threads have finished
- for (Thread* th : Threads)
- if (th != this)
- th->wait_for_search_finished();
+ Threads.wait_for_search_finished();
// When playing in 'nodes as time' mode, subtract the searched nodes from
// the available ones before exiting.
Thread* bestThread = this;
- // Check if there are threads with a better score than main thread
- if ( Options["MultiPV"] == 1
+ if ( int(Options["MultiPV"]) == 1
&& !Limits.depth
- && !(Skill(Options["Skill Level"]).enabled() || Options["UCI_LimitStrength"])
- && rootMoves[0].pv[0] != MOVE_NONE)
- {
- std::map<Move, int64_t> votes;
- Value minScore = this->rootMoves[0].score;
+ && !(Skill(Options["Skill Level"]).enabled() || int(Options["UCI_LimitStrength"]))
+ && rootMoves[0].pv[0] != MOVE_NONE)
+ bestThread = Threads.get_best_thread();
- // Find out minimum score
- for (Thread* th: Threads)
- minScore = std::min(minScore, th->rootMoves[0].score);
-
- // Vote according to score and depth, and select the best thread
- for (Thread* th : Threads)
- {
- votes[th->rootMoves[0].pv[0]] +=
- (th->rootMoves[0].score - minScore + 14) * int(th->completedDepth);
-
- if (bestThread->rootMoves[0].score >= VALUE_MATE_IN_MAX_PLY)
- {
- // Make sure we pick the shortest mate
- if (th->rootMoves[0].score > bestThread->rootMoves[0].score)
- bestThread = th;
- }
- else if ( th->rootMoves[0].score >= VALUE_MATE_IN_MAX_PLY
- || votes[th->rootMoves[0].pv[0]] > votes[bestThread->rootMoves[0].pv[0]])
- bestThread = th;
- }
- }
-
- previousScore = bestThread->rootMoves[0].score;
+ bestPreviousScore = bestThread->rootMoves[0].score;
// Send again PV info if we have a new best thread
if (bestThread != this)
if (mainThread)
{
- if (mainThread->previousScore == VALUE_INFINITE)
- for (int i=0; i<4; ++i)
+ if (mainThread->bestPreviousScore == VALUE_INFINITE)
+ for (int i = 0; i < 4; ++i)
mainThread->iterValue[i] = VALUE_ZERO;
else
- for (int i=0; i<4; ++i)
- mainThread->iterValue[i] = mainThread->previousScore;
+ for (int i = 0; i < 4; ++i)
+ mainThread->iterValue[i] = mainThread->bestPreviousScore;
}
- size_t multiPV = Options["MultiPV"];
+ std::copy(&lowPlyHistory[2][0], &lowPlyHistory.back().back() + 1, &lowPlyHistory[0][0]);
+ std::fill(&lowPlyHistory[MAX_LPH - 2][0], &lowPlyHistory.back().back() + 1, 0);
+
+ size_t multiPV = size_t(Options["MultiPV"]);
// Pick integer skill levels, but non-deterministically round up or down
// such that the average integer skill corresponds to the input floating point one.
// for match (TC 60+0.6) results spanning a wide range of k values.
PRNG rng(now());
double floatLevel = Options["UCI_LimitStrength"] ?
- clamp(std::pow((Options["UCI_Elo"] - 1346.6) / 143.4, 1 / 0.806), 0.0, 20.0) :
+ Utility::clamp(std::pow((Options["UCI_Elo"] - 1346.6) / 143.4, 1 / 0.806), 0.0, 20.0) :
double(Options["Skill Level"]);
int intLevel = int(floatLevel) +
((floatLevel - int(floatLevel)) * 1024 > rng.rand<unsigned>() % 1024 ? 1 : 0);
multiPV = std::max(multiPV, (size_t)4);
multiPV = std::min(multiPV, rootMoves.size());
- ttHitAverage = ttHitAverageWindow * ttHitAverageResolution / 2;
+ ttHitAverage = TtHitAverageWindow * TtHitAverageResolution / 2;
int ct = int(Options["Contempt"]) * PawnValueEg / 100; // From centipawns
// Reset aspiration window starting size
if (rootDepth >= 4)
{
- Value previousScore = rootMoves[pvIdx].previousScore;
- delta = Value(21 + abs(previousScore) / 256);
- alpha = std::max(previousScore - delta,-VALUE_INFINITE);
- beta = std::min(previousScore + delta, VALUE_INFINITE);
+ Value prev = rootMoves[pvIdx].previousScore;
+ delta = Value(19);
+ alpha = std::max(prev - delta,-VALUE_INFINITE);
+ beta = std::min(prev + delta, VALUE_INFINITE);
// Adjust contempt based on root move's previousScore (dynamic contempt)
- int dct = ct + (102 - ct / 2) * previousScore / (abs(previousScore) + 157);
+ int dct = ct + (110 - ct / 2) * prev / (abs(prev) + 140);
contempt = (us == WHITE ? make_score(dct, dct / 2)
: -make_score(dct, dct / 2));
&& !Threads.stop
&& !mainThread->stopOnPonderhit)
{
- double fallingEval = (332 + 6 * (mainThread->previousScore - bestValue)
- + 6 * (mainThread->iterValue[iterIdx] - bestValue)) / 704.0;
- fallingEval = clamp(fallingEval, 0.5, 1.5);
+ double fallingEval = (296 + 6 * (mainThread->bestPreviousScore - bestValue)
+ + 6 * (mainThread->iterValue[iterIdx] - bestValue)) / 725.0;
+ fallingEval = Utility::clamp(fallingEval, 0.5, 1.5);
// If the bestMove is stable over several iterations, reduce time accordingly
- timeReduction = lastBestMoveDepth + 9 < completedDepth ? 1.94 : 0.91;
- double reduction = (1.41 + mainThread->previousTimeReduction) / (2.27 * timeReduction);
+ timeReduction = lastBestMoveDepth + 10 < completedDepth ? 1.92 : 0.95;
+ double reduction = (1.47 + mainThread->previousTimeReduction) / (2.22 * timeReduction);
// Use part of the gained time from a previous stable move for the current move
for (Thread* th : Threads)
}
double bestMoveInstability = 1 + totBestMoveChanges / Threads.size();
- // Stop the search if we have only one legal move, or if available time elapsed
- if ( rootMoves.size() == 1
- || Time.elapsed() > Time.optimum() * fallingEval * reduction * bestMoveInstability)
+ double totalTime = rootMoves.size() == 1 ? 0 :
+ Time.optimum() * fallingEval * reduction * bestMoveInstability;
+
+ // Stop the search if we have exceeded the totalTime, at least 1ms search
+ if (Time.elapsed() > totalTime)
{
// If we are allowed to ponder do not stop the search now but
// keep pondering until the GUI sends "ponderhit" or "stop".
}
else if ( Threads.increaseDepth
&& !mainThread->ponder
- && Time.elapsed() > Time.optimum() * fallingEval * reduction * bestMoveInstability * 0.6)
+ && Time.elapsed() > totalTime * 0.56)
Threads.increaseDepth = false;
else
Threads.increaseDepth = true;
Key posKey;
Move ttMove, move, excludedMove, bestMove;
Depth extension, newDepth;
- Value bestValue, value, ttValue, eval, maxValue;
- bool ttHit, ttPv, inCheck, givesCheck, improving, didLMR, priorCapture;
- bool captureOrPromotion, doFullDepthSearch, moveCountPruning, ttCapture, singularLMR;
+ Value bestValue, value, ttValue, eval, maxValue, probcutBeta;
+ bool ttHit, ttPv, formerPv, givesCheck, improving, didLMR, priorCapture;
+ bool captureOrPromotion, doFullDepthSearch, moveCountPruning,
+ ttCapture, singularQuietLMR;
Piece movedPiece;
int moveCount, captureCount, quietCount;
// Step 1. Initialize node
Thread* thisThread = pos.this_thread();
- inCheck = pos.checkers();
+ ss->inCheck = pos.checkers();
priorCapture = pos.captured_piece();
Color us = pos.side_to_move();
moveCount = captureCount = quietCount = ss->moveCount = 0;
if ( Threads.stop.load(std::memory_order_relaxed)
|| pos.is_draw(ss->ply)
|| ss->ply >= MAX_PLY)
- return (ss->ply >= MAX_PLY && !inCheck) ? evaluate(pos)
- : value_draw(pos.this_thread());
+ return (ss->ply >= MAX_PLY && !ss->inCheck) ? evaluate(pos)
+ : value_draw(pos.this_thread());
// Step 3. Mate distance pruning. Even if we mate at the next move our score
// would be at best mate_in(ss->ply+1), but if alpha is already bigger because
// search to overwrite a previous full search TT value, so we use a different
// position key in case of an excluded move.
excludedMove = ss->excludedMove;
- posKey = pos.key() ^ Key(excludedMove << 16); // Isn't a very good hash
+ posKey = excludedMove == MOVE_NONE ? pos.key() : pos.key() ^ make_key(excludedMove);
tte = TT.probe(posKey, ttHit);
ttValue = ttHit ? value_from_tt(tte->value(), ss->ply, pos.rule50_count()) : VALUE_NONE;
ttMove = rootNode ? thisThread->rootMoves[thisThread->pvIdx].pv[0]
: ttHit ? tte->move() : MOVE_NONE;
ttPv = PvNode || (ttHit && tte->is_pv());
+ formerPv = ttPv && !PvNode;
+
+ if ( ttPv
+ && depth > 12
+ && ss->ply - 1 < MAX_LPH
+ && !priorCapture
+ && is_ok((ss-1)->currentMove))
+ thisThread->lowPlyHistory[ss->ply - 1][from_to((ss-1)->currentMove)] << stat_bonus(depth - 5);
+
// thisThread->ttHitAverage can be used to approximate the running average of ttHit
- thisThread->ttHitAverage = (ttHitAverageWindow - 1) * thisThread->ttHitAverage / ttHitAverageWindow
- + ttHitAverageResolution * ttHit;
+ thisThread->ttHitAverage = (TtHitAverageWindow - 1) * thisThread->ttHitAverage / TtHitAverageWindow
+ + TtHitAverageResolution * ttHit;
// At non-PV nodes we check for an early TT cutoff
if ( !PvNode
if (ttValue >= beta)
{
if (!pos.capture_or_promotion(ttMove))
- update_quiet_stats(pos, ss, ttMove, stat_bonus(depth));
+ update_quiet_stats(pos, ss, ttMove, stat_bonus(depth), depth);
// Extra penalty for early quiet moves of the previous ply
if ((ss-1)->moveCount <= 2 && !priorCapture)
int drawScore = TB::UseRule50 ? 1 : 0;
- value = wdl < -drawScore ? -VALUE_MATE + MAX_PLY + ss->ply + 1
- : wdl > drawScore ? VALUE_MATE - MAX_PLY - ss->ply - 1
- : VALUE_DRAW + 2 * wdl * drawScore;
+ // use the range VALUE_MATE_IN_MAX_PLY to VALUE_TB_WIN_IN_MAX_PLY to score
+ value = wdl < -drawScore ? VALUE_MATED_IN_MAX_PLY + ss->ply + 1
+ : wdl > drawScore ? VALUE_MATE_IN_MAX_PLY - ss->ply - 1
+ : VALUE_DRAW + 2 * wdl * drawScore;
Bound b = wdl < -drawScore ? BOUND_UPPER
: wdl > drawScore ? BOUND_LOWER : BOUND_EXACT;
}
}
+ CapturePieceToHistory& captureHistory = thisThread->captureHistory;
+
// Step 6. Static evaluation of the position
- if (inCheck)
+ if (ss->inCheck)
{
+ // Skip early pruning when in check
ss->staticEval = eval = VALUE_NONE;
improving = false;
- goto moves_loop; // Skip early pruning when in check
+ goto moves_loop;
}
else if (ttHit)
{
ss->staticEval = eval = evaluate(pos) + bonus;
}
else
- ss->staticEval = eval = -(ss-1)->staticEval + 2 * Eval::Tempo;
+ ss->staticEval = eval = -(ss-1)->staticEval + 2 * Tempo;
tte->save(posKey, VALUE_NONE, ttPv, BOUND_NONE, DEPTH_NONE, MOVE_NONE, eval);
}
// Step 7. Razoring (~1 Elo)
if ( !rootNode // The required rootNode PV handling is not available in qsearch
- && depth < 2
+ && depth == 1
&& eval <= alpha - RazorMargin)
return qsearch<NT>(pos, ss, alpha, beta);
- improving = (ss-2)->staticEval == VALUE_NONE ? (ss->staticEval >= (ss-4)->staticEval
- || (ss-4)->staticEval == VALUE_NONE) : ss->staticEval >= (ss-2)->staticEval;
+ improving = (ss-2)->staticEval == VALUE_NONE ? (ss->staticEval > (ss-4)->staticEval
+ || (ss-4)->staticEval == VALUE_NONE) : ss->staticEval > (ss-2)->staticEval;
// Step 8. Futility pruning: child node (~50 Elo)
if ( !PvNode
// Step 9. Null move search with verification search (~40 Elo)
if ( !PvNode
&& (ss-1)->currentMove != MOVE_NULL
- && (ss-1)->statScore < 23397
+ && (ss-1)->statScore < 23824
&& eval >= beta
&& eval >= ss->staticEval
- && ss->staticEval >= beta - 32 * depth + 292 - improving * 30
+ && ss->staticEval >= beta - 33 * depth - 33 * improving + 112 * ttPv + 311
&& !excludedMove
&& pos.non_pawn_material(us)
&& (ss->ply >= thisThread->nmpMinPly || us != thisThread->nmpColor))
assert(eval - beta >= 0);
// Null move dynamic reduction based on depth and value
- Depth R = (854 + 68 * depth) / 258 + std::min(int(eval - beta) / 192, 3);
+ Depth R = (737 + 77 * depth) / 246 + std::min(int(eval - beta) / 192, 3);
ss->currentMove = MOVE_NULL;
ss->continuationHistory = &thisThread->continuationHistory[0][0][NO_PIECE][0];
if (nullValue >= beta)
{
- // Do not return unproven mate scores
- if (nullValue >= VALUE_MATE_IN_MAX_PLY)
+ // Do not return unproven mate or TB scores
+ if (nullValue >= VALUE_TB_WIN_IN_MAX_PLY)
nullValue = beta;
if (thisThread->nmpMinPly || (abs(beta) < VALUE_KNOWN_WIN && depth < 13))
}
}
+ probcutBeta = beta + 176 - 49 * improving;
+
// Step 10. ProbCut (~10 Elo)
// If we have a good enough capture and a reduced search returns a value
// much above beta, we can (almost) safely prune the previous move.
if ( !PvNode
- && depth >= 5
- && abs(beta) < VALUE_MATE_IN_MAX_PLY)
+ && depth > 4
+ && abs(beta) < VALUE_TB_WIN_IN_MAX_PLY
+ && !( ttHit
+ && tte->depth() >= depth - 3
+ && ttValue != VALUE_NONE
+ && ttValue < probcutBeta))
{
- Value raisedBeta = std::min(beta + 189 - 45 * improving, VALUE_INFINITE);
- MovePicker mp(pos, ttMove, raisedBeta - ss->staticEval, &thisThread->captureHistory);
+ if ( ttHit
+ && tte->depth() >= depth - 3
+ && ttValue != VALUE_NONE
+ && ttValue >= probcutBeta
+ && ttMove
+ && pos.capture_or_promotion(ttMove))
+ return probcutBeta;
+
+ assert(probcutBeta < VALUE_INFINITE);
+ MovePicker mp(pos, ttMove, probcutBeta - ss->staticEval, &captureHistory);
int probCutCount = 0;
- while ( (move = mp.next_move()) != MOVE_NONE
+ while ( (move = mp.next_move()) != MOVE_NONE
&& probCutCount < 2 + 2 * cutNode)
if (move != excludedMove && pos.legal(move))
{
probCutCount++;
ss->currentMove = move;
- ss->continuationHistory = &thisThread->continuationHistory[inCheck]
+ ss->continuationHistory = &thisThread->continuationHistory[ss->inCheck]
[captureOrPromotion]
[pos.moved_piece(move)]
[to_sq(move)];
pos.do_move(move, st);
// Perform a preliminary qsearch to verify that the move holds
- value = -qsearch<NonPV>(pos, ss+1, -raisedBeta, -raisedBeta+1);
+ value = -qsearch<NonPV>(pos, ss+1, -probcutBeta, -probcutBeta+1);
// If the qsearch held, perform the regular search
- if (value >= raisedBeta)
- value = -search<NonPV>(pos, ss+1, -raisedBeta, -raisedBeta+1, depth - 4, !cutNode);
+ if (value >= probcutBeta)
+ value = -search<NonPV>(pos, ss+1, -probcutBeta, -probcutBeta+1, depth - 4, !cutNode);
pos.undo_move(move);
- if (value >= raisedBeta)
+ if (value >= probcutBeta)
+ {
+ if ( !(ttHit
+ && tte->depth() >= depth - 3
+ && ttValue != VALUE_NONE))
+ tte->save(posKey, value_to_tt(value, ss->ply), ttPv,
+ BOUND_LOWER,
+ depth - 3, move, ss->staticEval);
return value;
+ }
}
}
Move countermove = thisThread->counterMoves[pos.piece_on(prevSq)][prevSq];
MovePicker mp(pos, ttMove, depth, &thisThread->mainHistory,
- &thisThread->captureHistory,
+ &thisThread->lowPlyHistory,
+ &captureHistory,
contHist,
countermove,
- ss->killers);
+ ss->killers,
+ ss->ply);
value = bestValue;
- singularLMR = moveCountPruning = false;
+ singularQuietLMR = moveCountPruning = false;
ttCapture = ttMove && pos.capture_or_promotion(ttMove);
// Mark this node as being searched
// Step 13. Pruning at shallow depth (~200 Elo)
if ( !rootNode
&& pos.non_pawn_material(us)
- && bestValue > VALUE_MATED_IN_MAX_PLY)
+ && bestValue > VALUE_TB_LOSS_IN_MAX_PLY)
{
// Skip quiet moves if movecount exceeds our FutilityMoveCount threshold
moveCountPruning = moveCount >= futility_move_count(improving, depth);
+ // Reduced depth of the next LMR search
+ int lmrDepth = std::max(newDepth - reduction(improving, depth, moveCount), 0);
+
if ( !captureOrPromotion
&& !givesCheck)
{
- // Reduced depth of the next LMR search
- int lmrDepth = std::max(newDepth - reduction(improving, depth, moveCount), 0);
-
// Countermoves based pruning (~20 Elo)
if ( lmrDepth < 4 + ((ss-1)->statScore > 0 || (ss-1)->moveCount == 1)
&& (*contHist[0])[movedPiece][to_sq(move)] < CounterMovePruneThreshold
// Futility pruning: parent node (~5 Elo)
if ( lmrDepth < 6
- && !inCheck
- && ss->staticEval + 235 + 172 * lmrDepth <= alpha
- && thisThread->mainHistory[us][from_to(move)]
- + (*contHist[0])[movedPiece][to_sq(move)]
+ && !ss->inCheck
+ && ss->staticEval + 284 + 188 * lmrDepth <= alpha
+ && (*contHist[0])[movedPiece][to_sq(move)]
+ (*contHist[1])[movedPiece][to_sq(move)]
- + (*contHist[3])[movedPiece][to_sq(move)] < 25000)
+ + (*contHist[3])[movedPiece][to_sq(move)]
+ + (*contHist[5])[movedPiece][to_sq(move)] / 2 < 28388)
continue;
// Prune moves with negative SEE (~20 Elo)
- if (!pos.see_ge(move, Value(-(32 - std::min(lmrDepth, 18)) * lmrDepth * lmrDepth)))
+ if (!pos.see_ge(move, Value(-(29 - std::min(lmrDepth, 17)) * lmrDepth * lmrDepth)))
continue;
}
- else if (!pos.see_ge(move, Value(-194) * depth)) // (~25 Elo)
+ else
+ {
+ // Capture history based pruning when the move doesn't give check
+ if ( !givesCheck
+ && lmrDepth < 1
+ && captureHistory[movedPiece][to_sq(move)][type_of(pos.piece_on(to_sq(move)))] < 0)
+ continue;
+
+ // Futility pruning for captures
+ if ( !givesCheck
+ && lmrDepth < 6
+ && !(PvNode && abs(bestValue) < 2)
+ && PieceValue[MG][type_of(movedPiece)] >= PieceValue[MG][type_of(pos.piece_on(to_sq(move)))]
+ && !ss->inCheck
+ && ss->staticEval + 267 + 391 * lmrDepth
+ + PieceValue[MG][type_of(pos.piece_on(to_sq(move)))] <= alpha)
+ continue;
+
+ // See based pruning
+ if (!pos.see_ge(move, Value(-202) * depth)) // (~25 Elo)
continue;
+ }
}
// Step 14. Extensions (~75 Elo)
// search of (alpha-s, beta-s), and just one fails high on (alpha, beta),
// then that move is singular and should be extended. To verify this we do
// a reduced search on all the other moves but the ttMove and if the
- // result is lower than ttValue minus a margin then we will extend the ttMove.
+ // result is lower than ttValue minus a margin, then we will extend the ttMove.
if ( depth >= 6
&& move == ttMove
&& !rootNode
&& tte->depth() >= depth - 3
&& pos.legal(move))
{
- Value singularBeta = ttValue - 2 * depth;
- Depth halfDepth = depth / 2;
+ Value singularBeta = ttValue - ((formerPv + 4) * depth) / 2;
+ Depth singularDepth = (depth - 1 + 3 * formerPv) / 2;
ss->excludedMove = move;
- value = search<NonPV>(pos, ss, singularBeta - 1, singularBeta, halfDepth, cutNode);
+ value = search<NonPV>(pos, ss, singularBeta - 1, singularBeta, singularDepth, cutNode);
ss->excludedMove = MOVE_NONE;
if (value < singularBeta)
{
extension = 1;
- singularLMR = true;
+ singularQuietLMR = !ttCapture;
}
// Multi-cut pruning
// a soft bound.
else if (singularBeta >= beta)
return singularBeta;
+
+ // If the eval of ttMove is greater than beta we try also if there is another
+ // move that pushes it over beta, if so also produce a cutoff.
+ else if (ttValue >= beta)
+ {
+ ss->excludedMove = move;
+ value = search<NonPV>(pos, ss, beta - 1, beta, (depth + 3) / 2, cutNode);
+ ss->excludedMove = MOVE_NONE;
+
+ if (value >= beta)
+ return beta;
+ }
}
// Check extension (~2 Elo)
// Update the current move (this must be done after singular extension search)
ss->currentMove = move;
- ss->continuationHistory = &thisThread->continuationHistory[inCheck]
+ ss->continuationHistory = &thisThread->continuationHistory[ss->inCheck]
[captureOrPromotion]
[movedPiece]
[to_sq(move)];
// Step 16. Reduced depth search (LMR, ~200 Elo). If the move fails high it will be
// re-searched at full depth.
if ( depth >= 3
- && moveCount > 1 + rootNode + (rootNode && bestValue < alpha)
+ && moveCount > 1 + 2 * rootNode
&& (!rootNode || thisThread->best_move_count(move) == 0)
&& ( !captureOrPromotion
|| moveCountPruning
|| ss->staticEval + PieceValue[EG][pos.captured_piece()] <= alpha
|| cutNode
- || thisThread->ttHitAverage < 375 * ttHitAverageResolution * ttHitAverageWindow / 1024))
+ || thisThread->ttHitAverage < 415 * TtHitAverageResolution * TtHitAverageWindow / 1024))
{
Depth r = reduction(improving, depth, moveCount);
+ // Decrease reduction at non-check cut nodes for second move at low depths
+ if ( cutNode
+ && depth <= 10
+ && moveCount <= 2
+ && !ss->inCheck)
+ r--;
+
// Decrease reduction if the ttHit running average is large
- if (thisThread->ttHitAverage > 500 * ttHitAverageResolution * ttHitAverageWindow / 1024)
+ if (thisThread->ttHitAverage > 473 * TtHitAverageResolution * TtHitAverageWindow / 1024)
r--;
- // Reduction if other threads are searching this position.
+ // Reduction if other threads are searching this position
if (th.marked())
r++;
if (ttPv)
r -= 2;
+ if (moveCountPruning && !formerPv)
+ r++;
+
// Decrease reduction if opponent's move count is high (~5 Elo)
- if ((ss-1)->moveCount > 14)
+ if ((ss-1)->moveCount > 13)
r--;
// Decrease reduction if ttMove has been singularly extended (~3 Elo)
- if (singularLMR)
- r -= 2;
+ if (singularQuietLMR)
+ r -= 1 + formerPv;
if (!captureOrPromotion)
{
// hence break make_move(). (~2 Elo)
else if ( type_of(move) == NORMAL
&& !pos.see_ge(reverse_move(move)))
- r -= 2;
+ r -= 2 + ttPv - (type_of(movedPiece) == PAWN);
ss->statScore = thisThread->mainHistory[us][from_to(move)]
+ (*contHist[0])[movedPiece][to_sq(move)]
+ (*contHist[1])[movedPiece][to_sq(move)]
+ (*contHist[3])[movedPiece][to_sq(move)]
- - 4926;
-
- // Reset statScore to zero if negative and most stats shows >= 0
- if ( ss->statScore < 0
- && (*contHist[0])[movedPiece][to_sq(move)] >= 0
- && (*contHist[1])[movedPiece][to_sq(move)] >= 0
- && thisThread->mainHistory[us][from_to(move)] >= 0)
- ss->statScore = 0;
+ - 4826;
// Decrease/increase reduction by comparing opponent's stat score (~10 Elo)
- if (ss->statScore >= -102 && (ss-1)->statScore < -114)
+ if (ss->statScore >= -100 && (ss-1)->statScore < -112)
r--;
- else if ((ss-1)->statScore >= -116 && ss->statScore < -154)
+ else if ((ss-1)->statScore >= -125 && ss->statScore < -138)
r++;
// Decrease/increase reduction for moves with a good/bad history (~30 Elo)
- r -= ss->statScore / 16384;
+ r -= ss->statScore / 14615;
+ }
+ else
+ {
+ // Increase reduction for captures/promotions if late move and at low depth
+ if (depth < 8 && moveCount > 2)
+ r++;
+
+ // Unless giving check, this capture is likely bad
+ if ( !givesCheck
+ && ss->staticEval + PieceValue[EG][pos.captured_piece()] + 211 * depth <= alpha)
+ r++;
}
- // Increase reduction for captures/promotions if late move and at low depth
- else if (depth < 8 && moveCount > 2)
- r++;
-
- Depth d = clamp(newDepth - r, 1, newDepth);
+ Depth d = Utility::clamp(newDepth - r, 1, newDepth);
value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, d, true);
- doFullDepthSearch = (value > alpha && d != newDepth), didLMR = true;
+ doFullDepthSearch = value > alpha && d != newDepth;
+
+ didLMR = true;
}
else
- doFullDepthSearch = !PvNode || moveCount > 1, didLMR = false;
+ {
+ doFullDepthSearch = !PvNode || moveCount > 1;
+
+ didLMR = false;
+ }
// Step 17. Full depth search when LMR is skipped or fails high
if (doFullDepthSearch)
rm.pv.push_back(*m);
// We record how often the best move has been changed in each
- // iteration. This information is used for time management: When
+ // iteration. This information is used for time management: when
// the best move changes frequently, we allocate some more time.
if (moveCount > 1)
++thisThread->bestMoveChanges;
// must be a mate or a stalemate. If we are in a singular extension search then
// return a fail low score.
- assert(moveCount || !inCheck || excludedMove || !MoveList<LEGAL>(pos).size());
+ assert(moveCount || !ss->inCheck || excludedMove || !MoveList<LEGAL>(pos).size());
if (!moveCount)
bestValue = excludedMove ? alpha
- : inCheck ? mated_in(ss->ply) : VALUE_DRAW;
+ : ss->inCheck ? mated_in(ss->ply) : VALUE_DRAW;
else if (bestMove)
update_all_stats(pos, ss, bestMove, bestValue, beta, prevSq,
if (PvNode)
bestValue = std::min(bestValue, maxValue);
- if (!excludedMove)
+ if (!excludedMove && !(rootNode && thisThread->pvIdx))
tte->save(posKey, value_to_tt(bestValue, ss->ply), ttPv,
bestValue >= beta ? BOUND_LOWER :
PvNode && bestMove ? BOUND_EXACT : BOUND_UPPER,
Move ttMove, move, bestMove;
Depth ttDepth;
Value bestValue, value, ttValue, futilityValue, futilityBase, oldAlpha;
- bool ttHit, pvHit, inCheck, givesCheck, captureOrPromotion, evasionPrunable;
+ bool ttHit, pvHit, givesCheck, captureOrPromotion;
int moveCount;
if (PvNode)
Thread* thisThread = pos.this_thread();
(ss+1)->ply = ss->ply + 1;
bestMove = MOVE_NONE;
- inCheck = pos.checkers();
+ ss->inCheck = pos.checkers();
moveCount = 0;
// Check for an immediate draw or maximum ply reached
if ( pos.is_draw(ss->ply)
|| ss->ply >= MAX_PLY)
- return (ss->ply >= MAX_PLY && !inCheck) ? evaluate(pos) : VALUE_DRAW;
+ return (ss->ply >= MAX_PLY && !ss->inCheck) ? evaluate(pos) : VALUE_DRAW;
assert(0 <= ss->ply && ss->ply < MAX_PLY);
// Decide whether or not to include checks: this fixes also the type of
// TT entry depth that we are going to use. Note that in qsearch we use
// only two types of depth in TT: DEPTH_QS_CHECKS or DEPTH_QS_NO_CHECKS.
- ttDepth = inCheck || depth >= DEPTH_QS_CHECKS ? DEPTH_QS_CHECKS
+ ttDepth = ss->inCheck || depth >= DEPTH_QS_CHECKS ? DEPTH_QS_CHECKS
: DEPTH_QS_NO_CHECKS;
// Transposition table lookup
posKey = pos.key();
return ttValue;
// Evaluate the position statically
- if (inCheck)
+ if (ss->inCheck)
{
ss->staticEval = VALUE_NONE;
bestValue = futilityBase = -VALUE_INFINITE;
else
ss->staticEval = bestValue =
(ss-1)->currentMove != MOVE_NULL ? evaluate(pos)
- : -(ss-1)->staticEval + 2 * Eval::Tempo;
+ : -(ss-1)->staticEval + 2 * Tempo;
// Stand pat. Return immediately if static value is at least beta
if (bestValue >= beta)
{
if (!ttHit)
- tte->save(posKey, value_to_tt(bestValue, ss->ply), pvHit, BOUND_LOWER,
+ tte->save(posKey, value_to_tt(bestValue, ss->ply), false, BOUND_LOWER,
DEPTH_NONE, MOVE_NONE, ss->staticEval);
return bestValue;
if (PvNode && bestValue > alpha)
alpha = bestValue;
- futilityBase = bestValue + 154;
+ futilityBase = bestValue + 141;
}
const PieceToHistory* contHist[] = { (ss-1)->continuationHistory, (ss-2)->continuationHistory,
// Initialize a MovePicker object for the current position, and prepare
// to search the moves. Because the depth is <= 0 here, only captures,
- // queen promotions and checks (only if depth >= DEPTH_QS_CHECKS) will
- // be generated.
+ // queen and checking knight promotions, and other checks(only if depth >= DEPTH_QS_CHECKS)
+ // will be generated.
MovePicker mp(pos, ttMove, depth, &thisThread->mainHistory,
&thisThread->captureHistory,
contHist,
moveCount++;
// Futility pruning
- if ( !inCheck
+ if ( !ss->inCheck
&& !givesCheck
&& futilityBase > -VALUE_KNOWN_WIN
&& !pos.advanced_pawn_push(move))
}
}
- // Detect non-capture evasions that are candidates to be pruned
- evasionPrunable = inCheck
- && (depth != 0 || moveCount > 2)
- && bestValue > VALUE_MATED_IN_MAX_PLY
- && !pos.capture(move);
-
- // Don't search moves with negative SEE values
- if ( (!inCheck || evasionPrunable) && !pos.see_ge(move))
+ // Do not search moves with negative SEE values
+ if ( !ss->inCheck && !pos.see_ge(move))
continue;
// Speculative prefetch as early as possible
}
ss->currentMove = move;
- ss->continuationHistory = &thisThread->continuationHistory[inCheck]
+ ss->continuationHistory = &thisThread->continuationHistory[ss->inCheck]
[captureOrPromotion]
[pos.moved_piece(move)]
[to_sq(move)];
}
}
- // All legal moves have been searched. A special case: If we're in check
+ // All legal moves have been searched. A special case: if we're in check
// and no legal moves were found, it is checkmate.
- if (inCheck && bestValue == -VALUE_INFINITE)
+ if (ss->inCheck && bestValue == -VALUE_INFINITE)
return mated_in(ss->ply); // Plies to mate from the root
tte->save(posKey, value_to_tt(bestValue, ss->ply), pvHit,
}
- // value_to_tt() adjusts a mate score from "plies to mate from the root" to
- // "plies to mate from the current position". Non-mate scores are unchanged.
+ // value_to_tt() adjusts a mate or TB score from "plies to mate from the root" to
+ // "plies to mate from the current position". Standard scores are unchanged.
// The function is called before storing a value in the transposition table.
Value value_to_tt(Value v, int ply) {
assert(v != VALUE_NONE);
- return v >= VALUE_MATE_IN_MAX_PLY ? v + ply
- : v <= VALUE_MATED_IN_MAX_PLY ? v - ply : v;
+ return v >= VALUE_TB_WIN_IN_MAX_PLY ? v + ply
+ : v <= VALUE_TB_LOSS_IN_MAX_PLY ? v - ply : v;
}
- // value_from_tt() is the inverse of value_to_tt(): It adjusts a mate score
- // from the transposition table (which refers to the plies to mate/be mated
- // from current position) to "plies to mate/be mated from the root".
+ // value_from_tt() is the inverse of value_to_tt(): it adjusts a mate or TB score
+ // from the transposition table (which refers to the plies to mate/be mated from
+ // current position) to "plies to mate/be mated (TB win/loss) from the root". However,
+ // for mate scores, to avoid potentially false mate scores related to the 50 moves rule
+ // and the graph history interaction, we return an optimal TB score instead.
Value value_from_tt(Value v, int ply, int r50c) {
- return v == VALUE_NONE ? VALUE_NONE
- : v >= VALUE_MATE_IN_MAX_PLY ? VALUE_MATE - v > 99 - r50c ? VALUE_MATE_IN_MAX_PLY : v - ply
- : v <= VALUE_MATED_IN_MAX_PLY ? VALUE_MATE + v > 99 - r50c ? VALUE_MATED_IN_MAX_PLY : v + ply : v;
+ if (v == VALUE_NONE)
+ return VALUE_NONE;
+
+ if (v >= VALUE_TB_WIN_IN_MAX_PLY) // TB win or better
+ {
+ if (v >= VALUE_MATE_IN_MAX_PLY && VALUE_MATE - v > 99 - r50c)
+ return VALUE_MATE_IN_MAX_PLY - 1; // do not return a potentially false mate score
+
+ return v - ply;
+ }
+
+ if (v <= VALUE_TB_LOSS_IN_MAX_PLY) // TB loss or worse
+ {
+ if (v <= VALUE_MATED_IN_MAX_PLY && VALUE_MATE + v > 99 - r50c)
+ return VALUE_MATED_IN_MAX_PLY + 1; // do not return a potentially false mate score
+
+ return v + ply;
+ }
+
+ return v;
}
if (!pos.capture_or_promotion(bestMove))
{
- update_quiet_stats(pos, ss, bestMove, bonus2);
+ update_quiet_stats(pos, ss, bestMove, bonus2, depth);
// Decrease all the non-best quiet moves
for (int i = 0; i < quietCount; ++i)
// update_continuation_histories() updates histories of the move pairs formed
- // by moves at ply -1, -2, and -4 with current move.
+ // by moves at ply -1, -2, -4, and -6 with current move.
void update_continuation_histories(Stack* ss, Piece pc, Square to, int bonus) {
for (int i : {1, 2, 4, 6})
+ {
+ if (ss->inCheck && i > 2)
+ break;
if (is_ok((ss-i)->currentMove))
(*(ss-i)->continuationHistory)[pc][to] << bonus;
+ }
}
// update_quiet_stats() updates move sorting heuristics
- void update_quiet_stats(const Position& pos, Stack* ss, Move move, int bonus) {
+ void update_quiet_stats(const Position& pos, Stack* ss, Move move, int bonus, int depth) {
if (ss->killers[0] != move)
{
Square prevSq = to_sq((ss-1)->currentMove);
thisThread->counterMoves[pos.piece_on(prevSq)][prevSq] = move;
}
+
+ if (depth > 11 && ss->ply < MAX_LPH)
+ thisThread->lowPlyHistory[ss->ply][from_to(move)] << stat_bonus(depth - 6);
}
// When playing with strength handicap, choose best move among a set of RootMoves
} // namespace
+
/// MainThread::check_time() is used to print debug info and, more importantly,
/// to detect when we are out of available time and thus stop the search.
Depth d = updated ? depth : depth - 1;
Value v = updated ? rootMoves[i].score : rootMoves[i].previousScore;
- bool tb = TB::RootInTB && abs(v) < VALUE_MATE - MAX_PLY;
+ bool tb = TB::RootInTB && abs(v) < VALUE_MATE_IN_MAX_PLY;
v = tb ? rootMoves[i].tbScore : v;
if (ss.rdbuf()->in_avail()) // Not at first line
<< " multipv " << i + 1
<< " score " << UCI::value(v);
+ if (Options["UCI_ShowWDL"])
+ ss << UCI::wdl(v, pos.game_ply());
+
if (!tb && i == pvIdx)
ss << (v >= beta ? " lowerbound" : v <= alpha ? " upperbound" : "");
Value staticEval;
int statScore;
int moveCount;
+ bool inCheck;
};
}
bool use_time_management() const {
- return !(mate | movetime | depth | nodes | perft | infinite);
+ return time[WHITE] || time[BLACK];
}
std::vector<Move> searchmoves;
constexpr int TBPIECES = 7; // Max number of supported pieces
enum { BigEndian, LittleEndian };
-enum TBType { KEY, WDL, DTZ }; // Used as template parameter
+enum TBType { WDL, DTZ }; // Used as template parameter
// Each table has a set of flags: all of them refer to DTZ tables, the last one to WDL tables
enum TBFlag { STM = 1, Mapped = 2, WinPlies = 4, LossPlies = 8, Wide = 16, SingleValue = 128 };
inline WDLScore operator-(WDLScore d) { return WDLScore(-int(d)); }
-inline Square operator^=(Square& s, int i) { return s = Square(int(s) ^ i); }
inline Square operator^(Square s, int i) { return Square(int(s) ^ i); }
const std::string PieceToChar = " PNBRQK pnbrqk";
// at init time, accessed at probe time.
class TBTables {
- typedef std::tuple<Key, TBTable<WDL>*, TBTable<DTZ>*> Entry;
+ struct Entry
+ {
+ Key key;
+ TBTable<WDL>* wdl;
+ TBTable<DTZ>* dtz;
+
+ template <TBType Type>
+ TBTable<Type>* get() const {
+ return (TBTable<Type>*)(Type == WDL ? (void*)wdl : (void*)dtz);
+ }
+ };
static constexpr int Size = 1 << 12; // 4K table, indexed by key's 12 lsb
static constexpr int Overflow = 1; // Number of elements allowed to map to the last bucket
void insert(Key key, TBTable<WDL>* wdl, TBTable<DTZ>* dtz) {
uint32_t homeBucket = (uint32_t)key & (Size - 1);
- Entry entry = std::make_tuple(key, wdl, dtz);
+ Entry entry{ key, wdl, dtz };
// Ensure last element is empty to avoid overflow when looking up
for (uint32_t bucket = homeBucket; bucket < Size + Overflow - 1; ++bucket) {
- Key otherKey = std::get<KEY>(hashTable[bucket]);
- if (otherKey == key || !std::get<WDL>(hashTable[bucket])) {
+ Key otherKey = hashTable[bucket].key;
+ if (otherKey == key || !hashTable[bucket].get<WDL>()) {
hashTable[bucket] = entry;
return;
}
// insert here and search for a new spot for the other element instead.
uint32_t otherHomeBucket = (uint32_t)otherKey & (Size - 1);
if (otherHomeBucket > homeBucket) {
- swap(entry, hashTable[bucket]);
+ std::swap(entry, hashTable[bucket]);
key = otherKey;
homeBucket = otherHomeBucket;
}
template<TBType Type>
TBTable<Type>* get(Key key) {
for (const Entry* entry = &hashTable[(uint32_t)key & (Size - 1)]; ; ++entry) {
- if (std::get<KEY>(*entry) == key || !std::get<Type>(*entry))
- return std::get<Type>(*entry);
+ if (entry->key == key || !entry->get<Type>())
+ return entry->get<Type>();
}
}
// I(k) = k * d->span + d->span / 2 (1)
// First step is to get the 'k' of the I(k) nearest to our idx, using definition (1)
- uint32_t k = idx / d->span;
+ uint32_t k = uint32_t(idx / d->span);
// Then we read the corresponding SparseIndex[] entry
uint32_t block = number<uint32_t, LittleEndian>(&d->sparseIndex[k].block);
// All the symbols of a given length are consecutive integers (numerical
// sequence property), so we can compute the offset of our symbol of
// length len, stored at the beginning of buf64.
- sym = (buf64 - d->base64[len]) >> (64 - len - d->minSymLen);
+ sym = Sym((buf64 - d->base64[len]) >> (64 - len - d->minSymLen));
// Now add the value of the lowest symbol of length len to get our symbol
sym += number<Sym, LittleEndian>(&d->lowestSym[len]);
std::swap(squares[0], *std::max_element(squares, squares + leadPawnsCnt, pawns_comp));
- tbFile = map_to_queenside(file_of(squares[0]));
+ tbFile = File(edge_distance(file_of(squares[0])));
}
// DTZ tables are one-sided, i.e. they store positions only for white to
// the triangle A1-D1-D4.
if (file_of(squares[0]) > FILE_D)
for (int i = 0; i < size; ++i)
- squares[i] ^= 7; // Horizontal flip: SQ_H1 -> SQ_A1
+ squares[i] = flip_file(squares[i]);
// Encode leading pawns starting with the one with minimum MapPawns[] and
// proceeding in ascending order.
// piece is below RANK_5.
if (rank_of(squares[0]) > RANK_4)
for (int i = 0; i < size; ++i)
- squares[i] ^= SQ_A8; // Vertical flip: SQ_A8 -> SQ_A1
+ squares[i] = flip_rank(squares[i]);
// Look for the first piece of the leading group not on the A1-D4 diagonal
// and ensure it is mapped below the diagonal.
if (!off_A1H8(squares[i]))
continue;
- if (off_A1H8(squares[i]) > 0) // A1-H8 diagonal flip: SQ_A3 -> SQ_C3
+ if (off_A1H8(squares[i]) > 0) // A1-H8 diagonal flip: SQ_A3 -> SQ_C1
for (int j = i; j < size; ++j)
squares[j] = Square(((squares[j] >> 3) | (squares[j] << 3)) & 63);
break;
d->sizeofBlock = 1ULL << *data++;
d->span = 1ULL << *data++;
- d->sparseIndexSize = (tbSize + d->span - 1) / d->span; // Round up
+ d->sparseIndexSize = size_t((tbSize + d->span - 1) / d->span); // Round up
auto padding = number<uint8_t, LittleEndian>(data++);
d->blocksNum = number<uint32_t, LittleEndian>(data); data += sizeof(uint32_t);
d->blockLengthSize = d->blocksNum + padding; // Padded to ensure SparseIndex[]
auto moveList = MoveList<LEGAL>(pos);
size_t totalCount = moveList.size(), moveCount = 0;
- for (const Move& move : moveList)
+ for (const Move move : moveList)
{
if ( !pos.capture(move)
&& (!CheckZeroingMoves || type_of(pos.moved_piece(move)) != PAWN))
if (leadPawnsCnt == 1)
{
MapPawns[sq] = availableSquares--;
- MapPawns[sq ^ 7] = availableSquares--; // Horizontal flip
+ MapPawns[flip_file(sq)] = availableSquares--;
}
LeadPawnIdx[leadPawnsCnt][sq] = idx;
idx += Binomial[leadPawnsCnt - 1][MapPawns[sq]];
LeadPawnsSize[leadPawnsCnt][f] = idx;
}
- // Add entries in TB tables if the corresponding ".rtbw" file exsists
+ // Add entries in TB tables if the corresponding ".rtbw" file exists
for (PieceType p1 = PAWN; p1 < KING; ++p1) {
TBTables.add({KING, p1, KING});
StateInfo st;
int minDTZ = 0xFFFF;
- for (const Move& move : MoveList<LEGAL>(pos))
+ for (const Move move : MoveList<LEGAL>(pos))
{
bool zeroing = pos.capture(move) || type_of(pos.moved_piece(move)) == PAWN;
stdThread.join();
}
+
/// Thread::bestMoveCount(Move move) return best move counter for the given root move
-int Thread::best_move_count(Move move) {
+int Thread::best_move_count(Move move) const {
auto rm = std::find(rootMoves.begin() + pvIdx,
rootMoves.begin() + pvLast, move);
return rm != rootMoves.begin() + pvLast ? rm->bestMoveCount : 0;
}
+
/// Thread::clear() reset histories, usually before a new game
void Thread::clear() {
counterMoves.fill(MOVE_NONE);
mainHistory.fill(0);
+ lowPlyHistory.fill(0);
captureHistory.fill(0);
for (bool inCheck : { false, true })
- for (StatsType c : { NoCaptures, Captures })
- for (auto& to : continuationHistory[inCheck][c])
- for (auto& h : to)
- h->fill(0);
-
- for (bool inCheck : { false, true })
- for (StatsType c : { NoCaptures, Captures })
- continuationHistory[inCheck][c][NO_PIECE][0]->fill(Search::CounterMovePruneThreshold - 1);
+ for (StatsType c : { NoCaptures, Captures })
+ {
+ for (auto& to : continuationHistory[inCheck][c])
+ for (auto& h : to)
+ h->fill(0);
+ continuationHistory[inCheck][c][NO_PIECE][0]->fill(Search::CounterMovePruneThreshold - 1);
+ }
}
+
/// Thread::start_searching() wakes up the thread that will start the search
void Thread::start_searching() {
clear();
// Reallocate the hash with the new threadpool size
- TT.resize(Options["Hash"]);
+ TT.resize(size_t(Options["Hash"]));
// Init thread number dependent search params.
Search::init();
}
}
-/// ThreadPool::clear() sets threadPool data to initial values.
+
+/// ThreadPool::clear() sets threadPool data to initial values
void ThreadPool::clear() {
th->clear();
main()->callsCnt = 0;
- main()->previousScore = VALUE_INFINITE;
+ main()->bestPreviousScore = VALUE_INFINITE;
main()->previousTimeReduction = 1.0;
}
+
/// ThreadPool::start_thinking() wakes up main thread waiting in idle_loop() and
/// returns immediately. Main thread will wake up other threads and start the search.
for (Thread* th : *this)
{
- th->nodes = th->tbHits = th->nmpMinPly = 0;
+ th->nodes = th->tbHits = th->nmpMinPly = th->bestMoveChanges = 0;
th->rootDepth = th->completedDepth = 0;
th->rootMoves = rootMoves;
th->rootPos.set(pos.fen(), pos.is_chess960(), &setupStates->back(), th);
main()->start_searching();
}
+
+Thread* ThreadPool::get_best_thread() const {
+
+ Thread* bestThread = front();
+ std::map<Move, int64_t> votes;
+ Value minScore = VALUE_NONE;
+
+ // Find minimum score of all threads
+ for (Thread* th: *this)
+ minScore = std::min(minScore, th->rootMoves[0].score);
+
+ // Vote according to score and depth, and select the best thread
+ for (Thread* th : *this)
+ {
+ votes[th->rootMoves[0].pv[0]] +=
+ (th->rootMoves[0].score - minScore + 14) * int(th->completedDepth);
+
+ if (abs(bestThread->rootMoves[0].score) >= VALUE_TB_WIN_IN_MAX_PLY)
+ {
+ // Make sure we pick the shortest mate / TB conversion or stave off mate the longest
+ if (th->rootMoves[0].score > bestThread->rootMoves[0].score)
+ bestThread = th;
+ }
+ else if ( th->rootMoves[0].score >= VALUE_TB_WIN_IN_MAX_PLY
+ || ( th->rootMoves[0].score > VALUE_TB_LOSS_IN_MAX_PLY
+ && votes[th->rootMoves[0].pv[0]] > votes[bestThread->rootMoves[0].pv[0]]))
+ bestThread = th;
+ }
+
+ return bestThread;
+}
+
+
+/// Start non-main threads
+
+void ThreadPool::start_searching() {
+
+ for (Thread* th : *this)
+ if (th != front())
+ th->start_searching();
+}
+
+
+/// Wait for non-main threads
+
+void ThreadPool::wait_for_search_finished() const {
+
+ for (Thread* th : *this)
+ if (th != front())
+ th->wait_for_search_finished();
+}
void idle_loop();
void start_searching();
void wait_for_search_finished();
- int best_move_count(Move move);
+ int best_move_count(Move move) const;
Pawns::Table pawnsTable;
Material::Table materialTable;
Depth rootDepth, completedDepth;
CounterMoveHistory counterMoves;
ButterflyHistory mainHistory;
+ LowPlyHistory lowPlyHistory;
CapturePieceToHistory captureHistory;
ContinuationHistory continuationHistory[2][2];
Score contempt;
void check_time();
double previousTimeReduction;
- Value previousScore;
+ Value bestPreviousScore;
Value iterValue[4];
int callsCnt;
bool stopOnPonderhit;
MainThread* main() const { return static_cast<MainThread*>(front()); }
uint64_t nodes_searched() const { return accumulate(&Thread::nodes); }
uint64_t tb_hits() const { return accumulate(&Thread::tbHits); }
+ Thread* get_best_thread() const;
+ void start_searching();
+ void wait_for_search_finished() const;
std::atomic_bool stop, increaseDepth;
TimeManagement Time; // Our global time management object
-namespace {
- enum TimeType { OptimumTime, MaxTime };
-
- constexpr int MoveHorizon = 50; // Plan time management at most this many moves ahead
- constexpr double MaxRatio = 7.3; // When in trouble, we can step over reserved time with this ratio
- constexpr double StealRatio = 0.34; // However we must not steal time from remaining moves over this ratio
-
-
- // move_importance() is a skew-logistic function based on naive statistical
- // analysis of "how many games are still undecided after n half-moves". Game
- // is considered "undecided" as long as neither side has >275cp advantage.
- // Data was extracted from the CCRL game database with some simple filtering criteria.
-
- double move_importance(int ply) {
-
- constexpr double XScale = 6.85;
- constexpr double XShift = 64.5;
- constexpr double Skew = 0.171;
-
- return pow((1 + exp((ply - XShift) / XScale)), -Skew) + DBL_MIN; // Ensure non-zero
- }
-
- template<TimeType T>
- TimePoint remaining(TimePoint myTime, int movesToGo, int ply, TimePoint slowMover) {
-
- constexpr double TMaxRatio = (T == OptimumTime ? 1.0 : MaxRatio);
- constexpr double TStealRatio = (T == OptimumTime ? 0.0 : StealRatio);
-
- double moveImportance = (move_importance(ply) * slowMover) / 100.0;
- double otherMovesImportance = 0.0;
-
- for (int i = 1; i < movesToGo; ++i)
- otherMovesImportance += move_importance(ply + 2 * i);
-
- double ratio1 = (TMaxRatio * moveImportance) / (TMaxRatio * moveImportance + otherMovesImportance);
- double ratio2 = (moveImportance + TStealRatio * otherMovesImportance) / (moveImportance + otherMovesImportance);
-
- return TimePoint(myTime * std::min(ratio1, ratio2)); // Intel C++ asks for an explicit cast
- }
-
-} // namespace
-
-
-/// init() is called at the beginning of the search and calculates the allowed
-/// thinking time out of the time control and current game ply. We support four
-/// different kinds of time controls, passed in 'limits':
-///
-/// inc == 0 && movestogo == 0 means: x basetime [sudden death!]
-/// inc == 0 && movestogo != 0 means: x moves in y minutes
-/// inc > 0 && movestogo == 0 means: x basetime + z increment
-/// inc > 0 && movestogo != 0 means: x moves in y minutes + z increment
+/// TimeManagement::init() is called at the beginning of the search and calculates
+/// the bounds of time allowed for the current game ply. We currently support:
+// 1) x basetime (+ z increment)
+// 2) x moves in y seconds (+ z increment)
void TimeManagement::init(Search::LimitsType& limits, Color us, int ply) {
- TimePoint minThinkingTime = Options["Minimum Thinking Time"];
- TimePoint moveOverhead = Options["Move Overhead"];
- TimePoint slowMover = Options["Slow Mover"];
- TimePoint npmsec = Options["nodestime"];
- TimePoint hypMyTime;
+ TimePoint moveOverhead = TimePoint(Options["Move Overhead"]);
+ TimePoint slowMover = TimePoint(Options["Slow Mover"]);
+ TimePoint npmsec = TimePoint(Options["nodestime"]);
+
+ // opt_scale is a percentage of available time to use for the current move.
+ // max_scale is a multiplier applied to optimumTime.
+ double opt_scale, max_scale;
// If we have to play in 'nodes as time' mode, then convert from time
// to nodes, and use resulting values in time management formulas.
}
startTime = limits.startTime;
- optimumTime = maximumTime = std::max(limits.time[us], minThinkingTime);
- const int maxMTG = limits.movestogo ? std::min(limits.movestogo, MoveHorizon) : MoveHorizon;
+ // Maximum move horizon of 50 moves
+ int mtg = limits.movestogo ? std::min(limits.movestogo, 50) : 50;
- // We calculate optimum time usage for different hypothetical "moves to go" values
- // and choose the minimum of calculated search time values. Usually the greatest
- // hypMTG gives the minimum values.
- for (int hypMTG = 1; hypMTG <= maxMTG; ++hypMTG)
- {
- // Calculate thinking time for hypothetical "moves to go"-value
- hypMyTime = limits.time[us]
- + limits.inc[us] * (hypMTG - 1)
- - moveOverhead * (2 + std::min(hypMTG, 40));
+ // Make sure timeLeft is > 0 since we may use it as a divisor
+ TimePoint timeLeft = std::max(TimePoint(1),
+ limits.time[us] + limits.inc[us] * (mtg - 1) - moveOverhead * (2 + mtg));
- hypMyTime = std::max(hypMyTime, TimePoint(0));
+ // A user may scale time usage by setting UCI option "Slow Mover"
+ // Default is 100 and changing this value will probably lose elo.
+ timeLeft = slowMover * timeLeft / 100;
- TimePoint t1 = minThinkingTime + remaining<OptimumTime>(hypMyTime, hypMTG, ply, slowMover);
- TimePoint t2 = minThinkingTime + remaining<MaxTime >(hypMyTime, hypMTG, ply, slowMover);
+ // x basetime (+ z increment)
+ // If there is a healthy increment, timeLeft can exceed actual available
+ // game time for the current move, so also cap to 20% of available game time.
+ if (limits.movestogo == 0)
+ {
+ opt_scale = std::min(0.008 + std::pow(ply + 3.0, 0.5) / 250.0,
+ 0.2 * limits.time[us] / double(timeLeft));
+ max_scale = std::min(7.0, 4.0 + ply / 12.0);
+ }
- optimumTime = std::min(t1, optimumTime);
- maximumTime = std::min(t2, maximumTime);
+ // x moves in y seconds (+ z increment)
+ else
+ {
+ opt_scale = std::min((0.8 + ply / 128.0) / mtg,
+ 0.8 * limits.time[us] / double(timeLeft));
+ max_scale = std::min(6.3, 1.5 + 0.11 * mtg);
}
+ // Never use more than 80% of the available time for this move
+ optimumTime = TimePoint(opt_scale * timeLeft);
+ maximumTime = TimePoint(std::min(0.8 * limits.time[us] - moveOverhead, max_scale * optimumTime));
+
if (Options["Ponder"])
optimumTime += optimumTime / 4;
}
TranspositionTable TT; // Our global transposition table
-/// TTEntry::save populates the TTEntry with a new node's data, possibly
+/// TTEntry::save() populates the TTEntry with a new node's data, possibly
/// overwriting an old position. Update is not atomic and can be racy.
void TTEntry::save(Key k, Value v, bool pv, Bound b, Depth d, Move m, Value ev) {
// Preserve any existing move for the same position
- if (m || (k >> 48) != key16)
+ if (m || (uint16_t)k != key16)
move16 = (uint16_t)m;
// Overwrite less valuable entries
- if ( (k >> 48) != key16
+ if ((uint16_t)k != key16
|| d - DEPTH_OFFSET > depth8 - 4
|| b == BOUND_EXACT)
{
assert(d >= DEPTH_OFFSET);
- key16 = (uint16_t)(k >> 48);
+ key16 = (uint16_t)k;
value16 = (int16_t)v;
eval16 = (int16_t)ev;
genBound8 = (uint8_t)(TT.generation8 | uint8_t(pv) << 2 | b);
Threads.main()->wait_for_search_finished();
- clusterCount = mbSize * 1024 * 1024 / sizeof(Cluster);
-
- free(mem);
- mem = malloc(clusterCount * sizeof(Cluster) + CacheLineSize - 1);
+ aligned_ttmem_free(mem);
+ clusterCount = mbSize * 1024 * 1024 / sizeof(Cluster);
+ table = static_cast<Cluster*>(aligned_ttmem_alloc(clusterCount * sizeof(Cluster), mem));
if (!mem)
{
std::cerr << "Failed to allocate " << mbSize
exit(EXIT_FAILURE);
}
- table = (Cluster*)((uintptr_t(mem) + CacheLineSize - 1) & ~(CacheLineSize - 1));
clear();
}
WinProcGroup::bindThisThread(idx);
// Each thread will zero its part of the hash table
- const size_t stride = clusterCount / Options["Threads"],
- start = stride * idx,
+ const size_t stride = size_t(clusterCount / Options["Threads"]),
+ start = size_t(stride * idx),
len = idx != Options["Threads"] - 1 ?
stride : clusterCount - start;
});
}
- for (std::thread& th: threads)
+ for (std::thread& th : threads)
th.join();
}
+
/// TranspositionTable::probe() looks up the current position in the transposition
/// table. It returns true and a pointer to the TTEntry if the position is found.
/// Otherwise, it returns false and a pointer to an empty or least valuable TTEntry
TTEntry* TranspositionTable::probe(const Key key, bool& found) const {
TTEntry* const tte = first_entry(key);
- const uint16_t key16 = key >> 48; // Use the high 16 bits as key inside the cluster
+ const uint16_t key16 = (uint16_t)key; // Use the low 16 bits as key inside the cluster
for (int i = 0; i < ClusterSize; ++i)
if (!tte[i].key16 || tte[i].key16 == key16)
int TranspositionTable::hashfull() const {
int cnt = 0;
- for (int i = 0; i < 1000 / ClusterSize; ++i)
+ for (int i = 0; i < 1000; ++i)
for (int j = 0; j < ClusterSize; ++j)
cnt += (table[i].entry[j].genBound8 & 0xF8) == generation8;
- return cnt * 1000 / (ClusterSize * (1000 / ClusterSize));
+ return cnt / ClusterSize;
}
Value value() const { return (Value)value16; }
Value eval() const { return (Value)eval16; }
Depth depth() const { return (Depth)depth8 + DEPTH_OFFSET; }
- bool is_pv() const { return (bool)(genBound8 & 0x4); }
+ bool is_pv() const { return (bool)(genBound8 & 0x4); }
Bound bound() const { return (Bound)(genBound8 & 0x3); }
void save(Key k, Value v, bool pv, Bound b, Depth d, Move m, Value ev);
};
-/// A TranspositionTable consists of a power of 2 number of clusters and each
-/// cluster consists of ClusterSize number of TTEntry. Each non-empty entry
-/// contains information of exactly one position. The size of a cluster should
-/// divide the size of a cache line size, to ensure that clusters never cross
-/// cache lines. This ensures best cache performance, as the cacheline is
-/// prefetched, as soon as possible.
+/// A TranspositionTable is an array of Cluster, of size clusterCount. Each
+/// cluster consists of ClusterSize number of TTEntry. Each non-empty TTEntry
+/// contains information on exactly one position. The size of a Cluster should
+/// divide the size of a cache line for best performance, as the cacheline is
+/// prefetched when possible.
class TranspositionTable {
- static constexpr int CacheLineSize = 64;
static constexpr int ClusterSize = 3;
struct Cluster {
TTEntry entry[ClusterSize];
- char padding[2]; // Align to a divisor of the cache line size
+ char padding[2]; // Pad to 32 bytes
};
- static_assert(CacheLineSize % sizeof(Cluster) == 0, "Cluster size incorrect");
+ static_assert(sizeof(Cluster) == 32, "Unexpected Cluster size");
public:
- ~TranspositionTable() { free(mem); }
+ ~TranspositionTable() { aligned_ttmem_free(mem); }
void new_search() { generation8 += 8; } // Lower 3 bits are used by PV flag and Bound
TTEntry* probe(const Key key, bool& found) const;
int hashfull() const;
void resize(size_t mbSize);
void clear();
- // The 32 lowest order bits of the key are used to get the index of the cluster
TTEntry* first_entry(const Key key) const {
- return &table[(uint32_t(key) * uint64_t(clusterCount)) >> 32].entry[0];
+ return &table[mul_hi64(key, clusterCount)].entry[0];
}
private:
--- /dev/null
+/*
+ Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+ Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
+ Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2015-2020 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+
+ Stockfish is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ Stockfish is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <algorithm>
+#include <iostream>
+#include <sstream>
+
+#include "types.h"
+#include "misc.h"
+#include "uci.h"
+
+using std::string;
+
+bool Tune::update_on_last;
+const UCI::Option* LastOption = nullptr;
+BoolConditions Conditions;
+static std::map<std::string, int> TuneResults;
+
+string Tune::next(string& names, bool pop) {
+
+ string name;
+
+ do {
+ string token = names.substr(0, names.find(','));
+
+ if (pop)
+ names.erase(0, token.size() + 1);
+
+ std::stringstream ws(token);
+ name += (ws >> token, token); // Remove trailing whitespace
+
+ } while ( std::count(name.begin(), name.end(), '(')
+ - std::count(name.begin(), name.end(), ')'));
+
+ return name;
+}
+
+static void on_tune(const UCI::Option& o) {
+
+ if (!Tune::update_on_last || LastOption == &o)
+ Tune::read_options();
+}
+
+static void make_option(const string& n, int v, const SetRange& r) {
+
+ // Do not generate option when there is nothing to tune (ie. min = max)
+ if (r(v).first == r(v).second)
+ return;
+
+ if (TuneResults.count(n))
+ v = TuneResults[n];
+
+ Options[n] << UCI::Option(v, r(v).first, r(v).second, on_tune);
+ LastOption = &Options[n];
+
+ // Print formatted parameters, ready to be copy-pasted in Fishtest
+ std::cout << n << ","
+ << v << ","
+ << r(v).first << "," << r(v).second << ","
+ << (r(v).second - r(v).first) / 20.0 << ","
+ << "0.0020"
+ << std::endl;
+}
+
+template<> void Tune::Entry<int>::init_option() { make_option(name, value, range); }
+
+template<> void Tune::Entry<int>::read_option() {
+ if (Options.count(name))
+ value = int(Options[name]);
+}
+
+template<> void Tune::Entry<Value>::init_option() { make_option(name, value, range); }
+
+template<> void Tune::Entry<Value>::read_option() {
+ if (Options.count(name))
+ value = Value(int(Options[name]));
+}
+
+template<> void Tune::Entry<Score>::init_option() {
+ make_option("m" + name, mg_value(value), range);
+ make_option("e" + name, eg_value(value), range);
+}
+
+template<> void Tune::Entry<Score>::read_option() {
+ if (Options.count("m" + name))
+ value = make_score(int(Options["m" + name]), eg_value(value));
+
+ if (Options.count("e" + name))
+ value = make_score(mg_value(value), int(Options["e" + name]));
+}
+
+// Instead of a variable here we have a PostUpdate function: just call it
+template<> void Tune::Entry<Tune::PostUpdate>::init_option() {}
+template<> void Tune::Entry<Tune::PostUpdate>::read_option() { value(); }
+
+
+// Set binary conditions according to a probability that depends
+// on the corresponding parameter value.
+
+void BoolConditions::set() {
+
+ static PRNG rng(now());
+ static bool startup = true; // To workaround fishtest bench
+
+ for (size_t i = 0; i < binary.size(); i++)
+ binary[i] = !startup && (values[i] + int(rng.rand<unsigned>() % variance) > threshold);
+
+ startup = false;
+
+ for (size_t i = 0; i < binary.size(); i++)
+ sync_cout << binary[i] << sync_endl;
+}
+
+
+// Init options with tuning session results instead of default values. Useful to
+// get correct bench signature after a tuning session or to test tuned values.
+// Just copy fishtest tuning results in a result.txt file and extract the
+// values with:
+//
+// cat results.txt | sed 's/^param: \([^,]*\), best: \([^,]*\).*/ TuneResults["\1"] = int(round(\2));/'
+//
+// Then paste the output below, as the function body
+
+#include <cmath>
+
+void Tune::read_results() {
+
+ /* ...insert your values here... */
+}
--- /dev/null
+/*
+ Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+ Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
+ Copyright (C) 2008-2017 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2015-2018 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+
+ Stockfish is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ Stockfish is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef TUNE_H_INCLUDED
+#define TUNE_H_INCLUDED
+
+#include <memory>
+#include <string>
+#include <type_traits>
+#include <vector>
+
+typedef std::pair<int, int> Range; // Option's min-max values
+typedef Range (RangeFun) (int);
+
+// Default Range function, to calculate Option's min-max values
+inline Range default_range(int v) {
+ return v > 0 ? Range(0, 2 * v) : Range(2 * v, 0);
+}
+
+struct SetRange {
+ explicit SetRange(RangeFun f) : fun(f) {}
+ SetRange(int min, int max) : fun(nullptr), range(min, max) {}
+ Range operator()(int v) const { return fun ? fun(v) : range; }
+
+ RangeFun* fun;
+ Range range;
+};
+
+#define SetDefaultRange SetRange(default_range)
+
+
+/// BoolConditions struct is used to tune boolean conditions in the
+/// code by toggling them on/off according to a probability that
+/// depends on the value of a tuned integer parameter: for high
+/// values of the parameter condition is always disabled, for low
+/// values is always enabled, otherwise it is enabled with a given
+/// probability that depnends on the parameter under tuning.
+
+struct BoolConditions {
+ void init(size_t size) { values.resize(size, defaultValue), binary.resize(size, 0); }
+ void set();
+
+ std::vector<int> binary, values;
+ int defaultValue = 465, variance = 40, threshold = 500;
+ SetRange range = SetRange(0, 1000);
+};
+
+extern BoolConditions Conditions;
+
+inline void set_conditions() { Conditions.set(); }
+
+
+/// Tune class implements the 'magic' code that makes the setup of a fishtest
+/// tuning session as easy as it can be. Mainly you have just to remove const
+/// qualifiers from the variables you want to tune and flag them for tuning, so
+/// if you have:
+///
+/// const Score myScore = S(10, 15);
+/// const Value myValue[][2] = { { V(100), V(20) }, { V(7), V(78) } };
+///
+/// If you have a my_post_update() function to run after values have been updated,
+/// and a my_range() function to set custom Option's min-max values, then you just
+/// remove the 'const' qualifiers and write somewhere below in the file:
+///
+/// TUNE(SetRange(my_range), myScore, myValue, my_post_update);
+///
+/// You can also set the range directly, and restore the default at the end
+///
+/// TUNE(SetRange(-100, 100), myScore, SetDefaultRange);
+///
+/// In case update function is slow and you have many parameters, you can add:
+///
+/// UPDATE_ON_LAST();
+///
+/// And the values update, including post update function call, will be done only
+/// once, after the engine receives the last UCI option, that is the one defined
+/// and created as the last one, so the GUI should send the options in the same
+/// order in which have been defined.
+
+class Tune {
+
+ typedef void (PostUpdate) (); // Post-update function
+
+ Tune() { read_results(); }
+ Tune(const Tune&) = delete;
+ void operator=(const Tune&) = delete;
+ void read_results();
+
+ static Tune& instance() { static Tune t; return t; } // Singleton
+
+ // Use polymorphism to accomodate Entry of different types in the same vector
+ struct EntryBase {
+ virtual ~EntryBase() = default;
+ virtual void init_option() = 0;
+ virtual void read_option() = 0;
+ };
+
+ template<typename T>
+ struct Entry : public EntryBase {
+
+ static_assert(!std::is_const<T>::value, "Parameter cannot be const!");
+
+ static_assert( std::is_same<T, int>::value
+ || std::is_same<T, Value>::value
+ || std::is_same<T, Score>::value
+ || std::is_same<T, PostUpdate>::value, "Parameter type not supported!");
+
+ Entry(const std::string& n, T& v, const SetRange& r) : name(n), value(v), range(r) {}
+ void operator=(const Entry&) = delete; // Because 'value' is a reference
+ void init_option() override;
+ void read_option() override;
+
+ std::string name;
+ T& value;
+ SetRange range;
+ };
+
+ // Our facilty to fill the container, each Entry corresponds to a parameter to tune.
+ // We use variadic templates to deal with an unspecified number of entries, each one
+ // of a possible different type.
+ static std::string next(std::string& names, bool pop = true);
+
+ int add(const SetRange&, std::string&&) { return 0; }
+
+ template<typename T, typename... Args>
+ int add(const SetRange& range, std::string&& names, T& value, Args&&... args) {
+ list.push_back(std::unique_ptr<EntryBase>(new Entry<T>(next(names), value, range)));
+ return add(range, std::move(names), args...);
+ }
+
+ // Template specialization for arrays: recursively handle multi-dimensional arrays
+ template<typename T, size_t N, typename... Args>
+ int add(const SetRange& range, std::string&& names, T (&value)[N], Args&&... args) {
+ for (size_t i = 0; i < N; i++)
+ add(range, next(names, i == N - 1) + "[" + std::to_string(i) + "]", value[i]);
+ return add(range, std::move(names), args...);
+ }
+
+ // Template specialization for SetRange
+ template<typename... Args>
+ int add(const SetRange&, std::string&& names, SetRange& value, Args&&... args) {
+ return add(value, (next(names), std::move(names)), args...);
+ }
+
+ // Template specialization for BoolConditions
+ template<typename... Args>
+ int add(const SetRange& range, std::string&& names, BoolConditions& cond, Args&&... args) {
+ for (size_t size = cond.values.size(), i = 0; i < size; i++)
+ add(cond.range, next(names, i == size - 1) + "_" + std::to_string(i), cond.values[i]);
+ return add(range, std::move(names), args...);
+ }
+
+ std::vector<std::unique_ptr<EntryBase>> list;
+
+public:
+ template<typename... Args>
+ static int add(const std::string& names, Args&&... args) {
+ return instance().add(SetDefaultRange, names.substr(1, names.size() - 2), args...); // Remove trailing parenthesis
+ }
+ static void init() { for (auto& e : instance().list) e->init_option(); read_options(); } // Deferred, due to UCI::Options access
+ static void read_options() { for (auto& e : instance().list) e->read_option(); }
+ static bool update_on_last;
+};
+
+// Some macro magic :-) we define a dummy int variable that compiler initializes calling Tune::add()
+#define STRINGIFY(x) #x
+#define UNIQUE2(x, y) x ## y
+#define UNIQUE(x, y) UNIQUE2(x, y) // Two indirection levels to expand __LINE__
+#define TUNE(...) int UNIQUE(p, __LINE__) = Tune::add(STRINGIFY((__VA_ARGS__)), __VA_ARGS__)
+
+#define UPDATE_ON_LAST() bool UNIQUE(p, __LINE__) = Tune::update_on_last = true
+
+// Some macro to tune toggling of boolean conditions
+#define CONDITION(x) (Conditions.binary[__COUNTER__] || (x))
+#define TUNE_CONDITIONS() int UNIQUE(c, __LINE__) = (Conditions.init(__COUNTER__), 0); \
+ TUNE(Conditions, set_conditions)
+
+#endif // #ifndef TUNE_H_INCLUDED
#include <cassert>
#include <cctype>
-#include <climits>
#include <cstdint>
#include <cstdlib>
#include <algorithm>
VALUE_INFINITE = 32001,
VALUE_NONE = 32002,
- VALUE_MATE_IN_MAX_PLY = VALUE_MATE - 2 * MAX_PLY,
- VALUE_MATED_IN_MAX_PLY = -VALUE_MATE + 2 * MAX_PLY,
+ VALUE_TB_WIN_IN_MAX_PLY = VALUE_MATE - 2 * MAX_PLY,
+ VALUE_TB_LOSS_IN_MAX_PLY = -VALUE_TB_WIN_IN_MAX_PLY,
+ VALUE_MATE_IN_MAX_PLY = VALUE_MATE - MAX_PLY,
+ VALUE_MATED_IN_MAX_PLY = -VALUE_MATE_IN_MAX_PLY,
- PawnValueMg = 128, PawnValueEg = 213,
+ PawnValueMg = 124, PawnValueEg = 206,
KnightValueMg = 781, KnightValueEg = 854,
BishopValueMg = 825, BishopValueEg = 915,
RookValueMg = 1276, RookValueEg = 1380,
QueenValueMg = 2538, QueenValueEg = 2682,
+ Tempo = 28,
MidgameLimit = 15258, EndgameLimit = 3915
};
PIECE_NB = 16
};
-extern Value PieceValue[PHASE_NB][PIECE_NB];
+constexpr Value PieceValue[PHASE_NB][PIECE_NB] = {
+ { VALUE_ZERO, PawnValueMg, KnightValueMg, BishopValueMg, RookValueMg, QueenValueMg, VALUE_ZERO, VALUE_ZERO,
+ VALUE_ZERO, PawnValueMg, KnightValueMg, BishopValueMg, RookValueMg, QueenValueMg, VALUE_ZERO, VALUE_ZERO },
+ { VALUE_ZERO, PawnValueEg, KnightValueEg, BishopValueEg, RookValueEg, QueenValueEg, VALUE_ZERO, VALUE_ZERO,
+ VALUE_ZERO, PawnValueEg, KnightValueEg, BishopValueEg, RookValueEg, QueenValueEg, VALUE_ZERO, VALUE_ZERO }
+};
typedef int Depth;
enum : int {
-
DEPTH_QS_CHECKS = 0,
DEPTH_QS_NO_CHECKS = -1,
DEPTH_QS_RECAPTURES = -5,
DEPTH_NONE = -6,
- DEPTH_OFFSET = DEPTH_NONE,
+ DEPTH_OFFSET = DEPTH_NONE
};
enum Square : int {
}
#define ENABLE_BASE_OPERATORS_ON(T) \
-constexpr T operator+(T d1, T d2) { return T(int(d1) + int(d2)); } \
-constexpr T operator-(T d1, T d2) { return T(int(d1) - int(d2)); } \
+constexpr T operator+(T d1, int d2) { return T(int(d1) + d2); } \
+constexpr T operator-(T d1, int d2) { return T(int(d1) - d2); } \
constexpr T operator-(T d) { return T(-int(d)); } \
-inline T& operator+=(T& d1, T d2) { return d1 = d1 + d2; } \
-inline T& operator-=(T& d1, T d2) { return d1 = d1 - d2; }
+inline T& operator+=(T& d1, int d2) { return d1 = d1 + d2; } \
+inline T& operator-=(T& d1, int d2) { return d1 = d1 - d2; }
#define ENABLE_INCR_OPERATORS_ON(T) \
inline T& operator++(T& d) { return d = T(int(d) + 1); } \
ENABLE_FULL_OPERATORS_ON(Direction)
ENABLE_INCR_OPERATORS_ON(PieceType)
-ENABLE_INCR_OPERATORS_ON(Piece)
ENABLE_INCR_OPERATORS_ON(Square)
ENABLE_INCR_OPERATORS_ON(File)
ENABLE_INCR_OPERATORS_ON(Rank)
#undef ENABLE_INCR_OPERATORS_ON
#undef ENABLE_BASE_OPERATORS_ON
-/// Additional operators to add integers to a Value
-constexpr Value operator+(Value v, int i) { return Value(int(v) + i); }
-constexpr Value operator-(Value v, int i) { return Value(int(v) - i); }
-inline Value& operator+=(Value& v, int i) { return v = v + i; }
-inline Value& operator-=(Value& v, int i) { return v = v - i; }
-
/// Additional operators to add a Direction to a Square
constexpr Square operator+(Square s, Direction d) { return Square(int(s) + int(d)); }
constexpr Square operator-(Square s, Direction d) { return Square(int(s) - int(d)); }
/// Multiplication of a Score by a boolean
inline Score operator*(Score s, bool b) {
- return Score(int(s) * int(b));
+ return b ? s : SCORE_ZERO;
}
constexpr Color operator~(Color c) {
return Color(c ^ BLACK); // Toggle color
}
-constexpr Square operator~(Square s) {
- return Square(s ^ SQ_A8); // Vertical flip SQ_A1 -> SQ_A8
+constexpr Square flip_rank(Square s) { // Swap A1 <-> A8
+ return Square(s ^ SQ_A8);
}
-constexpr Piece operator~(Piece pc) {
- return Piece(pc ^ 8); // Swap color of piece B_KNIGHT -> W_KNIGHT
+constexpr Square flip_file(Square s) { // Swap A1 <-> H1
+ return Square(s ^ SQ_H1);
}
-inline File map_to_queenside(File f) {
- return std::min(f, File(FILE_H - f)); // Map files ABCDEFGH to files ABCDDCBA
+constexpr Piece operator~(Piece pc) {
+ return Piece(pc ^ 8); // Swap color of piece B_KNIGHT <-> W_KNIGHT
}
constexpr CastlingRights operator&(Color c, CastlingRights cr) {
return from_sq(m) != to_sq(m); // Catch MOVE_NULL and MOVE_NONE
}
+/// Based on a congruential pseudo random number generator
+constexpr Key make_key(uint64_t seed) {
+ return seed * 6364136223846793005ULL + 1442695040888963407ULL;
+}
+
#endif // #ifndef TYPES_H_INCLUDED
+
+#include "tune.h" // Global visibility to tuning setup
*/
#include <cassert>
+#include <cmath>
#include <iostream>
#include <sstream>
#include <string>
limits.startTime = now(); // As early as possible!
while (is >> token)
- if (token == "searchmoves")
+ if (token == "searchmoves") // Needs to be the last command on the line
while (is >> token)
limits.searchmoves.push_back(UCI::to_move(pos, token));
<< "\nNodes/second : " << 1000 * nodes / elapsed << endl;
}
+ // The win rate model returns the probability (per mille) of winning given an eval
+ // and a game-ply. The model fits rather accurately the LTC fishtest statistics.
+ int win_rate_model(Value v, int ply) {
+
+ // The model captures only up to 240 plies, so limit input (and rescale)
+ double m = std::min(240, ply) / 64.0;
+
+ // Coefficients of a 3rd order polynomial fit based on fishtest data
+ // for two parameters needed to transform eval to the argument of a
+ // logistic function.
+ double as[] = {-8.24404295, 64.23892342, -95.73056462, 153.86478679};
+ double bs[] = {-3.37154371, 28.44489198, -56.67657741, 72.05858751};
+ double a = (((as[0] * m + as[1]) * m + as[2]) * m) + as[3];
+ double b = (((bs[0] * m + bs[1]) * m + bs[2]) * m) + bs[3];
+
+ // Transform eval to centipawns with limited range
+ double x = Utility::clamp(double(100 * v) / PawnValueEg, -1000.0, 1000.0);
+
+ // Return win rate in per mille (rounded to nearest)
+ return int(0.5 + 1000 / (1 + std::exp((a - x) / b)));
+ }
+
} // namespace
stringstream ss;
- if (abs(v) < VALUE_MATE - MAX_PLY)
+ if (abs(v) < VALUE_MATE_IN_MAX_PLY)
ss << "cp " << v * 100 / PawnValueEg;
else
ss << "mate " << (v > 0 ? VALUE_MATE - v + 1 : -VALUE_MATE - v) / 2;
}
+/// UCI::wdl() report WDL statistics given an evaluation and a game ply, based on
+/// data gathered for fishtest LTC games.
+
+string UCI::wdl(Value v, int ply) {
+
+ stringstream ss;
+
+ int wdl_w = win_rate_model( v, ply);
+ int wdl_l = win_rate_model(-v, ply);
+ int wdl_d = 1000 - wdl_w - wdl_l;
+ ss << " wdl " << wdl_w << " " << wdl_d << " " << wdl_l;
+
+ return ss.str();
+}
+
+
/// UCI::square() converts a Square to a string in algebraic notation (g1, a7, etc.)
std::string UCI::square(Square s) {
std::string square(Square s);
std::string move(Move m, bool chess960);
std::string pv(const Position& pos, Depth depth, Value alpha, Value beta);
+std::string wdl(Value v, int ply);
Move to_move(const Position& pos, std::string& str);
} // namespace UCI
/// 'On change' actions, triggered by an option's value change
void on_clear_hash(const Option&) { Search::clear(); }
-void on_hash_size(const Option& o) { TT.resize(o); }
+void on_hash_size(const Option& o) { TT.resize(size_t(o)); }
void on_logger(const Option& o) { start_logger(o); }
-void on_threads(const Option& o) { Threads.set(o); }
+void on_threads(const Option& o) { Threads.set(size_t(o)); }
void on_tb_path(const Option& o) { Tablebases::init(o); }
void on_rpc_server_address(const Option& o) {
if (hash_probe_thread) {
}
-/// init() initializes the UCI options to their hard-coded default values
+/// UCI::init() initializes the UCI options to their hard-coded default values
void init(OptionsMap& o) {
- // at most 2^32 clusters.
- constexpr int MaxHashMB = Is64Bit ? 131072 : 2048;
+ constexpr int MaxHashMB = Is64Bit ? 33554432 : 2048;
o["Debug Log File"] << Option("", on_logger);
o["Contempt"] << Option(24, -100, 100);
o["Ponder"] << Option(false);
o["MultiPV"] << Option(1, 1, 500);
o["Skill Level"] << Option(20, 0, 20);
- o["Move Overhead"] << Option(30, 0, 5000);
- o["Minimum Thinking Time"] << Option(20, 0, 5000);
- o["Slow Mover"] << Option(84, 10, 1000);
+ o["Move Overhead"] << Option(10, 0, 5000);
+ o["Slow Mover"] << Option(100, 10, 1000);
o["nodestime"] << Option(0, 0, 10000);
o["UCI_Chess960"] << Option(false);
o["UCI_AnalyseMode"] << Option(false);
o["UCI_LimitStrength"] << Option(false);
o["UCI_Elo"] << Option(1350, 1350, 2850);
+ o["UCI_ShowWDL"] << Option(false);
o["SyzygyPath"] << Option("<empty>", on_tb_path);
o["SyzygyProbeDepth"] << Option(1, 1, 100);
o["Syzygy50MoveRule"] << Option(true);
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