X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbitboard.h;h=38870a2be69fbd8a33ca8a50e610db4a29dd7c86;hp=59de12886e513f55b6ba2ffae18cfe4ce96986bd;hb=27ba611a3da37423a3502e49beeebe11c9a11d8e;hpb=c2c185423b13b0227c86009c6006e48e8d258896 diff --git a/src/bitboard.h b/src/bitboard.h index 59de1288..38870a2b 100644 --- a/src/bitboard.h +++ b/src/bitboard.h @@ -1,14 +1,14 @@ /* Stockfish, a UCI chess playing engine derived from Glaurung 2.1 Copyright (C) 2004-2008 Tord Romstad (Glaurung author) - Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2015-2017 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 @@ -18,12 +18,28 @@ along with this program. If not, see . */ -#if !defined(BITBOARD_H_INCLUDED) +#ifndef BITBOARD_H_INCLUDED #define BITBOARD_H_INCLUDED +#include + #include "types.h" -const Bitboard EmptyBoardBB = 0; +namespace Bitbases { + +void init(); +bool probe(Square wksq, Square wpsq, Square bksq, Color us); + +} + +namespace Bitboards { + +void init(); +const std::string pretty(Bitboard b); + +} + +const Bitboard DarkSquares = 0xAA55AA55AA55AA55ULL; const Bitboard FileABB = 0x0101010101010101ULL; const Bitboard FileBBB = FileABB << 1; @@ -43,70 +59,65 @@ const Bitboard Rank6BB = Rank1BB << (8 * 5); const Bitboard Rank7BB = Rank1BB << (8 * 6); const Bitboard Rank8BB = Rank1BB << (8 * 7); -extern Bitboard SquaresByColorBB[2]; -extern Bitboard FileBB[8]; -extern Bitboard NeighboringFilesBB[8]; -extern Bitboard ThisAndNeighboringFilesBB[8]; -extern Bitboard RankBB[8]; -extern Bitboard InFrontBB[2][8]; - -extern Bitboard SetMaskBB[65]; -extern Bitboard ClearMaskBB[65]; - -extern Bitboard StepAttacksBB[16][64]; -extern Bitboard BetweenBB[64][64]; +extern int SquareDistance[SQUARE_NB][SQUARE_NB]; -extern Bitboard SquaresInFrontMask[2][64]; -extern Bitboard PassedPawnMask[2][64]; -extern Bitboard AttackSpanMask[2][64]; +extern Bitboard SquareBB[SQUARE_NB]; +extern Bitboard FileBB[FILE_NB]; +extern Bitboard RankBB[RANK_NB]; +extern Bitboard AdjacentFilesBB[FILE_NB]; +extern Bitboard InFrontBB[COLOR_NB][RANK_NB]; +extern Bitboard BetweenBB[SQUARE_NB][SQUARE_NB]; +extern Bitboard LineBB[SQUARE_NB][SQUARE_NB]; +extern Bitboard DistanceRingBB[SQUARE_NB][8]; +extern Bitboard ForwardBB[COLOR_NB][SQUARE_NB]; +extern Bitboard PassedPawnMask[COLOR_NB][SQUARE_NB]; +extern Bitboard PawnAttackSpan[COLOR_NB][SQUARE_NB]; +extern Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB]; +extern Bitboard PawnAttacks[COLOR_NB][SQUARE_NB]; -extern uint64_t RMult[64]; -extern int RShift[64]; -extern Bitboard RMask[64]; -extern Bitboard* RAttacks[64]; -extern uint64_t BMult[64]; -extern int BShift[64]; -extern Bitboard BMask[64]; -extern Bitboard* BAttacks[64]; +/// Magic holds all magic bitboards relevant data for a single square +struct Magic { + Bitboard mask; + Bitboard magic; + Bitboard* attacks; + unsigned shift; +}; -extern Bitboard BishopPseudoAttacks[64]; -extern Bitboard RookPseudoAttacks[64]; -extern Bitboard QueenPseudoAttacks[64]; +extern Magic RookMagics[SQUARE_NB]; +extern Magic BishopMagics[SQUARE_NB]; -extern uint8_t BitCount8Bit[256]; +/// 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. -/// Functions for testing whether a given bit is set in a bitboard, and for -/// setting and clearing bits. - -inline Bitboard bit_is_set(Bitboard b, Square s) { - return b & SetMaskBB[s]; +inline Bitboard operator&(Bitboard b, Square s) { + return b & SquareBB[s]; } -inline void set_bit(Bitboard *b, Square s) { - *b |= SetMaskBB[s]; +inline Bitboard operator|(Bitboard b, Square s) { + return b | SquareBB[s]; } -inline void clear_bit(Bitboard *b, Square s) { - *b &= ClearMaskBB[s]; +inline Bitboard operator^(Bitboard b, Square s) { + return b ^ SquareBB[s]; } +inline Bitboard& operator|=(Bitboard& b, Square s) { + return b |= SquareBB[s]; +} -/// Functions used to update a bitboard after a move. This is faster -/// then calling a sequence of clear_bit() + set_bit() - -inline Bitboard make_move_bb(Square from, Square to) { - return SetMaskBB[from] | SetMaskBB[to]; +inline Bitboard& operator^=(Bitboard& b, Square s) { + return b ^= SquareBB[s]; } -inline void do_move_bb(Bitboard *b, Bitboard move_bb) { - *b ^= move_bb; +inline bool more_than_one(Bitboard b) { + return b & (b - 1); } -/// rank_bb() and file_bb() take a file or a square as input and return -/// a bitboard representing all squares on the given file or rank. +/// rank_bb() and file_bb() return a bitboard representing all the squares on +/// the given file or rank. inline Bitboard rank_bb(Rank r) { return RankBB[r]; @@ -125,167 +136,203 @@ inline Bitboard file_bb(Square s) { } -/// neighboring_files_bb takes a file or a square as input and returns a -/// bitboard representing all squares on the neighboring files. +/// shift() moves a bitboard one step along direction D. Mainly for pawns -inline Bitboard neighboring_files_bb(File f) { - return NeighboringFilesBB[f]; -} - -inline Bitboard neighboring_files_bb(Square s) { - return NeighboringFilesBB[file_of(s)]; +template +inline Bitboard shift(Bitboard b) { + return D == NORTH ? b << 8 : D == SOUTH ? b >> 8 + : D == NORTH_EAST ? (b & ~FileHBB) << 9 : D == SOUTH_EAST ? (b & ~FileHBB) >> 7 + : D == NORTH_WEST ? (b & ~FileABB) << 7 : D == SOUTH_WEST ? (b & ~FileABB) >> 9 + : 0; } -/// this_and_neighboring_files_bb takes a file or a square as input and returns -/// a bitboard representing all squares on the given and neighboring files. +/// adjacent_files_bb() returns a bitboard representing all the squares on the +/// adjacent files of the given one. -inline Bitboard this_and_neighboring_files_bb(File f) { - return ThisAndNeighboringFilesBB[f]; +inline Bitboard adjacent_files_bb(File f) { + return AdjacentFilesBB[f]; } -inline Bitboard this_and_neighboring_files_bb(Square s) { - return ThisAndNeighboringFilesBB[file_of(s)]; + +/// between_bb() returns a bitboard representing all the squares between the two +/// given ones. For instance, between_bb(SQ_C4, SQ_F7) returns a bitboard with +/// the bits for square d5 and e6 set. If s1 and s2 are not on the same rank, file +/// or diagonal, 0 is returned. + +inline Bitboard between_bb(Square s1, Square s2) { + return BetweenBB[s1][s2]; } -/// in_front_bb() takes a color and a rank or square as input, and returns a -/// bitboard representing all the squares on all ranks in front of the rank -/// (or square), from the given color's point of view. For instance, -/// in_front_bb(WHITE, RANK_5) will give all squares on ranks 6, 7 and 8, while -/// in_front_bb(BLACK, SQ_D3) will give all squares on ranks 1 and 2. +/// in_front_bb() returns a bitboard representing all the squares on all the ranks +/// in front of the given one, from the point of view of the given color. For +/// instance, in_front_bb(BLACK, RANK_3) will return the squares on ranks 1 and 2. inline Bitboard in_front_bb(Color c, Rank r) { return InFrontBB[c][r]; } -inline Bitboard in_front_bb(Color c, Square s) { - return InFrontBB[c][rank_of(s)]; -} +/// forward_bb() returns a bitboard representing all the squares along the line +/// in front of the given one, from the point of view of the given color: +/// ForwardBB[c][s] = in_front_bb(c, rank_of(s)) & file_bb(s) + +inline Bitboard forward_bb(Color c, Square s) { + return ForwardBB[c][s]; +} -/// Functions for computing sliding attack bitboards. rook_attacks_bb(), -/// bishop_attacks_bb() and queen_attacks_bb() all take a square and a -/// bitboard of occupied squares as input, and return a bitboard representing -/// all squares attacked by a rook, bishop or queen on the given square. -#if defined(IS_64BIT) +/// pawn_attack_span() returns a bitboard representing all the squares that can be +/// attacked by a pawn of the given color when it moves along its file, starting +/// from the given square: +/// PawnAttackSpan[c][s] = in_front_bb(c, rank_of(s)) & adjacent_files_bb(s); -inline Bitboard rook_attacks_bb(Square s, Bitboard occ) { - return RAttacks[s][((occ & RMask[s]) * RMult[s]) >> RShift[s]]; +inline Bitboard pawn_attack_span(Color c, Square s) { + return PawnAttackSpan[c][s]; } -inline Bitboard bishop_attacks_bb(Square s, Bitboard occ) { - return BAttacks[s][((occ & BMask[s]) * BMult[s]) >> BShift[s]]; -} -#else // if !defined(IS_64BIT) +/// passed_pawn_mask() returns a bitboard mask which can be used to test if a +/// pawn of the given color and on the given square is a passed pawn: +/// PassedPawnMask[c][s] = pawn_attack_span(c, s) | forward_bb(c, s) -inline Bitboard rook_attacks_bb(Square s, Bitboard occ) { - Bitboard b = occ & RMask[s]; - return RAttacks[s] - [unsigned(int(b) * int(RMult[s]) ^ int(b >> 32) * int(RMult[s] >> 32)) >> RShift[s]]; +inline Bitboard passed_pawn_mask(Color c, Square s) { + return PassedPawnMask[c][s]; } -inline Bitboard bishop_attacks_bb(Square s, Bitboard occ) { - Bitboard b = occ & BMask[s]; - return BAttacks[s] - [unsigned(int(b) * int(BMult[s]) ^ int(b >> 32) * int(BMult[s] >> 32)) >> BShift[s]]; -} -#endif +/// aligned() returns true if the squares s1, s2 and s3 are aligned either on a +/// straight or on a diagonal line. -inline Bitboard queen_attacks_bb(Square s, Bitboard blockers) { - return rook_attacks_bb(s, blockers) | bishop_attacks_bb(s, blockers); +inline bool aligned(Square s1, Square s2, Square s3) { + return LineBB[s1][s2] & s3; } -/// squares_between returns a bitboard representing all squares between -/// two squares. For instance, squares_between(SQ_C4, SQ_F7) returns a -/// bitboard with the bits for square d5 and e6 set. If s1 and s2 are not -/// on the same line, file or diagonal, EmptyBoardBB is returned. +/// distance() functions return the distance between x and y, defined as the +/// number of steps for a king in x to reach y. Works with squares, ranks, files. -inline Bitboard squares_between(Square s1, Square s2) { - return BetweenBB[s1][s2]; -} +template inline int distance(T x, T y) { return x < y ? y - x : x - y; } +template<> inline int distance(Square x, Square y) { return SquareDistance[x][y]; } +template inline int distance(T2 x, T2 y); +template<> inline int distance(Square x, Square y) { return distance(file_of(x), file_of(y)); } +template<> inline int distance(Square x, Square y) { return distance(rank_of(x), rank_of(y)); } -/// squares_in_front_of takes a color and a square as input, and returns a -/// bitboard representing all squares along the line in front of the square, -/// from the point of view of the given color. Definition of the table is: -/// SquaresInFrontOf[c][s] = in_front_bb(c, s) & file_bb(s) -inline Bitboard squares_in_front_of(Color c, Square s) { - return SquaresInFrontMask[c][s]; -} +/// attacks_bb() returns a bitboard representing all the squares attacked by a +/// piece of type Pt (bishop or rook) placed on 's'. The helper magic_index() +/// looks up the index using the 'magic bitboards' approach. +inline unsigned magic_index(const Magic& m, Bitboard occupied) { + if (HasPext) + return unsigned(pext(occupied, m.mask)); -/// passed_pawn_mask takes a color and a square as input, and returns a -/// bitboard mask which can be used to test if a pawn of the given color on -/// the given square is a passed pawn. Definition of the table is: -/// PassedPawnMask[c][s] = in_front_bb(c, s) & this_and_neighboring_files_bb(s) + if (Is64Bit) + return unsigned(((occupied & m.mask) * m.magic) >> m.shift); -inline Bitboard passed_pawn_mask(Color c, Square s) { - return PassedPawnMask[c][s]; + unsigned lo = unsigned(occupied) & unsigned(m.mask); + unsigned hi = unsigned(occupied >> 32) & unsigned(m.mask >> 32); + return (lo * unsigned(m.magic) ^ hi * unsigned(m.magic >> 32)) >> m.shift; +} + +template +inline Bitboard attacks_bb(Square s, Bitboard occupied) { + + const Magic& M = Pt == ROOK ? RookMagics[s] : BishopMagics[s]; + return M.attacks[magic_index(M, occupied)]; } +inline Bitboard attacks_bb(PieceType pt, Square s, Bitboard occupied) { -/// attack_span_mask takes a color and a square as input, and returns a bitboard -/// representing all squares that can be attacked by a pawn of the given color -/// when it moves along its file starting from the given square. Definition is: -/// AttackSpanMask[c][s] = in_front_bb(c, s) & neighboring_files_bb(s); + assert(pt != PAWN); -inline Bitboard attack_span_mask(Color c, Square s) { - return AttackSpanMask[c][s]; + switch (pt) + { + case BISHOP: return attacks_bb(s, occupied); + case ROOK : return attacks_bb(s, occupied); + case QUEEN : return attacks_bb(s, occupied) | attacks_bb(s, occupied); + default : return PseudoAttacks[pt][s]; + } } -/// squares_aligned returns true if the squares s1, s2 and s3 are aligned -/// either on a straight or on a diagonal line. +/// popcount() counts the number of non-zero bits in a bitboard + +inline int popcount(Bitboard b) { + +#ifndef USE_POPCNT + + extern uint8_t PopCnt16[1 << 16]; + union { Bitboard bb; uint16_t u[4]; } v = { b }; + return PopCnt16[v.u[0]] + PopCnt16[v.u[1]] + PopCnt16[v.u[2]] + PopCnt16[v.u[3]]; + +#elif defined(_MSC_VER) || defined(__INTEL_COMPILER) + + return (int)_mm_popcnt_u64(b); + +#else // Assumed gcc or compatible compiler + + return __builtin_popcountll(b); -inline bool squares_aligned(Square s1, Square s2, Square s3) { - return (BetweenBB[s1][s2] | BetweenBB[s1][s3] | BetweenBB[s2][s3]) - & ( SetMaskBB[s1] | SetMaskBB[s2] | SetMaskBB[s3]); +#endif } -/// first_1() finds the least significant nonzero bit in a nonzero bitboard. -/// pop_1st_bit() finds and clears the least significant nonzero bit in a -/// nonzero bitboard. +/// lsb() and msb() return the least/most significant bit in a non-zero bitboard -#if defined(USE_BSFQ) +#if defined(__GNUC__) -#if defined(_MSC_VER) && !defined(__INTEL_COMPILER) +inline Square lsb(Bitboard b) { + assert(b); + return Square(__builtin_ctzll(b)); +} -FORCE_INLINE Square first_1(Bitboard b) { - unsigned long index; - _BitScanForward64(&index, b); - return (Square) index; +inline Square msb(Bitboard b) { + assert(b); + return Square(63 ^ __builtin_clzll(b)); } -#else -FORCE_INLINE Square first_1(Bitboard b) { // Assembly code by Heinz van Saanen - Bitboard dummy; - __asm__("bsfq %1, %0": "=r"(dummy): "rm"(b) ); - return (Square) dummy; +#elif defined(_WIN64) && defined(_MSC_VER) + +inline Square lsb(Bitboard b) { + assert(b); + unsigned long idx; + _BitScanForward64(&idx, b); + return (Square) idx; } -#endif -FORCE_INLINE Square pop_1st_bit(Bitboard* b) { - const Square s = first_1(*b); - *b &= ~(1ULL<