X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbitboard.h;h=390966e3494273969bdb53a50c6953a6c9782611;hp=90dec8165678811ae71f8efce50e11bbf400a5c6;hb=4c95edddbf1aaec22c343adaca4796df0137e4c3;hpb=ea4e22be1da1ccbf316d27f2eb3b14d0e13388e4 diff --git a/src/bitboard.h b/src/bitboard.h index 90dec816..390966e3 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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2015-2016 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 @@ -18,49 +18,61 @@ along with this program. If not, see . */ -#if !defined(BITBOARD_H_INCLUDED) +#ifndef BITBOARD_H_INCLUDED #define BITBOARD_H_INCLUDED +#include + #include "types.h" -namespace Bitboards { +namespace Bitbases { void init(); -void print(Bitboard b); +bool probe(Square wksq, Square wpsq, Square bksq, Color us); } -namespace Bitbases { +namespace Bitboards { -void init_kpk(); -bool probe_kpk(Square wksq, Square wpsq, Square bksq, Color us); +void init(); +const std::string pretty(Bitboard b); } -CACHE_LINE_ALIGNMENT +const Bitboard DarkSquares = 0xAA55AA55AA55AA55ULL; + +const Bitboard FileABB = 0x0101010101010101ULL; +const Bitboard FileBBB = FileABB << 1; +const Bitboard FileCBB = FileABB << 2; +const Bitboard FileDBB = FileABB << 3; +const Bitboard FileEBB = FileABB << 4; +const Bitboard FileFBB = FileABB << 5; +const Bitboard FileGBB = FileABB << 6; +const Bitboard FileHBB = FileABB << 7; -extern Bitboard RMasks[SQUARE_NB]; -extern Bitboard RMagics[SQUARE_NB]; -extern Bitboard* RAttacks[SQUARE_NB]; -extern unsigned RShifts[SQUARE_NB]; +const Bitboard Rank1BB = 0xFF; +const Bitboard Rank2BB = Rank1BB << (8 * 1); +const Bitboard Rank3BB = Rank1BB << (8 * 2); +const Bitboard Rank4BB = Rank1BB << (8 * 3); +const Bitboard Rank5BB = Rank1BB << (8 * 4); +const Bitboard Rank6BB = Rank1BB << (8 * 5); +const Bitboard Rank7BB = Rank1BB << (8 * 6); +const Bitboard Rank8BB = Rank1BB << (8 * 7); -extern Bitboard BMasks[SQUARE_NB]; -extern Bitboard BMagics[SQUARE_NB]; -extern Bitboard* BAttacks[SQUARE_NB]; -extern unsigned BShifts[SQUARE_NB]; +extern int SquareDistance[SQUARE_NB][SQUARE_NB]; extern Bitboard SquareBB[SQUARE_NB]; extern Bitboard FileBB[FILE_NB]; extern Bitboard RankBB[RANK_NB]; extern Bitboard AdjacentFilesBB[FILE_NB]; -extern Bitboard ThisAndAdjacentFilesBB[FILE_NB]; extern Bitboard InFrontBB[COLOR_NB][RANK_NB]; extern Bitboard StepAttacksBB[PIECE_NB][SQUARE_NB]; extern Bitboard BetweenBB[SQUARE_NB][SQUARE_NB]; -extern Bitboard DistanceRingsBB[SQUARE_NB][8]; +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 AttackSpanMask[COLOR_NB][SQUARE_NB]; +extern Bitboard PawnAttackSpan[COLOR_NB][SQUARE_NB]; extern Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB]; @@ -71,14 +83,6 @@ inline Bitboard operator&(Bitboard b, Square s) { return b & SquareBB[s]; } -inline Bitboard& operator|=(Bitboard& b, Square s) { - return b |= SquareBB[s]; -} - -inline Bitboard& operator^=(Bitboard& b, Square s) { - return b ^= SquareBB[s]; -} - inline Bitboard operator|(Bitboard b, Square s) { return b | SquareBB[s]; } @@ -87,16 +91,21 @@ inline Bitboard operator^(Bitboard b, Square s) { return b ^ SquareBB[s]; } +inline Bitboard& operator|=(Bitboard& b, Square s) { + return b |= SquareBB[s]; +} -/// more_than_one() returns true if in 'b' there is more than one bit set +inline Bitboard& operator^=(Bitboard& b, Square s) { + return b ^= SquareBB[s]; +} inline bool more_than_one(Bitboard b) { return b & (b - 1); } -/// rank_bb() and file_bb() take a file or a square as input and return -/// a bitboard representing all squares on the given file or rank. +/// rank_bb() and file_bb() return a bitboard representing all the squares on +/// the given file or rank. inline Bitboard rank_bb(Rank r) { return RankBB[r]; @@ -115,181 +124,215 @@ inline Bitboard file_bb(Square s) { } -/// adjacent_files_bb takes a file as input and returns a bitboard representing -/// all squares on the adjacent files. +/// shift_bb() moves a bitboard one step along direction Delta. Mainly for pawns + +template +inline Bitboard shift_bb(Bitboard b) { + return Delta == DELTA_N ? b << 8 : Delta == DELTA_S ? b >> 8 + : Delta == DELTA_NE ? (b & ~FileHBB) << 9 : Delta == DELTA_SE ? (b & ~FileHBB) >> 7 + : Delta == DELTA_NW ? (b & ~FileABB) << 7 : Delta == DELTA_SW ? (b & ~FileABB) >> 9 + : 0; +} + + +/// adjacent_files_bb() returns a bitboard representing all the squares on the +/// adjacent files of the given one. inline Bitboard adjacent_files_bb(File f) { return AdjacentFilesBB[f]; } -/// this_and_adjacent_files_bb takes a file as input and returns a bitboard -/// representing all squares on the given and adjacent files. +/// 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 this_and_adjacent_files_bb(File f) { - return ThisAndAdjacentFilesBB[f]; +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)]; -} - -/// between_bb returns a bitboard representing all squares between two squares. -/// For instance, between_bb(SQ_C4, SQ_F7) returns a bitboard with the bits for -/// square d5 and e6 set. If s1 and s2 are not on the same line, file or diagonal, -/// 0 is returned. +/// forward_bb() returns a bitboard representing all the squares along the line +/// in front of the given one, from the point of view of the given color: +/// ForwardBB[c][s] = in_front_bb(c, s) & file_bb(s) -inline Bitboard between_bb(Square s1, Square s2) { - return BetweenBB[s1][s2]; +inline Bitboard forward_bb(Color c, Square s) { + return ForwardBB[c][s]; } -/// forward_bb takes a color and a square as input, and returns a bitboard -/// representing all squares along the line in front of the square, from the -/// point of view of the given color. Definition of the table is: -/// ForwardBB[c][s] = in_front_bb(c, s) & file_bb(s) +/// pawn_attack_span() returns a bitboard representing all the squares that can be +/// attacked by a pawn of the given color when it moves along its file, starting +/// from the given square: +/// PawnAttackSpan[c][s] = in_front_bb(c, s) & adjacent_files_bb(s); -inline Bitboard forward_bb(Color c, Square s) { - return ForwardBB[c][s]; +inline Bitboard pawn_attack_span(Color c, Square s) { + return PawnAttackSpan[c][s]; } -/// passed_pawn_mask takes a color and a square as input, and returns a -/// bitboard mask which can be used to test if a pawn of the given color on -/// the given square is a passed pawn. Definition of the table is: -/// PassedPawnMask[c][s] = in_front_bb(c, s) & this_and_adjacent_files_bb(s) +/// passed_pawn_mask() returns a bitboard mask which can be used to test if a +/// pawn of the given color and on the given square is a passed pawn: +/// PassedPawnMask[c][s] = pawn_attack_span(c, s) | forward_bb(c, s) inline Bitboard passed_pawn_mask(Color c, Square s) { return PassedPawnMask[c][s]; } -/// attack_span_mask takes a color and a square as input, and returns a bitboard -/// representing all squares that can be attacked by a pawn of the given color -/// when it moves along its file starting from the given square. Definition is: -/// AttackSpanMask[c][s] = in_front_bb(c, s) & adjacent_files_bb(s); +/// aligned() returns true if the squares s1, s2 and s3 are aligned either on a +/// straight or on a diagonal line. -inline Bitboard attack_span_mask(Color c, Square s) { - return AttackSpanMask[c][s]; +inline bool aligned(Square s1, Square s2, Square s3) { + return LineBB[s1][s2] & s3; } -/// squares_aligned returns true if the squares s1, s2 and s3 are aligned -/// either on a straight or on a diagonal line. +/// 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 bool squares_aligned(Square s1, Square s2, Square s3) { - return (BetweenBB[s1][s2] | BetweenBB[s1][s3] | BetweenBB[s2][s3]) - & ( SquareBB[s1] | SquareBB[s2] | SquareBB[s3]); -} +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)); } -/// same_color_squares() returns a bitboard representing all squares with -/// the same color of the given square. -inline Bitboard same_color_squares(Square s) { - return Bitboard(0xAA55AA55AA55AA55ULL) & s ? 0xAA55AA55AA55AA55ULL - : ~0xAA55AA55AA55AA55ULL; -} +/// attacks_bb() returns a bitboard representing all the squares attacked by a +/// piece of type Pt (bishop or rook) placed on 's'. The helper magic_index() +/// looks up the index using the 'magic bitboards' approach. +template +inline unsigned magic_index(Square s, Bitboard occupied) { + extern Bitboard RookMasks[SQUARE_NB]; + extern Bitboard RookMagics[SQUARE_NB]; + extern unsigned RookShifts[SQUARE_NB]; + extern Bitboard BishopMasks[SQUARE_NB]; + extern Bitboard BishopMagics[SQUARE_NB]; + extern unsigned BishopShifts[SQUARE_NB]; -/// Functions for computing sliding attack bitboards. Function attacks_bb() takes -/// a square and a bitboard of occupied squares as input, and returns a bitboard -/// representing all squares attacked by Pt (bishop or rook) on the given square. -template -FORCE_INLINE unsigned magic_index(Square s, Bitboard occ) { + Bitboard* const Masks = Pt == ROOK ? RookMasks : BishopMasks; + Bitboard* const Magics = Pt == ROOK ? RookMagics : BishopMagics; + unsigned* const Shifts = Pt == ROOK ? RookShifts : BishopShifts; - Bitboard* const Masks = Pt == ROOK ? RMasks : BMasks; - Bitboard* const Magics = Pt == ROOK ? RMagics : BMagics; - unsigned* const Shifts = Pt == ROOK ? RShifts : BShifts; + if (HasPext) + return unsigned(pext(occupied, Masks[s])); if (Is64Bit) - return unsigned(((occ & Masks[s]) * Magics[s]) >> Shifts[s]); + return unsigned(((occupied & Masks[s]) * Magics[s]) >> Shifts[s]); - unsigned lo = unsigned(occ) & unsigned(Masks[s]); - unsigned hi = unsigned(occ >> 32) & unsigned(Masks[s] >> 32); + unsigned lo = unsigned(occupied) & unsigned(Masks[s]); + unsigned hi = unsigned(occupied >> 32) & unsigned(Masks[s] >> 32); return (lo * unsigned(Magics[s]) ^ hi * unsigned(Magics[s] >> 32)) >> Shifts[s]; } template -inline Bitboard attacks_bb(Square s, Bitboard occ) { - return (Pt == ROOK ? RAttacks : BAttacks)[s][magic_index(s, occ)]; +inline Bitboard attacks_bb(Square s, Bitboard occupied) { + + extern Bitboard* RookAttacks[SQUARE_NB]; + extern Bitboard* BishopAttacks[SQUARE_NB]; + + return (Pt == ROOK ? RookAttacks : BishopAttacks)[s][magic_index(s, occupied)]; } +inline Bitboard attacks_bb(Piece pc, Square s, Bitboard occupied) { -/// lsb()/msb() finds the least/most significant bit in a nonzero bitboard. -/// pop_lsb() finds and clears the least significant bit in a nonzero bitboard. + switch (type_of(pc)) + { + 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 StepAttacksBB[pc][s]; + } +} -#if defined(USE_BSFQ) -# if defined(_MSC_VER) && !defined(__INTEL_COMPILER) +/// popcount() counts the number of non-zero bits in a bitboard -FORCE_INLINE Square lsb(Bitboard b) { - unsigned long index; - _BitScanForward64(&index, b); - return (Square) index; -} +inline int popcount(Bitboard b) { -FORCE_INLINE Square msb(Bitboard b) { - unsigned long index; - _BitScanReverse64(&index, b); - return (Square) index; -} +#ifndef USE_POPCNT -# elif defined(__arm__) + 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]]; -FORCE_INLINE int lsb32(uint32_t v) { - __asm__("rbit %0, %1" : "=r"(v) : "r"(v)); - return __builtin_clz(v); +#elif defined(_MSC_VER) || defined(__INTEL_COMPILER) + + return (int)_mm_popcnt_u64(b); + +#else // Assumed gcc or compatible compiler + + return __builtin_popcountll(b); + +#endif } -FORCE_INLINE Square msb(Bitboard b) { - return (Square) (63 - __builtin_clzll(b)); + +/// lsb() and msb() return the least/most significant bit in a non-zero bitboard + +#if defined(__GNUC__) + +inline Square lsb(Bitboard b) { + assert(b); + return Square(__builtin_ctzll(b)); } -FORCE_INLINE Square lsb(Bitboard b) { - return (Square) (uint32_t(b) ? lsb32(uint32_t(b)) : 32 + lsb32(uint32_t(b >> 32))); +inline Square msb(Bitboard b) { + assert(b); + return Square(63 - __builtin_clzll(b)); } -# else +#elif defined(_WIN64) && defined(_MSC_VER) -FORCE_INLINE Square lsb(Bitboard b) { // Assembly code by Heinz van Saanen - Bitboard index; - __asm__("bsfq %1, %0": "=r"(index): "rm"(b) ); - return (Square) index; +inline Square lsb(Bitboard b) { + assert(b); + unsigned long idx; + _BitScanForward64(&idx, b); + return (Square) idx; } -FORCE_INLINE Square msb(Bitboard b) { - Bitboard index; - __asm__("bsrq %1, %0": "=r"(index): "rm"(b) ); - return (Square) index; +inline Square msb(Bitboard b) { + assert(b); + unsigned long idx; + _BitScanReverse64(&idx, b); + return (Square) idx; } -# endif +#else -FORCE_INLINE Square pop_lsb(Bitboard* b) { +#define NO_BSF // Fallback on software implementation for other cases + +Square lsb(Bitboard b); +Square msb(Bitboard b); + +#endif + + +/// pop_lsb() finds and clears the least significant bit in a non-zero bitboard + +inline Square pop_lsb(Bitboard* b) { const Square s = lsb(*b); *b &= *b - 1; return s; } -#else // if !defined(USE_BSFQ) -extern Square msb(Bitboard b); -extern Square lsb(Bitboard b); -extern Square pop_lsb(Bitboard* b); +/// frontmost_sq() and backmost_sq() return the square corresponding to the +/// most/least advanced bit relative to the given color. -#endif +inline Square frontmost_sq(Color c, Bitboard b) { return c == WHITE ? msb(b) : lsb(b); } +inline Square backmost_sq(Color c, Bitboard b) { return c == WHITE ? lsb(b) : msb(b); } -#endif // !defined(BITBOARD_H_INCLUDED) +#endif // #ifndef BITBOARD_H_INCLUDED