X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbitboard.h;h=aa4e17119c1b5f7e81c56631641e8916c369d2d5;hp=ce198c22c4b9a628aefd18b3adcbe1b68cd46322;hb=6fa6da3ee13d2b7bdbec3cd24ff8ca43233c74fb;hpb=b05fbb3733df535a3fdf99e8d832001e57929699 diff --git a/src/bitboard.h b/src/bitboard.h index ce198c22..aa4e1711 100644 --- a/src/bitboard.h +++ b/src/bitboard.h @@ -1,7 +1,7 @@ /* Stockfish, a UCI chess playing engine derived from Glaurung 2.1 Copyright (C) 2004-2008 Tord Romstad (Glaurung author) - Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -18,72 +18,104 @@ along with this program. If not, see . */ -#if !defined(BITBOARD_H_INCLUDED) +#ifndef BITBOARD_H_INCLUDED #define BITBOARD_H_INCLUDED -#include "types.h" - -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]; +#include -extern Bitboard StepAttacksBB[16][64]; -extern Bitboard BetweenBB[64][64]; - -extern Bitboard SquaresInFrontMask[2][64]; -extern Bitboard PassedPawnMask[2][64]; -extern Bitboard AttackSpanMask[2][64]; - -extern uint64_t RMagics[64]; -extern int RShifts[64]; -extern Bitboard RMasks[64]; -extern Bitboard* RAttacks[64]; +#include "types.h" -extern uint64_t BMagics[64]; -extern int BShifts[64]; -extern Bitboard BMasks[64]; -extern Bitboard* BAttacks[64]; +namespace Bitbases { -extern Bitboard PseudoAttacks[6][64]; +void init(); +bool probe(Square wksq, Square wpsq, Square bksq, Color us); -extern uint8_t BitCount8Bit[256]; +} +namespace Bitboards { -/// Functions for testing whether a given bit is set in a bitboard, and for -/// setting and clearing bits. +void init(); +const std::string pretty(Bitboard b); -inline Bitboard bit_is_set(Bitboard b, Square s) { - return b & SetMaskBB[s]; } -inline void set_bit(Bitboard* b, Square s) { - *b |= SetMaskBB[s]; +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; + +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 int SquareDistance[SQUARE_NB][SQUARE_NB]; + +extern Bitboard RookMasks [SQUARE_NB]; +extern Bitboard RookMagics [SQUARE_NB]; +extern Bitboard* RookAttacks[SQUARE_NB]; +extern unsigned RookShifts [SQUARE_NB]; + +extern Bitboard BishopMasks [SQUARE_NB]; +extern Bitboard BishopMagics [SQUARE_NB]; +extern Bitboard* BishopAttacks[SQUARE_NB]; +extern unsigned BishopShifts [SQUARE_NB]; + +extern Bitboard SquareBB[SQUARE_NB]; +extern Bitboard FileBB[FILE_NB]; +extern Bitboard RankBB[RANK_NB]; +extern Bitboard AdjacentFilesBB[FILE_NB]; +extern Bitboard InFrontBB[COLOR_NB][RANK_NB]; +extern Bitboard StepAttacksBB[PIECE_NB][SQUARE_NB]; +extern Bitboard BetweenBB[SQUARE_NB][SQUARE_NB]; +extern Bitboard LineBB[SQUARE_NB][SQUARE_NB]; +extern Bitboard DistanceRingBB[SQUARE_NB][8]; +extern Bitboard ForwardBB[COLOR_NB][SQUARE_NB]; +extern Bitboard PassedPawnMask[COLOR_NB][SQUARE_NB]; +extern Bitboard PawnAttackSpan[COLOR_NB][SQUARE_NB]; +extern Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB]; + + +/// Overloads of bitwise operators between a Bitboard and a Square for testing +/// whether a given bit is set in a bitboard, and for setting and clearing bits. + +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& operator|=(Bitboard& b, Square s) { + return b |= SquareBB[s]; +} -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]; @@ -102,173 +134,207 @@ inline Bitboard file_bb(Square s) { } -/// neighboring_files_bb takes a file as input and returns a bitboard representing -/// all squares on the neighboring files. +/// shift_bb() moves a bitboard one step along direction Delta. Mainly for pawns -inline Bitboard neighboring_files_bb(File f) { - return NeighboringFilesBB[f]; +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; } -/// this_and_neighboring_files_bb takes a file 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]; } -/// 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. +/// 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() 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, s) & file_bb(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. +inline Bitboard forward_bb(Color c, Square s) { + return ForwardBB[c][s]; +} -#if defined(IS_64BIT) -FORCE_INLINE unsigned rook_index(Square s, Bitboard occ) { - return unsigned(((occ & RMasks[s]) * RMagics[s]) >> RShifts[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); -FORCE_INLINE unsigned bishop_index(Square s, Bitboard occ) { - return unsigned(((occ & BMasks[s]) * BMagics[s]) >> BShifts[s]); +inline Bitboard pawn_attack_span(Color c, Square s) { + return PawnAttackSpan[c][s]; } -#else // if !defined(IS_64BIT) -FORCE_INLINE unsigned rook_index(Square s, Bitboard occ) { - Bitboard b = occ & RMasks[s]; - return unsigned(int(b) * int(RMagics[s]) ^ int(b >> 32) * int(RMagics[s] >> 32)) >> RShifts[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) -FORCE_INLINE unsigned bishop_index(Square s, Bitboard occ) { - Bitboard b = occ & BMasks[s]; - return unsigned(int(b) * int(BMagics[s]) ^ int(b >> 32) * int(BMagics[s] >> 32)) >> BShifts[s]; +inline Bitboard passed_pawn_mask(Color c, Square s) { + return PassedPawnMask[c][s]; } -#endif -inline Bitboard rook_attacks_bb(Square s, Bitboard occ) { - return RAttacks[s][rook_index(s, occ)]; -} -inline Bitboard bishop_attacks_bb(Square s, Bitboard occ) { - return BAttacks[s][bishop_index(s, occ)]; -} +/// squares_of_color() returns a bitboard representing all the squares of the +/// same color of the given one. -inline Bitboard queen_attacks_bb(Square s, Bitboard blockers) { - return rook_attacks_bb(s, blockers) | bishop_attacks_bb(s, blockers); +inline Bitboard squares_of_color(Square s) { + return DarkSquares & s ? DarkSquares : ~DarkSquares; } -/// 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. +/// aligned() returns true if the squares s1, s2 and s3 are aligned either on a +/// straight or on a diagonal line. -inline Bitboard squares_between(Square s1, Square s2) { - return BetweenBB[s1][s2]; +inline bool aligned(Square s1, Square s2, Square s3) { + return LineBB[s1][s2] & s3; } -/// 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) +/// 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_in_front_of(Color c, Square s) { - return SquaresInFrontMask[c][s]; -} +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)); } -/// 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) -inline Bitboard passed_pawn_mask(Color c, Square s) { - return PassedPawnMask[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. +template +FORCE_INLINE unsigned magic_index(Square s, Bitboard occupied) { + + Bitboard* const Masks = Pt == ROOK ? RookMasks : BishopMasks; + Bitboard* const Magics = Pt == ROOK ? RookMagics : BishopMagics; + unsigned* const Shifts = Pt == ROOK ? RookShifts : BishopShifts; + if (HasPext) + return unsigned(pext(occupied, Masks[s])); -/// 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); + if (Is64Bit) + return unsigned(((occupied & Masks[s]) * Magics[s]) >> Shifts[s]); -inline Bitboard attack_span_mask(Color c, Square s) { - return AttackSpanMask[c][s]; + 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 occupied) { + return (Pt == ROOK ? RookAttacks : BishopAttacks)[s][magic_index(s, occupied)]; +} -/// squares_aligned returns true if the squares s1, s2 and s3 are aligned -/// either on a straight or on a diagonal line. +inline Bitboard attacks_bb(Piece pc, Square s, Bitboard occupied) { -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]); + 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]; + } } -/// same_color_squares() returns a bitboard representing all squares with -/// the same color of the given square. +/// lsb() and msb() return the least/most significant bit in a non-zero bitboard + +#ifdef USE_BSFQ + +# if defined(_MSC_VER) && !defined(__INTEL_COMPILER) -inline Bitboard same_color_squares(Square s) { - return bit_is_set(0xAA55AA55AA55AA55ULL, s) ? 0xAA55AA55AA55AA55ULL - : ~0xAA55AA55AA55AA55ULL; +FORCE_INLINE Square lsb(Bitboard b) { + unsigned long idx; + _BitScanForward64(&idx, b); + return (Square) idx; } +FORCE_INLINE Square msb(Bitboard b) { + unsigned long idx; + _BitScanReverse64(&idx, b); + return (Square) idx; +} -/// 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. +# elif defined(__arm__) -#if defined(USE_BSFQ) +FORCE_INLINE int lsb32(uint32_t v) { + __asm__("rbit %0, %1" : "=r"(v) : "r"(v)); + return __builtin_clz(v); +} -#if defined(_MSC_VER) && !defined(__INTEL_COMPILER) +FORCE_INLINE Square msb(Bitboard b) { + return (Square) (63 - __builtin_clzll(b)); +} -FORCE_INLINE Square first_1(Bitboard b) { - unsigned long index; - _BitScanForward64(&index, b); - return (Square) index; +FORCE_INLINE Square lsb(Bitboard b) { + return (Square) (uint32_t(b) ? lsb32(uint32_t(b)) : 32 + lsb32(uint32_t(b >> 32))); } -#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; +# else // Assumed gcc or compatible compiler + +FORCE_INLINE Square lsb(Bitboard b) { // Assembly code by Heinz van Saanen + Bitboard idx; + __asm__("bsfq %1, %0": "=r"(idx): "rm"(b) ); + return (Square) idx; } -#endif -FORCE_INLINE Square pop_1st_bit(Bitboard* b) { - const Square s = first_1(*b); - *b &= ~(1ULL<