X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbitboard.h;h=ed7e318ca3198ed970aa9508752bf10e1e7d4ded;hp=f6f1eba681e6d0030d0e8dccba75565bf9c82070;hb=69eb391cd779223c331fb0de80392cbd323055a9;hpb=6c040c821a50475840607ef5f11c270ee21d61da diff --git a/src/bitboard.h b/src/bitboard.h index f6f1eba6..ed7e318c 100644 --- a/src/bitboard.h +++ b/src/bitboard.h @@ -2,13 +2,13 @@ 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) 2015-2017 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 @@ -61,22 +61,11 @@ 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]; @@ -84,6 +73,33 @@ 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]; + + +/// Magic holds all magic bitboards relevant data for a single square +struct Magic { + Bitboard mask; + Bitboard magic; + Bitboard* attacks; + unsigned shift; + + /// looks up the index using the 'magic bitboards' approach. + unsigned index(Bitboard occupied) const { + + if (HasPext) + return unsigned(pext(occupied, mask)); + + if (Is64Bit) + return unsigned(((occupied & mask) * magic) >> shift); + + unsigned lo = unsigned(occupied) & unsigned(mask); + unsigned hi = unsigned(occupied >> 32) & unsigned(mask >> 32); + return (lo * unsigned(magic) ^ hi * unsigned(magic >> 32)) >> shift; + } +}; + +extern Magic RookMagics[SQUARE_NB]; +extern Magic BishopMagics[SQUARE_NB]; /// Overloads of bitwise operators between a Bitboard and a Square for testing @@ -134,13 +150,13 @@ inline Bitboard file_bb(Square s) { } -/// shift_bb() moves a bitboard one step along direction Delta. Mainly for pawns +/// shift() moves a bitboard one step along direction D. 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 +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; } @@ -174,7 +190,7 @@ inline Bitboard in_front_bb(Color c, Rank r) { /// 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) +/// 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]; @@ -184,7 +200,7 @@ inline Bitboard forward_bb(Color c, Square 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); +/// PawnAttackSpan[c][s] = in_front_bb(c, rank_of(s)) & adjacent_files_bb(file_of(s)); inline Bitboard pawn_attack_span(Color c, Square s) { return PawnAttackSpan[c][s]; @@ -200,14 +216,6 @@ inline Bitboard passed_pawn_mask(Color c, Square s) { } -/// squares_of_color() returns a bitboard representing all the squares of the -/// same color of the given one. - -inline Bitboard squares_of_color(Square s) { - return DarkSquares & s ? DarkSquares : ~DarkSquares; -} - - /// aligned() returns true if the squares s1, s2 and s3 are aligned either on a /// straight or on a diagonal line. @@ -228,93 +236,84 @@ template<> inline int distance(Square x, Square y) { return distance(rank_ /// 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) { - - 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])); - - if (Is64Bit) - return unsigned(((occupied & Masks[s]) * Magics[s]) >> Shifts[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]; -} +/// piece of type Pt (bishop or rook) placed on 's'. template inline Bitboard attacks_bb(Square s, Bitboard occupied) { - return (Pt == ROOK ? RookAttacks : BishopAttacks)[s][magic_index(s, occupied)]; + + const Magic& M = Pt == ROOK ? RookMagics[s] : BishopMagics[s]; + return M.attacks[M.index(occupied)]; } -inline Bitboard attacks_bb(Piece pc, Square s, Bitboard occupied) { +inline Bitboard attacks_bb(PieceType pt, Square s, Bitboard occupied) { - switch (type_of(pc)) + assert(pt != PAWN); + + switch (pt) { case BISHOP: return attacks_bb(s, occupied); - case ROOK : return attacks_bb(s, occupied); + case ROOK : return attacks_bb< ROOK>(s, occupied); case QUEEN : return attacks_bb(s, occupied) | attacks_bb(s, occupied); - default : return StepAttacksBB[pc][s]; + default : return PseudoAttacks[pt][s]; } } -/// lsb() and msb() return the least/most significant bit in a non-zero bitboard +/// popcount() counts the number of non-zero bits in a bitboard -#ifdef USE_BSFQ +inline int popcount(Bitboard b) { -# if defined(_MSC_VER) && !defined(__INTEL_COMPILER) +#ifndef USE_POPCNT -inline Square lsb(Bitboard b) { - unsigned long idx; - _BitScanForward64(&idx, b); - return (Square) idx; -} + 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]]; -inline Square msb(Bitboard b) { - unsigned long idx; - _BitScanReverse64(&idx, b); - return (Square) idx; -} +#elif defined(_MSC_VER) || defined(__INTEL_COMPILER) -# elif defined(__arm__) + return (int)_mm_popcnt_u64(b); -inline int lsb32(uint32_t v) { - __asm__("rbit %0, %1" : "=r"(v) : "r"(v)); - return __builtin_clz(v); -} +#else // Assumed gcc or compatible compiler -inline Square msb(Bitboard b) { - return (Square) (63 - __builtin_clzll(b)); + return __builtin_popcountll(b); + +#endif } + +/// lsb() and msb() return the least/most significant bit in a non-zero bitboard + +#if defined(__GNUC__) + inline Square lsb(Bitboard b) { - return (Square) (uint32_t(b) ? lsb32(uint32_t(b)) : 32 + lsb32(uint32_t(b >> 32))); + assert(b); + return Square(__builtin_ctzll(b)); +} + +inline Square msb(Bitboard b) { + assert(b); + return Square(63 ^ __builtin_clzll(b)); } -# else // Assumed gcc or compatible compiler +#elif defined(_WIN64) && defined(_MSC_VER) -inline Square lsb(Bitboard b) { // Assembly code by Heinz van Saanen - Bitboard idx; - __asm__("bsfq %1, %0": "=r"(idx): "rm"(b) ); +inline Square lsb(Bitboard b) { + assert(b); + unsigned long idx; + _BitScanForward64(&idx, b); return (Square) idx; } inline Square msb(Bitboard b) { - Bitboard idx; - __asm__("bsrq %1, %0": "=r"(idx): "rm"(b) ); + assert(b); + unsigned long idx; + _BitScanReverse64(&idx, b); return (Square) idx; } -# endif +#else -#else // ifdef(USE_BSFQ) +#define NO_BSF // Fallback on software implementation for other cases Square lsb(Bitboard b); Square msb(Bitboard b);