X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbitboard.h;h=3ea92bdf2e56400b273cafaf4f1689bc12a5de7e;hp=77a824ba62106965ba9513803a19c650c092bb4c;hb=659990b43ff1a089be9878561048fa4c60ba2705;hpb=f256388e0808b45d8468b088cdc141a41feac3fb diff --git a/src/bitboard.h b/src/bitboard.h index 77a824ba..3ea92bdf 100644 --- a/src/bitboard.h +++ b/src/bitboard.h @@ -2,7 +2,7 @@ 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) 2015-2016 Marco Costalba, Joona Kiiski, Gary Linscott, 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 @@ -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 +73,7 @@ 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]; /// Overloads of bitwise operators between a Bitboard and a Square for testing @@ -134,13 +124,13 @@ 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 +164,7 @@ 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 +174,7 @@ 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(s); inline Bitboard pawn_attack_span(Color c, Square s) { return PawnAttackSpan[c][s]; @@ -219,44 +209,85 @@ template<> inline int distance(Square x, Square y) { return distance(file_ template<> inline int distance(Square x, Square y) { return distance(rank_of(x), rank_of(y)); } +/// Magic holds all magic relevant data for a single square +struct Magic { + + Bitboard mask; + Bitboard magic; + Bitboard* attacks; + unsigned shift; +}; + /// 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; + extern Magic RookMagics[SQUARE_NB]; + extern Magic BishopMagics[SQUARE_NB]; + + const Magic* Magics = Pt == ROOK ? RookMagics : BishopMagics; + Bitboard mask = Magics[s].mask; + Bitboard magic = Magics[s].magic; + unsigned shift = Magics[s].shift; if (HasPext) - return unsigned(pext(occupied, Masks[s])); + return unsigned(pext(occupied, mask)); if (Is64Bit) - return unsigned(((occupied & Masks[s]) * Magics[s]) >> Shifts[s]); + return unsigned(((occupied & mask) * magic) >> shift); - 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]; + unsigned lo = unsigned(occupied) & unsigned(mask); + unsigned hi = unsigned(occupied >> 32) & unsigned(mask >> 32); + return (lo * unsigned(magic) ^ hi * unsigned(magic >> 32)) >> shift; } template inline Bitboard attacks_bb(Square s, Bitboard occupied) { - return (Pt == ROOK ? RookAttacks : BishopAttacks)[s][magic_index(s, occupied)]; + + extern Magic RookMagics[SQUARE_NB]; + extern Magic BishopMagics[SQUARE_NB]; + + return (Pt == ROOK ? RookMagics : BishopMagics)[s].attacks[magic_index(s, occupied)]; } -inline Bitboard attacks_bb(Piece pc, Square s, Bitboard occupied) { +inline Bitboard attacks_bb(PieceType pt, Square s, Bitboard occupied) { + + assert(pt != PAWN); - switch (type_of(pc)) + 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 StepAttacksBB[pc][s]; + default : return PseudoAttacks[pt][s]; } } +/// 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); + +#endif +} + + /// lsb() and msb() return the least/most significant bit in a non-zero bitboard #if defined(__GNUC__) @@ -268,7 +299,7 @@ inline Square lsb(Bitboard b) { inline Square msb(Bitboard b) { assert(b); - return Square(63 - __builtin_clzll(b)); + return Square(63 ^ __builtin_clzll(b)); } #elif defined(_WIN64) && defined(_MSC_VER)