X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbitboard.h;h=63f668b9b8a7307243c1146d55e079c1a713e5d7;hp=390966e3494273969bdb53a50c6953a6c9782611;hb=2c237da54647bb7526f3512bea183eb44919cdda;hpb=5e4cd3fc0d4b88eeb09ae458b9cb9f73db8c4ae7 diff --git a/src/bitboard.h b/src/bitboard.h index 390966e3..63f668b9 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 @@ -66,7 +66,6 @@ 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]; @@ -74,6 +73,19 @@ 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; +}; + +extern Magic RookMagics[SQUARE_NB]; +extern Magic BishopMagics[SQUARE_NB]; /// Overloads of bitwise operators between a Bitboard and a Square for testing @@ -124,13 +136,13 @@ 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; } @@ -164,7 +176,7 @@ 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]; @@ -174,7 +186,7 @@ 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]; @@ -212,48 +224,36 @@ 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) { - - 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]; - - Bitboard* const Masks = Pt == ROOK ? RookMasks : BishopMasks; - Bitboard* const Magics = Pt == ROOK ? RookMagics : BishopMagics; - unsigned* const Shifts = Pt == ROOK ? RookShifts : BishopShifts; +inline unsigned magic_index(const Magic& m, Bitboard occupied) { if (HasPext) - return unsigned(pext(occupied, Masks[s])); + return unsigned(pext(occupied, m.mask)); if (Is64Bit) - return unsigned(((occupied & Masks[s]) * Magics[s]) >> Shifts[s]); + return unsigned(((occupied & m.mask) * m.magic) >> m.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(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) { - extern Bitboard* RookAttacks[SQUARE_NB]; - extern Bitboard* BishopAttacks[SQUARE_NB]; - - return (Pt == ROOK ? RookAttacks : BishopAttacks)[s][magic_index(s, occupied)]; + const Magic& M = Pt == ROOK ? RookMagics[s] : BishopMagics[s]; + return M.attacks[magic_index(M, 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 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]; } } @@ -291,7 +291,7 @@ 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)