X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbitboard.cpp;h=9598aa706552f5f38da88c50bc7b734dd6b35919;hp=dd5b57995056a356b0b2235253596e6e8bd7325b;hb=49e110c52b19f5c99954d4797b8e991b0b60007c;hpb=09acdac56bd419a68126e8a0ac6dc868d3d11ec5 diff --git a/src/bitboard.cpp b/src/bitboard.cpp index dd5b5799..9598aa70 100644 --- a/src/bitboard.cpp +++ b/src/bitboard.cpp @@ -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) 2008-2013 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 @@ -28,45 +28,43 @@ CACHE_LINE_ALIGNMENT -Bitboard RMasks[64]; -Bitboard RMagics[64]; -Bitboard* RAttacks[64]; -unsigned RShifts[64]; - -Bitboard BMasks[64]; -Bitboard BMagics[64]; -Bitboard* BAttacks[64]; -unsigned BShifts[64]; - -Bitboard SquareBB[64]; -Bitboard FileBB[8]; -Bitboard RankBB[8]; -Bitboard AdjacentFilesBB[8]; -Bitboard ThisAndAdjacentFilesBB[8]; -Bitboard InFrontBB[2][8]; -Bitboard StepAttacksBB[16][64]; -Bitboard BetweenBB[64][64]; -Bitboard DistanceRingsBB[64][8]; -Bitboard ForwardBB[2][64]; -Bitboard PassedPawnMask[2][64]; -Bitboard AttackSpanMask[2][64]; -Bitboard PseudoAttacks[6][64]; - -int SquareDistance[64][64]; +Bitboard RMasks[SQUARE_NB]; +Bitboard RMagics[SQUARE_NB]; +Bitboard* RAttacks[SQUARE_NB]; +unsigned RShifts[SQUARE_NB]; + +Bitboard BMasks[SQUARE_NB]; +Bitboard BMagics[SQUARE_NB]; +Bitboard* BAttacks[SQUARE_NB]; +unsigned BShifts[SQUARE_NB]; + +Bitboard SquareBB[SQUARE_NB]; +Bitboard FileBB[FILE_NB]; +Bitboard RankBB[RANK_NB]; +Bitboard AdjacentFilesBB[FILE_NB]; +Bitboard InFrontBB[COLOR_NB][RANK_NB]; +Bitboard StepAttacksBB[PIECE_NB][SQUARE_NB]; +Bitboard BetweenBB[SQUARE_NB][SQUARE_NB]; +Bitboard DistanceRingsBB[SQUARE_NB][8]; +Bitboard ForwardBB[COLOR_NB][SQUARE_NB]; +Bitboard PassedPawnMask[COLOR_NB][SQUARE_NB]; +Bitboard PawnAttackSpan[COLOR_NB][SQUARE_NB]; +Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB]; + +int SquareDistance[SQUARE_NB][SQUARE_NB]; namespace { // De Bruijn sequences. See chessprogramming.wikispaces.com/BitScan - const uint64_t DeBruijn_64 = 0x218A392CD3D5DBFULL; + const uint64_t DeBruijn_64 = 0x3F79D71B4CB0A89ULL; const uint32_t DeBruijn_32 = 0x783A9B23; CACHE_LINE_ALIGNMENT int MS1BTable[256]; - Square BSFTable[64]; + Square BSFTable[SQUARE_NB]; Bitboard RTable[0x19000]; // Storage space for rook attacks Bitboard BTable[0x1480]; // Storage space for bishop attacks - uint8_t BitCount8Bit[256]; typedef unsigned (Fn)(Square, Bitboard); @@ -75,19 +73,17 @@ namespace { FORCE_INLINE unsigned bsf_index(Bitboard b) { - if (Is64Bit) - return ((b & -b) * DeBruijn_64) >> 58; - - // Use Matt Taylor's folding trick for 32 bit systems + // Matt Taylor's folding for 32 bit systems, extended to 64 bits by Kim Walisch b ^= (b - 1); - return ((unsigned(b) ^ unsigned(b >> 32)) * DeBruijn_32) >> 26; + return Is64Bit ? (b * DeBruijn_64) >> 58 + : ((unsigned(b) ^ unsigned(b >> 32)) * DeBruijn_32) >> 26; } } /// 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. -#if !defined(USE_BSFQ) +#ifndef USE_BSFQ Square lsb(Bitboard b) { return BSFTable[bsf_index(b)]; } @@ -126,7 +122,7 @@ Square msb(Bitboard b) { return (Square)(result + MS1BTable[b32]); } -#endif // !defined(USE_BSFQ) +#endif // ifndef USE_BSFQ /// Bitboards::print() prints a bitboard in an easily readable format to the @@ -161,9 +157,6 @@ void Bitboards::init() { for (int i = 0; i < 64; i++) BSFTable[bsf_index(1ULL << i)] = Square(i); - for (Bitboard b = 0; b < 256; b++) - BitCount8Bit[b] = (uint8_t)popcount(b); - for (Square s = SQ_A1; s <= SQ_H8; s++) SquareBB[s] = 1ULL << s; @@ -177,10 +170,7 @@ void Bitboards::init() { } for (File f = FILE_A; f <= FILE_H; f++) - { AdjacentFilesBB[f] = (f > FILE_A ? FileBB[f - 1] : 0) | (f < FILE_H ? FileBB[f + 1] : 0); - ThisAndAdjacentFilesBB[f] = FileBB[f] | AdjacentFilesBB[f]; - } for (Rank r = RANK_1; r < RANK_8; r++) InFrontBB[WHITE][r] = ~(InFrontBB[BLACK][r + 1] = InFrontBB[BLACK][r] | RankBB[r]); @@ -189,19 +179,17 @@ void Bitboards::init() { for (Square s = SQ_A1; s <= SQ_H8; s++) { ForwardBB[c][s] = InFrontBB[c][rank_of(s)] & FileBB[file_of(s)]; - PassedPawnMask[c][s] = InFrontBB[c][rank_of(s)] & ThisAndAdjacentFilesBB[file_of(s)]; - AttackSpanMask[c][s] = InFrontBB[c][rank_of(s)] & AdjacentFilesBB[file_of(s)]; + PawnAttackSpan[c][s] = InFrontBB[c][rank_of(s)] & AdjacentFilesBB[file_of(s)]; + PassedPawnMask[c][s] = ForwardBB[c][s] | PawnAttackSpan[c][s]; } for (Square s1 = SQ_A1; s1 <= SQ_H8; s1++) for (Square s2 = SQ_A1; s2 <= SQ_H8; s2++) + { SquareDistance[s1][s2] = std::max(file_distance(s1, s2), rank_distance(s1, s2)); - - for (Square s1 = SQ_A1; s1 <= SQ_H8; s1++) - for (int d = 1; d < 8; d++) - for (Square s2 = SQ_A1; s2 <= SQ_H8; s2++) - if (SquareDistance[s1][s2] == d) - DistanceRingsBB[s1][d - 1] |= s2; + if (s1 != s2) + DistanceRingsBB[s1][SquareDistance[s1][s2] - 1] |= s2; + } int steps[][9] = { {}, { 7, 9 }, { 17, 15, 10, 6, -6, -10, -15, -17 }, {}, {}, {}, { 9, 7, -7, -9, 8, 1, -1, -8 } }; @@ -326,9 +314,9 @@ namespace { // until we find the one that passes the verification test. do { do magics[s] = pick_random(rk, booster); - while (BitCount8Bit[(magics[s] * masks[s]) >> 56] < 6); + while (popcount((magics[s] * masks[s]) >> 56) < 6); - memset(attacks[s], 0, size * sizeof(Bitboard)); + std::memset(attacks[s], 0, size * sizeof(Bitboard)); // A good magic must map every possible occupancy to an index that // looks up the correct sliding attack in the attacks[s] database.