X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbitboard.cpp;h=9adf1407bd5471436e360b79aa4af7eb30f4065a;hp=7687cbb4441cb5cf66c40277c39a5532be4f8178;hb=c9dcda6ac488c0058ebd567e1f52e30b8cd0db20;hpb=091aff044516fcd8700a8a194f9e9ffaabed8bb4 diff --git a/src/bitboard.cpp b/src/bitboard.cpp index 7687cbb4..9adf1407 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) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2008-2014 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 @@ -19,11 +19,10 @@ #include #include -#include +#include #include "bitboard.h" #include "bitcount.h" -#include "misc.h" #include "rkiss.h" CACHE_LINE_ALIGNMENT @@ -81,8 +80,8 @@ namespace { } } -/// 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. +/// lsb()/msb() finds the least/most significant bit in a non-zero bitboard. +/// pop_lsb() finds and clears the least significant bit in a non-zero bitboard. #ifndef USE_BSFQ @@ -120,55 +119,49 @@ Square msb(Bitboard b) { result += 8; } - return (Square)(result + MS1BTable[b32]); + return Square(result + MS1BTable[b32]); } #endif // ifndef USE_BSFQ -/// Bitboards::print() prints a bitboard in an easily readable format to the -/// standard output. This is sometimes useful for debugging. +/// Bitboards::pretty() returns an ASCII representation of a bitboard to be +/// printed to standard output. This is sometimes useful for debugging. -void Bitboards::print(Bitboard b) { +const std::string Bitboards::pretty(Bitboard b) { - sync_cout; + std::ostringstream ss; for (Rank rank = RANK_8; rank >= RANK_1; --rank) { - std::cout << "+---+---+---+---+---+---+---+---+" << '\n'; + ss << "+---+---+---+---+---+---+---+---+" << '\n'; for (File file = FILE_A; file <= FILE_H; ++file) - std::cout << "| " << (b & (file | rank) ? "X " : " "); + ss << "| " << (b & (file | rank) ? "X " : " "); - std::cout << "|\n"; + ss << "|\n"; } - std::cout << "+---+---+---+---+---+---+---+---+" << sync_endl; + ss << "+---+---+---+---+---+---+---+---+"; + return ss.str(); } -/// Bitboards::init() initializes various bitboard arrays. It is called during -/// program initialization. +/// Bitboards::init() initializes various bitboard tables. It is called at +/// startup and relies on global objects to be already zero-initialized. void Bitboards::init() { - for (int k = 0, i = 0; i < 8; ++i) - while (k < (2 << i)) - MS1BTable[k++] = i; - - for (int i = 0; i < 64; ++i) - BSFTable[bsf_index(1ULL << i)] = Square(i); - for (Square s = SQ_A1; s <= SQ_H8; ++s) - SquareBB[s] = 1ULL << s; + BSFTable[bsf_index(SquareBB[s] = 1ULL << s)] = s; - FileBB[FILE_A] = FileABB; - RankBB[RANK_1] = Rank1BB; + for (Bitboard b = 1; b < 256; ++b) + MS1BTable[b] = more_than_one(b) ? MS1BTable[b - 1] : lsb(b); - for (int i = 1; i < 8; ++i) - { - FileBB[i] = FileBB[i - 1] << 1; - RankBB[i] = RankBB[i - 1] << 8; - } + for (File f = FILE_A; f <= FILE_H; ++f) + FileBB[f] = f > FILE_A ? FileBB[f - 1] << 1 : FileABB; + + for (Rank r = RANK_1; r <= RANK_8; ++r) + RankBB[r] = r > RANK_1 ? RankBB[r - 1] << 8 : Rank1BB; 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); @@ -186,11 +179,11 @@ void Bitboards::init() { 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)); if (s1 != s2) - DistanceRingsBB[s1][SquareDistance[s1][s2] - 1] |= s2; - } + { + SquareDistance[s1][s2] = std::max(file_distance(s1, s2), rank_distance(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 } }; @@ -198,9 +191,9 @@ void Bitboards::init() { for (Color c = WHITE; c <= BLACK; ++c) for (PieceType pt = PAWN; pt <= KING; ++pt) for (Square s = SQ_A1; s <= SQ_H8; ++s) - for (int k = 0; steps[pt][k]; ++k) + for (int i = 0; steps[pt][i]; ++i) { - Square to = s + Square(c == WHITE ? steps[pt][k] : -steps[pt][k]); + Square to = s + Square(c == WHITE ? steps[pt][i] : -steps[pt][i]); if (is_ok(to) && square_distance(s, to) < 3) StepAttacksBB[make_piece(c, pt)][s] |= to; @@ -212,24 +205,23 @@ void Bitboards::init() { init_magics(RTable, RAttacks, RMagics, RMasks, RShifts, RDeltas, magic_index); init_magics(BTable, BAttacks, BMagics, BMasks, BShifts, BDeltas, magic_index); - for (Square s = SQ_A1; s <= SQ_H8; ++s) + for (Square s1 = SQ_A1; s1 <= SQ_H8; ++s1) { - PseudoAttacks[QUEEN][s] = PseudoAttacks[BISHOP][s] = attacks_bb(s, 0); - PseudoAttacks[QUEEN][s] |= PseudoAttacks[ ROOK][s] = attacks_bb< ROOK>(s, 0); - } + PseudoAttacks[QUEEN][s1] = PseudoAttacks[BISHOP][s1] = attacks_bb(s1, 0); + PseudoAttacks[QUEEN][s1] |= PseudoAttacks[ ROOK][s1] = attacks_bb< ROOK>(s1, 0); - for (Square s1 = SQ_A1; s1 <= SQ_H8; ++s1) for (Square s2 = SQ_A1; s2 <= SQ_H8; ++s2) - if (PseudoAttacks[QUEEN][s1] & s2) - { - Square delta = (s2 - s1) / square_distance(s1, s2); + { + Piece pc = (PseudoAttacks[BISHOP][s1] & s2) ? W_BISHOP : + (PseudoAttacks[ROOK][s1] & s2) ? W_ROOK : NO_PIECE; - for (Square s = s1 + delta; s != s2; s += delta) - BetweenBB[s1][s2] |= s; + if (pc == NO_PIECE) + continue; - PieceType pc = (PseudoAttacks[BISHOP][s1] & s2) ? BISHOP : ROOK; - LineBB[s1][s2] = (PseudoAttacks[pc][s1] & PseudoAttacks[pc][s2]) | s1 | s2; - } + LineBB[s1][s2] = (attacks_bb(pc, s1, 0) & attacks_bb(pc, s2, 0)) | s1 | s2; + BetweenBB[s1][s2] = attacks_bb(pc, s1, SquareBB[s2]) & attacks_bb(pc, s2, SquareBB[s1]); + } + } } @@ -257,7 +249,7 @@ namespace { Bitboard pick_random(RKISS& rk, int booster) { // Values s1 and s2 are used to rotate the candidate magic of a - // quantity known to be the optimal to quickly find the magics. + // quantity known to be optimal to quickly find the magics. int s1 = booster & 63, s2 = (booster >> 6) & 63; Bitboard m = rk.rand();