X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbitboard.cpp;h=ff10b4ff7026524955953dc0d76806b3e32b2d3f;hp=19599a5124bdc54cf4e93a9b77c2b02a45a62b39;hb=9b30913996355f7d18eb18f1510620380921f1f2;hpb=a8af78c833458adaea64b8fc1035fafbdf4ba083 diff --git a/src/bitboard.cpp b/src/bitboard.cpp index 19599a51..ff10b4ff 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 @@ -18,8 +18,7 @@ */ #include -#include -#include +#include // For memset #include "bitboard.h" #include "bitcount.h" @@ -119,7 +118,7 @@ Square msb(Bitboard b) { result += 8; } - return (Square)(result + MS1BTable[b32]); + return Square(result + MS1BTable[b32]); } #endif // ifndef USE_BSFQ @@ -130,45 +129,39 @@ Square msb(Bitboard b) { const std::string Bitboards::pretty(Bitboard b) { - std::ostringstream ss; + std::string s = "+---+---+---+---+---+---+---+---+\n"; - for (Rank rank = RANK_8; rank >= RANK_1; --rank) + for (Rank r = RANK_8; r >= RANK_1; --r) { - ss << "+---+---+---+---+---+---+---+---+" << '\n'; + for (File f = FILE_A; f <= FILE_H; ++f) + s.append(b & make_square(f, r) ? "| X " : "| "); - for (File file = FILE_A; file <= FILE_H; ++file) - ss << "| " << (b & (file | rank) ? "X " : " "); - - ss << "|\n"; + s.append("|\n+---+---+---+---+---+---+---+---+\n"); } - ss << "+---+---+---+---+---+---+---+---+"; - return ss.str(); + + return s; } -/// 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])] = 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 } }; @@ -253,20 +246,6 @@ 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 optimal to quickly find the magics. - int s1 = booster & 63, s2 = (booster >> 6) & 63; - - Bitboard m = rk.rand(); - m = (m >> s1) | (m << (64 - s1)); - m &= rk.rand(); - m = (m >> s2) | (m << (64 - s2)); - return m & rk.rand(); - } - - // init_magics() computes all rook and bishop attacks at startup. Magic // bitboards are used to look up attacks of sliding pieces. As a reference see // chessprogramming.wikispaces.com/Magic+Bitboards. In particular, here we @@ -275,8 +254,9 @@ namespace { void init_magics(Bitboard table[], Bitboard* attacks[], Bitboard magics[], Bitboard masks[], unsigned shifts[], Square deltas[], Fn index) { - int MagicBoosters[][8] = { { 3191, 2184, 1310, 3618, 2091, 1308, 2452, 3996 }, - { 1059, 3608, 605, 3234, 3326, 38, 2029, 3043 } }; + int MagicBoosters[][8] = { { 969, 1976, 2850, 542, 2069, 2852, 1708, 164 }, + { 3101, 552, 3555, 926, 834, 26, 2131, 1117 } }; + RKISS rk; Bitboard occupancy[4096], reference[4096], edges, b; int i, size, booster; @@ -302,7 +282,12 @@ namespace { b = size = 0; do { occupancy[size] = b; - reference[size++] = sliding_attack(deltas, s, b); + reference[size] = sliding_attack(deltas, s, b); + + if (HasPext) + attacks[s][_pext_u64(b, masks[s])] = reference[size]; + + size++; b = (b - masks[s]) & masks[s]; } while (b); @@ -311,12 +296,16 @@ namespace { if (s < SQ_H8) attacks[s + 1] = attacks[s] + size; + if (HasPext) + continue; + booster = MagicBoosters[Is64Bit][rank_of(s)]; // Find a magic for square 's' picking up an (almost) random number // until we find the one that passes the verification test. do { - do magics[s] = pick_random(rk, booster); + do + magics[s] = rk.magic_rand(booster); while (popcount((magics[s] * masks[s]) >> 56) < 6); std::memset(attacks[s], 0, size * sizeof(Bitboard)); @@ -332,11 +321,11 @@ namespace { if (attack && attack != reference[i]) break; - assert(reference[i] != 0); + assert(reference[i]); attack = reference[i]; } - } while (i != size); + } while (i < size); } } }