X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbitboard.cpp;h=8c1be7390a14a02a04dba241710a27c6550123a1;hp=72e208ffc7c3c2a95e15c84e58489768e1df57ff;hb=611a29f7675d3e5dc7e5e2b63cca9274eae05578;hpb=4dded4e72f9b9582db8adc9a478e9eda5841d8c5 diff --git a/src/bitboard.cpp b/src/bitboard.cpp index 72e208ff..8c1be739 100644 --- a/src/bitboard.cpp +++ b/src/bitboard.cpp @@ -213,6 +213,8 @@ const Bitboard InFrontBB[2][8] = { } }; +// Global bitboards definitions with static storage duration are +// automatically set to zero before enter main(). Bitboard RMask[64]; int RAttackIndex[64]; Bitboard RAttacks[0x19000]; @@ -224,7 +226,7 @@ Bitboard BAttacks[0x1480]; Bitboard SetMaskBB[65]; Bitboard ClearMaskBB[65]; -Bitboard StepAttackBB[16][64]; +Bitboard NonSlidingAttacksBB[16][64]; Bitboard BetweenBB[64][64]; Bitboard SquaresInFrontMask[2][64]; @@ -236,21 +238,14 @@ Bitboard RookPseudoAttacks[64]; Bitboard QueenPseudoAttacks[64]; uint8_t BitCount8Bit[256]; -int8_t DirectionTable[64][64]; -//// -//// Local definitions -//// - namespace { - SquareDelta get_direction(Square orig, Square dest); - void init_direction_table(); void init_masks(); - void init_attacks(); - void init_between_bitboards(); + void init_non_sliding_attacks(); void init_pseudo_attacks(); + void init_between_bitboards(); Bitboard index_to_bitboard(int index, Bitboard mask); Bitboard sliding_attacks(int sq, Bitboard block, int dirs, int deltas[][2], int fmin, int fmax, int rmin, int rmax); @@ -259,45 +254,23 @@ namespace { } -//// -//// Functions -//// - /// print_bitboard() prints a bitboard in an easily readable format to the -/// standard output. This is sometimes useful for debugging. +/// standard output. This is sometimes useful for debugging. void print_bitboard(Bitboard b) { for (Rank r = RANK_8; r >= RANK_1; r--) { - std::cout << "+---+---+---+---+---+---+---+---+" << std::endl; + std::cout << "+---+---+---+---+---+---+---+---+" << '\n'; for (File f = FILE_A; f <= FILE_H; f++) std::cout << "| " << (bit_is_set(b, make_square(f, r))? 'X' : ' ') << ' '; - std::cout << "|" << std::endl; + std::cout << "|\n"; } std::cout << "+---+---+---+---+---+---+---+---+" << std::endl; } -/// init_bitboards() initializes various bitboard arrays. It is called during -/// program initialization. - -void init_bitboards() { - - int rookDeltas[4][2] = {{0,1},{0,-1},{1,0},{-1,0}}; - int bishopDeltas[4][2] = {{1,1},{-1,1},{1,-1},{-1,-1}}; - - init_direction_table(); - init_masks(); - init_attacks(); - init_between_bitboards(); - init_sliding_attacks(RAttacks, RAttackIndex, RMask, RShift, RMult, rookDeltas); - init_sliding_attacks(BAttacks, BAttackIndex, BMask, BShift, BMult, bishopDeltas); - init_pseudo_attacks(); -} - - /// first_1() finds the least significant nonzero bit in a nonzero bitboard. /// pop_1st_bit() finds and clears the least significant nonzero bit in a /// nonzero bitboard. @@ -377,6 +350,22 @@ Square pop_1st_bit(Bitboard* bb) { #endif +/// init_bitboards() initializes various bitboard arrays. It is called during +/// program initialization. + +void init_bitboards() { + + int rookDeltas[4][2] = {{0,1},{0,-1},{1,0},{-1,0}}; + int bishopDeltas[4][2] = {{1,1},{-1,1},{1,-1},{-1,-1}}; + + init_masks(); + init_non_sliding_attacks(); + init_sliding_attacks(RAttacks, RAttackIndex, RMask, RShift, RMult, rookDeltas); + init_sliding_attacks(BAttacks, BAttackIndex, BMask, BShift, BMult, bishopDeltas); + init_pseudo_attacks(); + init_between_bitboards(); +} + namespace { // All functions below are used to precompute various bitboards during @@ -384,39 +373,9 @@ namespace { // understand, but they all seem to work correctly, and it should never // be necessary to touch any of them. - SquareDelta get_direction(Square orig, Square dest) { - - const SquareDelta directions[] = { - DELTA_E, DELTA_N, DELTA_NE, DELTA_NW, DELTA_W, DELTA_S, DELTA_SW, DELTA_SE - }; - - for (int idx = 0; idx < 8; idx++) - { - Square from = orig; - Square to = from + directions[idx]; - - while (to != dest && square_distance(to, from) == 1 && square_is_ok(to)) - { - from = to; - to += directions[idx]; - } - - if (to == dest && square_distance(from, to) == 1) - return directions[idx]; - } - return DELTA_NONE; - } - - void init_direction_table() { - - for (Square s1 = SQ_A1; s1 <= SQ_H8; s1++) - for (Square s2 = SQ_A1; s2 <= SQ_H8; s2++) - DirectionTable[s1][s2] = uint8_t(get_direction(s1, s2)); - } - void init_masks() { - SetMaskBB[SQ_NONE] = 0ULL; + SetMaskBB[SQ_NONE] = EmptyBoardBB; ClearMaskBB[SQ_NONE] = ~SetMaskBB[SQ_NONE]; for (Square s = SQ_A1; s <= SQ_H8; s++) @@ -437,32 +396,30 @@ namespace { BitCount8Bit[b] = (uint8_t)count_1s(b); } - void init_attacks() { + void init_non_sliding_attacks() { - const int step[16][8] = { + const int step[][9] = { {0}, - {7,9,0}, {17,15,10,6,-6,-10,-15,-17}, {9,7,-7,-9,0}, {8,1,-1,-8,0}, - {9,7,-7,-9,8,1,-1,-8}, {9,7,-7,-9,8,1,-1,-8}, {0}, {0}, - {-7,-9,0}, {17,15,10,6,-6,-10,-15,-17}, {9,7,-7,-9,0}, {8,1,-1,-8,0}, - {9,7,-7,-9,8,1,-1,-8}, {9,7,-7,-9,8,1,-1,-8} + {7,9,0}, {17,15,10,6,-6,-10,-15,-17,0}, {0}, {0}, {0}, + {9,7,-7,-9,8,1,-1,-8,0}, {0}, {0}, + {-7,-9,0}, {17,15,10,6,-6,-10,-15,-17,0}, {0}, {0}, {0}, + {9,7,-7,-9,8,1,-1,-8,0} }; - for (int i = 0; i < 64; i++) - for (int j = 0; j <= int(BK); j++) - { - StepAttackBB[j][i] = EmptyBoardBB; - for (int k = 0; k < 8 && step[j][k] != 0; k++) + for (Square s = SQ_A1; s <= SQ_H8; s++) + for (Piece pc = WP; pc <= BK; pc++) + for (int k = 0; step[pc][k] != 0; k++) { - int l = i + step[j][k]; - if (l >= 0 && l < 64 && abs((i & 7) - (l & 7)) < 3) - StepAttackBB[j][i] |= (1ULL << l); + Square to = s + Square(step[pc][k]); + + if (square_is_ok(to) && square_distance(s, to) < 3) + set_bit(&NonSlidingAttacksBB[pc][s], to); } - } } Bitboard sliding_attacks(int sq, Bitboard block, int dirs, int deltas[][2], int fmin=0, int fmax=7, int rmin=0, int rmax=7) { - Bitboard result = 0ULL; + Bitboard result = 0; int rk = sq / 8; int fl = sq % 8; @@ -487,35 +444,17 @@ namespace { return result; } - void init_between_bitboards() { - - Square s1, s2, s3; - SquareDelta d; - - for (s1 = SQ_A1; s1 <= SQ_H8; s1++) - for (s2 = SQ_A1; s2 <= SQ_H8; s2++) - { - BetweenBB[s1][s2] = EmptyBoardBB; - d = SquareDelta(DirectionTable[s1][s2]); - - if (d == DELTA_NONE) - continue; - - for (s3 = s1 + d; s3 != s2; s3 += d) - set_bit(&(BetweenBB[s1][s2]), s3); - } - } - Bitboard index_to_bitboard(int index, Bitboard mask) { - Bitboard result = 0ULL; - int bits = count_1s(mask); + Bitboard result = EmptyBoardBB; + int sq, cnt = 0; - for (int i = 0; i < bits; i++) + while (mask) { - int j = pop_1st_bit(&mask); - if (index & (1 << i)) - result |= (1ULL << j); + sq = pop_1st_bit(&mask); + + if (index & (1 << cnt++)) + result |= (1ULL << sq); } return result; } @@ -559,4 +498,24 @@ namespace { } } + void init_between_bitboards() { + + Square s1, s2, s3; + SquareDelta d; + int f, r; + + for (s1 = SQ_A1; s1 <= SQ_H8; s1++) + for (s2 = SQ_A1; s2 <= SQ_H8; s2++) + if (bit_is_set(QueenPseudoAttacks[s1], s2)) + { + f = file_distance(s1, s2); + r = rank_distance(s1, s2); + + d = SquareDelta(s2 - s1) / Max(f, r); + + for (s3 = s1 + d; s3 != s2; s3 += d) + set_bit(&(BetweenBB[s1][s2]), s3); + } + } + }