X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbitboard.cpp;h=40cdbb21ff956601238b0db0dc72176e5cb081cb;hp=a5b80b0b5e9bf44dc4d4a6c851b7419f2264e085;hb=797c960d2004eacbbd19c656f483f070130bb358;hpb=a492a9dd079d95faf136a744ff6d47a3d109ad68 diff --git a/src/bitboard.cpp b/src/bitboard.cpp index a5b80b0b..40cdbb21 100644 --- a/src/bitboard.cpp +++ b/src/bitboard.cpp @@ -30,12 +30,12 @@ CACHE_LINE_ALIGNMENT Bitboard RMasks[64]; Bitboard RMagics[64]; Bitboard* RAttacks[64]; -int RShifts[64]; +unsigned RShifts[64]; Bitboard BMasks[64]; Bitboard BMagics[64]; Bitboard* BAttacks[64]; -int BShifts[64]; +unsigned BShifts[64]; Bitboard SquareBB[64]; Bitboard FileBB[8]; @@ -58,33 +58,16 @@ namespace { CACHE_LINE_ALIGNMENT int BSFTable[64]; + int MS1BTable[256]; Bitboard RTable[0x19000]; // Storage space for rook attacks Bitboard BTable[0x1480]; // Storage space for bishop attacks typedef unsigned (Fn)(Square, Bitboard); void init_magics(Bitboard table[], Bitboard* attacks[], Bitboard magics[], - Bitboard masks[], int shifts[], Square deltas[], Fn get_index); + Bitboard masks[], unsigned shifts[], Square deltas[], Fn index); } - -/// print_bitboard() prints a bitboard in an easily readable format to the -/// standard output. This is sometimes useful for debugging. - -void print_bitboard(Bitboard b) { - - for (Rank r = RANK_8; r >= RANK_1; r--) - { - std::cout << "+---+---+---+---+---+---+---+---+" << '\n'; - for (File f = FILE_A; f <= FILE_H; f++) - std::cout << "| " << ((b & make_square(f, r)) ? "X " : " "); - - std::cout << "|\n"; - } - std::cout << "+---+---+---+---+---+---+---+---+" << std::endl; -} - - /// 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. @@ -109,48 +92,72 @@ Square first_1(Bitboard b) { return Square(BSFTable[(fold * 0x783A9B23) >> 26]); } -// Use type-punning -union b_union { - - Bitboard b; - struct { -#if defined (BIGENDIAN) - uint32_t h; - uint32_t l; -#else - uint32_t l; - uint32_t h; -#endif - } dw; -}; - -Square pop_1st_bit(Bitboard* bb) { - - b_union u; - Square ret; - - u.b = *bb; - - if (u.dw.l) - { - ret = Square(BSFTable[((u.dw.l ^ (u.dw.l - 1)) * 0x783A9B23) >> 26]); - u.dw.l &= (u.dw.l - 1); - *bb = u.b; - return ret; - } - ret = Square(BSFTable[((~(u.dw.h ^ (u.dw.h - 1))) * 0x783A9B23) >> 26]); - u.dw.h &= (u.dw.h - 1); - *bb = u.b; - return ret; +Square pop_1st_bit(Bitboard* b) { + + Bitboard bb = *b; + *b = bb & (bb - 1); + bb ^= (bb - 1); + uint32_t fold = unsigned(bb) ^ unsigned(bb >> 32); + return Square(BSFTable[(fold * 0x783A9B23) >> 26]); +} + +Square last_1(Bitboard b) { + + unsigned b32; + int result = 0; + + if (b > 0xFFFFFFFF) + { + b >>= 32; + result = 32; + } + + b32 = unsigned(b); + + if (b32 > 0xFFFF) + { + b32 >>= 16; + result += 16; + } + + if (b32 > 0xFF) + { + b32 >>= 8; + result += 8; + } + + return Square(result + MS1BTable[b32]); } #endif // !defined(USE_BSFQ) -/// bitboards_init() initializes various bitboard arrays. It is called during +/// Bitboards::print() prints a bitboard in an easily readable format to the +/// standard output. This is sometimes useful for debugging. + +void Bitboards::print(Bitboard b) { + + for (Rank rank = RANK_8; rank >= RANK_1; rank--) + { + std::cout << "+---+---+---+---+---+---+---+---+" << '\n'; + + for (File file = FILE_A; file <= FILE_H; file++) + std::cout << "| " << ((b & make_square(file, rank)) ? "X " : " "); + + std::cout << "|\n"; + } + std::cout << "+---+---+---+---+---+---+---+---+" << std::endl; +} + + +/// Bitboards::init() initializes various bitboard arrays. It is called during /// program initialization. -void bitboards_init() { +void Bitboards::init() { + + for (int k = 0, i = 0; i < 8; i++) + while (k < (2 << i)) + MS1BTable[k++] = i; for (Bitboard b = 0; b < 256; b++) BitCount8Bit[b] = (uint8_t)popcount(b); @@ -212,20 +219,20 @@ void bitboards_init() { { Square to = s + Square(c == WHITE ? steps[pt][k] : -steps[pt][k]); - if (square_is_ok(to) && square_distance(s, to) < 3) + if (is_ok(to) && square_distance(s, to) < 3) StepAttacksBB[make_piece(c, pt)][s] |= to; } Square RDeltas[] = { DELTA_N, DELTA_E, DELTA_S, DELTA_W }; Square BDeltas[] = { DELTA_NE, DELTA_SE, DELTA_SW, DELTA_NW }; - init_magics(RTable, RAttacks, RMagics, RMasks, RShifts, RDeltas, r_index); - init_magics(BTable, BAttacks, BMagics, BMasks, BShifts, BDeltas, b_index); + 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++) { - PseudoAttacks[BISHOP][s] = bishop_attacks_bb(s, 0); - PseudoAttacks[ROOK][s] = rook_attacks_bb(s, 0); + PseudoAttacks[BISHOP][s] = attacks_bb(s, 0); + PseudoAttacks[ROOK][s] = attacks_bb(s, 0); PseudoAttacks[QUEEN][s] = PseudoAttacks[BISHOP][s] | PseudoAttacks[ROOK][s]; } @@ -249,7 +256,7 @@ namespace { for (int i = 0; i < 4; i++) for (Square s = sq + deltas[i]; - square_is_ok(s) && square_distance(s, s - deltas[i]) == 1; + is_ok(s) && square_distance(s, s - deltas[i]) == 1; s += deltas[i]) { attack |= s; @@ -290,7 +297,7 @@ namespace { // use the so called "fancy" approach. void init_magics(Bitboard table[], Bitboard* attacks[], Bitboard magics[], - Bitboard masks[], int shifts[], Square deltas[], Fn get_index) { + 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 } }; @@ -342,7 +349,7 @@ namespace { // effect of verifying the magic. for (i = 0; i < size; i++) { - Bitboard& attack = attacks[s][get_index(s, occupancy[i])]; + Bitboard& attack = attacks[s][index(s, occupancy[i])]; if (attack && attack != reference[i]) break;