From be5b32bb9cbf134ccf8df7c17554557e9828957d Mon Sep 17 00:00:00 2001 From: Marco Costalba Date: Mon, 3 Jan 2011 11:50:41 +0100 Subject: [PATCH] Another round of bitboard.cpp cleanups Also renamed StepAttackBB[] in NonSlidingAttacksBB[] No functional change. Signed-off-by: Marco Costalba --- src/bitbase.cpp | 6 +- src/bitboard.cpp | 144 ++++++++++++++++++++++------------------------- src/bitboard.h | 2 +- src/position.cpp | 4 +- src/position.h | 4 +- 5 files changed, 74 insertions(+), 86 deletions(-) diff --git a/src/bitbase.cpp b/src/bitbase.cpp index ac03120f..5d20fbc6 100644 --- a/src/bitbase.cpp +++ b/src/bitbase.cpp @@ -47,9 +47,9 @@ namespace { bool is_legal() const; bool is_immediate_draw() const; bool is_immediate_win() const; - Bitboard wk_attacks() const { return StepAttackBB[WK][whiteKingSquare]; } - Bitboard bk_attacks() const { return StepAttackBB[BK][blackKingSquare]; } - Bitboard pawn_attacks() const { return StepAttackBB[WP][pawnSquare]; } + Bitboard wk_attacks() const { return NonSlidingAttacksBB[WK][whiteKingSquare]; } + Bitboard bk_attacks() const { return NonSlidingAttacksBB[BK][blackKingSquare]; } + Bitboard pawn_attacks() const { return NonSlidingAttacksBB[WP][pawnSquare]; } Square whiteKingSquare, blackKingSquare, pawnSquare; Color sideToMove; diff --git a/src/bitboard.cpp b/src/bitboard.cpp index 1e07c8ce..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]; @@ -238,16 +240,12 @@ Bitboard QueenPseudoAttacks[64]; uint8_t BitCount8Bit[256]; -//// -//// Local definitions -//// - namespace { 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); @@ -256,44 +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_masks(); - init_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(); -} - - /// 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. @@ -373,6 +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 @@ -382,7 +375,7 @@ namespace { 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++) @@ -403,32 +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; @@ -453,40 +444,17 @@ namespace { return result; } - 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++) - { - BetweenBB[s1][s2] = EmptyBoardBB; - - 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); - } - } - } - 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; } @@ -530,4 +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); + } + } + } diff --git a/src/bitboard.h b/src/bitboard.h index 6239953e..42c096d1 100644 --- a/src/bitboard.h +++ b/src/bitboard.h @@ -66,7 +66,7 @@ extern const Bitboard InFrontBB[2][8]; extern Bitboard SetMaskBB[65]; extern Bitboard ClearMaskBB[65]; -extern Bitboard StepAttackBB[16][64]; +extern Bitboard NonSlidingAttacksBB[16][64]; extern Bitboard BetweenBB[64][64]; extern Bitboard SquaresInFrontMask[2][64]; diff --git a/src/position.cpp b/src/position.cpp index bc6efb7f..cf2c7bac 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -524,7 +524,7 @@ Bitboard Position::attacks_from(Piece p, Square s) const { case WB: case BB: return attacks_from(s); case WR: case BR: return attacks_from(s); case WQ: case BQ: return attacks_from(s); - default: return StepAttackBB[p][s]; + default: return NonSlidingAttacksBB[p][s]; } } @@ -537,7 +537,7 @@ Bitboard Position::attacks_from(Piece p, Square s, Bitboard occ) { case WB: case BB: return bishop_attacks_bb(s, occ); case WR: case BR: return rook_attacks_bb(s, occ); case WQ: case BQ: return bishop_attacks_bb(s, occ) | rook_attacks_bb(s, occ); - default: return StepAttackBB[p][s]; + default: return NonSlidingAttacksBB[p][s]; } } diff --git a/src/position.h b/src/position.h index 600c1648..91b341ad 100644 --- a/src/position.h +++ b/src/position.h @@ -456,12 +456,12 @@ inline Square Position::initial_qr_square(Color c) const { template<> inline Bitboard Position::attacks_from(Square s, Color c) const { - return StepAttackBB[piece_of_color_and_type(c, PAWN)][s]; + return NonSlidingAttacksBB[piece_of_color_and_type(c, PAWN)][s]; } template // Knight and King and white pawns inline Bitboard Position::attacks_from(Square s) const { - return StepAttackBB[Piece][s]; + return NonSlidingAttacksBB[Piece][s]; } template<> -- 2.39.2