X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=e33b65fc050e4988f646cbdc2324c9962ccb4eb8;hp=6de3f08c89e69b6baf72cc502343e85cfc2e363e;hb=af59cb1d63234fe5c711f4a0dc28d56fe79d1274;hpb=3b857d1625c87ae3b87ea9e960b2c8d2d3284b9a diff --git a/src/position.cpp b/src/position.cpp index 6de3f08c..e33b65fc 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -1,13 +1,14 @@ /* - Glaurung, a UCI chess playing engine. - Copyright (C) 2004-2008 Tord Romstad + Stockfish, a UCI chess playing engine derived from Glaurung 2.1 + Copyright (C) 2004-2008 Tord Romstad (Glaurung author) + Copyright (C) 2008 Marco Costalba - Glaurung is free software: you can redistribute it and/or modify + Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. - Glaurung is distributed in the hope that it will be useful, + Stockfish is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. @@ -48,13 +49,6 @@ Key Position::zobSideToMove; Value Position::MgPieceSquareTable[16][64]; Value Position::EgPieceSquareTable[16][64]; -const Piece_attacks_fn piece_attacks_fn[] = - { 0, 0, - &Position::knight_attacks, - &Position::bishop_attacks, - &Position::rook_attacks, - &Position::queen_attacks, - &Position::king_attacks }; //// //// Functions @@ -302,40 +296,53 @@ void Position::copy(const Position &pos) { } -/// Position:pinned_pieces() returns a bitboard of all pinned (against the -/// king) pieces for the given color. +/// Position:pinned_pieces<>() returns a bitboard of all pinned (against the +/// king) pieces for the given color and for the given pinner type. +template +Bitboard Position::pinned_pieces(Color c, Square ksq) const { -Bitboard Position::pinned_pieces(Color c) const { - Bitboard b1, b2, pinned, pinners, sliders; - Square ksq = king_square(c), s; - Color them = opposite_color(c); + Square s; + Bitboard sliders, pinned = EmptyBoardBB; + + if (Piece == ROOK) // Resolved at compile time + sliders = rooks_and_queens(opposite_color(c)) & RookPseudoAttacks[ksq]; + else + sliders = bishops_and_queens(opposite_color(c)) & BishopPseudoAttacks[ksq]; - pinned = EmptyBoardBB; - b1 = occupied_squares(); + if (sliders && (sliders & ~checkersBB)) + { + // Our king blockers are candidate pinned pieces + Bitboard candidate_pinned = piece_attacks(ksq) & pieces_of_color(c); + + // Pinners are sliders, not checkers, that give check when + // candidate pinned are removed. + Bitboard pinners = sliders & ~checkersBB; + if (Piece == ROOK) + pinners &= rook_attacks_bb(ksq, occupied_squares() ^ candidate_pinned); + else + pinners &= bishop_attacks_bb(ksq, occupied_squares() ^ candidate_pinned); - sliders = rooks_and_queens(them) & ~checkers(); - if(sliders & RookPseudoAttacks[ksq]) { - b2 = rook_attacks(ksq) & pieces_of_color(c); - pinners = rook_attacks_bb(ksq, b1 ^ b2) & sliders; - while(pinners) { - s = pop_1st_bit(&pinners); - pinned |= (squares_between(s, ksq) & b2); - } + // Finally for each pinner find the corresponding pinned piece + // among the candidates. + while (pinners) + { + s = pop_1st_bit(&pinners); + pinned |= (squares_between(s, ksq) & candidate_pinned); + } } + return pinned; +} - sliders = bishops_and_queens(them) & ~checkers(); - if(sliders & BishopPseudoAttacks[ksq]) { - b2 = bishop_attacks(ksq) & pieces_of_color(c); - pinners = bishop_attacks_bb(ksq, b1 ^ b2) & sliders; - while(pinners) { - s = pop_1st_bit(&pinners); - pinned |= (squares_between(s, ksq) & b2); - } - } - return pinned; +/// Position:pinned_pieces() returns a bitboard of all pinned (against the +/// king) pieces for the given color. +Bitboard Position::pinned_pieces(Color c) const { + + Square ksq = king_square(c); + return pinned_pieces(c, ksq) | pinned_pieces(c, ksq); } + /// Position:discovered_check_candidates() returns a bitboard containing all /// pieces for the given side which are candidates for giving a discovered /// check. The code is almost the same as the function for finding pinned @@ -350,7 +357,7 @@ Bitboard Position::discovered_check_candidates(Color c) const { sliders = rooks_and_queens(c); if(sliders & RookPseudoAttacks[ksq]) { - b2 = rook_attacks(ksq) & pieces_of_color(c); + b2 = piece_attacks(ksq) & pieces_of_color(c); checkers = rook_attacks_bb(ksq, b1 ^ b2) & sliders; while(checkers) { s = pop_1st_bit(&checkers); @@ -360,7 +367,7 @@ Bitboard Position::discovered_check_candidates(Color c) const { sliders = bishops_and_queens(c); if(sliders & BishopPseudoAttacks[ksq]) { - b2 = bishop_attacks(ksq) & pieces_of_color(c); + b2 = piece_attacks(ksq) & pieces_of_color(c); checkers = bishop_attacks_bb(ksq, b1 ^ b2) & sliders; while(checkers) { s = pop_1st_bit(&checkers); @@ -378,10 +385,10 @@ Bitboard Position::discovered_check_candidates(Color c) const { bool Position::square_is_attacked(Square s, Color c) const { return (pawn_attacks(opposite_color(c), s) & pawns(c)) || - (knight_attacks(s) & knights(c)) || - (king_attacks(s) & kings(c)) || - (rook_attacks(s) & rooks_and_queens(c)) || - (bishop_attacks(s) & bishops_and_queens(c)); + (piece_attacks(s) & knights(c)) || + (piece_attacks(s) & kings(c)) || + (piece_attacks(s) & rooks_and_queens(c)) || + (piece_attacks(s) & bishops_and_queens(c)); } @@ -392,12 +399,12 @@ bool Position::square_is_attacked(Square s, Color c) const { Bitboard Position::attacks_to(Square s) const { return - (black_pawn_attacks(s) & pawns(WHITE)) | - (white_pawn_attacks(s) & pawns(BLACK)) | - (knight_attacks(s) & pieces_of_type(KNIGHT)) | - (rook_attacks(s) & rooks_and_queens()) | - (bishop_attacks(s) & bishops_and_queens()) | - (king_attacks(s) & pieces_of_type(KING)); + (pawn_attacks(BLACK, s) & pawns(WHITE)) | + (pawn_attacks(WHITE, s) & pawns(BLACK)) | + (piece_attacks(s) & pieces_of_type(KNIGHT)) | + (piece_attacks(s) & rooks_and_queens()) | + (piece_attacks(s) & bishops_and_queens()) | + (piece_attacks(s) & pieces_of_type(KING)); } Bitboard Position::attacks_to(Square s, Color c) const { @@ -413,13 +420,13 @@ bool Position::piece_attacks_square(Square f, Square t) const { assert(square_is_ok(t)); switch(piece_on(f)) { - case WP: return white_pawn_attacks_square(f, t); - case BP: return black_pawn_attacks_square(f, t); - case WN: case BN: return knight_attacks_square(f, t); - case WB: case BB: return bishop_attacks_square(f, t); - case WR: case BR: return rook_attacks_square(f, t); - case WQ: case BQ: return queen_attacks_square(f, t); - case WK: case BK: return king_attacks_square(f, t); + case WP: return pawn_attacks_square(WHITE, f, t); + case BP: return pawn_attacks_square(BLACK, f, t); + case WN: case BN: return piece_attacks_square(f, t); + case WB: case BB: return piece_attacks_square(f, t); + case WR: case BR: return piece_attacks_square(f, t); + case WQ: case BQ: return piece_attacks_square(f, t); + case WK: case BK: return piece_attacks_square(f, t); default: return false; } @@ -556,7 +563,7 @@ bool Position::move_is_check(Move m, Bitboard dcCandidates) const { switch(move_promotion(m)) { case KNIGHT: - return knight_attacks_square(to, ksq); + return piece_attacks_square(to, ksq); case BISHOP: return bit_is_set(bishop_attacks_bb(to, b), ksq); case ROOK: @@ -588,7 +595,7 @@ bool Position::move_is_check(Move m, Bitboard dcCandidates) const { return true; // Normal check? else - return bit_is_set(knight_attacks(ksq), to); + return bit_is_set(piece_attacks(ksq), to); case BISHOP: // Discovered check? @@ -596,7 +603,7 @@ bool Position::move_is_check(Move m, Bitboard dcCandidates) const { return true; // Normal check? else - return bit_is_set(bishop_attacks(ksq), to); + return bit_is_set(piece_attacks(ksq), to); case ROOK: // Discovered check? @@ -604,13 +611,13 @@ bool Position::move_is_check(Move m, Bitboard dcCandidates) const { return true; // Normal check? else - return bit_is_set(rook_attacks(ksq), to); + return bit_is_set(piece_attacks(ksq), to); case QUEEN: // Discovered checks are impossible! assert(!bit_is_set(dcCandidates, from)); // Normal check? - return bit_is_set(queen_attacks(ksq), to); + return bit_is_set(piece_attacks(ksq), to); case KING: // Discovered check? @@ -675,13 +682,13 @@ bool Position::move_attacks_square(Move m, Square s) const { assert(square_is_occupied(f)); switch(piece_on(f)) { - case WP: return white_pawn_attacks_square(t, s); - case BP: return black_pawn_attacks_square(t, s); - case WN: case BN: return knight_attacks_square(t, s); - case WB: case BB: return bishop_attacks_square(t, s); - case WR: case BR: return rook_attacks_square(t, s); - case WQ: case BQ: return queen_attacks_square(t, s); - case WK: case BK: return king_attacks_square(t, s); + case WP: return pawn_attacks_square(WHITE, t, s); + case BP: return pawn_attacks_square(BLACK, t, s); + case WN: case BN: return piece_attacks_square(t, s); + case WB: case BB: return piece_attacks_square(t, s); + case WR: case BR: return piece_attacks_square(t, s); + case WQ: case BQ: return piece_attacks_square(t, s); + case WK: case BK: return piece_attacks_square(t, s); default: assert(false); } @@ -854,9 +861,9 @@ void Position::do_move(Move m, UndoInfo &u, Bitboard dcCandidates) { } if(piece == PAWN) { if(abs(int(to) - int(from)) == 16) { - if((us == WHITE && (white_pawn_attacks(from + DELTA_N) & + if((us == WHITE && (pawn_attacks(WHITE, from + DELTA_N) & pawns(BLACK))) || - (us == BLACK && (black_pawn_attacks(from + DELTA_S) & + (us == BLACK && (pawn_attacks(BLACK, from + DELTA_S) & pawns(WHITE)))) { epSquare = Square((int(from) + int(to)) / 2); key ^= zobEp[epSquare]; @@ -889,45 +896,45 @@ void Position::do_move(Move m, UndoInfo &u, Bitboard dcCandidates) { set_bit(&checkersBB, to); if(bit_is_set(dcCandidates, from)) checkersBB |= - ((rook_attacks(ksq) & rooks_and_queens(us)) | - (bishop_attacks(ksq) & bishops_and_queens(us))); + ((piece_attacks(ksq) & rooks_and_queens(us)) | + (piece_attacks(ksq) & bishops_and_queens(us))); break; case KNIGHT: - if(bit_is_set(knight_attacks(ksq), to)) + if(bit_is_set(piece_attacks(ksq), to)) set_bit(&checkersBB, to); if(bit_is_set(dcCandidates, from)) checkersBB |= - ((rook_attacks(ksq) & rooks_and_queens(us)) | - (bishop_attacks(ksq) & bishops_and_queens(us))); + ((piece_attacks(ksq) & rooks_and_queens(us)) | + (piece_attacks(ksq) & bishops_and_queens(us))); break; case BISHOP: - if(bit_is_set(bishop_attacks(ksq), to)) + if(bit_is_set(piece_attacks(ksq), to)) set_bit(&checkersBB, to); if(bit_is_set(dcCandidates, from)) checkersBB |= - (rook_attacks(ksq) & rooks_and_queens(us)); + (piece_attacks(ksq) & rooks_and_queens(us)); break; case ROOK: - if(bit_is_set(rook_attacks(ksq), to)) + if(bit_is_set(piece_attacks(ksq), to)) set_bit(&checkersBB, to); if(bit_is_set(dcCandidates, from)) checkersBB |= - (bishop_attacks(ksq) & bishops_and_queens(us)); + (piece_attacks(ksq) & bishops_and_queens(us)); break; case QUEEN: - if(bit_is_set(queen_attacks(ksq), to)) + if(bit_is_set(piece_attacks(ksq), to)) set_bit(&checkersBB, to); break; case KING: if(bit_is_set(dcCandidates, from)) checkersBB |= - ((rook_attacks(ksq) & rooks_and_queens(us)) | - (bishop_attacks(ksq) & bishops_and_queens(us))); + ((piece_attacks(ksq) & rooks_and_queens(us)) | + (piece_attacks(ksq) & bishops_and_queens(us))); break; default: @@ -1637,10 +1644,10 @@ int Position::see(Square from, Square to) const { attackers = (rook_attacks_bb(to, occ) & rooks_and_queens()) | (bishop_attacks_bb(to, occ) & bishops_and_queens()) | - (knight_attacks(to) & knights()) | - (king_attacks(to) & kings()) | - (white_pawn_attacks(to) & pawns(BLACK)) | - (black_pawn_attacks(to) & pawns(WHITE)); + (piece_attacks(to) & knights()) | + (piece_attacks(to) & kings()) | + (pawn_attacks(WHITE, to) & pawns(BLACK)) | + (pawn_attacks(BLACK, to) & pawns(WHITE)); attackers &= occ; // If the opponent has no attackers, we are finished: @@ -2116,7 +2123,7 @@ void Position::flipped_copy(const Position &pos) { /// Position::is_ok() performs some consitency checks for the position object. /// This is meant to be helpful when debugging. -bool Position::is_ok() const { +bool Position::is_ok(int* failedStep) const { // What features of the position should be verified? static const bool debugBitboards = false; @@ -2131,23 +2138,30 @@ bool Position::is_ok() const { static const bool debugPieceCounts = false; static const bool debugPieceList = false; + if (failedStep) *failedStep = 1; + // Side to move OK? if(!color_is_ok(side_to_move())) return false; // Are the king squares in the position correct? + if (failedStep) (*failedStep)++; if(piece_on(king_square(WHITE)) != WK) return false; + + if (failedStep) (*failedStep)++; if(piece_on(king_square(BLACK)) != BK) return false; // Castle files OK? + if (failedStep) (*failedStep)++; if(!file_is_ok(initialKRFile)) return false; if(!file_is_ok(initialQRFile)) return false; // Do both sides have exactly one king? + if (failedStep) (*failedStep)++; if(debugKingCount) { int kingCount[2] = {0, 0}; for(Square s = SQ_A1; s <= SQ_H8; s++) @@ -2158,6 +2172,7 @@ bool Position::is_ok() const { } // Can the side to move capture the opponent's king? + if (failedStep) (*failedStep)++; if(debugKingCapture) { Color us = side_to_move(); Color them = opposite_color(us); @@ -2167,10 +2182,12 @@ bool Position::is_ok() const { } // Is there more than 2 checkers? + if (failedStep) (*failedStep)++; if(debugCheckerCount && count_1s(checkersBB) > 2) return false; // Bitboards OK? + if (failedStep) (*failedStep)++; if(debugBitboards) { // The intersection of the white and black pieces must be empty: if((pieces_of_color(WHITE) & pieces_of_color(BLACK)) @@ -2191,6 +2208,7 @@ bool Position::is_ok() const { } // En passant square OK? + if (failedStep) (*failedStep)++; if(ep_square() != SQ_NONE) { // The en passant square must be on rank 6, from the point of view of the // side to move. @@ -2199,18 +2217,22 @@ bool Position::is_ok() const { } // Hash key OK? + if (failedStep) (*failedStep)++; if(debugKey && key != compute_key()) return false; // Pawn hash key OK? + if (failedStep) (*failedStep)++; if(debugPawnKey && pawnKey != compute_pawn_key()) return false; // Material hash key OK? + if (failedStep) (*failedStep)++; if(debugMaterialKey && materialKey != compute_material_key()) return false; // Incremental eval OK? + if (failedStep) (*failedStep)++; if(debugIncrementalEval) { if(mgValue != compute_mg_value()) return false; @@ -2219,6 +2241,7 @@ bool Position::is_ok() const { } // Non-pawn material OK? + if (failedStep) (*failedStep)++; if(debugNonPawnMaterial) { if(npMaterial[WHITE] != compute_non_pawn_material(WHITE)) return false; @@ -2227,12 +2250,14 @@ bool Position::is_ok() const { } // Piece counts OK? + if (failedStep) (*failedStep)++; if(debugPieceCounts) for(Color c = WHITE; c <= BLACK; c++) for(PieceType pt = PAWN; pt <= KING; pt++) if(pieceCount[c][pt] != count_1s(pieces_of_color_and_type(c, pt))) return false; + if (failedStep) (*failedStep)++; if(debugPieceList) { for(Color c = WHITE; c <= BLACK; c++) for(PieceType pt = PAWN; pt <= KING; pt++) @@ -2244,6 +2269,6 @@ bool Position::is_ok() const { return false; } } - + if (failedStep) *failedStep = 0; return true; }