/*
- 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.
}
-/// 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<PieceType Piece>
+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<Piece>(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 = piece_attacks<ROOK>(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 = piece_attacks<BISHOP>(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<ROOK>(c, ksq) | pinned_pieces<BISHOP>(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
Bitboard Position::attacks_to(Square s) const {
return
- (black_pawn_attacks(s) & pawns(WHITE)) |
- (white_pawn_attacks(s) & pawns(BLACK)) |
+ (pawn_attacks(BLACK, s) & pawns(WHITE)) |
+ (pawn_attacks(WHITE, s) & pawns(BLACK)) |
(piece_attacks<KNIGHT>(s) & pieces_of_type(KNIGHT)) |
(piece_attacks<ROOK>(s) & rooks_and_queens()) |
(piece_attacks<BISHOP>(s) & bishops_and_queens()) |
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<KNIGHT>(f, t);
+ case WB: case BB: return piece_attacks_square<BISHOP>(f, t);
+ case WR: case BR: return piece_attacks_square<ROOK>(f, t);
+ case WQ: case BQ: return piece_attacks_square<QUEEN>(f, t);
+ case WK: case BK: return piece_attacks_square<KING>(f, t);
default: return false;
}
switch(move_promotion(m)) {
case KNIGHT:
- return knight_attacks_square(to, ksq);
+ return piece_attacks_square<KNIGHT>(to, ksq);
case BISHOP:
return bit_is_set(bishop_attacks_bb(to, b), ksq);
case ROOK:
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<KNIGHT>(t, s);
+ case WB: case BB: return piece_attacks_square<BISHOP>(t, s);
+ case WR: case BR: return piece_attacks_square<ROOK>(t, s);
+ case WQ: case BQ: return piece_attacks_square<QUEEN>(t, s);
+ case WK: case BK: return piece_attacks_square<KING>(t, s);
default: assert(false);
}
}
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];
(bishop_attacks_bb(to, occ) & bishops_and_queens()) |
(piece_attacks<KNIGHT>(to) & knights()) |
(piece_attacks<KING>(to) & kings()) |
- (white_pawn_attacks(to) & pawns(BLACK)) |
- (black_pawn_attacks(to) & pawns(WHITE));
+ (pawn_attacks(WHITE, to) & pawns(BLACK)) |
+ (pawn_attacks(BLACK, to) & pawns(WHITE));
attackers &= occ;
// If the opponent has no attackers, we are finished:
projects / stockfish / blobdiff