X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovegen.cpp;h=75997845a2f007620b0b588a1adbe4360b258154;hp=9c405defab4b75e9845e18ec809fc1310843669d;hb=33ddeec5e043d4731866a18cbda51a337d417958;hpb=76381cbd6903f8be571cbc0d644a0f78026134bc diff --git a/src/movegen.cpp b/src/movegen.cpp index 9c405def..75997845 100644 --- a/src/movegen.cpp +++ b/src/movegen.cpp @@ -107,7 +107,6 @@ namespace { template MoveStack* generate_piece_checks(const Position&, Bitboard, Bitboard, Square, MoveStack*); - MoveStack* generate_piece_checks_king(const Position&, Square, Bitboard, Square, MoveStack*); template MoveStack* generate_piece_blocking_evasions(const Position&, Bitboard, Bitboard, MoveStack*); @@ -214,7 +213,7 @@ int generate_checks(const Position& pos, MoveStack* mlist, Bitboard dc) { mlist = generate_piece_checks(pos, b, dc, ksq, mlist); // Hopefully we always have a king ;-) - mlist = generate_piece_checks_king(pos, pos.king_square(us), dc, ksq, mlist); + mlist = generate_piece_checks(pos, pos.kings(us), dc, ksq, mlist); // Castling moves that give check. Very rare but nice to have! if ( pos.can_castle_queenside(us) @@ -249,34 +248,51 @@ int generate_evasions(const Position& pos, MoveStack* mlist) { assert(pos.piece_on(ksq) == king_of_color(us)); - // Generate evasions for king - Bitboard b1 = pos.piece_attacks(ksq) & ~pos.pieces_of_color(us); + // The bitboard of occupied pieces without our king Bitboard b2 = pos.occupied_squares(); clear_bit(&b2, ksq); + // Find squares attacked by slider checkers, we will + // remove them from king evasions set so to avoid a couple + // of cycles in the slow king evasions legality check loop. + Bitboard checkers = pos.checkers(); + Bitboard checkersAttacks = EmptyBoardBB; + Bitboard b = checkers & (pos.queens() | pos.bishops()); + while (b) + { + from = pop_1st_bit(&b); + checkersAttacks |= bishop_attacks_bb(from, b2); + } + + b = checkers & (pos.queens() | pos.rooks()); + while (b) + { + from = pop_1st_bit(&b); + checkersAttacks |= rook_attacks_bb(from, b2); + } + + // Generate evasions for king + Bitboard b1 = pos.piece_attacks(ksq) & ~pos.pieces_of_color(us) & ~checkersAttacks; while (b1) { - to = pop_1st_bit(&b1); - - // Make sure 'to' is not attacked by the other side. This is a bit ugly, - // because we can't use Position::square_is_attacked. Instead we use - // the low-level bishop_attacks_bb and rook_attacks_bb with the bitboard - // b2 (the occupied squares with the king removed) in order to test whether - // the king will remain in check on the destination square. - if (!( (pos.piece_attacks(to) & pos.knights(them)) - || (pos.pawn_attacks(us, to) & pos.pawns(them)) - || (bishop_attacks_bb(to, b2) & pos.bishops_and_queens(them)) - || (rook_attacks_bb(to, b2) & pos.rooks_and_queens(them)) - || (pos.piece_attacks(to) & pos.kings(them)))) - - (*mlist++).move = make_move(ksq, to); + to = pop_1st_bit(&b1); + + // Make sure 'to' is not attacked by the other side. This is a bit ugly, + // because we can't use Position::square_is_attacked. Instead we use + // the low-level bishop_attacks_bb and rook_attacks_bb with the bitboard + // b2 (the occupied squares with the king removed) in order to test whether + // the king will remain in check on the destination square. + if (!( (pos.piece_attacks(to) & pos.knights(them)) + || (pos.pawn_attacks(us, to) & pos.pawns(them)) + || (bishop_attacks_bb(to, b2) & pos.bishops_and_queens(them)) + || (rook_attacks_bb(to, b2) & pos.rooks_and_queens(them)) + || (pos.piece_attacks(to) & pos.kings(them)))) + (*mlist++).move = make_move(ksq, to); } // Generate evasions for other pieces only if not double check. We use a // simple bit twiddling hack here rather than calling count_1s in order to // save some time (we know that pos.checkers() has at most two nonzero bits). - Bitboard checkers = pos.checkers(); - if (!(checkers & (checkers - 1))) // Only one bit set? { Square checksq = first_1(checkers); @@ -767,7 +783,7 @@ namespace { template MoveStack* do_generate_pawn_checks(const Position& pos, Bitboard dc, Square ksq, MoveStack* mlist) { - // Pawn moves which give discovered check. This is possible only if the + // Pawn moves which gives discovered check. This is possible only if the // pawn is not on the same file as the enemy king, because we don't // generate captures. Bitboard empty = pos.empty_squares(); @@ -826,8 +842,15 @@ namespace { { Square from = pop_1st_bit(&b); Bitboard bb = pos.piece_attacks(from) & pos.empty_squares(); + if (Piece == KING) + bb &= ~QueenPseudoAttacks[ksq]; + SERIALIZE_MOVES(bb); } + + if (Piece == KING) + return mlist; + // Direct checks b = target & ~dc; Bitboard checkSqs = pos.piece_attacks(ksq) & pos.empty_squares(); @@ -840,19 +863,6 @@ namespace { return mlist; } - MoveStack* generate_piece_checks_king(const Position& pos, Square from, Bitboard dc, - Square ksq, MoveStack* mlist) { - if (bit_is_set(dc, from)) - { - Bitboard b = pos.piece_attacks(from) - & pos.empty_squares() - & ~QueenPseudoAttacks[ksq]; - SERIALIZE_MOVES(b); - } - return mlist; - } - - template MoveStack* do_generate_pawn_blocking_evasions(const Position& pos, Bitboard not_pinned, Bitboard blockSquares, MoveStack* mlist) { @@ -945,11 +955,10 @@ namespace { File rookFile = (side == QUEEN_SIDE ? FILE_D : FILE_F); Color us = pos.side_to_move(); Square ksq = pos.king_square(us); - Bitboard occ = pos.occupied_squares(), oppKingBB = EmptyBoardBB; + Bitboard occ = pos.occupied_squares(); - set_bit(&oppKingBB, pos.king_square(opposite_color(us))); clear_bit(&occ, ksq); // Remove our king from the board Square rsq = make_square(rookFile, square_rank(ksq)); - return (rook_attacks_bb(rsq, occ) & oppKingBB); + return bit_is_set(rook_attacks_bb(rsq, occ), pos.king_square(opposite_color(us))); } }