X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovegen.cpp;h=75997845a2f007620b0b588a1adbe4360b258154;hp=397732b522b8ed96e5bce3a1eb1d578acfb2bc49;hb=33ddeec5e043d4731866a18cbda51a337d417958;hpb=74f1efee263aadcceb1df716ebd87776b932238a diff --git a/src/movegen.cpp b/src/movegen.cpp index 397732b5..75997845 100644 --- a/src/movegen.cpp +++ b/src/movegen.cpp @@ -35,7 +35,16 @@ namespace { + enum CastlingSide { + KING_SIDE, + QUEEN_SIDE + }; + // Function + bool castling_is_check(const Position&, CastlingSide); + + // Template + template MoveStack* generate_castle_moves(const Position&, MoveStack*); // Template generate_pawn_captures() with specializations @@ -98,7 +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*); @@ -122,15 +130,16 @@ int generate_captures(const Position& pos, MoveStack* mlist) { Bitboard target = pos.pieces_of_color(opposite_color(us)); MoveStack* mlist_start = mlist; + mlist = generate_piece_moves(pos, mlist, us, target); + mlist = generate_piece_moves(pos, mlist, us, target); + mlist = generate_piece_moves(pos, mlist, us, target); + mlist = generate_piece_moves(pos, mlist, us, target); + if (us == WHITE) mlist = generate_pawn_captures(pos, mlist); else mlist = generate_pawn_captures(pos, mlist); - mlist = generate_piece_moves(pos, mlist, us, target); - mlist = generate_piece_moves(pos, mlist, us, target); - mlist = generate_piece_moves(pos, mlist, us, target); - mlist = generate_piece_moves(pos, mlist, us, target); mlist = generate_piece_moves(pos, mlist, us, target); return int(mlist - mlist_start); } @@ -158,14 +167,14 @@ int generate_noncaptures(const Position& pos, MoveStack* mlist) { mlist = generate_piece_moves(pos, mlist, us, target); mlist = generate_piece_moves(pos, mlist, us, target); mlist = generate_piece_moves(pos, mlist, us, target); - mlist = generate_castle_moves(pos, mlist); + mlist = generate_castle_moves(pos, mlist); + mlist = generate_castle_moves(pos, mlist); return int(mlist - mlist_start); } /// generate_checks() generates all pseudo-legal non-capturing, non-promoting -/// checks, except castling moves (will add this later). It returns the -/// number of generated moves. +/// checks. It returns the number of generated moves. int generate_checks(const Position& pos, MoveStack* mlist, Bitboard dc) { @@ -204,9 +213,18 @@ 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) + && (square_rank(ksq) == square_rank(pos.king_square(us)) || square_file(ksq) == FILE_D) + && castling_is_check(pos, QUEEN_SIDE)) + mlist = generate_castle_moves(pos, mlist); - // TODO: Castling moves! + if ( pos.can_castle_kingside(us) + && (square_rank(ksq) == square_rank(pos.king_square(us)) || square_file(ksq) == FILE_F) + && castling_is_check(pos, KING_SIDE)) + mlist = generate_castle_moves(pos, mlist); return int(mlist - mlist_start); } @@ -214,7 +232,7 @@ int generate_checks(const Position& pos, MoveStack* mlist, Bitboard dc) { /// generate_evasions() generates all check evasions when the side to move is /// in check. Unlike the other move generation functions, this one generates -/// only legal moves. It returns the number of generated moves. This +/// only legal moves. It returns the number of generated moves. This /// function is very ugly, and needs cleaning up some time later. FIXME int generate_evasions(const Position& pos, MoveStack* mlist) { @@ -230,34 +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); @@ -306,26 +341,26 @@ int generate_evasions(const Position& pos, MoveStack* mlist) { // Pawn moves. Because a blocking evasion can never be a capture, we // only generate pawn pushes. if (us == WHITE) - generate_pawn_blocking_evasions(pos, not_pinned, blockSquares, mlist); + mlist = generate_pawn_blocking_evasions(pos, not_pinned, blockSquares, mlist); else - generate_pawn_blocking_evasions(pos, not_pinned, blockSquares, mlist); + mlist = generate_pawn_blocking_evasions(pos, not_pinned, blockSquares, mlist); // Pieces moves b1 = pos.knights(us) & not_pinned; if (b1) - generate_piece_blocking_evasions(pos, b1, blockSquares, mlist); + mlist = generate_piece_blocking_evasions(pos, b1, blockSquares, mlist); b1 = pos.bishops(us) & not_pinned; if (b1) - generate_piece_blocking_evasions(pos, b1, blockSquares, mlist); + mlist = generate_piece_blocking_evasions(pos, b1, blockSquares, mlist); b1 = pos.rooks(us) & not_pinned; if (b1) - generate_piece_blocking_evasions(pos, b1, blockSquares, mlist); + mlist = generate_piece_blocking_evasions(pos, b1, blockSquares, mlist); b1 = pos.queens(us) & not_pinned; if (b1) - generate_piece_blocking_evasions(pos, b1, blockSquares, mlist); + mlist = generate_piece_blocking_evasions(pos, b1, blockSquares, mlist); } // Finally, the ugly special case of en passant captures. An en passant @@ -365,8 +400,8 @@ int generate_evasions(const Position& pos, MoveStack* mlist) { /// generate_legal_moves() computes a complete list of legal moves in the -/// current position. This function is not very fast, and should be used -/// only in situations where performance is unimportant. It wouldn't be +/// current position. This function is not very fast, and should be used +/// only in situations where performance is unimportant. It wouldn't be /// very hard to write an efficient legal move generator, but for the moment /// we don't need it. @@ -722,10 +757,10 @@ namespace { b2 = b1 & TRank8BB; while (b2) { - to = pop_1st_bit(&b2); - (*mlist++).move = make_promotion_move(to - TDELTA_N, to, ROOK); - (*mlist++).move = make_promotion_move(to - TDELTA_N, to, BISHOP); - (*mlist++).move = make_promotion_move(to - TDELTA_N, to, KNIGHT); + to = pop_1st_bit(&b2); + (*mlist++).move = make_promotion_move(to - TDELTA_N, to, ROOK); + (*mlist++).move = make_promotion_move(to - TDELTA_N, to, BISHOP); + (*mlist++).move = make_promotion_move(to - TDELTA_N, to, KNIGHT); } b2 = b1 & ~TRank8BB; while (b2) @@ -738,8 +773,8 @@ namespace { b2 = (Us == WHITE ? (b1 & TRank3BB) << 8 : (b1 & TRank3BB) >> 8) & emptySquares; while (b2) { - to = pop_1st_bit(&b2); - (*mlist++).move = make_move(to - TDELTA_N - TDELTA_N, to); + to = pop_1st_bit(&b2); + (*mlist++).move = make_move(to - TDELTA_N - TDELTA_N, to); } return mlist; } @@ -748,7 +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(); @@ -756,8 +791,8 @@ namespace { // Find all friendly pawns not on the enemy king's file Bitboard b1 = pos.pawns(Us) & ~file_bb(ksq), b2, b3; - // Discovered checks, single pawn pushes - b2 = b3 = (Us == WHITE ? (b1 & dc) << 8 : (b1 & dc) >> 8) & ~TRank8BB & empty; + // Discovered checks, single pawn pushes, no promotions + b2 = b3 = (Us == WHITE ? (b1 & dc) << 8 : (b1 & dc) >> 8) & empty & ~TRank8BB; while (b3) { Square to = pop_1st_bit(&b3); @@ -774,8 +809,7 @@ namespace { // Direct checks. These are possible only for pawns on neighboring files // of the enemy king - - b1 &= (~dc & neighboring_files_bb(ksq)); // FIXME why ~dc ?? + b1 &= (~dc & neighboring_files_bb(ksq)); // Direct checks, single pawn pushes b2 = (Us == WHITE ? b1 << 8 : b1 >> 8) & empty; @@ -808,8 +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(); @@ -822,19 +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) { @@ -878,70 +906,59 @@ namespace { return mlist; } - + template MoveStack* generate_castle_moves(const Position& pos, MoveStack* mlist) { Color us = pos.side_to_move(); - if (pos.can_castle(us)) + if ( (Side == KING_SIDE && pos.can_castle_kingside(us)) + ||(Side == QUEEN_SIDE && pos.can_castle_queenside(us))) { Color them = opposite_color(us); Square ksq = pos.king_square(us); assert(pos.piece_on(ksq) == king_of_color(us)); - if (pos.can_castle_kingside(us)) - { - Square rsq = pos.initial_kr_square(us); - Square g1 = relative_square(us, SQ_G1); - Square f1 = relative_square(us, SQ_F1); - Square s; - bool illegal = false; + Square rsq = (Side == KING_SIDE ? pos.initial_kr_square(us) : pos.initial_qr_square(us)); + Square s1 = relative_square(us, Side == KING_SIDE ? SQ_G1 : SQ_C1); + Square s2 = relative_square(us, Side == KING_SIDE ? SQ_F1 : SQ_D1); + Square s; + bool illegal = false; - assert(pos.piece_on(rsq) == rook_of_color(us)); + assert(pos.piece_on(rsq) == rook_of_color(us)); - for (s = Min(ksq, g1); s <= Max(ksq, g1); s++) - if ( (s != ksq && s != rsq && pos.square_is_occupied(s)) - || pos.square_is_attacked(s, them)) - illegal = true; + // It is a bit complicated to correctly handle Chess960 + for (s = Min(ksq, s1); s <= Max(ksq, s1); s++) + if ( (s != ksq && s != rsq && pos.square_is_occupied(s)) + || pos.square_is_attacked(s, them)) + illegal = true; - for (s = Min(rsq, f1); s <= Max(rsq, f1); s++) - if (s != ksq && s != rsq && pos.square_is_occupied(s)) - illegal = true; + for (s = Min(rsq, s2); s <= Max(rsq, s2); s++) + if (s != ksq && s != rsq && pos.square_is_occupied(s)) + illegal = true; - if (!illegal) - (*mlist++).move = make_castle_move(ksq, rsq); - } - - if (pos.can_castle_queenside(us)) - { - Square rsq = pos.initial_qr_square(us); - Square c1 = relative_square(us, SQ_C1); - Square d1 = relative_square(us, SQ_D1); - Square s; - bool illegal = false; - - assert(pos.piece_on(rsq) == rook_of_color(us)); - - for (s = Min(ksq, c1); s <= Max(ksq, c1); s++) - if ( (s != ksq && s != rsq && pos.square_is_occupied(s)) - || pos.square_is_attacked(s, them)) - illegal = true; - - for (s = Min(rsq, d1); s <= Max(rsq, d1); s++) - if (s != ksq && s != rsq && pos.square_is_occupied(s)) - illegal = true; - - if ( square_file(rsq) == FILE_B + if ( Side == QUEEN_SIDE + && square_file(rsq) == FILE_B && ( pos.piece_on(relative_square(us, SQ_A1)) == rook_of_color(them) || pos.piece_on(relative_square(us, SQ_A1)) == queen_of_color(them))) illegal = true; if (!illegal) (*mlist++).move = make_castle_move(ksq, rsq); - } } return mlist; } + bool castling_is_check(const Position& pos, CastlingSide side) { + + // After castling opponent king is attacked by the castled rook? + 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(); + + clear_bit(&occ, ksq); // Remove our king from the board + Square rsq = make_square(rookFile, square_rank(ksq)); + return bit_is_set(rook_attacks_bb(rsq, occ), pos.king_square(opposite_color(us))); + } }