X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovegen.cpp;h=5917c9e486a7a92e46af70298ba5e227b1f29aa4;hp=ecda2c2d4640cd10b620ec5f85230850d089b6ac;hb=1156eb865babe7b07443548aa5e81211205bc7b5;hpb=2f8961beef5fe63aabeb77a8d4f20c59f6470b5e diff --git a/src/movegen.cpp b/src/movegen.cpp index ecda2c2d..5917c9e4 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 @@ -122,15 +131,16 @@ 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 +168,14 @@ 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) { @@ -206,7 +216,16 @@ int generate_checks(const Position& pos, MoveStack* mlist, Bitboard dc) { // Hopefully we always have a king ;-) mlist = generate_piece_checks_king(pos, pos.king_square(us), dc, ksq, mlist); - // TODO: Castling moves! + // 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); + + 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 +233,7 @@ 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) { @@ -306,26 +325,26 @@ 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 +384,8 @@ 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. @@ -385,24 +404,25 @@ int generate_legal_moves(const Position& pos, MoveStack* mlist) { // Remove illegal moves from the list for (int i = 0; i < n; i++) - if (!pos.move_is_legal(mlist[i].move, pinned)) + if (!pos.pl_move_is_legal(mlist[i].move, pinned)) mlist[i--].move = mlist[--n].move; return n; } -/// generate_move_if_legal() takes a position and a (not necessarily -/// pseudo-legal) move and a pinned pieces bitboard as input, and tests -/// whether the move is legal. If the move is legal, the move itself is -/// returned. If not, the function returns MOVE_NONE. This function must +/// move_is_legal() takes a position and a (not necessarily pseudo-legal) +/// move and a pinned pieces bitboard as input, and tests whether +/// the move is legal. If the move is legal, the move itself is +/// returned. If not, the function returns false. This function must /// only be used when the side to move is not in check. -Move generate_move_if_legal(const Position& pos, Move m, Bitboard pinned) { +bool move_is_legal(const Position& pos, const Move m, Bitboard pinned) { assert(pos.is_ok()); assert(!pos.is_check()); assert(move_is_ok(m)); + assert(pinned == pos.pinned_pieces(pos.side_to_move())); Color us = pos.side_to_move(); Color them = opposite_color(us); @@ -412,7 +432,7 @@ Move generate_move_if_legal(const Position& pos, Move m, Bitboard pinned) { // If the from square is not occupied by a piece belonging to the side to // move, the move is obviously not legal. if (color_of_piece(pc) != us) - return MOVE_NONE; + return false; Square to = move_to(m); @@ -423,13 +443,13 @@ Move generate_move_if_legal(const Position& pos, Move m, Bitboard pinned) { // en passant square. if ( type_of_piece(pc) != PAWN || to != pos.ep_square()) - return MOVE_NONE; + return false; assert(pos.square_is_empty(to)); assert(pos.piece_on(to - pawn_push(us)) == pawn_of_color(them)); - // The move is pseudo-legal. If it is legal, return it. - return (pos.move_is_legal(m) ? m : MOVE_NONE); + // The move is pseudo-legal, check if it is also legal + return pos.pl_move_is_legal(m, pinned); } // Castling moves @@ -439,7 +459,7 @@ Move generate_move_if_legal(const Position& pos, Move m, Bitboard pinned) { // the right to castle kingside. if ( type_of_piece(pc) != KING ||!pos.can_castle_kingside(us)) - return MOVE_NONE; + return false; assert(from == pos.king_square(us)); assert(to == pos.initial_kr_square(us)); @@ -463,7 +483,7 @@ Move generate_move_if_legal(const Position& pos, Move m, Bitboard pinned) { if (s != from && s != to && !pos.square_is_empty(s)) illegal = true; - return (!illegal ? m : MOVE_NONE); + return !illegal; } if (move_is_long_castle(m)) @@ -472,7 +492,7 @@ Move generate_move_if_legal(const Position& pos, Move m, Bitboard pinned) { // the right to castle kingside. if ( type_of_piece(pc) != KING ||!pos.can_castle_queenside(us)) - return MOVE_NONE; + return false; assert(from == pos.king_square(us)); assert(to == pos.initial_qr_square(us)); @@ -497,14 +517,14 @@ Move generate_move_if_legal(const Position& pos, Move m, Bitboard pinned) { || pos.piece_on(to + DELTA_W) == queen_of_color(them))) illegal = true; - return (!illegal ? m : MOVE_NONE); + return !illegal; } // Normal moves // The destination square cannot be occupied by a friendly piece if (pos.color_of_piece_on(to) == us) - return MOVE_NONE; + return false; // Proceed according to the type of the moving piece. if (type_of_piece(pc) == PAWN) @@ -514,7 +534,7 @@ Move generate_move_if_legal(const Position& pos, Move m, Bitboard pinned) { if ( ( (square_rank(to) == RANK_8 && us == WHITE) ||(square_rank(to) == RANK_1 && us != WHITE)) && !move_promotion(m)) - return MOVE_NONE; + return false; // Proceed according to the square delta between the source and // destionation squares. @@ -527,14 +547,14 @@ Move generate_move_if_legal(const Position& pos, Move m, Bitboard pinned) { // Capture. The destination square must be occupied by an enemy // piece (en passant captures was handled earlier). if (pos.color_of_piece_on(to) != them) - return MOVE_NONE; + return false; break; case DELTA_N: case DELTA_S: // Pawn push. The destination square must be empty. if (!pos.square_is_empty(to)) - return MOVE_NONE; + return false; break; case DELTA_NN: @@ -544,7 +564,7 @@ Move generate_move_if_legal(const Position& pos, Move m, Bitboard pinned) { if ( square_rank(to) != RANK_4 || !pos.square_is_empty(to) || !pos.square_is_empty(from + DELTA_N)) - return MOVE_NONE; + return false; break; case DELTA_SS: @@ -554,20 +574,20 @@ Move generate_move_if_legal(const Position& pos, Move m, Bitboard pinned) { if ( square_rank(to) != RANK_5 || !pos.square_is_empty(to) || !pos.square_is_empty(from + DELTA_S)) - return MOVE_NONE; + return false; break; default: - return MOVE_NONE; + return false; } - // The move is pseudo-legal. Return it if it is legal. - return (pos.move_is_legal(m) ? m : MOVE_NONE); + // The move is pseudo-legal, check if it is also legal + return pos.pl_move_is_legal(m, pinned); } // Luckly we can handle all the other pieces in one go return ( pos.piece_attacks_square(from, to) - && pos.move_is_legal(m) - && !move_promotion(m) ? m : MOVE_NONE); + && pos.pl_move_is_legal(m, pinned) + && !move_promotion(m)); } @@ -615,7 +635,7 @@ namespace { template - MoveStack* do_generate_pawn_captures(const Position& pos, MoveStack* mlist) { + MoveStack* do_generate_pawn_captures(const Position& pos, MoveStack* mlist) { Square to; Bitboard pawns = pos.pawns(Us); @@ -688,7 +708,7 @@ namespace { template - MoveStack* do_generate_pawn_noncaptures(const Position& pos, MoveStack* mlist) { + MoveStack* do_generate_pawn_noncaptures(const Position& pos, MoveStack* mlist) { Bitboard pawns = pos.pawns(Us); Bitboard enemyPieces = pos.pieces_of_color(Them); @@ -721,10 +741,10 @@ 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) @@ -737,8 +757,8 @@ 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; } @@ -755,8 +775,8 @@ 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); @@ -773,8 +793,7 @@ 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; @@ -877,70 +896,59 @@ 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; - - assert(pos.piece_on(rsq) == rook_of_color(us)); + 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; - 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; + assert(pos.piece_on(rsq) == rook_of_color(us)); - for (s = Min(rsq, f1); s <= Max(rsq, f1); 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; + // 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; - assert(pos.piece_on(rsq) == rook_of_color(us)); + for (s = Min(rsq, s2); s <= Max(rsq, s2); s++) + if (s != ksq && s != rsq && pos.square_is_occupied(s)) + illegal = true; - 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))); + } }