X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovegen.cpp;h=f22df724952a81d82cac66616c6921641b560d5e;hp=b844075600ba6c74d3717418091050143ca8fcca;hb=9bffe811c44b88ba3b5dd0904539c8ca14257a35;hpb=2d867109d94a8aaabe3771525e7ee568865069f8 diff --git a/src/movegen.cpp b/src/movegen.cpp index b8440756..f22df724 100644 --- a/src/movegen.cpp +++ b/src/movegen.cpp @@ -25,6 +25,9 @@ #include "movegen.h" +// Simple macro to wrap a very common while loop, no facny, no flexibility, +// hardcoded list name 'mlist' and from square 'from'. +#define SERIALIZE_MOVES(b) while (b) (*mlist++).move = make_move(from, pop_1st_bit(&b)) //// //// Local definitions @@ -32,73 +35,73 @@ namespace { + enum CastlingSide { + KING_SIDE, + QUEEN_SIDE + }; + + static const bool CAPTURE = true; + static const bool NON_CAPTURE = false; + // Function + bool castling_is_check(const Position&, CastlingSide); + + // Main templates + template MoveStack* generate_castle_moves(const Position&, MoveStack*); - // Template generate_pawn_captures() with specializations + template + MoveStack* generate_piece_checks(const Position&, MoveStack*, Color us, Bitboard, Square); + + // Helper templates + template + MoveStack* do_generate_pawn_blocking_evasions(const Position& pos, Bitboard not_pinned, + Bitboard blockSquares, MoveStack* mlist); + template MoveStack* do_generate_pawn_captures(const Position& pos, MoveStack* mlist); - template - inline MoveStack* generate_pawn_captures(const Position& p, MoveStack* m) { - return do_generate_pawn_captures(p, m); - } - template<> - inline MoveStack* generate_pawn_captures(const Position& p, MoveStack* m) { - return do_generate_pawn_captures(p, m); - } - - // Template generate_pawn_noncaptures() with specializations template MoveStack* do_generate_pawn_noncaptures(const Position& pos, MoveStack* mlist); - template - inline MoveStack* generate_pawn_noncaptures(const Position& p, MoveStack* m) { - return do_generate_pawn_noncaptures(p, m); - } - template<> - inline MoveStack* generate_pawn_noncaptures(const Position& p, MoveStack* m) { - return do_generate_pawn_noncaptures(p, m); - } - - // Template generate_pawn_blocking_evasions() with specializations - template - MoveStack* do_generate_pawn_blocking_evasions(const Position& pos, Bitboard not_pinned, - Bitboard blockSquares, MoveStack* mlist); - template - inline MoveStack* generate_pawn_blocking_evasions(const Position& p, Bitboard np, Bitboard bs, MoveStack* m) { - return do_generate_pawn_blocking_evasions(p, np, bs, m); - } - template<> - inline MoveStack* generate_pawn_blocking_evasions(const Position& p, Bitboard np, Bitboard bs, MoveStack* m) { - return do_generate_pawn_blocking_evasions(p, np, bs, m); - } - // Template generate_pawn_checks() with specializations template MoveStack* do_generate_pawn_checks(const Position&, Bitboard, Square, MoveStack*); template - inline MoveStack* generate_pawn_checks(const Position& p, Bitboard dc, Square ksq, MoveStack* m) { + inline MoveStack* generate_pawn_checks(const Position& p, MoveStack* m, Bitboard dc, Square ksq) { return do_generate_pawn_checks(p, dc, ksq, m); } template<> - inline MoveStack* generate_pawn_checks(const Position& p, Bitboard dc, Square ksq, MoveStack* m) { + inline MoveStack* generate_pawn_checks(const Position& p, MoveStack* m, Bitboard dc, Square ksq) { return do_generate_pawn_checks(p, dc, ksq, m); } - // non-pawn templates + // Template generate_piece_moves() with specializations template MoveStack* generate_piece_moves(const Position&, MoveStack*, Color us, Bitboard); template<> MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target); - template - MoveStack* generate_piece_checks(const Position&, Bitboard, Bitboard, Square, MoveStack*); - MoveStack* generate_piece_checks_king(const Position&, Square, Bitboard, Square, MoveStack*); + template + inline MoveStack* generate_piece_moves(const Position& p, MoveStack* m, Color us) { + + assert(Piece == PAWN); + + if (Capture) + return (us == WHITE ? do_generate_pawn_captures(p, m) + : do_generate_pawn_captures(p, m)); + else + return (us == WHITE ? do_generate_pawn_noncaptures(p, m) + : do_generate_pawn_noncaptures(p, m)); + } + // Template generate_piece_blocking_evasions() with specializations template - MoveStack* generate_piece_blocking_evasions(const Position&, Bitboard, Bitboard, MoveStack*); + MoveStack* generate_piece_blocking_evasions(const Position&, MoveStack*, Color us, Bitboard, Bitboard); + + template<> + MoveStack* generate_piece_blocking_evasions(const Position& p, MoveStack* m, Color us, Bitboard np, Bitboard bs); } @@ -119,22 +122,18 @@ int generate_captures(const Position& pos, MoveStack* mlist) { Bitboard target = pos.pieces_of_color(opposite_color(us)); MoveStack* mlist_start = mlist; - 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); + mlist = generate_piece_moves(pos, mlist, us, target); + mlist = generate_piece_moves(pos, mlist, us, target); + mlist = generate_piece_moves(pos, mlist, us); mlist = generate_piece_moves(pos, mlist, us, target); return int(mlist - mlist_start); } /// generate_noncaptures() generates all pseudo-legal non-captures and -/// underpromotions. The return value is the number of moves generated. +/// underpromotions. The return value is the number of moves generated. int generate_noncaptures(const Position& pos, MoveStack* mlist) { @@ -145,24 +144,20 @@ int generate_noncaptures(const Position& pos, MoveStack* mlist) { Bitboard target = pos.empty_squares(); MoveStack* mlist_start = mlist; - if (us == WHITE) - mlist = generate_pawn_noncaptures(pos, mlist); - else - mlist = generate_pawn_noncaptures(pos, mlist); - + mlist = generate_piece_moves(pos, mlist, us); 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); - 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) { @@ -175,35 +170,29 @@ int generate_checks(const Position& pos, MoveStack* mlist, Bitboard dc) { assert(pos.piece_on(ksq) == king_of_color(opposite_color(us))); - dc = pos.discovered_check_candidates(us); - // Pawn moves if (us == WHITE) - mlist = generate_pawn_checks(pos, dc, ksq, mlist); + mlist = generate_pawn_checks(pos, mlist, dc, ksq); else - mlist = generate_pawn_checks(pos, dc, ksq, mlist); + mlist = generate_pawn_checks(pos, mlist, dc, ksq); // Pieces moves - Bitboard b = pos.knights(us); - if (b) - mlist = generate_piece_checks(pos, b, dc, ksq, mlist); - - b = pos.bishops(us); - if (b) - mlist = generate_piece_checks(pos, b, dc, ksq, mlist); - - b = pos.rooks(us); - if (b) - mlist = generate_piece_checks(pos, b, dc, ksq, mlist); - - b = pos.queens(us); - if (b) - 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); - - // TODO: Castling moves! + mlist = generate_piece_checks(pos, mlist, us, dc, ksq); + mlist = generate_piece_checks(pos, mlist, us, dc, ksq); + mlist = generate_piece_checks(pos, mlist, us, dc, ksq); + mlist = generate_piece_checks(pos, mlist, us, dc, ksq); + mlist = generate_piece_checks(pos, mlist, us, dc, ksq); + + // 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); } @@ -211,7 +200,7 @@ 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) { @@ -227,34 +216,51 @@ 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); @@ -300,29 +306,12 @@ int generate_evasions(const Position& pos, MoveStack* mlist) { assert((pos.occupied_squares() & blockSquares) == EmptyBoardBB); - // 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); - else - 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); - - b1 = pos.bishops(us) & not_pinned; - if (b1) - generate_piece_blocking_evasions(pos, b1, blockSquares, mlist); - - b1 = pos.rooks(us) & not_pinned; - if (b1) - 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, mlist, us, not_pinned, blockSquares); + mlist = generate_piece_blocking_evasions(pos, mlist, us, not_pinned, blockSquares); + mlist = generate_piece_blocking_evasions(pos, mlist, us, not_pinned, blockSquares); + mlist = generate_piece_blocking_evasions(pos, mlist, us, not_pinned, blockSquares); + mlist = generate_piece_blocking_evasions(pos, mlist, us, not_pinned, blockSquares); } // Finally, the ugly special case of en passant captures. An en passant @@ -362,8 +351,8 @@ 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. @@ -382,24 +371,25 @@ 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); @@ -409,7 +399,7 @@ 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); @@ -420,13 +410,13 @@ 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 @@ -436,7 +426,7 @@ 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)); @@ -460,7 +450,7 @@ 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)) @@ -469,7 +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_queenside(us)) - return MOVE_NONE; + return false; assert(from == pos.king_square(us)); assert(to == pos.initial_qr_square(us)); @@ -494,14 +484,14 @@ 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) @@ -511,7 +501,7 @@ 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. @@ -524,14 +514,14 @@ 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: @@ -541,7 +531,7 @@ 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: @@ -551,20 +541,20 @@ 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)); } @@ -573,18 +563,14 @@ namespace { template MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) { - Square from, to; + Square from; Bitboard b; - for (int i = 0; i < pos.piece_count(us, Piece); i++) + for (int i = 0, e = pos.piece_count(us, Piece); i < e; i++) { from = pos.piece_list(us, Piece, i); b = pos.piece_attacks(from) & target; - while (b) - { - to = pop_1st_bit(&b); - (*mlist++).move = make_move(from, to); - } + SERIALIZE_MOVES(b); } return mlist; } @@ -593,40 +579,42 @@ namespace { MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) { Bitboard b; - Square to, from = pos.king_square(us); + Square from = pos.king_square(us); b = pos.piece_attacks(from) & target; - while (b) - { - to = pop_1st_bit(&b); - (*mlist++).move = make_move(from, to); - } + SERIALIZE_MOVES(b); return mlist; } template - MoveStack* generate_piece_blocking_evasions(const Position& pos, Bitboard b, - Bitboard blockSquares, MoveStack* mlist) { + MoveStack* generate_piece_blocking_evasions(const Position& pos, MoveStack* mlist, Color us, + Bitboard not_pinned, Bitboard blockSquares) { + + Bitboard b = pos.pieces_of_color_and_type(us, Piece) & not_pinned; while (b) { Square from = pop_1st_bit(&b); Bitboard bb = pos.piece_attacks(from) & blockSquares; - while (bb) - { - Square to = pop_1st_bit(&bb); - (*mlist++).move = make_move(from, to); - } + SERIALIZE_MOVES(bb); } return mlist; } + template<> + MoveStack* generate_piece_blocking_evasions(const Position& p, MoveStack* m, Color us, + Bitboard np, Bitboard bs) { + if (us == WHITE) + return do_generate_pawn_blocking_evasions(p, np, bs, m); + else + return do_generate_pawn_blocking_evasions(p, np, bs, m); + } template - MoveStack* do_generate_pawn_captures(const Position& pos, MoveStack* mlist) { + MoveStack* do_generate_pawn_captures(const Position& pos, MoveStack* mlist) { - Square sq; + Square to; Bitboard pawns = pos.pawns(Us); Bitboard enemyPieces = pos.pieces_of_color(Them); @@ -637,16 +625,16 @@ namespace { Bitboard b2 = b1 & TRank8BB; while (b2) { - sq = pop_1st_bit(&b2); - (*mlist++).move = make_promotion_move(sq - TDELTA_NE, sq, QUEEN); + to = pop_1st_bit(&b2); + (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, QUEEN); } // Capturing non-promotions b2 = b1 & ~TRank8BB; while (b2) { - sq = pop_1st_bit(&b2); - (*mlist++).move = make_move(sq - TDELTA_NE, sq); + to = pop_1st_bit(&b2); + (*mlist++).move = make_move(to - TDELTA_NE, to); } // Captures in the h1-a8 (h8-a1 for black) direction @@ -656,24 +644,24 @@ namespace { b2 = b1 & TRank8BB; while (b2) { - sq = pop_1st_bit(&b2); - (*mlist++).move = make_promotion_move(sq - TDELTA_NW, sq, QUEEN); + to = pop_1st_bit(&b2); + (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, QUEEN); } // Capturing non-promotions b2 = b1 & ~TRank8BB; while (b2) { - sq = pop_1st_bit(&b2); - (*mlist++).move = make_move(sq - TDELTA_NW, sq); + to = pop_1st_bit(&b2); + (*mlist++).move = make_move(to - TDELTA_NW, to); } // Non-capturing promotions b1 = (Us == WHITE ? pawns << 8 : pawns >> 8) & pos.empty_squares() & TRank8BB; while (b1) { - sq = pop_1st_bit(&b1); - (*mlist++).move = make_promotion_move(sq - TDELTA_N, sq, QUEEN); + to = pop_1st_bit(&b1); + (*mlist++).move = make_promotion_move(to - TDELTA_N, to, QUEEN); } // En passant captures @@ -687,8 +675,8 @@ namespace { while (b1) { - sq = pop_1st_bit(&b1); - (*mlist++).move = make_ep_move(sq, pos.ep_square()); + to = pop_1st_bit(&b1); + (*mlist++).move = make_ep_move(to, pos.ep_square()); } } return mlist; @@ -697,32 +685,32 @@ 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); Bitboard emptySquares = pos.empty_squares(); Bitboard b1, b2; - Square sq; + Square to; // Underpromotion captures in the a1-h8 (a8-h1 for black) direction b1 = (Us == WHITE ? pawns << 9 : pawns >> 7) & ~FileABB & enemyPieces & TRank8BB; while (b1) { - sq = pop_1st_bit(&b1); - (*mlist++).move = make_promotion_move(sq - TDELTA_NE, sq, ROOK); - (*mlist++).move = make_promotion_move(sq - TDELTA_NE, sq, BISHOP); - (*mlist++).move = make_promotion_move(sq - TDELTA_NE, sq, KNIGHT); + to = pop_1st_bit(&b1); + (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, ROOK); + (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, BISHOP); + (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, KNIGHT); } // Underpromotion captures in the h1-a8 (h8-a1 for black) direction b1 = (Us == WHITE ? pawns << 7 : pawns >> 9) & ~FileHBB & enemyPieces & TRank8BB; while (b1) { - sq = pop_1st_bit(&b1); - (*mlist++).move = make_promotion_move(sq - TDELTA_NW, sq, ROOK); - (*mlist++).move = make_promotion_move(sq - TDELTA_NW, sq, BISHOP); - (*mlist++).move = make_promotion_move(sq - TDELTA_NW, sq, KNIGHT); + to = pop_1st_bit(&b1); + (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, ROOK); + (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, BISHOP); + (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, KNIGHT); } // Single pawn pushes @@ -730,24 +718,24 @@ namespace { b2 = b1 & TRank8BB; while (b2) { - sq = pop_1st_bit(&b2); - (*mlist++).move = make_promotion_move(sq - TDELTA_N, sq, ROOK); - (*mlist++).move = make_promotion_move(sq - TDELTA_N, sq, BISHOP); - (*mlist++).move = make_promotion_move(sq - TDELTA_N, sq, 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) { - sq = pop_1st_bit(&b2); - (*mlist++).move = make_move(sq - TDELTA_N, sq); + to = pop_1st_bit(&b2); + (*mlist++).move = make_move(to - TDELTA_N, to); } // Double pawn pushes b2 = (Us == WHITE ? (b1 & TRank3BB) << 8 : (b1 & TRank3BB) >> 8) & emptySquares; while (b2) { - sq = pop_1st_bit(&b2); - (*mlist++).move = make_move(sq - TDELTA_N - TDELTA_N, sq); + to = pop_1st_bit(&b2); + (*mlist++).move = make_move(to - TDELTA_N - TDELTA_N, to); } return mlist; } @@ -756,34 +744,37 @@ 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 is not on the same file as the enemy king, because we don't - // generate captures. - Bitboard empty = pos.empty_squares(); - // Find all friendly pawns not on the enemy king's file - Bitboard b1 = pos.pawns(Us) & ~file_bb(ksq), b2, b3; + Bitboard b1, b2, b3; + Bitboard empty = pos.empty_squares(); - // Discovered checks, single pawn pushes - b2 = b3 = (Us == WHITE ? (b1 & dc) << 8 : (b1 & dc) >> 8) & ~TRank8BB & empty; - while (b3) + if (dc != EmptyBoardBB) { - Square to = pop_1st_bit(&b3); - (*mlist++).move = make_move(to - TDELTA_N, to); - } + // 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. + b1 = pos.pawns(Us) & ~file_bb(ksq); + + // 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); + (*mlist++).move = make_move(to - TDELTA_N, to); + } - // Discovered checks, double pawn pushes - b3 = (Us == WHITE ? (b2 & TRank3BB) << 8 : (b2 & TRank3BB) >> 8) & empty; - while (b3) - { - Square to = pop_1st_bit(&b3); - (*mlist++).move = make_move(to - TDELTA_N - TDELTA_N, to); + // Discovered checks, double pawn pushes + b3 = (Us == WHITE ? (b2 & TRank3BB) << 8 : (b2 & TRank3BB) >> 8) & empty; + while (b3) + { + Square to = pop_1st_bit(&b3); + (*mlist++).move = make_move(to - TDELTA_N - TDELTA_N, to); + } } // Direct checks. These are possible only for pawns on neighboring files - // of the enemy king - - b1 &= (~dc & neighboring_files_bb(ksq)); // FIXME why ~dc ?? + // of the enemy king. + b1 = pos.pawns(Us) & neighboring_files_bb(ksq) & ~dc; // Direct checks, single pawn pushes b2 = (Us == WHITE ? b1 << 8 : b1 >> 8) & empty; @@ -798,7 +789,6 @@ namespace { b3 = (Us == WHITE ? (b2 & TRank3BB) << 8 : (b2 & TRank3BB) >> 8) & empty & pos.pawn_attacks(Them, ksq); - while (b3) { Square to = pop_1st_bit(&b3); @@ -808,56 +798,43 @@ namespace { } template - MoveStack* generate_piece_checks(const Position& pos, Bitboard target, Bitboard dc, - Square ksq, MoveStack* mlist) { + MoveStack* generate_piece_checks(const Position& pos, MoveStack* mlist, Color us, + Bitboard dc, Square ksq) { + + Bitboard target = pos.pieces_of_color_and_type(us, Piece); + // Discovered checks Bitboard b = target & dc; while (b) { Square from = pop_1st_bit(&b); Bitboard bb = pos.piece_attacks(from) & pos.empty_squares(); - while (bb) - { - Square to = pop_1st_bit(&bb); - (*mlist++).move = make_move(from, to); - } + if (Piece == KING) + bb &= ~QueenPseudoAttacks[ksq]; + + SERIALIZE_MOVES(bb); } + // Direct checks b = target & ~dc; + if (Piece == KING || !b) + return mlist; + Bitboard checkSqs = pos.piece_attacks(ksq) & pos.empty_squares(); while (b) { Square from = pop_1st_bit(&b); Bitboard bb = pos.piece_attacks(from) & checkSqs; - while (bb) - { - Square to = pop_1st_bit(&bb); - (*mlist++).move = make_move(from, to); - } + SERIALIZE_MOVES(bb); } 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]; - while (b) - { - Square to = pop_1st_bit(&b); - (*mlist++).move = make_move(from, to); - } - } - return mlist; - } - - - template + template MoveStack* do_generate_pawn_blocking_evasions(const Position& pos, Bitboard not_pinned, Bitboard blockSquares, MoveStack* mlist) { + Square to; + // Find non-pinned pawns Bitboard b1 = pos.pawns(Us) & not_pinned; @@ -866,7 +843,7 @@ namespace { Bitboard b2 = (Us == WHITE ? b1 << 8 : b1 >> 8) & blockSquares; while (b2) { - Square to = pop_1st_bit(&b2); + to = pop_1st_bit(&b2); assert(pos.piece_on(to) == EMPTY); @@ -885,7 +862,7 @@ namespace { b2 = (Us == WHITE ? b2 << 8 : b2 >> 8) & blockSquares;; while (b2) { - Square to = pop_1st_bit(&b2); + to = pop_1st_bit(&b2); assert(pos.piece_on(to) == EMPTY); assert(Us != WHITE || square_rank(to) == RANK_4); @@ -896,70 +873,59 @@ 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))); + } }