X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovegen.cpp;h=12260e3b9dd99fd3b67bddce75dc9498bcd81499;hp=9c405defab4b75e9845e18ec809fc1310843669d;hb=9d044cf4ee933257c65cbd8c01589dd88778a1dd;hpb=76381cbd6903f8be571cbc0d644a0f78026134bc diff --git a/src/movegen.cpp b/src/movegen.cpp index 9c405def..12260e3b 100644 --- a/src/movegen.cpp +++ b/src/movegen.cpp @@ -40,77 +40,74 @@ namespace { QUEEN_SIDE }; - // Function + const bool CAPTURE = true; + const bool NON_CAPTURE = false; + + // Functions bool castling_is_check(const Position&, CastlingSide); - // Template + // Helper templates template - MoveStack* generate_castle_moves(const Position&, MoveStack*); + MoveStack* generate_castle_moves(const Position& pos, MoveStack* mlist); - // Template generate_pawn_captures() with specializations - template - MoveStack* do_generate_pawn_captures(const Position& pos, MoveStack* mlist); + template + MoveStack* generate_pawn_blocking_evasions(const Position&, Bitboard, Bitboard, MoveStack*); - 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 + MoveStack* generate_pawn_captures(const Position& pos, MoveStack* mlist); - // Template generate_pawn_noncaptures() with specializations template - MoveStack* do_generate_pawn_noncaptures(const Position& pos, MoveStack* mlist); + MoveStack* 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 + MoveStack* generate_pawn_checks(const Position&, Bitboard, Square, MoveStack*); + + // Template generate_piece_checks() with specializations + template + MoveStack* generate_piece_checks(const Position&, MoveStack*, Color, Bitboard, Square); - // 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); - } + inline MoveStack* generate_piece_checks(const Position& p, MoveStack* m, Color us, Bitboard dc, Square ksq) { - // Template generate_pawn_checks() with specializations - template - MoveStack* do_generate_pawn_checks(const Position&, Bitboard, Square, MoveStack*); + if (us == WHITE) + return generate_pawn_checks(p, dc, ksq, m); + else + return generate_pawn_checks(p, dc, ksq, m); - template - inline MoveStack* generate_pawn_checks(const Position& p, Bitboard dc, Square ksq, MoveStack* m) { - return do_generate_pawn_checks(p, dc, ksq, m); - } - template<> - inline MoveStack* generate_pawn_checks(const Position& p, Bitboard dc, Square ksq, MoveStack* m) { - 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 ? generate_pawn_captures(p, m) + : generate_pawn_captures(p, m)); + else + return (us == WHITE ? generate_pawn_noncaptures(p, m) + : 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<> + inline MoveStack* generate_piece_blocking_evasions(const Position& p, MoveStack* m, Color us, + Bitboard np, Bitboard bs) { + if (us == WHITE) + return generate_pawn_blocking_evasions(p, np, bs, m); + else + return generate_pawn_blocking_evasions(p, np, bs, m); + } } @@ -135,19 +132,14 @@ int generate_captures(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); - - if (us == WHITE) - mlist = generate_pawn_captures(pos, mlist); - else - mlist = generate_pawn_captures(pos, mlist); - + 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) { @@ -158,11 +150,7 @@ 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); @@ -188,33 +176,13 @@ 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); - else - mlist = generate_pawn_checks(pos, dc, ksq, mlist); - // 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); + 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); + 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) @@ -249,34 +217,51 @@ 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); @@ -322,29 +307,12 @@ 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) - mlist = generate_pawn_blocking_evasions(pos, not_pinned, blockSquares, mlist); - else - mlist = generate_pawn_blocking_evasions(pos, not_pinned, blockSquares, mlist); - // Pieces moves - b1 = pos.knights(us) & not_pinned; - if (b1) - mlist = generate_piece_blocking_evasions(pos, b1, blockSquares, mlist); - - b1 = pos.bishops(us) & not_pinned; - if (b1) - mlist = generate_piece_blocking_evasions(pos, b1, blockSquares, mlist); - - b1 = pos.rooks(us) & not_pinned; - if (b1) - mlist = generate_piece_blocking_evasions(pos, b1, blockSquares, mlist); - - b1 = pos.queens(us) & not_pinned; - if (b1) - mlist = 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 @@ -620,8 +588,10 @@ namespace { } 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); @@ -631,11 +601,10 @@ namespace { return mlist; } - template - MoveStack* do_generate_pawn_captures(const Position& pos, MoveStack* mlist) { + MoveStack* generate_pawn_captures(const Position& pos, MoveStack* mlist) { Square to; Bitboard pawns = pos.pawns(Us); @@ -708,7 +677,7 @@ namespace { template - MoveStack* do_generate_pawn_noncaptures(const Position& pos, MoveStack* mlist) { + MoveStack* generate_pawn_noncaptures(const Position& pos, MoveStack* mlist) { Bitboard pawns = pos.pawns(Us); Bitboard enemyPieces = pos.pieces_of_color(Them); @@ -765,35 +734,39 @@ namespace { template - MoveStack* do_generate_pawn_checks(const Position& pos, Bitboard dc, Square ksq, MoveStack* mlist) + MoveStack* 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, no promotions - b2 = b3 = (Us == WHITE ? (b1 & dc) << 8 : (b1 & dc) >> 8) & empty & ~TRank8BB; - 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)); + // 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; @@ -808,7 +781,6 @@ namespace { b3 = (Us == WHITE ? (b2 & TRank3BB) << 8 : (b2 & TRank3BB) >> 8) & empty & pos.pawn_attacks(Them, ksq); - while (b3) { Square to = pop_1st_bit(&b3); @@ -818,18 +790,28 @@ 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(); + 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) { @@ -840,22 +822,9 @@ 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) { + MoveStack* generate_pawn_blocking_evasions(const Position& pos, Bitboard not_pinned, + Bitboard blockSquares, MoveStack* mlist) { Square to; // Find non-pinned pawns @@ -945,11 +914,10 @@ 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))); } }