X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovegen.cpp;h=9cb588a385e6534b0a5db52a5fad5b19230ca768;hp=e7ac705feeea78716923ca21b7aa4f44f8247a0d;hb=84870690583ddbdf0a9bd51dd5d5f821b0fadb63;hpb=62a8f393f17fd8240315d4454fea1ddf5493687b diff --git a/src/movegen.cpp b/src/movegen.cpp index e7ac705f..9cb588a3 100644 --- a/src/movegen.cpp +++ b/src/movegen.cpp @@ -66,11 +66,8 @@ namespace { template MoveStack* generate_pawn_captures_diagonal(MoveStack* mlist, Bitboard pawns, Bitboard enemyPieces, bool promotion); - template - MoveStack* generate_pawn_noncaptures(const Position& pos, MoveStack* mlist); - - template - MoveStack* generate_pawn_checks(const Position&, Bitboard, Square, MoveStack*); + template + MoveStack* generate_pawn_noncaptures(const Position& pos, MoveStack* mlist, Bitboard dc = EmptyBoardBB, Square ksq = SQ_NONE); template inline Bitboard move_pawns(Bitboard p) { @@ -92,8 +89,8 @@ namespace { template<> inline MoveStack* generate_piece_checks(const Position& p, MoveStack* m, Color us, Bitboard dc, Square ksq) { - return (us == WHITE ? generate_pawn_checks(p, dc, ksq, m) - : generate_pawn_checks(p, dc, ksq, m)); + return (us == WHITE ? generate_pawn_noncaptures(p, m, dc, ksq) + : generate_pawn_noncaptures(p, m, dc, ksq)); } // Template generate_piece_moves() with specializations and overloads @@ -112,8 +109,8 @@ namespace { 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)); + return (us == WHITE ? generate_pawn_noncaptures(p, m) + : generate_pawn_noncaptures(p, m)); } template @@ -225,6 +222,8 @@ MoveStack* generate_evasions(const Position& pos, MoveStack* mlist, Bitboard pin Color us = pos.side_to_move(); Color them = opposite_color(us); Square ksq = pos.king_square(us); + Bitboard sliderAttacks = EmptyBoardBB; + Bitboard checkers = pos.checkers(); assert(pos.piece_on(ksq) == piece_of_color_and_type(us, KING)); @@ -235,31 +234,30 @@ MoveStack* generate_evasions(const Position& pos, MoveStack* mlist, Bitboard pin // 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 - // and to be able to use attacks_to(). - Bitboard checkers = pos.checkers(); - Bitboard checkersAttacks = EmptyBoardBB; + // and to be able to use attackers_to(). Bitboard b = checkers & pos.pieces(BISHOP, QUEEN); while (b) { from = pop_1st_bit(&b); - checkersAttacks |= bishop_attacks_bb(from, b_noKing); + sliderAttacks |= bishop_attacks_bb(from, b_noKing); } b = checkers & pos.pieces(ROOK, QUEEN); while (b) { from = pop_1st_bit(&b); - checkersAttacks |= rook_attacks_bb(from, b_noKing); + sliderAttacks |= rook_attacks_bb(from, b_noKing); } - // Generate evasions for king - Bitboard b1 = pos.piece_attacks(ksq) & ~pos.pieces_of_color(us) & ~checkersAttacks; + // Generate evasions for king, both captures and non captures + Bitboard b1 = pos.attacks_from(ksq) & ~pos.pieces_of_color(us) & ~sliderAttacks; + Bitboard enemy = pos.pieces_of_color(them); while (b1) { to = pop_1st_bit(&b1); - // Note that we can use attacks_to() only because we - // have already removed slider checkers. - if (!pos.attacks_to(to, them)) + // Note that we can use attackers_to() only because we + // have already removed slider checkers attacked squares. + if (!(pos.attackers_to(to) & enemy)) (*mlist++).move = make_move(ksq, to); } @@ -275,7 +273,7 @@ MoveStack* generate_evasions(const Position& pos, MoveStack* mlist, Bitboard pin // Generate captures of the checking piece // Pawn captures - b1 = pos.pawn_attacks(them, checksq) & pos.pieces(PAWN, us) & ~pinned; + b1 = pos.attacks_from(checksq, them) & pos.pieces(PAWN, us) & ~pinned; while (b1) { from = pop_1st_bit(&b1); @@ -290,9 +288,9 @@ MoveStack* generate_evasions(const Position& pos, MoveStack* mlist, Bitboard pin } // Pieces captures - b1 = ( (pos.piece_attacks(checksq) & pos.pieces(KNIGHT, us)) - | (pos.piece_attacks(checksq) & pos.pieces(BISHOP, QUEEN, us)) - | (pos.piece_attacks(checksq) & pos.pieces(ROOK, QUEEN, us)) ) & ~pinned; + b1 = ( (pos.attacks_from(checksq) & pos.pieces(KNIGHT, us)) + | (pos.attacks_from(checksq) & pos.pieces(BISHOP, QUEEN, us)) + | (pos.attacks_from(checksq) & pos.pieces(ROOK, QUEEN, us)) ) & ~pinned; while (b1) { @@ -300,15 +298,14 @@ MoveStack* generate_evasions(const Position& pos, MoveStack* mlist, Bitboard pin (*mlist++).move = make_move(from, checksq); } - // Blocking check evasions are possible only if the checking piece is - // a slider. - if (checkers & (pos.pieces(BISHOP) | pos.pieces(ROOK) | pos.pieces(QUEEN))) + // Blocking check evasions are possible only if the checking piece is a slider + if (sliderAttacks) { Bitboard blockSquares = squares_between(checksq, ksq); assert((pos.occupied_squares() & blockSquares) == EmptyBoardBB); - if (blockSquares != EmptyBoardBB) + if (blockSquares) { mlist = generate_piece_moves(pos, mlist, us, blockSquares, pinned); mlist = generate_piece_moves(pos, mlist, us, blockSquares, pinned); @@ -326,7 +323,7 @@ MoveStack* generate_evasions(const Position& pos, MoveStack* mlist, Bitboard pin if (pos.ep_square() != SQ_NONE && (checkers & pos.pieces(PAWN, them))) { to = pos.ep_square(); - b1 = pos.pawn_attacks(them, to) & pos.pieces(PAWN, us); + b1 = pos.attacks_from(to, them) & pos.pieces(PAWN, us); // The checking pawn cannot be a discovered (bishop) check candidate // otherwise we were in check also before last double push move. @@ -348,13 +345,11 @@ MoveStack* generate_evasions(const Position& pos, MoveStack* mlist, Bitboard pin } -/// 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 -/// very hard to write an efficient legal move generator, but for the moment -/// we don't need it. +/// generate_moves() computes a complete list of legal or pseudo legal moves in +/// the current position. This function is not very fast, and should be used +/// only in situations where performance is unimportant. -MoveStack* generate_legal_moves(const Position& pos, MoveStack* mlist) { +MoveStack* generate_moves(const Position& pos, MoveStack* mlist, bool pseudoLegal) { assert(pos.is_ok()); @@ -366,6 +361,8 @@ MoveStack* generate_legal_moves(const Position& pos, MoveStack* mlist) { // Generate pseudo-legal moves MoveStack* last = generate_captures(pos, mlist); last = generate_noncaptures(pos, last); + if (pseudoLegal) + return last; // Remove illegal moves from the list for (MoveStack* cur = mlist; cur != last; cur++) @@ -379,10 +376,24 @@ MoveStack* generate_legal_moves(const Position& pos, MoveStack* mlist) { /// 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 and tests whether the move is legal. This version is not very fast +/// and should be used only for non time-critical paths. + +bool move_is_legal(const Position& pos, const Move m) { + + MoveStack mlist[256]; + MoveStack* last = generate_moves(pos, mlist, true); + for (MoveStack* cur = mlist; cur != last; cur++) + if (cur->move == m) + return pos.pl_move_is_legal(m); + + return false; +} + + +/// Fast version of move_is_legal() that takes a position a move and +/// a pinned pieces bitboard as input, and tests whether the move is legal. +/// This version must only be used when the side to move is not in check. bool move_is_legal(const Position& pos, const Move m, Bitboard pinned) { @@ -391,6 +402,10 @@ bool move_is_legal(const Position& pos, const Move m, Bitboard pinned) { assert(move_is_ok(m)); assert(pinned == pos.pinned_pieces(pos.side_to_move())); + // Use a slower but simpler function for uncommon cases + if (move_is_ep(m) || move_is_castle(m)) + return move_is_legal(pos, m); + Color us = pos.side_to_move(); Square from = move_from(m); Piece pc = pos.piece_on(from); @@ -403,92 +418,6 @@ bool move_is_legal(const Position& pos, const Move m, Bitboard pinned) { Color them = opposite_color(us); Square to = move_to(m); - // En passant moves - if (move_is_ep(m)) - { - // The piece must be a pawn and destination square must be the - // en passant square. - if ( type_of_piece(pc) != PAWN - || to != pos.ep_square()) - return false; - - assert(pos.square_is_empty(to)); - assert(pos.piece_on(to - pawn_push(us)) == piece_of_color_and_type(them, PAWN)); - - // The move is pseudo-legal, check if it is also legal - return pos.pl_move_is_legal(m, pinned); - } - - // Castling moves - if (move_is_short_castle(m)) - { - // The piece must be a king and side to move must still have - // the right to castle kingside. - if ( type_of_piece(pc) != KING - ||!pos.can_castle_kingside(us)) - return false; - - assert(from == pos.king_square(us)); - assert(to == pos.initial_kr_square(us)); - assert(pos.piece_on(to) == piece_of_color_and_type(us, ROOK)); - - Square g1 = relative_square(us, SQ_G1); - Square f1 = relative_square(us, SQ_F1); - Square s; - bool illegal = false; - - // Check if any of the squares between king and rook - // is occupied or under attack. - for (s = Min(from, g1); s <= Max(from, g1); s++) - if ( (s != from && s != to && !pos.square_is_empty(s)) - || pos.attacks_to(s, them)) - illegal = true; - - // Check if any of the squares between king and rook - // is occupied. - for (s = Min(to, f1); s <= Max(to, f1); s++) - if (s != from && s != to && !pos.square_is_empty(s)) - illegal = true; - - return !illegal; - } - - if (move_is_long_castle(m)) - { - // The piece must be a king and side to move must still have - // the right to castle kingside. - if ( type_of_piece(pc) != KING - ||!pos.can_castle_queenside(us)) - return false; - - assert(from == pos.king_square(us)); - assert(to == pos.initial_qr_square(us)); - assert(pos.piece_on(to) == piece_of_color_and_type(us, ROOK)); - - Square c1 = relative_square(us, SQ_C1); - Square d1 = relative_square(us, SQ_D1); - Square s; - bool illegal = false; - - for (s = Min(from, c1); s <= Max(from, c1); s++) - if( (s != from && s != to && !pos.square_is_empty(s)) - || pos.attacks_to(s, them)) - illegal = true; - - for (s = Min(to, d1); s <= Max(to, d1); s++) - if(s != from && s != to && !pos.square_is_empty(s)) - illegal = true; - - if ( square_file(to) == FILE_B - && ( pos.piece_on(to + DELTA_W) == piece_of_color_and_type(them, ROOK) - || pos.piece_on(to + DELTA_W) == piece_of_color_and_type(them, QUEEN))) - illegal = true; - - return !illegal; - } - - // Normal moves - // The destination square cannot be occupied by a friendly piece if (pos.color_of_piece_on(to) == us) return false; @@ -557,36 +486,12 @@ bool move_is_legal(const Position& pos, const Move m, Bitboard pinned) { } // Luckly we can handle all the other pieces in one go - return ( pos.piece_attacks_square(pos.piece_on(from), from, to) + return ( bit_is_set(pos.attacks_from(pc, from), to) && pos.pl_move_is_legal(m, pinned) && !move_is_promotion(m)); } -/// Another version of move_is_legal(), which takes only a position and a move -/// as input. This function does not require that the side to move is not in -/// check. It is not optimized for speed, and is only used for verifying move -/// legality when building a PV from the transposition table. - -bool move_is_legal(const Position& pos, const Move m) { - - Bitboard pinned = pos.pinned_pieces(pos.side_to_move()); - if (!pos.is_check()) - return move_is_legal(pos, m, pinned); - else - { - Position p(pos); - MoveStack mlist[64]; - MoveStack* last = generate_evasions(p, mlist, pinned); - for (MoveStack* cur = mlist; cur != last; cur++) - if (cur->move == m) - return true; - - return false; - } -} - - namespace { template @@ -598,7 +503,7 @@ namespace { 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; + b = pos.attacks_from(from) & target; SERIALIZE_MOVES(b); } return mlist; @@ -616,7 +521,7 @@ namespace { if (pinned && bit_is_set(pinned, from)) continue; - b = pos.piece_attacks(from) & target; + b = pos.attacks_from(from) & target; SERIALIZE_MOVES(b); } return mlist; @@ -628,7 +533,7 @@ namespace { Bitboard b; Square from = pos.king_square(us); - b = pos.piece_attacks(from) & target; + b = pos.attacks_from(from) & target; SERIALIZE_MOVES(b); return mlist; } @@ -700,7 +605,7 @@ namespace { assert(Us != WHITE || square_rank(pos.ep_square()) == RANK_6); assert(Us != BLACK || square_rank(pos.ep_square()) == RANK_3); - Bitboard b1 = pawns & pos.pawn_attacks(Them, pos.ep_square()); + Bitboard b1 = pawns & pos.attacks_from(pos.ep_square(), Them); assert(b1 != EmptyBoardBB); while (b1) @@ -712,10 +617,11 @@ namespace { return mlist; } - template - MoveStack* generate_pawn_noncaptures(const Position& pos, MoveStack* mlist) { + template + MoveStack* generate_pawn_noncaptures(const Position& pos, MoveStack* mlist, Bitboard dc, Square ksq) { // Calculate our parametrized parameters at compile time + const Color Them = (Us == WHITE ? BLACK : WHITE); const Bitboard TRank8BB = (Us == WHITE ? Rank8BB : Rank1BB); const Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB); const Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB); @@ -723,17 +629,20 @@ namespace { const SquareDelta TDELTA_NW = (Us == WHITE ? DELTA_NW : DELTA_SW); const SquareDelta TDELTA_N = (Us == WHITE ? DELTA_N : DELTA_S); - Bitboard b1, b2; + Bitboard b1, b2, dcPawns1, dcPawns2; Square to; Bitboard pawns = pos.pieces(PAWN, Us); Bitboard emptySquares = pos.empty_squares(); if (pawns & TRank7BB) // There is some promotion candidate ? { - Bitboard enemyPieces = pos.pieces_of_color(opposite_color(Us)); + // When generating checks consider under-promotion moves (both captures + // and non captures) only if can give a discovery check. + Bitboard pp = GenerateChecks ? pawns & dc : pawns; + Bitboard enemyPieces = pos.pieces_of_color(opposite_color(Us)); // Underpromotion captures in the a1-h8 (a8-h1 for black) direction - b1 = move_pawns(pawns) & ~FileABB & enemyPieces & TRank8BB; + b1 = move_pawns(pp) & ~FileABB & enemyPieces & TRank8BB; while (b1) { to = pop_1st_bit(&b1); @@ -743,7 +652,7 @@ namespace { } // Underpromotion captures in the h1-a8 (h8-a1 for black) direction - b1 = move_pawns(pawns) & ~FileHBB & enemyPieces & TRank8BB; + b1 = move_pawns(pp) & ~FileHBB & enemyPieces & TRank8BB; while (b1) { to = pop_1st_bit(&b1); @@ -753,7 +662,7 @@ namespace { } // Underpromotion pawn pushes - b1 = move_pawns(pawns) & emptySquares & TRank8BB; + b1 = move_pawns(pp) & emptySquares & TRank8BB; while (b1) { to = pop_1st_bit(&b1); @@ -763,68 +672,25 @@ namespace { } } - // Single pawn pushes - b2 = b1 = move_pawns(pawns) & emptySquares & ~TRank8BB; - SERIALIZE_MOVES_D(b2, -TDELTA_N); - - // Double pawn pushes - b2 = move_pawns(b1 & TRank3BB) & emptySquares; - SERIALIZE_MOVES_D(b2, -TDELTA_N -TDELTA_N); - return mlist; - } - - - template - MoveStack* generate_pawn_checks(const Position& pos, Bitboard dc, Square ksq, MoveStack* mlist) - { - // Calculate our parametrized parameters at compile time - const Color Them = (Us == WHITE ? BLACK : WHITE); - const Bitboard TRank8BB = (Us == WHITE ? Rank8BB : Rank1BB); - const Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB); - const SquareDelta TDELTA_N = (Us == WHITE ? DELTA_N : DELTA_S); - const SquareDelta TDELTA_S = (Us == WHITE ? DELTA_S : DELTA_N); - - Square to; - Bitboard b1, b2, b3; - Bitboard pawns = pos.pieces(PAWN, Us); - - if (dc & pawns) + dcPawns1 = dcPawns2 = EmptyBoardBB; + if (GenerateChecks && (dc & pawns)) { - Bitboard empty = pos.empty_squares(); - // 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 = pawns & ~file_bb(ksq); - - // Discovered checks, single pawn pushes, no promotions - b2 = b3 = move_pawns(b1 & dc) & empty & ~TRank8BB; - SERIALIZE_MOVES_D(b3, -TDELTA_N); - - // Discovered checks, double pawn pushes - b3 = move_pawns(b2 & TRank3BB) & empty; - SERIALIZE_MOVES_D(b3, -TDELTA_N -TDELTA_N); + dcPawns1 = move_pawns(pawns & dc & ~file_bb(ksq)) & emptySquares & ~TRank8BB; + dcPawns2 = move_pawns(dcPawns1 & TRank3BB) & emptySquares; } - // Direct checks. These are possible only for pawns on neighboring files - // and in the two ranks that, after the push, are in front of the enemy king. - b1 = pawns & neighboring_files_bb(ksq) & ~dc; - - // We can get false positives if (ksq + x) is not in [0,63] range but - // is not a problem, they will be filtered out later. - b2 = b1 & (rank_bb(ksq + 2 * TDELTA_S) | rank_bb(ksq + 3 * TDELTA_S)); - if (!b2) - return mlist; - - // Direct checks, single pawn pushes - Bitboard empty = pos.empty_squares(); - b2 = move_pawns(b1) & empty; - b3 = b2 & pos.pawn_attacks(Them, ksq); - SERIALIZE_MOVES_D(b3, -TDELTA_N); + // Single pawn pushes + b1 = move_pawns(pawns) & emptySquares & ~TRank8BB; + b2 = GenerateChecks ? (b1 & pos.attacks_from(ksq, Them)) | dcPawns1 : b1; + SERIALIZE_MOVES_D(b2, -TDELTA_N); - // Direct checks, double pawn pushes - b3 = move_pawns(b2 & TRank3BB) & empty & pos.pawn_attacks(Them, ksq); - SERIALIZE_MOVES_D(b3, -TDELTA_N -TDELTA_N); + // Double pawn pushes + b1 = move_pawns(b1 & TRank3BB) & emptySquares; + b2 = GenerateChecks ? (b1 & pos.attacks_from(ksq, Them)) | dcPawns2 : b1; + SERIALIZE_MOVES_D(b2, -TDELTA_N -TDELTA_N); return mlist; } @@ -839,7 +705,7 @@ namespace { while (b) { Square from = pop_1st_bit(&b); - Bitboard bb = pos.piece_attacks(from) & pos.empty_squares(); + Bitboard bb = pos.attacks_from(from) & pos.empty_squares(); if (Piece == KING) bb &= ~QueenPseudoAttacks[ksq]; @@ -848,23 +714,20 @@ namespace { // Direct checks b = target & ~dc; - if (Piece != KING || b) + Bitboard checkSqs = pos.attacks_from(ksq) & pos.empty_squares(); + if (Piece == KING || !checkSqs) + return mlist; + + while (b) { - Bitboard checkSqs = pos.piece_attacks(ksq) & pos.empty_squares(); - if (!checkSqs) - return mlist; + Square from = pop_1st_bit(&b); + if ( (Piece == QUEEN && !(QueenPseudoAttacks[from] & checkSqs)) + || (Piece == ROOK && !(RookPseudoAttacks[from] & checkSqs)) + || (Piece == BISHOP && !(BishopPseudoAttacks[from] & checkSqs))) + continue; - while (b) - { - Square from = pop_1st_bit(&b); - if ( (Piece == QUEEN && !(QueenPseudoAttacks[from] & checkSqs)) - || (Piece == ROOK && !(RookPseudoAttacks[from] & checkSqs)) - || (Piece == BISHOP && !(BishopPseudoAttacks[from] & checkSqs))) - continue; - - Bitboard bb = pos.piece_attacks(from) & checkSqs; - SERIALIZE_MOVES(bb); - } + Bitboard bb = pos.attacks_from(from) & checkSqs; + SERIALIZE_MOVES(bb); } return mlist; } @@ -942,7 +805,7 @@ namespace { // 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.attacks_to(s, them)) + ||(pos.attackers_to(s) & pos.pieces_of_color(them))) illegal = true; for (s = Min(rsq, s2); s <= Max(rsq, s2); s++)