X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovegen.cpp;h=f38d42261ccfbdf827cdc5d9ad1c813f812a4aff;hp=f688bfef67054c138a5d96c72ef3a1478150fb9f;hb=b1929960f9b73cb8fcc86fdbdf7a8d2d1de4fc53;hpb=57c51dd1ef2037801b7b8a97837bec65eb98d827 diff --git a/src/movegen.cpp b/src/movegen.cpp index f688bfef..f38d4226 100644 --- a/src/movegen.cpp +++ b/src/movegen.cpp @@ -17,11 +17,6 @@ along with this program. If not, see . */ - -//// -//// Includes -//// - #include #include "bitcount.h" @@ -34,10 +29,6 @@ // Version used for pawns, where the 'from' square is given as a delta from the 'to' square #define SERIALIZE_MOVES_D(b, d) while (b) { to = pop_1st_bit(&b); (*mlist++).move = make_move(to + (d), to); } -//// -//// Local definitions -//// - namespace { enum CastlingSide { @@ -45,141 +36,180 @@ namespace { QUEEN_SIDE }; - enum MoveType { - CAPTURE, - NON_CAPTURE, - CHECK, - EVASION - }; - - // Helper templates - template - MoveStack* generate_castle_moves(const Position&, MoveStack*); + template + MoveStack* generate_castle_moves(const Position&, MoveStack*, Color us); - template + template MoveStack* generate_pawn_moves(const Position&, MoveStack*, Bitboard, Square); - // Template generate_piece_moves (captures and non-captures) with specializations and overloads - template - MoveStack* generate_piece_moves(const Position&, MoveStack*, Color, Bitboard); + template + inline MoveStack* generate_discovered_checks(const Position& pos, MoveStack* mlist, Square from) { - template<> - MoveStack* generate_piece_moves(const Position&, MoveStack*, Color, Bitboard); + assert(Pt != QUEEN); - template - inline MoveStack* generate_piece_moves(const Position& p, MoveStack* m, Color us, Bitboard t) { + Bitboard b = pos.attacks_from(from) & pos.empty_squares(); + if (Pt == KING) + { + Square ksq = pos.king_square(opposite_color(pos.side_to_move())); + b &= ~QueenPseudoAttacks[ksq]; + } + SERIALIZE_MOVES(b); + return mlist; + } - assert(Piece == PAWN); - assert(Type == CAPTURE || Type == NON_CAPTURE || Type == EVASION); + template + inline MoveStack* generate_direct_checks(const Position& pos, MoveStack* mlist, Color us, + Bitboard dc, Square ksq) { + assert(Pt != KING); - return (us == WHITE ? generate_pawn_moves(p, m, t, SQ_NONE) - : generate_pawn_moves(p, m, t, SQ_NONE)); - } + Bitboard checkSqs, b; + Square from; + const Square* ptr = pos.piece_list_begin(us, Pt); - // Templates for non-capture checks generation + if ((from = *ptr++) == SQ_NONE) + return mlist; - template - MoveStack* generate_discovered_checks(const Position&, MoveStack*, Square); + checkSqs = pos.attacks_from(ksq) & pos.empty_squares(); - template - MoveStack* generate_direct_checks(const Position&, MoveStack*, Color, Bitboard, Square); + do + { + if ( (Pt == QUEEN && !(QueenPseudoAttacks[from] & checkSqs)) + || (Pt == ROOK && !(RookPseudoAttacks[from] & checkSqs)) + || (Pt == BISHOP && !(BishopPseudoAttacks[from] & checkSqs))) + continue; - template<> - inline MoveStack* generate_direct_checks(const Position& p, MoveStack* m, Color us, Bitboard dc, Square ksq) { + if (dc && bit_is_set(dc, from)) + continue; - return (us == WHITE ? generate_pawn_moves(p, m, dc, ksq) - : generate_pawn_moves(p, m, dc, ksq)); - } -} + b = pos.attacks_from(from) & checkSqs; + SERIALIZE_MOVES(b); + } while ((from = *ptr++) != SQ_NONE); -//// -//// Functions -//// + return mlist; + } + template<> + FORCE_INLINE MoveStack* generate_direct_checks(const Position& p, MoveStack* m, Color us, Bitboard dc, Square ksq) { -/// generate_captures() generates all pseudo-legal captures and queen -/// promotions. Returns a pointer to the end of the move list. + return (us == WHITE ? generate_pawn_moves(p, m, dc, ksq) + : generate_pawn_moves(p, m, dc, ksq)); + } -MoveStack* generate_captures(const Position& pos, MoveStack* mlist) { + template + FORCE_INLINE MoveStack* generate_piece_moves(const Position& p, MoveStack* m, Color us, Bitboard t) { - assert(pos.is_ok()); - assert(!pos.is_check()); + assert(Pt == PAWN); + assert(Type == MV_CAPTURE || Type == MV_NON_CAPTURE || Type == MV_EVASION); - Color us = pos.side_to_move(); - Bitboard target = pos.pieces_of_color(opposite_color(us)); + return (us == WHITE ? generate_pawn_moves(p, m, t, SQ_NONE) + : generate_pawn_moves(p, m, t, SQ_NONE)); + } - 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 generate_piece_moves(pos, mlist, us, target); -} + template + FORCE_INLINE MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) { + Bitboard b; + Square from; + const Square* ptr = pos.piece_list_begin(us, Pt); -/// generate_noncaptures() generates all pseudo-legal non-captures and -/// underpromotions. Returns a pointer to the end of the move list. + if (*ptr != SQ_NONE) + { + do { + from = *ptr; + b = pos.attacks_from(from) & target; + SERIALIZE_MOVES(b); + } while (*++ptr != SQ_NONE); + } + return mlist; + } -MoveStack* generate_noncaptures(const Position& pos, MoveStack* mlist) { + template<> + FORCE_INLINE MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) { - assert(pos.is_ok()); - assert(!pos.is_check()); + Bitboard b; + Square from = pos.king_square(us); - Color us = pos.side_to_move(); - Bitboard target = pos.empty_squares(); + b = pos.attacks_from(from) & target; + SERIALIZE_MOVES(b); + return 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_castle_moves(pos, mlist); - return generate_castle_moves(pos, mlist); } -/// generate_non_evasions() generates all pseudo-legal captures and +/// generate generates all pseudo-legal captures and queen +/// promotions. Returns a pointer to the end of the move list. +/// +/// generate generates all pseudo-legal non-captures and +/// underpromotions. Returns a pointer to the end of the move list. +/// +/// generate generates all pseudo-legal captures and /// non-captures. Returns a pointer to the end of the move list. -MoveStack* generate_non_evasions(const Position& pos, MoveStack* mlist) { +template +MoveStack* generate(const Position& pos, MoveStack* mlist) { assert(pos.is_ok()); - assert(!pos.is_check()); + assert(!pos.in_check()); Color us = pos.side_to_move(); - Bitboard target = pos.pieces_of_color(opposite_color(us)); + Bitboard target; - mlist = generate_piece_moves(pos, mlist, us, target); - mlist = generate_piece_moves(pos, mlist, us, pos.empty_squares()); + if (Type == MV_CAPTURE || Type == MV_NON_EVASION) + target = pos.pieces_of_color(opposite_color(us)); + else if (Type == MV_NON_CAPTURE) + target = pos.empty_squares(); + else + assert(false); - target |= pos.empty_squares(); + if (Type == MV_NON_EVASION) + { + mlist = generate_piece_moves(pos, mlist, us, target); + mlist = generate_piece_moves(pos, mlist, us, pos.empty_squares()); + target |= pos.empty_squares(); + } + else + 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_castle_moves(pos, mlist); - return generate_castle_moves(pos, mlist); + + if (Type != MV_CAPTURE) + { + if (pos.can_castle_kingside(us)) + mlist = generate_castle_moves(pos, mlist, us); + + if (pos.can_castle_queenside(us)) + mlist = generate_castle_moves(pos, mlist, us); + } + + return mlist; } +// Explicit template instantiations +template MoveStack* generate(const Position& pos, MoveStack* mlist); +template MoveStack* generate(const Position& pos, MoveStack* mlist); +template MoveStack* generate(const Position& pos, MoveStack* mlist); + /// generate_non_capture_checks() generates all pseudo-legal non-captures and knight /// underpromotions that give check. Returns a pointer to the end of the move list. - -MoveStack* generate_non_capture_checks(const Position& pos, MoveStack* mlist) { +template<> +MoveStack* generate(const Position& pos, MoveStack* mlist) { assert(pos.is_ok()); - assert(!pos.is_check()); + assert(!pos.in_check()); Bitboard b, dc; Square from; Color us = pos.side_to_move(); Square ksq = pos.king_square(opposite_color(us)); - assert(pos.piece_on(ksq) == piece_of_color_and_type(opposite_color(us), KING)); + assert(pos.piece_on(ksq) == make_piece(opposite_color(us), KING)); // Discovered non-capture checks b = dc = pos.discovered_check_candidates(us); @@ -209,11 +239,11 @@ MoveStack* generate_non_capture_checks(const Position& pos, MoveStack* mlist) { /// generate_evasions() generates all pseudo-legal check evasions when /// the side to move is in check. Returns a pointer to the end of the move list. - -MoveStack* generate_evasions(const Position& pos, MoveStack* mlist) { +template<> +MoveStack* generate(const Position& pos, MoveStack* mlist) { assert(pos.is_ok()); - assert(pos.is_check()); + assert(pos.in_check()); Bitboard b, target; Square from, checksq; @@ -223,7 +253,7 @@ MoveStack* generate_evasions(const Position& pos, MoveStack* mlist) { Bitboard checkers = pos.checkers(); Bitboard sliderAttacks = EmptyBoardBB; - assert(pos.piece_on(ksq) == piece_of_color_and_type(us, KING)); + assert(pos.piece_on(ksq) == make_piece(us, KING)); assert(checkers); // Find squares attacked by slider checkers, we will remove @@ -266,7 +296,7 @@ MoveStack* generate_evasions(const Position& pos, MoveStack* mlist) { // checker piece is possible. target = squares_between(checksq, ksq) | checkers; - 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); @@ -274,177 +304,41 @@ MoveStack* generate_evasions(const Position& pos, MoveStack* mlist) { } -/// 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 non time-critical paths. +/// generate computes a complete list of legal +/// or pseudo-legal moves in the current position. +template<> +MoveStack* generate(const Position& pos, MoveStack* mlist) { -MoveStack* generate_moves(const Position& pos, MoveStack* mlist, bool pseudoLegal) { + assert(pos.is_ok()); + + return pos.in_check() ? generate(pos, mlist) + : generate(pos, mlist); +} + +template<> +MoveStack* generate(const Position& pos, MoveStack* mlist) { assert(pos.is_ok()); MoveStack *last, *cur = mlist; Bitboard pinned = pos.pinned_pieces(pos.side_to_move()); - // Generate pseudo-legal moves - last = pos.is_check() ? generate_evasions(pos, mlist) - : generate_non_evasions(pos, mlist); - if (pseudoLegal) - return last; + last = generate(pos, mlist); // Remove illegal moves from the list while (cur != last) - if (pos.pl_move_is_legal(cur->move, pinned)) - cur++; - else + if (!pos.pl_move_is_legal(cur->move, pinned)) cur->move = (--last)->move; + else + cur++; return last; } -/// move_is_legal() takes a position and a (not necessarily pseudo-legal) -/// move and tests whether the move is legal. This version is not very fast -/// and should be used only in non time-critical paths. - -bool move_is_legal(const Position& pos, const Move m) { - - MoveStack mlist[MOVES_MAX]; - MoveStack *cur, *last = generate_moves(pos, mlist, true); - - for (cur = mlist; cur != last; cur++) - if (cur->move == m) - return pos.pl_move_is_legal(m, pos.pinned_pieces(pos.side_to_move())); - - return false; -} - - -/// Fast version of move_is_legal() that takes a position a move and a -/// bitboard of pinned pieces as input, and tests whether the move is legal. - -bool move_is_legal(const Position& pos, const Move m, Bitboard pinned) { - - assert(pos.is_ok()); - 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); - Square from = move_from(m); - Square to = move_to(m); - Piece pc = pos.piece_on(from); - - // Use a slower but simpler function for uncommon cases - if (move_is_special(m)) - return move_is_legal(pos, m); - - // 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 false; - - // The destination square cannot be occupied by a friendly piece - if (pos.color_of_piece_on(to) == us) - return false; - - // Handle the special case of a pawn move - if (type_of_piece(pc) == PAWN) - { - // Move direction must be compatible with pawn color - int direction = to - from; - if ((us == WHITE) != (direction > 0)) - return false; - - // We have already handled promotion moves, so destination - // cannot be on the 8/1th rank. - if (square_rank(to) == RANK_8 || square_rank(to) == RANK_1) - return false; - - // Proceed according to the square delta between the origin and - // destination squares. - switch (direction) - { - case DELTA_NW: - case DELTA_NE: - case DELTA_SW: - case DELTA_SE: - // 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 false; - break; - - case DELTA_N: - case DELTA_S: - // Pawn push. The destination square must be empty. - if (!pos.square_is_empty(to)) - return false; - break; - - case DELTA_NN: - // Double white pawn push. The destination square must be on the fourth - // rank, and both the destination square and the square between the - // source and destination squares must be empty. - if ( square_rank(to) != RANK_4 - || !pos.square_is_empty(to) - || !pos.square_is_empty(from + DELTA_N)) - return false; - break; - - case DELTA_SS: - // Double black pawn push. The destination square must be on the fifth - // rank, and both the destination square and the square between the - // source and destination squares must be empty. - if ( square_rank(to) != RANK_5 - || !pos.square_is_empty(to) - || !pos.square_is_empty(from + DELTA_S)) - return false; - break; - - default: - return false; - } - } - else if (!bit_is_set(pos.attacks_from(pc, from), to)) - return false; - - // The move is pseudo-legal, check if it is also legal - return pos.is_check() ? pos.pl_move_is_evasion(m, pinned) : pos.pl_move_is_legal(m, pinned); -} - - namespace { - template - MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) { - - Bitboard b; - Square from; - const Square* ptr = pos.piece_list_begin(us, Piece); - - if (*ptr != SQ_NONE) - { - do { - from = *ptr; - b = pos.attacks_from(from) & target; - SERIALIZE_MOVES(b); - } while (*++ptr != SQ_NONE); - } - return mlist; - } - - template<> - MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) { - - Bitboard b; - Square from = pos.king_square(us); - - b = pos.attacks_from(from) & target; - SERIALIZE_MOVES(b); - return mlist; - } - - template + template inline Bitboard move_pawns(Bitboard p) { return Delta == DELTA_N ? p << 8 : Delta == DELTA_S ? p >> 8 : @@ -452,7 +346,7 @@ namespace { Delta == DELTA_NW ? p << 7 : Delta == DELTA_SW ? p >> 9 : p; } - template + template inline MoveStack* generate_pawn_captures(MoveStack* mlist, Bitboard pawns, Bitboard target) { const Bitboard TFileABB = (Delta == DELTA_NE || Delta == DELTA_SE ? FileABB : FileHBB); @@ -466,7 +360,7 @@ namespace { return mlist; } - template + template inline MoveStack* generate_promotions(const Position& pos, MoveStack* mlist, Bitboard pawnsOn7, Bitboard target) { const Bitboard TFileABB = (Delta == DELTA_NE || Delta == DELTA_SE ? FileABB : FileHBB); @@ -484,10 +378,10 @@ namespace { { to = pop_1st_bit(&b); - if (Type == CAPTURE || Type == EVASION) + if (Type == MV_CAPTURE || Type == MV_EVASION) (*mlist++).move = make_promotion_move(to - Delta, to, QUEEN); - if (Type == NON_CAPTURE || Type == EVASION) + if (Type == MV_NON_CAPTURE || Type == MV_EVASION) { (*mlist++).move = make_promotion_move(to - Delta, to, ROOK); (*mlist++).move = make_promotion_move(to - Delta, to, BISHOP); @@ -496,7 +390,7 @@ namespace { // This is the only possible under promotion that can give a check // not already included in the queen-promotion. - if ( Type == CHECK + if ( Type == MV_CHECK && bit_is_set(pos.attacks_from(to), pos.king_square(opposite_color(Us)))) (*mlist++).move = make_promotion_move(to - Delta, to, KNIGHT); else (void)pos; // Silence a warning under MSVC @@ -509,27 +403,27 @@ namespace { // Calculate our parametrized parameters at compile time, named // according to the point of view of white side. - const Color Them = (Us == WHITE ? BLACK : WHITE); - const Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB); - const Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB); - const SquareDelta TDELTA_N = (Us == WHITE ? DELTA_N : DELTA_S); - const SquareDelta TDELTA_NE = (Us == WHITE ? DELTA_NE : DELTA_SE); - const SquareDelta TDELTA_NW = (Us == WHITE ? DELTA_NW : DELTA_SW); + const Color Them = (Us == WHITE ? BLACK : WHITE); + const Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB); + const Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB); + const Square TDELTA_N = (Us == WHITE ? DELTA_N : DELTA_S); + const Square TDELTA_NE = (Us == WHITE ? DELTA_NE : DELTA_SE); + const Square TDELTA_NW = (Us == WHITE ? DELTA_NW : DELTA_SW); Square to; Bitboard b1, b2, dc1, dc2, pawnPushes, emptySquares; Bitboard pawns = pos.pieces(PAWN, Us); Bitboard pawnsOn7 = pawns & TRank7BB; - Bitboard enemyPieces = (Type == CAPTURE ? target : pos.pieces_of_color(Them)); + Bitboard enemyPieces = (Type == MV_CAPTURE ? target : pos.pieces_of_color(Them)); // Pre-calculate pawn pushes before changing emptySquares definition - if (Type != CAPTURE) + if (Type != MV_CAPTURE) { - emptySquares = (Type == NON_CAPTURE ? target : pos.empty_squares()); + emptySquares = (Type == MV_NON_CAPTURE ? target : pos.empty_squares()); pawnPushes = move_pawns(pawns & ~TRank7BB) & emptySquares; } - if (Type == EVASION) + if (Type == MV_EVASION) { emptySquares &= target; // Only blocking squares enemyPieces &= target; // Capture only the checker piece @@ -538,7 +432,7 @@ namespace { // Promotions and underpromotions if (pawnsOn7) { - if (Type == CAPTURE) + if (Type == MV_CAPTURE) emptySquares = pos.empty_squares(); pawns &= ~TRank7BB; @@ -548,19 +442,19 @@ namespace { } // Standard captures - if (Type == CAPTURE || Type == EVASION) + if (Type == MV_CAPTURE || Type == MV_EVASION) { mlist = generate_pawn_captures(mlist, pawns, enemyPieces); mlist = generate_pawn_captures(mlist, pawns, enemyPieces); } // Single and double pawn pushes - if (Type != CAPTURE) + if (Type != MV_CAPTURE) { b1 = pawnPushes & emptySquares; b2 = move_pawns(pawnPushes & TRank3BB) & emptySquares; - if (Type == CHECK) + if (Type == MV_CHECK) { // Consider only pawn moves which give direct checks b1 &= pos.attacks_from(ksq, Them); @@ -583,7 +477,7 @@ namespace { } // En passant captures - if ((Type == CAPTURE || Type == EVASION) && pos.ep_square() != SQ_NONE) + if ((Type == MV_CAPTURE || Type == MV_EVASION) && pos.ep_square() != SQ_NONE) { assert(Us != WHITE || square_rank(pos.ep_square()) == RANK_6); assert(Us != BLACK || square_rank(pos.ep_square()) == RANK_3); @@ -591,7 +485,7 @@ namespace { // An en passant capture can be an evasion only if the checking piece // is the double pushed pawn and so is in the target. Otherwise this // is a discovery check and we are forced to do otherwise. - if (Type == EVASION && !bit_is_set(target, pos.ep_square() - TDELTA_N)) + if (Type == MV_EVASION && !bit_is_set(target, pos.ep_square() - TDELTA_N)) return mlist; b1 = pawns & pos.attacks_from(pos.ep_square(), Them); @@ -607,93 +501,42 @@ namespace { return mlist; } - template - MoveStack* generate_discovered_checks(const Position& pos, MoveStack* mlist, Square from) { - - assert(Piece != QUEEN); - - Bitboard b = pos.attacks_from(from) & pos.empty_squares(); - if (Piece == KING) - { - Square ksq = pos.king_square(opposite_color(pos.side_to_move())); - b &= ~QueenPseudoAttacks[ksq]; - } - SERIALIZE_MOVES(b); - return mlist; - } - - template - MoveStack* generate_direct_checks(const Position& pos, MoveStack* mlist, Color us, - Bitboard dc, Square ksq) { - assert(Piece != KING); - - Bitboard checkSqs, b; - Square from; - const Square* ptr = pos.piece_list_begin(us, Piece); - - if ((from = *ptr++) == SQ_NONE) - return mlist; - - checkSqs = pos.attacks_from(ksq) & pos.empty_squares(); - - do - { - if ( (Piece == QUEEN && !(QueenPseudoAttacks[from] & checkSqs)) - || (Piece == ROOK && !(RookPseudoAttacks[from] & checkSqs)) - || (Piece == BISHOP && !(BishopPseudoAttacks[from] & checkSqs))) - continue; - - if (dc && bit_is_set(dc, from)) - continue; - - b = pos.attacks_from(from) & checkSqs; - SERIALIZE_MOVES(b); - - } while ((from = *ptr++) != SQ_NONE); - - return mlist; - } - template - MoveStack* generate_castle_moves(const Position& pos, MoveStack* mlist) { + MoveStack* generate_castle_moves(const Position& pos, MoveStack* mlist, Color us) { - Color us = pos.side_to_move(); + Color them = opposite_color(us); + Square ksq = pos.king_square(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) == make_piece(us, KING)); - assert(pos.piece_on(ksq) == piece_of_color_and_type(us, KING)); + 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; - 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) == make_piece(us, ROOK)); - assert(pos.piece_on(rsq) == piece_of_color_and_type(us, ROOK)); + // 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.attackers_to(s) & pos.pieces_of_color(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.attackers_to(s) & pos.pieces_of_color(them))) - illegal = true; + 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(rsq, s2); s <= Max(rsq, s2); s++) - if (s != ksq && s != rsq && pos.square_is_occupied(s)) - illegal = true; + if ( Side == QUEEN_SIDE + && square_file(rsq) == FILE_B + && ( pos.piece_on(relative_square(us, SQ_A1)) == make_piece(them, ROOK) + || pos.piece_on(relative_square(us, SQ_A1)) == make_piece(them, QUEEN))) + illegal = true; - if ( Side == QUEEN_SIDE - && square_file(rsq) == FILE_B - && ( pos.piece_on(relative_square(us, SQ_A1)) == piece_of_color_and_type(them, ROOK) - || pos.piece_on(relative_square(us, SQ_A1)) == piece_of_color_and_type(them, QUEEN))) - illegal = true; + if (!illegal) + (*mlist++).move = make_castle_move(ksq, rsq); - if (!illegal) - (*mlist++).move = make_castle_move(ksq, rsq); - } return mlist; } -} + +} // namespace