X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovegen.cpp;h=da8d08c3e4611ca9cce5f645e2616189d234ac2b;hp=0646c230f50c778360a48c368258d47998df2e68;hb=68c78400c8eb1b9946caa93d6013eff1d985e577;hpb=00bcc6478737caae740dbf511d3587b9332ad2e6 diff --git a/src/movegen.cpp b/src/movegen.cpp index 0646c230..da8d08c3 100644 --- a/src/movegen.cpp +++ b/src/movegen.cpp @@ -32,38 +32,125 @@ namespace { - inline Bitboard forward_white(Bitboard b) { return b << 8; } - inline Bitboard forward_right_white(Bitboard b) { return b << 9; } - inline Bitboard forward_left_white(Bitboard b) { return b << 7; } - - inline Bitboard forward_black(Bitboard b) { return b >> 8; } - inline Bitboard forward_right_black(Bitboard b) { return b >> 7; } - inline Bitboard forward_left_black(Bitboard b) { return b >> 9; } - struct PawnOffsets { Bitboard Rank3BB, Rank8BB; Rank RANK_8; SquareDelta DELTA_N, DELTA_NE, DELTA_NW; Color us, them; - typedef Bitboard (*Shift_fn)(Bitboard b); - Shift_fn forward, forward_left, forward_right; }; + const PawnOffsets WhitePawnOffsets = { Rank3BB, Rank8BB, RANK_8, DELTA_N, DELTA_NE, DELTA_NW, WHITE, BLACK }; + const PawnOffsets BlackPawnOffsets = { Rank6BB, Rank1BB, RANK_1, DELTA_S, DELTA_SE, DELTA_SW, BLACK, WHITE }; + + int generate_castle_moves(const Position&, MoveStack*, Color); - const PawnOffsets WhitePawnOffsets = { Rank3BB, Rank8BB, RANK_8, DELTA_N, DELTA_NE, DELTA_NW, WHITE, BLACK, - &forward_white, forward_left_white, forward_right_white }; + template + int generate_pawn_captures(const Position&, MoveStack*); - const PawnOffsets BlackPawnOffsets = { Rank6BB, Rank1BB, RANK_1, DELTA_S, DELTA_SE, DELTA_SW, BLACK, WHITE, - &forward_black, &forward_left_black, &forward_right_black }; + template + int generate_pawn_noncaptures(const Position&, MoveStack*); - int generate_pawn_captures(const PawnOffsets&, const Position&, MoveStack*); - int generate_pawn_noncaptures(const PawnOffsets&, const Position&, MoveStack*); - int generate_pawn_checks(const PawnOffsets&, const Position&, Bitboard, Square, MoveStack*, int); - int generate_piece_checks(PieceType, const Position&, Bitboard, Bitboard, Square, MoveStack*, int); - int generate_piece_moves(PieceType, const Position&, MoveStack*, Color, Bitboard); - int generate_castle_moves(const Position&, MoveStack*, Color); - int generate_piece_blocking_evasions(PieceType, const Position&, Bitboard, Bitboard, MoveStack*, int); - int generate_pawn_blocking_evasions(const PawnOffsets&, const Position&, Bitboard, Bitboard, MoveStack*, int); + template + int generate_pawn_checks(const Position&, Bitboard, Square, MoveStack*, int); + + template + int generate_pawn_blocking_evasions(const Position&, Bitboard, Bitboard, MoveStack*, int); + + template + int generate_piece_moves(const Position&, MoveStack*, Color, Bitboard); + + template + int generate_piece_checks(const Position&, Bitboard, Bitboard, Square, MoveStack*, int); + + template + int generate_piece_blocking_evasions(const Position&, Bitboard, Bitboard, MoveStack*, int); + + + /// Templates are defined here to avoid lookup issues with specializations + + template + int generate_piece_moves(const Position &pos, MoveStack *mlist, + Color side, Bitboard target) { + int n = 0; + for (int i = 0; i < pos.piece_count(side, Piece); i++) + { + Square from = pos.piece_list(side, Piece, i); + Bitboard b = pos.piece_attacks(from) & target; + while (b) + { + Square to = pop_1st_bit(&b); + mlist[n++].move = make_move(from, to); + } + } + return n; + } + + + template + int generate_piece_checks(const Position& pos, Bitboard target, Bitboard dc, + Square ksq, MoveStack* mlist, int n) { + // 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[n++].move = make_move(from, to); + } + } + // Direct checks + b = target & ~dc; + 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[n++].move = make_move(from, to); + } + } + return n; + } + + + template<> // Special case the King + int generate_piece_checks(const Position& pos, Bitboard, Bitboard dc, + Square ksq, MoveStack* mlist, int n) { + if (bit_is_set(dc, ksq)) + { + Bitboard bb = pos.piece_attacks(ksq) + & pos.empty_squares() + & ~QueenPseudoAttacks[ksq]; + while (bb) + { + Square to = pop_1st_bit(&bb); + mlist[n++].move = make_move(ksq, to); + } + } + return n; + } + + + template + int generate_piece_blocking_evasions(const Position& pos, Bitboard b, + Bitboard blockSquares, MoveStack* mlist, int n) { + while (b) + { + Square from = pop_1st_bit(&b); + Bitboard bb = pos.piece_attacks(from) & blockSquares; + while (bb) + { + Square to = pop_1st_bit(&bb); + mlist[n++].move = make_move(from, to); + } + } + return n; + } } @@ -85,13 +172,15 @@ int generate_captures(const Position& pos, MoveStack* mlist) { int n; if (us == WHITE) - n = generate_pawn_captures(WhitePawnOffsets, pos, mlist); + n = generate_pawn_captures(pos, mlist); else - n = generate_pawn_captures(BlackPawnOffsets, pos, mlist); - - for (PieceType pce = KNIGHT; pce <= KING; pce++) - n += generate_piece_moves(pce, pos, mlist+n, us, target); + n = generate_pawn_captures(pos, mlist); + n += generate_piece_moves(pos, mlist+n, us, target); + n += generate_piece_moves(pos, mlist+n, us, target); + n += generate_piece_moves(pos, mlist+n, us, target); + n += generate_piece_moves(pos, mlist+n, us, target); + n += generate_piece_moves(pos, mlist+n, us, target); return n; } @@ -109,12 +198,15 @@ int generate_noncaptures(const Position& pos, MoveStack *mlist) { int n; if (us == WHITE) - n = generate_pawn_noncaptures(WhitePawnOffsets, pos, mlist); + n = generate_pawn_noncaptures(pos, mlist); else - n = generate_pawn_noncaptures(BlackPawnOffsets, pos, mlist); + n = generate_pawn_noncaptures(pos, mlist); - for (PieceType pce = KNIGHT; pce <= KING; pce++) - n += generate_piece_moves(pce, pos, mlist+n, us, target); + n += generate_piece_moves(pos, mlist+n, us, target); + n += generate_piece_moves(pos, mlist+n, us, target); + n += generate_piece_moves(pos, mlist+n, us, target); + n += generate_piece_moves(pos, mlist+n, us, target); + n += generate_piece_moves(pos, mlist+n, us, target); n += generate_castle_moves(pos, mlist+n, us); return n; @@ -140,38 +232,29 @@ int generate_checks(const Position& pos, MoveStack* mlist, Bitboard dc) { // Pawn moves if (us == WHITE) - n = generate_pawn_checks(WhitePawnOffsets, pos, dc, ksq, mlist, 0); + n = generate_pawn_checks(pos, dc, ksq, mlist, 0); else - n = generate_pawn_checks(BlackPawnOffsets, pos, dc, ksq, mlist, 0); + n = generate_pawn_checks(pos, dc, ksq, mlist, 0); // Pieces moves Bitboard b = pos.knights(us); if (b) - n = generate_piece_checks(KNIGHT, pos, b, dc, ksq, mlist, n); + n = generate_piece_checks(pos, b, dc, ksq, mlist, n); b = pos.bishops(us); if (b) - n = generate_piece_checks(BISHOP, pos, b, dc, ksq, mlist, n); + n = generate_piece_checks(pos, b, dc, ksq, mlist, n); b = pos.rooks(us); if (b) - n = generate_piece_checks(ROOK, pos, b, dc, ksq, mlist, n); + n = generate_piece_checks(pos, b, dc, ksq, mlist, n); b = pos.queens(us); if (b) - n = generate_piece_checks(QUEEN, pos, b, dc, ksq, mlist, n); + n = generate_piece_checks(pos, b, dc, ksq, mlist, n); - // King moves - Square from = pos.king_square(us); - if (bit_is_set(dc, from)) - { - b = pos.king_attacks(from) & pos.empty_squares() & ~QueenPseudoAttacks[ksq]; - while (b) - { - Square to = pop_1st_bit(&b); - mlist[n++].move = make_move(from, to); - } - } + // Hopefully we always have a king ;-) + n = generate_piece_checks(pos, b, dc, pos.king_square(us), mlist, n); // TODO: Castling moves! @@ -198,7 +281,7 @@ int generate_evasions(const Position& pos, MoveStack* mlist) { assert(pos.piece_on(ksq) == king_of_color(us)); // Generate evasions for king - Bitboard b1 = pos.king_attacks(ksq) & ~pos.pieces_of_color(us); + Bitboard b1 = pos.piece_attacks(ksq) & ~pos.pieces_of_color(us); Bitboard b2 = pos.occupied_squares(); clear_bit(&b2, ksq); @@ -213,9 +296,9 @@ int generate_evasions(const Position& pos, MoveStack* mlist) { // the king will remain in check on the destination square. if (!( (bishop_attacks_bb(to, b2) & pos.bishops_and_queens(them)) || (rook_attacks_bb(to, b2) & pos.rooks_and_queens(them)) - || (pos.knight_attacks(to) & pos.knights(them)) + || (pos.piece_attacks(to) & pos.knights(them)) || (pos.pawn_attacks(us, to) & pos.pawns(them)) - || (pos.king_attacks(to) & pos.kings(them)))) + || (pos.piece_attacks(to) & pos.kings(them)))) mlist[n++].move = make_move(ksq, to); } @@ -252,9 +335,9 @@ int generate_evasions(const Position& pos, MoveStack* mlist) { } // Pieces captures - b1 = ( (pos.knight_attacks(checksq) & pos.knights(us)) - | (pos.bishop_attacks(checksq) & pos.bishops_and_queens(us)) - | (pos.rook_attacks(checksq) & pos.rooks_and_queens(us)) ) & not_pinned; + b1 = ( (pos.piece_attacks(checksq) & pos.knights(us)) + | (pos.piece_attacks(checksq) & pos.bishops_and_queens(us)) + | (pos.piece_attacks(checksq) & pos.rooks_and_queens(us)) ) & not_pinned; while (b1) { @@ -273,26 +356,26 @@ int generate_evasions(const Position& pos, MoveStack* mlist) { // Pawn moves. Because a blocking evasion can never be a capture, we // only generate pawn pushes. if (us == WHITE) - n = generate_pawn_blocking_evasions(WhitePawnOffsets, pos, not_pinned, blockSquares, mlist, n); + n = generate_pawn_blocking_evasions(pos, not_pinned, blockSquares, mlist, n); else - n = generate_pawn_blocking_evasions(BlackPawnOffsets, pos, not_pinned, blockSquares, mlist, n); + n = generate_pawn_blocking_evasions(pos, not_pinned, blockSquares, mlist, n); // Pieces moves b1 = pos.knights(us) & not_pinned; if (b1) - n = generate_piece_blocking_evasions(KNIGHT, pos, b1, blockSquares, mlist, n); + n = generate_piece_blocking_evasions(pos, b1, blockSquares, mlist, n); b1 = pos.bishops(us) & not_pinned; if (b1) - n = generate_piece_blocking_evasions(BISHOP, pos, b1, blockSquares, mlist, n); + n = generate_piece_blocking_evasions(pos, b1, blockSquares, mlist, n); b1 = pos.rooks(us) & not_pinned; if (b1) - n = generate_piece_blocking_evasions(ROOK, pos, b1, blockSquares, mlist, n); + n = generate_piece_blocking_evasions(pos, b1, blockSquares, mlist, n); b1 = pos.queens(us) & not_pinned; if (b1) - n = generate_piece_blocking_evasions(QUEEN, pos, b1, blockSquares, mlist, n); + n = generate_piece_blocking_evasions(pos, b1, blockSquares, mlist, n); } // Finally, the ugly special case of en passant captures. An en passant @@ -540,7 +623,10 @@ Move generate_move_if_legal(const Position &pos, Move m, Bitboard pinned) { namespace { - int generate_pawn_captures(const PawnOffsets& ofs, const Position& pos, MoveStack* mlist) { + template + int generate_pawn_captures(const Position& pos, MoveStack* mlist) { + + static const PawnOffsets ofs = (C == WHITE ? WhitePawnOffsets : BlackPawnOffsets); Bitboard pawns = pos.pawns(ofs.us); Bitboard enemyPieces = pos.pieces_of_color(ofs.them); @@ -548,7 +634,7 @@ namespace { int n = 0; // Captures in the a1-h8 (a8-h1 for black) direction - Bitboard b1 = (ofs.forward_right)(pawns) & ~FileABB & enemyPieces; + Bitboard b1 = (C == WHITE ? pawns << 9 : pawns >> 7) & ~FileABB & enemyPieces; // Capturing promotions Bitboard b2 = b1 & ofs.Rank8BB; @@ -567,7 +653,7 @@ namespace { } // Captures in the h1-a8 (h8-a1 for black) direction - b1 = (ofs.forward_left)(pawns) & ~FileHBB & enemyPieces; + b1 = (C == WHITE ? pawns << 7 : pawns >> 9) & ~FileHBB & enemyPieces; // Capturing promotions b2 = b1 & ofs.Rank8BB; @@ -586,7 +672,7 @@ namespace { } // Non-capturing promotions - b1 = (ofs.forward)(pawns) & pos.empty_squares() & Rank8BB; + b1 = (C == WHITE ? pawns << 8 : pawns >> 8) & pos.empty_squares() & Rank8BB; while (b1) { sq = pop_1st_bit(&b1); @@ -612,7 +698,10 @@ namespace { } - int generate_pawn_noncaptures(const PawnOffsets& ofs, const Position& pos, MoveStack* mlist) { + template + int generate_pawn_noncaptures(const Position& pos, MoveStack* mlist) { + + static const PawnOffsets ofs = (C == WHITE ? WhitePawnOffsets : BlackPawnOffsets); Bitboard pawns = pos.pawns(ofs.us); Bitboard enemyPieces = pos.pieces_of_color(ofs.them); @@ -622,7 +711,7 @@ namespace { int n = 0; // Underpromotion captures in the a1-h8 (a8-h1 for black) direction - b1 = ofs.forward_right(pawns) & ~FileABB & enemyPieces & ofs.Rank8BB; + b1 = (C == WHITE ? pawns << 9 : pawns >> 7) & ~FileABB & enemyPieces & ofs.Rank8BB; while (b1) { sq = pop_1st_bit(&b1); @@ -632,7 +721,7 @@ namespace { } // Underpromotion captures in the h1-a8 (h8-a1 for black) direction - b1 = ofs.forward_left(pawns) & ~FileHBB & enemyPieces & ofs.Rank8BB; + b1 = (C == WHITE ? pawns << 7 : pawns >> 9) & ~FileHBB & enemyPieces & ofs.Rank8BB; while (b1) { sq = pop_1st_bit(&b1); @@ -642,7 +731,7 @@ namespace { } // Single pawn pushes - b1 = ofs.forward(pawns) & emptySquares; + b1 = (C == WHITE ? pawns << 8 : pawns >> 8) & emptySquares; b2 = b1 & ofs.Rank8BB; while (b2) { @@ -659,7 +748,7 @@ namespace { } // Double pawn pushes - b2 = (ofs.forward(b1 & ofs.Rank3BB)) & emptySquares; + b2 = (C == WHITE ? (b1 & ofs.Rank3BB) << 8 : (b1 & ofs.Rank3BB) >> 8) & emptySquares; while (b2) { sq = pop_1st_bit(&b2); @@ -669,129 +758,11 @@ namespace { } - int generate_piece_moves(PieceType piece, const Position &pos, MoveStack *mlist, - Color side, Bitboard target) { - - const Piece_attacks_fn mem_fn = piece_attacks_fn[piece]; - Square from, to; - Bitboard b; - int n = 0; - - for (int i = 0; i < pos.piece_count(side, piece); i++) - { - from = pos.piece_list(side, piece, i); - b = (pos.*mem_fn)(from) & target; - while (b) - { - to = pop_1st_bit(&b); - mlist[n++].move = make_move(from, to); - } - } - return n; - } - - - int generate_castle_moves(const Position &pos, MoveStack *mlist, Color us) { - - int n = 0; - - if (pos.can_castle(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)); - - 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; - - 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[n++].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; - - assert(pos.piece_on(rsq) == rook_of_color(us)); - - 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 - && ( 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[n++].move = make_castle_move(ksq, rsq); - } - } - return n; - } - - int generate_piece_checks(PieceType pce, const Position& pos, Bitboard target, - Bitboard dc, Square ksq, MoveStack* mlist, int n) { - - const Piece_attacks_fn mem_fn = piece_attacks_fn[pce]; - - // Discovered checks - Bitboard b = target & dc; - while (b) - { - Square from = pop_1st_bit(&b); - Bitboard bb = (pos.*mem_fn)(from) & pos.empty_squares(); - while (bb) - { - Square to = pop_1st_bit(&bb); - mlist[n++].move = make_move(from, to); - } - } - - // Direct checks - b = target & ~dc; - Bitboard checkSqs = (pos.*mem_fn)(ksq) & pos.empty_squares(); - while (b) - { - Square from = pop_1st_bit(&b); - Bitboard bb = (pos.*mem_fn)(from) & checkSqs; - while (bb) - { - Square to = pop_1st_bit(&bb); - mlist[n++].move = make_move(from, to); - } - } - return n; - } - - int generate_pawn_checks(const PawnOffsets& ofs, const Position& pos, Bitboard dc, Square ksq, MoveStack* mlist, int n) + template + int generate_pawn_checks(const Position& pos, Bitboard dc, Square ksq, MoveStack* mlist, int n) { + static const PawnOffsets ofs = (C == WHITE ? WhitePawnOffsets : BlackPawnOffsets); + // 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. @@ -801,7 +772,7 @@ namespace { Bitboard b1 = pos.pawns(pos.side_to_move()) & ~file_bb(ksq), b2, b3; // Discovered checks, single pawn pushes - b2 = b3 = (ofs.forward)(b1 & dc) & ~ofs.Rank8BB & empty; + b2 = b3 = (C == WHITE ? (b1 & dc) << 8 : (b1 & dc) >> 8) & ~ofs.Rank8BB & empty; while (b3) { Square to = pop_1st_bit(&b3); @@ -809,7 +780,7 @@ namespace { } // Discovered checks, double pawn pushes - b3 = (ofs.forward)(b2 & ofs.Rank3BB) & empty; + b3 = (C == WHITE ? (b2 & ofs.Rank3BB) << 8 : (b2 & ofs.Rank3BB) >> 8) & empty; while (b3) { Square to = pop_1st_bit(&b3); @@ -822,7 +793,7 @@ namespace { b1 &= (~dc & neighboring_files_bb(ksq)); // FIXME why ~dc ?? // Direct checks, single pawn pushes - b2 = (ofs.forward)(b1) & empty; + b2 = (C == WHITE ? b1 << 8 : b1 >> 8) & empty; b3 = b2 & pos.pawn_attacks(ofs.them, ksq); while (b3) { @@ -831,7 +802,10 @@ namespace { } // Direct checks, double pawn pushes - b3 = (ofs.forward)(b2 & ofs.Rank3BB) & empty & pos.pawn_attacks(ofs.them, ksq); + b3 = (C == WHITE ? (b2 & ofs.Rank3BB) << 8 : (b2 & ofs.Rank3BB) >> 8) + & empty + & pos.pawn_attacks(ofs.them, ksq); + while (b3) { Square to = pop_1st_bit(&b3); @@ -840,34 +814,18 @@ namespace { return n; } + template + int generate_pawn_blocking_evasions(const Position& pos, Bitboard not_pinned, + Bitboard blockSquares, MoveStack* mlist, int n) { - int generate_piece_blocking_evasions(PieceType pce, const Position& pos, Bitboard b, - Bitboard blockSquares, MoveStack* mlist, int n) { - - const Piece_attacks_fn mem_fn = piece_attacks_fn[pce]; - - while (b) - { - Square from = pop_1st_bit(&b); - Bitboard bb = (pos.*mem_fn)(from) & blockSquares; - while (bb) - { - Square to = pop_1st_bit(&bb); - mlist[n++].move = make_move(from, to); - } - } - return n; - } - + static const PawnOffsets ofs = (C == WHITE ? WhitePawnOffsets : BlackPawnOffsets); - int generate_pawn_blocking_evasions(const PawnOffsets& ofs, const Position& pos, Bitboard not_pinned, - Bitboard blockSquares, MoveStack* mlist, int n) { // Find non-pinned pawns Bitboard b1 = pos.pawns(ofs.us) & not_pinned; // Single pawn pushes. We don't have to AND with empty squares here, // because the blocking squares will always be empty. - Bitboard b2 = (ofs.forward)(b1) & blockSquares; + Bitboard b2 = (C == WHITE ? b1 << 8 : b1 >> 8) & blockSquares; while (b2) { Square to = pop_1st_bit(&b2); @@ -885,7 +843,8 @@ namespace { } // Double pawn pushes - b2 = (ofs.forward)((ofs.forward)(b1) & pos.empty_squares() & ofs.Rank3BB) & blockSquares; + b2 = (C == WHITE ? b1 << 8 : b1 >> 8) & pos.empty_squares() & ofs.Rank3BB; + b2 = (C == WHITE ? b2 << 8 : b2 >> 8) & blockSquares;; while (b2) { Square to = pop_1st_bit(&b2); @@ -898,4 +857,70 @@ namespace { } return n; } + + + int generate_castle_moves(const Position &pos, MoveStack *mlist, Color us) { + + int n = 0; + + if (pos.can_castle(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)); + + 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; + + 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[n++].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; + + assert(pos.piece_on(rsq) == rook_of_color(us)); + + 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 + && ( 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[n++].move = make_castle_move(ksq, rsq); + } + } + return n; + } }