////
namespace {
+
+ struct PawnParams {
+ Bitboard Rank3BB, Rank8BB;
+ Rank RANK_8;
+ SquareDelta DELTA_N, DELTA_NE, DELTA_NW;
+ Color us, them;
+ };
+ const PawnParams WhitePawnParams = { Rank3BB, Rank8BB, RANK_8, DELTA_N, DELTA_NE, DELTA_NW, WHITE, BLACK };
+ const PawnParams BlackPawnParams = { Rank6BB, Rank1BB, RANK_1, DELTA_S, DELTA_SE, DELTA_SW, BLACK, WHITE };
+
+ int generate_castle_moves(const Position&, MoveStack*, Color);
+
+ template<Color>
+ int generate_pawn_captures(const Position&, MoveStack*);
+
+ template<Color>
+ int generate_pawn_noncaptures(const Position&, MoveStack*);
- int generate_white_pawn_captures(const Position&, MoveStack*);
- int generate_black_pawn_captures(const Position&, MoveStack*);
- int generate_white_pawn_noncaptures(const Position&, MoveStack*);
- int generate_black_pawn_noncaptures(const Position&, MoveStack*);
- int generate_piece_moves(PieceType, const Position&, MoveStack*, Color side, Bitboard t);
- int generate_castle_moves(const Position&, MoveStack*, Color us);
-
- int generate_piece_checks(PieceType pce, const Position& pos, Bitboard target,
- Bitboard dc, Square ksq, MoveStack* mlist);
+ template<Color>
+ int generate_pawn_checks(const Position&, Bitboard, Square, MoveStack*, int);
+
+ template<Color>
+ int generate_pawn_blocking_evasions(const Position&, Bitboard, Bitboard, MoveStack*, int);
+
+ template<PieceType>
+ int generate_piece_moves(const Position&, MoveStack*, Color, Bitboard);
+
+ template<PieceType>
+ int generate_piece_checks(const Position&, Bitboard, Bitboard, Square, MoveStack*, int);
+
+ template<PieceType>
+ int generate_piece_blocking_evasions(const Position&, Bitboard, Bitboard, MoveStack*, int);
+
+
+ /// Templates with specializations are defined here to avoid lookup issues
+
+ template<PieceType Piece>
+ 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<Piece>(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<Piece>(ksq) & pos.empty_squares();
+ while (b)
+ {
+ Square from = pop_1st_bit(&b);
+ Bitboard bb = pos.piece_attacks<Piece>(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<KING>(const Position& pos, Bitboard, Bitboard dc,
+ Square ksq, MoveStack* mlist, int n) {
+ if (bit_is_set(dc, ksq))
+ {
+ Bitboard bb = pos.piece_attacks<KING>(ksq)
+ & pos.empty_squares()
+ & ~QueenPseudoAttacks[ksq];
+ while (bb)
+ {
+ Square to = pop_1st_bit(&bb);
+ mlist[n++].move = make_move(ksq, to);
+ }
+ }
+ return n;
+ }
}
int n;
if (us == WHITE)
- n = generate_white_pawn_captures(pos, mlist);
+ n = generate_pawn_captures<WHITE>(pos, mlist);
else
- n = generate_black_pawn_captures(pos, mlist);
-
- for (PieceType pce = KNIGHT; pce <= KING; pce++)
- n += generate_piece_moves(pce, pos, mlist+n, us, target);
+ n = generate_pawn_captures<BLACK>(pos, mlist);
+ n += generate_piece_moves<KNIGHT>(pos, mlist+n, us, target);
+ n += generate_piece_moves<BISHOP>(pos, mlist+n, us, target);
+ n += generate_piece_moves<ROOK>(pos, mlist+n, us, target);
+ n += generate_piece_moves<QUEEN>(pos, mlist+n, us, target);
+ n += generate_piece_moves<KING>(pos, mlist+n, us, target);
return n;
}
int n;
if (us == WHITE)
- n = generate_white_pawn_noncaptures(pos, mlist);
+ n = generate_pawn_noncaptures<WHITE>(pos, mlist);
else
- n = generate_black_pawn_noncaptures(pos, mlist);
+ n = generate_pawn_noncaptures<BLACK>(pos, mlist);
- for (PieceType pce = KNIGHT; pce <= KING; pce++)
- n += generate_piece_moves(pce, pos, mlist+n, us, target);
+ n += generate_piece_moves<KNIGHT>(pos, mlist+n, us, target);
+ n += generate_piece_moves<BISHOP>(pos, mlist+n, us, target);
+ n += generate_piece_moves<ROOK>(pos, mlist+n, us, target);
+ n += generate_piece_moves<QUEEN>(pos, mlist+n, us, target);
+ n += generate_piece_moves<KING>(pos, mlist+n, us, target);
n += generate_castle_moves(pos, mlist+n, us);
return n;
assert(pos.is_ok());
assert(!pos.is_check());
- Color us, them;
- Square ksq, from, to;
- Bitboard empty, b1, b2, b3;
- int n = 0;
-
- us = pos.side_to_move();
- them = opposite_color(us);
+ int n;
+ Color us = pos.side_to_move();
+ Square ksq = pos.king_square(opposite_color(us));
- ksq = pos.king_square(them);
- assert(pos.piece_on(ksq) == king_of_color(them));
+ assert(pos.piece_on(ksq) == king_of_color(opposite_color(us)));
dc = pos.discovered_check_candidates(us);
- empty = pos.empty_squares();
-
- // Pawn moves. This is somewhat messy, and we use separate code for white
- // and black, because we can't shift by negative numbers in C/C++. :-(
-
- if (us == WHITE)
- {
- // 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.
-
- // Find all friendly pawns not on the enemy king's file
- b1 = pos.pawns(us) & ~file_bb(ksq);
-
- // Discovered checks, single pawn pushes
- b2 = b3 = ((b1 & dc) << 8) & ~Rank8BB & empty;
- while (b3)
- {
- to = pop_1st_bit(&b3);
- mlist[n++].move = make_move(to - DELTA_N, to);
- }
-
- // Discovered checks, double pawn pushes
- b3 = ((b2 & Rank3BB) << 8) & empty;
- while (b3)
- {
- to = pop_1st_bit(&b3);
- mlist[n++].move = make_move(to - DELTA_N - DELTA_N, to);
- }
-
- // Direct checks. These are possible only for pawns on neighboring files
- // of the enemy king
-
- b1 &= (~dc & neighboring_files_bb(ksq));
-
- // Direct checks, single pawn pushes
- b2 = (b1 << 8) & empty;
- b3 = b2 & pos.black_pawn_attacks(ksq);
- while(b3)
- {
- to = pop_1st_bit(&b3);
- mlist[n++].move = make_move(to - DELTA_N, to);
- }
- // Direct checks, double pawn pushes
- b3 = ((b2 & Rank3BB) << 8) & empty & pos.black_pawn_attacks(ksq);
- while (b3)
- {
- to = pop_1st_bit(&b3);
- mlist[n++].move = make_move(to - DELTA_N - DELTA_N, to);
- }
- }
- else { // (us == BLACK)
-
- // 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.
-
- // Find all friendly pawns not on the enemy king's file:
- b1 = pos.pawns(us) & ~file_bb(ksq);
-
- // Discovered checks, single pawn pushes
- b2 = b3 = ((b1 & dc) >> 8) & ~Rank1BB & empty;
- while (b3)
- {
- to = pop_1st_bit(&b3);
- mlist[n++].move = make_move(to - DELTA_S, to);
- }
-
- // Discovered checks, double pawn pushes
- b3 = ((b2 & Rank6BB) >> 8) & empty;
- while (b3)
- {
- to = pop_1st_bit(&b3);
- mlist[n++].move = make_move(to - DELTA_S - DELTA_S, to);
- }
+ // Pawn moves
+ if (us == WHITE)
+ n = generate_pawn_checks<WHITE>(pos, dc, ksq, mlist, 0);
+ else
+ n = generate_pawn_checks<BLACK>(pos, dc, ksq, mlist, 0);
- // Direct checks. These are possible only for pawns on neighboring files
- // of the enemy king
+ // Pieces moves
+ Bitboard b = pos.knights(us);
+ if (b)
+ n = generate_piece_checks<KNIGHT>(pos, b, dc, ksq, mlist, n);
- b1 &= (~dc & neighboring_files_bb(ksq));
+ b = pos.bishops(us);
+ if (b)
+ n = generate_piece_checks<BISHOP>(pos, b, dc, ksq, mlist, n);
- // Direct checks, single pawn pushes:
- b2 = (b1 >> 8) & empty;
- b3 = b2 & pos.white_pawn_attacks(ksq);
- while (b3)
- {
- to = pop_1st_bit(&b3);
- mlist[n++].move = make_move(to - DELTA_S, to);
- }
+ b = pos.rooks(us);
+ if (b)
+ n = generate_piece_checks<ROOK>(pos, b, dc, ksq, mlist, n);
- // Direct checks, double pawn pushes
- b3 = ((b2 & Rank6BB) >> 8) & empty & pos.black_pawn_attacks(ksq);
- while (b3)
- {
- to = pop_1st_bit(&b3);
- mlist[n++].move = make_move(to - DELTA_S - DELTA_S, to);
- }
- }
+ b = pos.queens(us);
+ if (b)
+ n = generate_piece_checks<QUEEN>(pos, b, dc, ksq, mlist, n);
- // Knight moves
- b1 = pos.knights(us);
- if (b1)
- n += generate_piece_checks(KNIGHT, pos, b1, dc, ksq, mlist);
-
- // Bishop moves
- b1 = pos.bishops(us);
- if (b1)
- n += generate_piece_checks(BISHOP, pos, b1, dc, ksq, mlist);
-
- // Rook moves
- b1 = pos.rooks(us);
- if (b1)
- n += generate_piece_checks(ROOK, pos, b1, dc, ksq, mlist);
-
- // Queen moves
- b1 = pos.queens(us);
- if (b1)
- n += generate_piece_checks(QUEEN, pos, b1, dc, ksq, mlist);
-
- // King moves
- from = pos.king_square(us);
- if (bit_is_set(dc, from))
- {
- b1 = pos.king_attacks(from) & empty & ~QueenPseudoAttacks[ksq];
- while (b1)
- {
- to = pop_1st_bit(&b1);
- mlist[n++].move = make_move(from, to);
- }
- }
+ // Hopefully we always have a king ;-)
+ n = generate_piece_checks<KING>(pos, b, dc, pos.king_square(us), mlist, n);
// TODO: Castling moves!
/// 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) {
+int generate_evasions(const Position& pos, MoveStack* mlist) {
assert(pos.is_ok());
assert(pos.is_check());
- Color us, them;
- Bitboard checkers = pos.checkers();
- Bitboard pinned, b1, b2;
- Square ksq, from, to;
+ Color us = pos.side_to_move();
+ Color them = opposite_color(us);
+ Square ksq = pos.king_square(us);
+ Square from, to;
int n = 0;
- us = pos.side_to_move();
- them = opposite_color(us);
-
- ksq = pos.king_square(us);
assert(pos.piece_on(ksq) == king_of_color(us));
- // Generate evasions for king:
- b1 = pos.king_attacks(ksq) & ~pos.pieces_of_color(us);
- b2 = pos.occupied_squares();
+ // Generate evasions for king
+ Bitboard b1 = pos.piece_attacks<KING>(ksq) & ~pos.pieces_of_color(us);
+ Bitboard b2 = pos.occupied_squares();
clear_bit(&b2, ksq);
- 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
+ while (b1)
+ {
+ Square 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.pawn_attacks(us, to) & pos.pawns(them)) == EmptyBoardBB) &&
- ((pos.knight_attacks(to) & pos.knights(them)) == EmptyBoardBB) &&
- ((pos.king_attacks(to) & pos.kings(them)) == EmptyBoardBB) &&
- ((bishop_attacks_bb(to, b2) & pos.bishops_and_queens(them))
- == EmptyBoardBB) &&
- ((rook_attacks_bb(to, b2) & pos.rooks_and_queens(them)) == EmptyBoardBB))
- mlist[n++].move = make_move(ksq, to);
- }
+ if (!( (bishop_attacks_bb(to, b2) & pos.bishops_and_queens(them))
+ || (rook_attacks_bb(to, b2) & pos.rooks_and_queens(them))
+ || (pos.piece_attacks<KNIGHT>(to) & pos.knights(them))
+ || (pos.pawn_attacks(us, to) & pos.pawns(them))
+ || (pos.piece_attacks<KING>(to) & pos.kings(them))))
+ mlist[n++].move = make_move(ksq, to);
+ }
- // Generate evasions for other pieces only if not double check. We use a
+ // 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).
- if(!(checkers & (checkers - 1))) {
- Square checksq = first_1(checkers);
- assert(pos.color_of_piece_on(checksq) == them);
-
- // Find pinned pieces:
- pinned = pos.pinned_pieces(us);
-
- // Generate captures of the checking piece:
-
- // Pawn captures:
- b1 = pos.pawn_attacks(them, checksq) & pos.pawns(us) & ~pinned;
- while(b1) {
- from = pop_1st_bit(&b1);
- if(relative_rank(us, checksq) == RANK_8) {
- mlist[n++].move = make_promotion_move(from, checksq, QUEEN);
- mlist[n++].move = make_promotion_move(from, checksq, ROOK);
- mlist[n++].move = make_promotion_move(from, checksq, BISHOP);
- mlist[n++].move = make_promotion_move(from, checksq, KNIGHT);
- }
- else
- mlist[n++].move = make_move(from, checksq);
- }
+ Bitboard checkers = pos.checkers();
- // Knight captures:
- b1 = pos.knight_attacks(checksq) & pos.knights(us) & ~pinned;
- while(b1) {
- from = pop_1st_bit(&b1);
- mlist[n++].move = make_move(from, checksq);
- }
+ if (!(checkers & (checkers - 1))) // Only one bit set?
+ {
+ Square checksq = first_1(checkers);
- // Bishop and queen captures:
- b1 = pos.bishop_attacks(checksq) & pos.bishops_and_queens(us)
- & ~pinned;
- while(b1) {
- from = pop_1st_bit(&b1);
- mlist[n++].move = make_move(from, checksq);
- }
+ assert(pos.color_of_piece_on(checksq) == them);
- // Rook and queen captures:
- b1 = pos.rook_attacks(checksq) & pos.rooks_and_queens(us)
- & ~pinned;
- while(b1) {
- from = pop_1st_bit(&b1);
- mlist[n++].move = make_move(from, checksq);
- }
+ // Find pinned pieces
+ Bitboard not_pinned = ~pos.pinned_pieces(us);
- // Blocking check evasions are possible only if the checking piece is
- // a slider:
- if(checkers & pos.sliders()) {
- Bitboard blockSquares = squares_between(checksq, ksq);
- assert((pos.occupied_squares() & blockSquares) == EmptyBoardBB);
-
- // Pawn moves. Because a blocking evasion can never be a capture, we
- // only generate pawn pushes. As so often, the code for pawns is a bit
- // ugly, and uses separate clauses for white and black pawns. :-(
- if(us == WHITE) {
- // Find non-pinned pawns:
- b1 = pos.pawns(WHITE) & ~pinned;
-
- // Single pawn pushes. We don't have to AND with empty squares here,
- // because the blocking squares will always be empty.
- b2 = (b1 << 8) & blockSquares;
- while(b2) {
- to = pop_1st_bit(&b2);
- assert(pos.piece_on(to) == EMPTY);
- if(square_rank(to) == RANK_8) {
- mlist[n++].move = make_promotion_move(to - DELTA_N, to, QUEEN);
- mlist[n++].move = make_promotion_move(to - DELTA_N, to, ROOK);
- mlist[n++].move = make_promotion_move(to - DELTA_N, to, BISHOP);
- mlist[n++].move = make_promotion_move(to - DELTA_N, to, KNIGHT);
- }
- else
- mlist[n++].move = make_move(to - DELTA_N, to);
- }
- // Double pawn pushes.
- b2 = (((b1 << 8) & pos.empty_squares() & Rank3BB) << 8) & blockSquares;
- while(b2) {
- to = pop_1st_bit(&b2);
- assert(pos.piece_on(to) == EMPTY);
- assert(square_rank(to) == RANK_4);
- mlist[n++].move = make_move(to - DELTA_N - DELTA_N, to);
- }
- }
- else { // (us == BLACK)
- // Find non-pinned pawns:
- b1 = pos.pawns(BLACK) & ~pinned;
-
- // Single pawn pushes. We don't have to AND with empty squares here,
- // because the blocking squares will always be empty.
- b2 = (b1 >> 8) & blockSquares;
- while(b2) {
- to = pop_1st_bit(&b2);
- assert(pos.piece_on(to) == EMPTY);
- if(square_rank(to) == RANK_1) {
- mlist[n++].move = make_promotion_move(to - DELTA_S, to, QUEEN);
- mlist[n++].move = make_promotion_move(to - DELTA_S, to, ROOK);
- mlist[n++].move = make_promotion_move(to - DELTA_S, to, BISHOP);
- mlist[n++].move = make_promotion_move(to - DELTA_S, to, KNIGHT);
- }
- else
- mlist[n++].move = make_move(to - DELTA_S, to);
- }
- // Double pawn pushes.
- b2 = (((b1 >> 8) & pos.empty_squares() & Rank6BB) >> 8) & blockSquares;
- while(b2) {
- to = pop_1st_bit(&b2);
- assert(pos.piece_on(to) == EMPTY);
- assert(square_rank(to) == RANK_5);
- mlist[n++].move = make_move(to - DELTA_S - DELTA_S, to);
- }
- }
+ // Generate captures of the checking piece
- // Knight moves
- b1 = pos.knights(us) & ~pinned;
- while(b1) {
- from = pop_1st_bit(&b1);
- b2 = pos.knight_attacks(from) & blockSquares;
- while(b2) {
- to = pop_1st_bit(&b2);
- mlist[n++].move = make_move(from, to);
- }
- }
-
- // Bishop moves
- b1 = pos.bishops(us) & ~pinned;
- while(b1) {
- from = pop_1st_bit(&b1);
- b2 = pos.bishop_attacks(from) & blockSquares;
- while(b2) {
- to = pop_1st_bit(&b2);
- mlist[n++].move = make_move(from, to);
- }
- }
-
- // Rook moves
- b1 = pos.rooks(us) & ~pinned;
- while(b1) {
- from = pop_1st_bit(&b1);
- b2 = pos.rook_attacks(from) & blockSquares;
- while(b2) {
- to = pop_1st_bit(&b2);
- mlist[n++].move = make_move(from, to);
- }
+ // Pawn captures
+ b1 = pos.pawn_attacks(them, checksq) & pos.pawns(us) & not_pinned;
+ while (b1)
+ {
+ from = pop_1st_bit(&b1);
+ if (relative_rank(us, checksq) == RANK_8)
+ {
+ mlist[n++].move = make_promotion_move(from, checksq, QUEEN);
+ mlist[n++].move = make_promotion_move(from, checksq, ROOK);
+ mlist[n++].move = make_promotion_move(from, checksq, BISHOP);
+ mlist[n++].move = make_promotion_move(from, checksq, KNIGHT);
+ } else
+ mlist[n++].move = make_move(from, checksq);
}
-
- // Queen moves
- b1 = pos.queens(us) & ~pinned;
- while(b1) {
- from = pop_1st_bit(&b1);
- b2 = pos.queen_attacks(from) & blockSquares;
- while(b2) {
- to = pop_1st_bit(&b2);
- mlist[n++].move = make_move(from, to);
- }
+
+ // Pieces captures
+ b1 = ( (pos.piece_attacks<KNIGHT>(checksq) & pos.knights(us))
+ | (pos.piece_attacks<BISHOP>(checksq) & pos.bishops_and_queens(us))
+ | (pos.piece_attacks<ROOK>(checksq) & pos.rooks_and_queens(us)) ) & not_pinned;
+
+ while (b1)
+ {
+ from = pop_1st_bit(&b1);
+ mlist[n++].move = make_move(from, checksq);
}
+
+ // Blocking check evasions are possible only if the checking piece is
+ // a slider
+ if (checkers & pos.sliders())
+ {
+ Bitboard blockSquares = squares_between(checksq, ksq);
+
+ 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)
+ n = generate_pawn_blocking_evasions<WHITE>(pos, not_pinned, blockSquares, mlist, n);
+ else
+ n = generate_pawn_blocking_evasions<BLACK>(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);
+
+ b1 = pos.bishops(us) & not_pinned;
+ if (b1)
+ n = generate_piece_blocking_evasions<BISHOP>(pos, b1, blockSquares, mlist, n);
+
+ b1 = pos.rooks(us) & not_pinned;
+ if (b1)
+ n = generate_piece_blocking_evasions<ROOK>(pos, b1, blockSquares, mlist, n);
+
+ b1 = pos.queens(us) & not_pinned;
+ if (b1)
+ n = generate_piece_blocking_evasions<QUEEN>(pos, b1, blockSquares, mlist, n);
}
- // Finally, the ugly special case of en passant captures. An en passant
+ // Finally, the ugly special case of en passant captures. An en passant
// capture can only be a check evasion if the check is not a discovered
- // check. If pos.ep_square() is set, the last move made must have been
- // a double pawn push. If, furthermore, the checking piece is a pawn,
+ // check. If pos.ep_square() is set, the last move made must have been
+ // a double pawn push. If, furthermore, the checking piece is a pawn,
// an en passant check evasion may be possible.
- if(pos.ep_square() != SQ_NONE && (checkers & pos.pawns(them))) {
- to = pos.ep_square();
- b1 = pos.pawn_attacks(them, to) & pos.pawns(us);
- assert(b1 != EmptyBoardBB);
- b1 &= ~pinned;
- while(b1) {
- from = pop_1st_bit(&b1);
-
- // Before generating the move, we have to make sure it is legal.
- // This is somewhat tricky, because the two disappearing pawns may
- // cause new "discovered checks". We test this by removing the
- // two relevant bits from the occupied squares bitboard, and using
- // the low-level bitboard functions for bishop and rook attacks.
- b2 = pos.occupied_squares();
- clear_bit(&b2, from);
- clear_bit(&b2, checksq);
- if(((bishop_attacks_bb(ksq, b2) & pos.bishops_and_queens(them))
- == EmptyBoardBB) &&
- ((rook_attacks_bb(ksq, b2) & pos.rooks_and_queens(them))
- == EmptyBoardBB))
- mlist[n++].move = make_ep_move(from, to);
- }
+ if (pos.ep_square() != SQ_NONE && (checkers & pos.pawns(them)))
+ {
+ to = pos.ep_square();
+ b1 = pos.pawn_attacks(them, to) & pos.pawns(us);
+
+ assert(b1 != EmptyBoardBB);
+
+ b1 &= not_pinned;
+ while (b1)
+ {
+ from = pop_1st_bit(&b1);
+
+ // Before generating the move, we have to make sure it is legal.
+ // This is somewhat tricky, because the two disappearing pawns may
+ // cause new "discovered checks". We test this by removing the
+ // two relevant bits from the occupied squares bitboard, and using
+ // the low-level bitboard functions for bishop and rook attacks.
+ b2 = pos.occupied_squares();
+ clear_bit(&b2, from);
+ clear_bit(&b2, checksq);
+ if (!( (bishop_attacks_bb(ksq, b2) & pos.bishops_and_queens(them))
+ ||(rook_attacks_bb(ksq, b2) & pos.rooks_and_queens(them))))
+
+ mlist[n++].move = make_ep_move(from, to);
+ }
}
}
-
return n;
}
namespace {
- int generate_white_pawn_captures(const Position &pos, MoveStack *mlist) {
-
- Bitboard pawns = pos.pawns(WHITE);
- Bitboard enemyPieces = pos.pieces_of_color(BLACK);
- Square sq;
+ template<PieceType Piece>
+ int generate_piece_moves(const Position &pos, MoveStack *mlist,
+ Color side, Bitboard target) {
int n = 0;
-
- // Captures in the a1-h8 direction
- Bitboard b1 = (pawns << 9) & ~FileABB & enemyPieces;
-
- // Capturing promotions
- Bitboard b2 = b1 & Rank8BB;
- while (b2)
+ for (int i = 0; i < pos.piece_count(side, Piece); i++)
{
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_promotion_move(sq - DELTA_NE, sq, QUEEN);
- }
-
- // Capturing non-promotions
- b2 = b1 & ~Rank8BB;
- while (b2)
- {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_move(sq - DELTA_NE, sq);
- }
-
- // Captures in the h1-a8 direction
- b1 = (pawns << 7) & ~FileHBB & enemyPieces;
-
- // Capturing promotions
- b2 = b1 & Rank8BB;
- while (b2)
- {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_promotion_move(sq - DELTA_NW, sq, QUEEN);
- }
-
- // Capturing non-promotions
- b2 = b1 & ~Rank8BB;
- while (b2)
- {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_move(sq - DELTA_NW, sq);
+ Square from = pos.piece_list(side, Piece, i);
+ Bitboard b = pos.piece_attacks<Piece>(from) & target;
+ while (b)
+ {
+ Square to = pop_1st_bit(&b);
+ mlist[n++].move = make_move(from, to);
+ }
}
+ return n;
+ }
- // Non-capturing promotions
- b1 = (pawns << 8) & pos.empty_squares() & Rank8BB;
- while (b1)
- {
- sq = pop_1st_bit(&b1);
- mlist[n++].move = make_promotion_move(sq - DELTA_N, sq, QUEEN);
- }
- // En passant captures
- if (pos.ep_square() != SQ_NONE)
+ template<PieceType Piece>
+ int generate_piece_blocking_evasions(const Position& pos, Bitboard b,
+ Bitboard blockSquares, MoveStack* mlist, int n) {
+ while (b)
{
- assert(square_rank(pos.ep_square()) == RANK_6);
- b1 = pawns & pos.black_pawn_attacks(pos.ep_square());
- assert(b1 != EmptyBoardBB);
- while (b1)
+ Square from = pop_1st_bit(&b);
+ Bitboard bb = pos.piece_attacks<Piece>(from) & blockSquares;
+ while (bb)
{
- sq = pop_1st_bit(&b1);
- mlist[n++].move = make_ep_move(sq, pos.ep_square());
+ Square to = pop_1st_bit(&bb);
+ mlist[n++].move = make_move(from, to);
}
}
return n;
}
- int generate_black_pawn_captures(const Position &pos, MoveStack *mlist) {
+ template<Color C>
+ int generate_pawn_captures(const Position& pos, MoveStack* mlist) {
+
+ static const PawnParams PP = (C == WHITE ? WhitePawnParams : BlackPawnParams);
- Bitboard pawns = pos.pawns(BLACK);
- Bitboard enemyPieces = pos.pieces_of_color(WHITE);
+ Bitboard pawns = pos.pawns(PP.us);
+ Bitboard enemyPieces = pos.pieces_of_color(PP.them);
Square sq;
int n = 0;
- // Captures in the a8-h1 direction
- Bitboard b1 = (pawns >> 7) & ~FileABB & enemyPieces;
+ // Captures in the a1-h8 (a8-h1 for black) direction
+ Bitboard b1 = (C == WHITE ? pawns << 9 : pawns >> 7) & ~FileABB & enemyPieces;
// Capturing promotions
- Bitboard b2 = b1 & Rank1BB;
+ Bitboard b2 = b1 & PP.Rank8BB;
while (b2)
{
sq = pop_1st_bit(&b2);
- mlist[n++].move = make_promotion_move(sq - DELTA_SE, sq, QUEEN);
+ mlist[n++].move = make_promotion_move(sq - PP.DELTA_NE, sq, QUEEN);
}
// Capturing non-promotions
- b2 = b1 & ~Rank1BB;
+ b2 = b1 & ~PP.Rank8BB;
while (b2)
{
sq = pop_1st_bit(&b2);
- mlist[n++].move = make_move(sq - DELTA_SE, sq);
+ mlist[n++].move = make_move(sq - PP.DELTA_NE, sq);
}
- // Captures in the h8-a1 direction
- b1 = (pawns >> 9) & ~FileHBB & enemyPieces;
+ // Captures in the h1-a8 (h8-a1 for black) direction
+ b1 = (C == WHITE ? pawns << 7 : pawns >> 9) & ~FileHBB & enemyPieces;
// Capturing promotions
- b2 = b1 & Rank1BB;
+ b2 = b1 & PP.Rank8BB;
while (b2)
{
sq = pop_1st_bit(&b2);
- mlist[n++].move = make_promotion_move(sq - DELTA_SW, sq, QUEEN);
+ mlist[n++].move = make_promotion_move(sq - PP.DELTA_NW, sq, QUEEN);
}
- // Capturing Non-promotions
- b2 = b1 & ~Rank1BB;
+ // Capturing non-promotions
+ b2 = b1 & ~PP.Rank8BB;
while (b2)
{
sq = pop_1st_bit(&b2);
- mlist[n++].move = make_move(sq - DELTA_SW, sq);
+ mlist[n++].move = make_move(sq - PP.DELTA_NW, sq);
}
// Non-capturing promotions
- b1 = (pawns >> 8) & pos.empty_squares() & Rank1BB;
+ b1 = (C == WHITE ? pawns << 8 : pawns >> 8) & pos.empty_squares() & Rank8BB;
while (b1)
{
sq = pop_1st_bit(&b1);
- mlist[n++].move = make_promotion_move(sq - DELTA_S, sq, QUEEN);
+ mlist[n++].move = make_promotion_move(sq - PP.DELTA_N, sq, QUEEN);
}
// En passant captures
if (pos.ep_square() != SQ_NONE)
{
- assert(square_rank(pos.ep_square()) == RANK_3);
- b1 = pawns & pos.white_pawn_attacks(pos.ep_square());
+ assert(PP.us != WHITE || square_rank(pos.ep_square()) == RANK_6);
+ assert(PP.us != BLACK || square_rank(pos.ep_square()) == RANK_3);
+
+ b1 = pawns & pos.pawn_attacks(PP.them, pos.ep_square());
assert(b1 != EmptyBoardBB);
+
while (b1)
{
sq = pop_1st_bit(&b1);
}
- int generate_white_pawn_noncaptures(const Position &pos, MoveStack *mlist) {
+ template<Color C>
+ int generate_pawn_noncaptures(const Position& pos, MoveStack* mlist) {
- Bitboard pawns = pos.pawns(WHITE);
- Bitboard enemyPieces = pos.pieces_of_color(BLACK);
+ static const PawnParams PP = (C == WHITE ? WhitePawnParams : BlackPawnParams);
+
+ Bitboard pawns = pos.pawns(PP.us);
+ Bitboard enemyPieces = pos.pieces_of_color(PP.them);
Bitboard emptySquares = pos.empty_squares();
Bitboard b1, b2;
Square sq;
int n = 0;
- // Underpromotion captures in the a1-h8 direction:
- b1 = (pawns << 9) & ~FileABB & enemyPieces & Rank8BB;
- while(b1) {
- sq = pop_1st_bit(&b1);
- mlist[n++].move = make_promotion_move(sq - DELTA_NE, sq, ROOK);
- mlist[n++].move = make_promotion_move(sq - DELTA_NE, sq, BISHOP);
- mlist[n++].move = make_promotion_move(sq - DELTA_NE, sq, KNIGHT);
+ // Underpromotion captures in the a1-h8 (a8-h1 for black) direction
+ b1 = (C == WHITE ? pawns << 9 : pawns >> 7) & ~FileABB & enemyPieces & PP.Rank8BB;
+ while (b1)
+ {
+ sq = pop_1st_bit(&b1);
+ mlist[n++].move = make_promotion_move(sq - PP.DELTA_NE, sq, ROOK);
+ mlist[n++].move = make_promotion_move(sq - PP.DELTA_NE, sq, BISHOP);
+ mlist[n++].move = make_promotion_move(sq - PP.DELTA_NE, sq, KNIGHT);
}
- // Underpromotion captures in the h1-a8 direction:
- b1 = (pawns << 7) & ~FileHBB & enemyPieces & Rank8BB;
- while(b1) {
- sq = pop_1st_bit(&b1);
- mlist[n++].move = make_promotion_move(sq - DELTA_NW, sq, ROOK);
- mlist[n++].move = make_promotion_move(sq - DELTA_NW, sq, BISHOP);
- mlist[n++].move = make_promotion_move(sq - DELTA_NW, sq, KNIGHT);
+ // Underpromotion captures in the h1-a8 (h8-a1 for black) direction
+ b1 = (C == WHITE ? pawns << 7 : pawns >> 9) & ~FileHBB & enemyPieces & PP.Rank8BB;
+ while (b1)
+ {
+ sq = pop_1st_bit(&b1);
+ mlist[n++].move = make_promotion_move(sq - PP.DELTA_NW, sq, ROOK);
+ mlist[n++].move = make_promotion_move(sq - PP.DELTA_NW, sq, BISHOP);
+ mlist[n++].move = make_promotion_move(sq - PP.DELTA_NW, sq, KNIGHT);
}
- // Single pawn pushes:
- b1 = (pawns << 8) & emptySquares;
- b2 = b1 & Rank8BB;
- while(b2) {
+ // Single pawn pushes
+ b1 = (C == WHITE ? pawns << 8 : pawns >> 8) & emptySquares;
+ b2 = b1 & PP.Rank8BB;
+ while (b2)
+ {
sq = pop_1st_bit(&b2);
- mlist[n++].move = make_promotion_move(sq - DELTA_N, sq, ROOK);
- mlist[n++].move = make_promotion_move(sq - DELTA_N, sq, BISHOP);
- mlist[n++].move = make_promotion_move(sq - DELTA_N, sq, KNIGHT);
+ mlist[n++].move = make_promotion_move(sq - PP.DELTA_N, sq, ROOK);
+ mlist[n++].move = make_promotion_move(sq - PP.DELTA_N, sq, BISHOP);
+ mlist[n++].move = make_promotion_move(sq - PP.DELTA_N, sq, KNIGHT);
}
- b2 = b1 & ~Rank8BB;
- while(b2) {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_move(sq - DELTA_N, sq);
+ b2 = b1 & ~PP.Rank8BB;
+ while (b2)
+ {
+ sq = pop_1st_bit(&b2);
+ mlist[n++].move = make_move(sq - PP.DELTA_N, sq);
}
- // Double pawn pushes:
- b2 = ((b1 & Rank3BB) << 8) & emptySquares;
- while(b2) {
+ // Double pawn pushes
+ b2 = (C == WHITE ? (b1 & PP.Rank3BB) << 8 : (b1 & PP.Rank3BB) >> 8) & emptySquares;
+ while (b2)
+ {
sq = pop_1st_bit(&b2);
- mlist[n++].move = make_move(sq - DELTA_N - DELTA_N, sq);
+ mlist[n++].move = make_move(sq - PP.DELTA_N - PP.DELTA_N, sq);
}
-
return n;
}
- int generate_black_pawn_noncaptures(const Position &pos, MoveStack *mlist) {
- Bitboard pawns = pos.pawns(BLACK);
- Bitboard enemyPieces = pos.pieces_of_color(WHITE);
- Bitboard emptySquares = pos.empty_squares();
- Bitboard b1, b2;
- Square sq;
- int n = 0;
+ template<Color C>
+ int generate_pawn_checks(const Position& pos, Bitboard dc, Square ksq, MoveStack* mlist, int n)
+ {
+ static const PawnParams PP = (C == WHITE ? WhitePawnParams : BlackPawnParams);
- // Underpromotion captures in the a8-h1 direction:
- b1 = (pawns >> 7) & ~FileABB & enemyPieces & Rank1BB;
- while(b1) {
- sq = pop_1st_bit(&b1);
- mlist[n++].move = make_promotion_move(sq - DELTA_SE, sq, ROOK);
- mlist[n++].move = make_promotion_move(sq - DELTA_SE, sq, BISHOP);
- mlist[n++].move = make_promotion_move(sq - DELTA_SE, sq, KNIGHT);
- }
+ // 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();
- // Underpromotion captures in the h8-a1 direction:
- b1 = (pawns >> 9) & ~FileHBB & enemyPieces & Rank1BB;
- while(b1) {
- sq = pop_1st_bit(&b1);
- mlist[n++].move = make_promotion_move(sq - DELTA_SW, sq, ROOK);
- mlist[n++].move = make_promotion_move(sq - DELTA_SW, sq, BISHOP);
- mlist[n++].move = make_promotion_move(sq - DELTA_SW, sq, KNIGHT);
- }
+ // Find all friendly pawns not on the enemy king's file
+ Bitboard b1 = pos.pawns(pos.side_to_move()) & ~file_bb(ksq), b2, b3;
- // Single pawn pushes:
- b1 = (pawns >> 8) & emptySquares;
- b2 = b1 & Rank1BB;
- while(b2) {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_promotion_move(sq - DELTA_S, sq, ROOK);
- mlist[n++].move = make_promotion_move(sq - DELTA_S, sq, BISHOP);
- mlist[n++].move = make_promotion_move(sq - DELTA_S, sq, KNIGHT);
- }
- b2 = b1 & ~Rank1BB;
- while(b2) {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_move(sq - DELTA_S, sq);
+ // Discovered checks, single pawn pushes
+ b2 = b3 = (C == WHITE ? (b1 & dc) << 8 : (b1 & dc) >> 8) & ~PP.Rank8BB & empty;
+ while (b3)
+ {
+ Square to = pop_1st_bit(&b3);
+ mlist[n++].move = make_move(to - PP.DELTA_N, to);
}
-
- // Double pawn pushes:
- b2 = ((b1 & Rank6BB) >> 8) & emptySquares;
- while(b2) {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_move(sq - DELTA_S - DELTA_S, sq);
+
+ // Discovered checks, double pawn pushes
+ b3 = (C == WHITE ? (b2 & PP.Rank3BB) << 8 : (b2 & PP.Rank3BB) >> 8) & empty;
+ while (b3)
+ {
+ Square to = pop_1st_bit(&b3);
+ mlist[n++].move = make_move(to - PP.DELTA_N - PP.DELTA_N, to);
}
- return n;
- }
+ // Direct checks. These are possible only for pawns on neighboring files
+ // of the enemy king
+ b1 &= (~dc & neighboring_files_bb(ksq)); // FIXME why ~dc ??
- int generate_piece_moves(PieceType piece, const Position &pos, MoveStack *mlist,
- Color side, Bitboard target) {
+ // Direct checks, single pawn pushes
+ b2 = (C == WHITE ? b1 << 8 : b1 >> 8) & empty;
+ b3 = b2 & pos.pawn_attacks(PP.them, ksq);
+ while (b3)
+ {
+ Square to = pop_1st_bit(&b3);
+ mlist[n++].move = make_move(to - PP.DELTA_N, to);
+ }
- const Piece_attacks_fn mem_fn = piece_attacks_fn[piece];
- Square from, to;
- Bitboard b;
- int n = 0;
+ // Direct checks, double pawn pushes
+ b3 = (C == WHITE ? (b2 & PP.Rank3BB) << 8 : (b2 & PP.Rank3BB) >> 8)
+ & empty
+ & pos.pawn_attacks(PP.them, ksq);
- for (int i = 0; i < pos.piece_count(side, piece); i++)
+ while (b3)
{
- 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);
- }
+ Square to = pop_1st_bit(&b3);
+ mlist[n++].move = make_move(to - PP.DELTA_N - PP.DELTA_N, to);
}
return n;
}
- int generate_castle_moves(const Position &pos, MoveStack *mlist, Color us) {
- int n = 0;
+ template<Color C>
+ int generate_pawn_blocking_evasions(const Position& pos, Bitboard not_pinned,
+ Bitboard blockSquares, MoveStack* mlist, int n) {
- 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;
+ static const PawnParams PP = (C == WHITE ? WhitePawnParams : BlackPawnParams);
- if(!illegal)
- mlist[n++].move = make_castle_move(ksq, rsq);
- }
+ // Find non-pinned pawns
+ Bitboard b1 = pos.pawns(PP.us) & not_pinned;
- 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;
+ // Single pawn pushes. We don't have to AND with empty squares here,
+ // because the blocking squares will always be empty.
+ Bitboard b2 = (C == WHITE ? b1 << 8 : b1 >> 8) & blockSquares;
+ while (b2)
+ {
+ Square to = pop_1st_bit(&b2);
- assert(pos.piece_on(rsq) == rook_of_color(us));
+ assert(pos.piece_on(to) == EMPTY);
- 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);
- }
+ if (square_rank(to) == PP.RANK_8)
+ {
+ mlist[n++].move = make_promotion_move(to - PP.DELTA_N, to, QUEEN);
+ mlist[n++].move = make_promotion_move(to - PP.DELTA_N, to, ROOK);
+ mlist[n++].move = make_promotion_move(to - PP.DELTA_N, to, BISHOP);
+ mlist[n++].move = make_promotion_move(to - PP.DELTA_N, to, KNIGHT);
+ } else
+ mlist[n++].move = make_move(to - PP.DELTA_N, to);
}
+ // Double pawn pushes
+ b2 = (C == WHITE ? b1 << 8 : b1 >> 8) & pos.empty_squares() & PP.Rank3BB;
+ b2 = (C == WHITE ? b2 << 8 : b2 >> 8) & blockSquares;;
+ while (b2)
+ {
+ Square to = pop_1st_bit(&b2);
+
+ assert(pos.piece_on(to) == EMPTY);
+ assert(PP.us != WHITE || square_rank(to) == RANK_4);
+ assert(PP.us != BLACK || square_rank(to) == RANK_5);
+
+ mlist[n++].move = make_move(to - PP.DELTA_N - PP.DELTA_N, to);
+ }
return n;
}
- int generate_piece_checks(PieceType pce, const Position& pos, Bitboard target,
- Bitboard dc, Square ksq, MoveStack* mlist) {
- const Piece_attacks_fn mem_fn = piece_attacks_fn[pce];
+ int generate_castle_moves(const Position &pos, MoveStack *mlist, Color us) {
+
int n = 0;
- // Discovered checks
- Bitboard b = target & dc;
- while (b)
+ if (pos.can_castle(us))
{
- 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);
- }
- }
+ Color them = opposite_color(us);
+ Square ksq = pos.king_square(us);
- // 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)
+ assert(pos.piece_on(ksq) == king_of_color(us));
+
+ if (pos.can_castle_kingside(us))
{
- Square to = pop_1st_bit(&bb);
- mlist[n++].move = make_move(from, to);
- }
+ 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;
}