namespace {
enum CastlingSide {
- KING_SIDE = 1,
- QUEEN_SIDE = 2
+ KING_SIDE,
+ QUEEN_SIDE
};
- // Functions
- MoveStack* generate_castle_moves(const Position&, MoveStack*, unsigned = (KING_SIDE | QUEEN_SIDE));
- bool castling_is_check(const Position& pos, CastlingSide side);
+ // Function
+ bool castling_is_check(const Position&, CastlingSide);
+
+ // Template
+ template<CastlingSide Side>
+ MoveStack* generate_castle_moves(const Position&, MoveStack*);
// Template generate_pawn_captures() with specializations
template<Color, Color, Bitboard, SquareDelta, SquareDelta, SquareDelta>
template<PieceType>
MoveStack* generate_piece_checks(const Position&, Bitboard, Bitboard, Square, MoveStack*);
- MoveStack* generate_piece_checks_king(const Position&, Square, Bitboard, Square, MoveStack*);
template<PieceType>
MoveStack* generate_piece_blocking_evasions(const Position&, Bitboard, Bitboard, MoveStack*);
mlist = generate_piece_moves<ROOK>(pos, mlist, us, target);
mlist = generate_piece_moves<QUEEN>(pos, mlist, us, target);
mlist = generate_piece_moves<KING>(pos, mlist, us, target);
- mlist = generate_castle_moves(pos, mlist);
+ mlist = generate_castle_moves<KING_SIDE>(pos, mlist);
+ mlist = generate_castle_moves<QUEEN_SIDE>(pos, mlist);
return int(mlist - mlist_start);
}
mlist = generate_piece_checks<QUEEN>(pos, b, dc, ksq, mlist);
// Hopefully we always have a king ;-)
- mlist = generate_piece_checks_king(pos, pos.king_square(us), dc, ksq, mlist);
+ mlist = generate_piece_checks<KING>(pos, pos.kings(us), dc, ksq, mlist);
// Castling moves that give check. Very rare but nice to have!
if ( pos.can_castle_queenside(us)
&& (square_rank(ksq) == square_rank(pos.king_square(us)) || square_file(ksq) == FILE_D)
&& castling_is_check(pos, QUEEN_SIDE))
- mlist = generate_castle_moves(pos, mlist, QUEEN_SIDE);
+ mlist = generate_castle_moves<QUEEN_SIDE>(pos, mlist);
if ( pos.can_castle_kingside(us)
&& (square_rank(ksq) == square_rank(pos.king_square(us)) || square_file(ksq) == FILE_F)
&& castling_is_check(pos, KING_SIDE))
- mlist = generate_castle_moves(pos, mlist, KING_SIDE);
+ mlist = generate_castle_moves<KING_SIDE>(pos, mlist);
return int(mlist - mlist_start);
}
/// generate_evasions() generates all check evasions when the side to move is
/// in check. Unlike the other move generation functions, this one generates
-/// only legal moves. It returns the number of generated moves. This
+/// 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) {
assert(pos.piece_on(ksq) == king_of_color(us));
- // Generate evasions for king
- Bitboard b1 = pos.piece_attacks<KING>(ksq) & ~pos.pieces_of_color(us);
+ // The bitboard of occupied pieces without our king
Bitboard b2 = pos.occupied_squares();
clear_bit(&b2, ksq);
+ // Find squares attacked by slider checkers, we will
+ // remove them from king evasions set so to avoid a couple
+ // of cycles in the slow king evasions legality check loop.
+ Bitboard checkers = pos.checkers();
+ Bitboard checkersAttacks = EmptyBoardBB;
+ Bitboard b = checkers & (pos.queens() | pos.bishops());
+ while (b)
+ {
+ from = pop_1st_bit(&b);
+ checkersAttacks |= bishop_attacks_bb(from, b2);
+ }
+
+ b = checkers & (pos.queens() | pos.rooks());
+ while (b)
+ {
+ from = pop_1st_bit(&b);
+ checkersAttacks |= rook_attacks_bb(from, b2);
+ }
+
+ // Generate evasions for king
+ Bitboard b1 = pos.piece_attacks<KING>(ksq) & ~pos.pieces_of_color(us) & ~checkersAttacks;
while (b1)
{
- to = pop_1st_bit(&b1);
-
- // Make sure 'to' is not attacked by the other side. This is a bit ugly,
- // because we can't use Position::square_is_attacked. Instead we use
- // the low-level bishop_attacks_bb and rook_attacks_bb with the bitboard
- // b2 (the occupied squares with the king removed) in order to test whether
- // the king will remain in check on the destination square.
- if (!( (pos.piece_attacks<KNIGHT>(to) & pos.knights(them))
- || (pos.pawn_attacks(us, to) & pos.pawns(them))
- || (bishop_attacks_bb(to, b2) & pos.bishops_and_queens(them))
- || (rook_attacks_bb(to, b2) & pos.rooks_and_queens(them))
- || (pos.piece_attacks<KING>(to) & pos.kings(them))))
-
- (*mlist++).move = make_move(ksq, to);
+ to = pop_1st_bit(&b1);
+
+ // Make sure 'to' is not attacked by the other side. This is a bit ugly,
+ // because we can't use Position::square_is_attacked. Instead we use
+ // the low-level bishop_attacks_bb and rook_attacks_bb with the bitboard
+ // b2 (the occupied squares with the king removed) in order to test whether
+ // the king will remain in check on the destination square.
+ if (!( (pos.piece_attacks<KNIGHT>(to) & pos.knights(them))
+ || (pos.pawn_attacks(us, to) & pos.pawns(them))
+ || (bishop_attacks_bb(to, b2) & pos.bishops_and_queens(them))
+ || (rook_attacks_bb(to, b2) & pos.rooks_and_queens(them))
+ || (pos.piece_attacks<KING>(to) & pos.kings(them))))
+ (*mlist++).move = make_move(ksq, to);
}
// Generate evasions for other pieces only if not double check. We use a
// simple bit twiddling hack here rather than calling count_1s in order to
// save some time (we know that pos.checkers() has at most two nonzero bits).
- Bitboard checkers = pos.checkers();
-
if (!(checkers & (checkers - 1))) // Only one bit set?
{
Square checksq = first_1(checkers);
/// 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
+/// 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.
b2 = b1 & TRank8BB;
while (b2)
{
- to = pop_1st_bit(&b2);
- (*mlist++).move = make_promotion_move(to - TDELTA_N, to, ROOK);
- (*mlist++).move = make_promotion_move(to - TDELTA_N, to, BISHOP);
- (*mlist++).move = make_promotion_move(to - TDELTA_N, to, KNIGHT);
+ to = pop_1st_bit(&b2);
+ (*mlist++).move = make_promotion_move(to - TDELTA_N, to, ROOK);
+ (*mlist++).move = make_promotion_move(to - TDELTA_N, to, BISHOP);
+ (*mlist++).move = make_promotion_move(to - TDELTA_N, to, KNIGHT);
}
b2 = b1 & ~TRank8BB;
while (b2)
b2 = (Us == WHITE ? (b1 & TRank3BB) << 8 : (b1 & TRank3BB) >> 8) & emptySquares;
while (b2)
{
- to = pop_1st_bit(&b2);
- (*mlist++).move = make_move(to - TDELTA_N - TDELTA_N, to);
+ to = pop_1st_bit(&b2);
+ (*mlist++).move = make_move(to - TDELTA_N - TDELTA_N, to);
}
return mlist;
}
template<Color Us, Color Them, Bitboard TRank8BB, Bitboard TRank3BB, SquareDelta TDELTA_N>
MoveStack* do_generate_pawn_checks(const Position& pos, Bitboard dc, Square ksq, MoveStack* mlist)
{
- // Pawn moves which give discovered check. This is possible only if the
+ // Pawn 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.
Bitboard empty = pos.empty_squares();
// Find all friendly pawns not on the enemy king's file
Bitboard b1 = pos.pawns(Us) & ~file_bb(ksq), b2, b3;
- // Discovered checks, single pawn pushes
- b2 = b3 = (Us == WHITE ? (b1 & dc) << 8 : (b1 & dc) >> 8) & ~TRank8BB & empty;
+ // Discovered checks, single pawn pushes, no promotions
+ b2 = b3 = (Us == WHITE ? (b1 & dc) << 8 : (b1 & dc) >> 8) & empty & ~TRank8BB;
while (b3)
{
Square to = pop_1st_bit(&b3);
// Direct checks. These are possible only for pawns on neighboring files
// of the enemy king
-
- b1 &= (~dc & neighboring_files_bb(ksq)); // FIXME why ~dc ??
+ b1 &= (~dc & neighboring_files_bb(ksq));
// Direct checks, single pawn pushes
b2 = (Us == WHITE ? b1 << 8 : b1 >> 8) & empty;
{
Square from = pop_1st_bit(&b);
Bitboard bb = pos.piece_attacks<Piece>(from) & pos.empty_squares();
+ if (Piece == KING)
+ bb &= ~QueenPseudoAttacks[ksq];
+
SERIALIZE_MOVES(bb);
}
+
+ if (Piece == KING)
+ return mlist;
+
// Direct checks
b = target & ~dc;
Bitboard checkSqs = pos.piece_attacks<Piece>(ksq) & pos.empty_squares();
return mlist;
}
- MoveStack* generate_piece_checks_king(const Position& pos, Square from, Bitboard dc,
- Square ksq, MoveStack* mlist) {
- if (bit_is_set(dc, from))
- {
- Bitboard b = pos.piece_attacks<KING>(from)
- & pos.empty_squares()
- & ~QueenPseudoAttacks[ksq];
- SERIALIZE_MOVES(b);
- }
- return mlist;
- }
-
-
template<Color Us, Rank TRANK_8, Bitboard TRank3BB, SquareDelta TDELTA_N>
MoveStack* do_generate_pawn_blocking_evasions(const Position& pos, Bitboard not_pinned,
Bitboard blockSquares, MoveStack* mlist) {
return mlist;
}
- MoveStack* generate_castle_moves(const Position& pos, MoveStack* mlist, unsigned side) {
+ template<CastlingSide Side>
+ MoveStack* generate_castle_moves(const Position& pos, MoveStack* mlist) {
Color us = pos.side_to_move();
- if (pos.can_castle_kingside(us) && (side & KING_SIDE))
+ 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) == king_of_color(us));
- Square rsq = pos.initial_kr_square(us);
- Square g1 = relative_square(us, SQ_G1);
- Square f1 = relative_square(us, SQ_F1);
+ 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) == rook_of_color(us));
- for (s = Min(ksq, g1); s <= Max(ksq, g1); s++)
+ // 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.square_is_attacked(s, them))
illegal = true;
- for (s = Min(rsq, f1); s <= Max(rsq, f1); s++)
+ 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)) == rook_of_color(them)
+ || pos.piece_on(relative_square(us, SQ_A1)) == queen_of_color(them)))
+ illegal = true;
+
if (!illegal)
(*mlist++).move = make_castle_move(ksq, rsq);
}
-
- if (pos.can_castle_queenside(us) && (side & QUEEN_SIDE))
- {
- Color them = opposite_color(us);
- Square ksq = pos.king_square(us);
-
- assert(pos.piece_on(ksq) == king_of_color(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++).move = make_castle_move(ksq, rsq);
- }
return mlist;
}
File rookFile = (side == QUEEN_SIDE ? FILE_D : FILE_F);
Color us = pos.side_to_move();
Square ksq = pos.king_square(us);
- Bitboard occ = pos.occupied_squares(), oppKingBB = EmptyBoardBB;
+ Bitboard occ = pos.occupied_squares();
- set_bit(&oppKingBB, pos.king_square(opposite_color(us)));
clear_bit(&occ, ksq); // Remove our king from the board
Square rsq = make_square(rookFile, square_rank(ksq));
- return (rook_attacks_bb(rsq, occ) & oppKingBB);
+ return bit_is_set(rook_attacks_bb(rsq, occ), pos.king_square(opposite_color(us)));
}
}
projects / stockfish / blobdiff