template<Color Us, SquareDelta Diagonal>
MoveStack* generate_pawn_captures_diagonal(MoveStack* mlist, Bitboard pawns, Bitboard enemyPieces, bool promotion);
- template<Color Us>
- MoveStack* generate_pawn_noncaptures(const Position& pos, MoveStack* mlist);
-
- template<Color Us>
- MoveStack* generate_pawn_checks(const Position&, Bitboard, Square, MoveStack*);
+ template<Color Us, bool Checks>
+ MoveStack* generate_pawn_noncaptures(const Position& pos, MoveStack* mlist, Bitboard dc = EmptyBoardBB, Square ksq = SQ_NONE);
template<Color Us, SquareDelta Direction>
inline Bitboard move_pawns(Bitboard p) {
template<>
inline MoveStack* generate_piece_checks<PAWN>(const Position& p, MoveStack* m, Color us, Bitboard dc, Square ksq) {
- return (us == WHITE ? generate_pawn_checks<WHITE>(p, dc, ksq, m)
- : generate_pawn_checks<BLACK>(p, dc, ksq, m));
+ return (us == WHITE ? generate_pawn_noncaptures<WHITE, true>(p, m, dc, ksq)
+ : generate_pawn_noncaptures<BLACK, true>(p, m, dc, ksq));
}
// Template generate_piece_moves() with specializations and overloads
return (us == WHITE ? generate_pawn_captures<WHITE>(p, m)
: generate_pawn_captures<BLACK>(p, m));
else
- return (us == WHITE ? generate_pawn_noncaptures<WHITE>(p, m)
- : generate_pawn_noncaptures<BLACK>(p, m));
+ return (us == WHITE ? generate_pawn_noncaptures<WHITE, false>(p, m)
+ : generate_pawn_noncaptures<BLACK, false>(p, m));
}
template<PieceType>
}
-/// generate_legal_moves() computes a complete list of legal moves in the
-/// current position. This function is not very fast, and should be used
-/// only in situations where performance is unimportant. It wouldn't be
-/// very hard to write an efficient legal move generator, but for the moment
-/// we don't need it.
+/// generate_moves() computes a complete list of legal or pseudo legal moves in
+/// the current position. This function is not very fast, and should be used
+/// only in situations where performance is unimportant.
-MoveStack* generate_legal_moves(const Position& pos, MoveStack* mlist) {
+MoveStack* generate_moves(const Position& pos, MoveStack* mlist, bool pseudoLegal) {
assert(pos.is_ok());
// Generate pseudo-legal moves
MoveStack* last = generate_captures(pos, mlist);
last = generate_noncaptures(pos, last);
+ if (pseudoLegal)
+ return last;
// Remove illegal moves from the list
for (MoveStack* cur = mlist; cur != last; cur++)
/// move_is_legal() takes a position and a (not necessarily pseudo-legal)
-/// move and a pinned pieces bitboard as input, and tests whether
-/// the move is legal. If the move is legal, the move itself is
-/// returned. If not, the function returns false. This function must
-/// only be used when the side to move is not in check.
+/// move and tests whether the move is legal. This version is not very fast
+/// and should be used only for non time-critical paths.
+
+bool move_is_legal(const Position& pos, const Move m) {
+
+ MoveStack mlist[256];
+ MoveStack* last = generate_moves(pos, mlist, true);
+ for (MoveStack* cur = mlist; cur != last; cur++)
+ if (cur->move == m)
+ return pos.pl_move_is_legal(m);
+
+ return false;
+}
+
+
+/// Fast version of move_is_legal() that takes a position a move and
+/// a pinned pieces bitboard as input, and tests whether the move is legal.
+/// This version must only be used when the side to move is not in check.
bool move_is_legal(const Position& pos, const Move m, Bitboard pinned) {
assert(move_is_ok(m));
assert(pinned == pos.pinned_pieces(pos.side_to_move()));
+ // Use a slower but simpler function for uncommon cases
+ if (move_is_ep(m) || move_is_castle(m))
+ return move_is_legal(pos, m);
+
Color us = pos.side_to_move();
Square from = move_from(m);
Piece pc = pos.piece_on(from);
Color them = opposite_color(us);
Square to = move_to(m);
- // En passant moves
- if (move_is_ep(m))
- {
- // The piece must be a pawn and destination square must be the
- // en passant square.
- if ( type_of_piece(pc) != PAWN
- || to != pos.ep_square())
- return false;
-
- assert(pos.square_is_empty(to));
- assert(pos.piece_on(to - pawn_push(us)) == piece_of_color_and_type(them, PAWN));
-
- // The move is pseudo-legal, check if it is also legal
- return pos.pl_move_is_legal(m, pinned);
- }
-
- // Castling moves
- if (move_is_short_castle(m))
- {
- // The piece must be a king and side to move must still have
- // the right to castle kingside.
- if ( type_of_piece(pc) != KING
- ||!pos.can_castle_kingside(us))
- return false;
-
- assert(from == pos.king_square(us));
- assert(to == pos.initial_kr_square(us));
- assert(pos.piece_on(to) == piece_of_color_and_type(us, ROOK));
-
- Square g1 = relative_square(us, SQ_G1);
- Square f1 = relative_square(us, SQ_F1);
- Square s;
- bool illegal = false;
-
- // Check if any of the squares between king and rook
- // is occupied or under attack.
- for (s = Min(from, g1); s <= Max(from, g1); s++)
- if ( (s != from && s != to && !pos.square_is_empty(s))
- ||(pos.attackers_to(s) & pos.pieces_of_color(them)))
- illegal = true;
-
- // Check if any of the squares between king and rook
- // is occupied.
- for (s = Min(to, f1); s <= Max(to, f1); s++)
- if (s != from && s != to && !pos.square_is_empty(s))
- illegal = true;
-
- return !illegal;
- }
-
- if (move_is_long_castle(m))
- {
- // The piece must be a king and side to move must still have
- // the right to castle kingside.
- if ( type_of_piece(pc) != KING
- ||!pos.can_castle_queenside(us))
- return false;
-
- assert(from == pos.king_square(us));
- assert(to == pos.initial_qr_square(us));
- assert(pos.piece_on(to) == piece_of_color_and_type(us, ROOK));
-
- Square c1 = relative_square(us, SQ_C1);
- Square d1 = relative_square(us, SQ_D1);
- Square s;
- bool illegal = false;
-
- for (s = Min(from, c1); s <= Max(from, c1); s++)
- if( (s != from && s != to && !pos.square_is_empty(s))
- ||(pos.attackers_to(s) & pos.pieces_of_color(them)))
- illegal = true;
-
- for (s = Min(to, d1); s <= Max(to, d1); s++)
- if(s != from && s != to && !pos.square_is_empty(s))
- illegal = true;
-
- if ( square_file(to) == FILE_B
- && ( pos.piece_on(to + DELTA_W) == piece_of_color_and_type(them, ROOK)
- || pos.piece_on(to + DELTA_W) == piece_of_color_and_type(them, QUEEN)))
- illegal = true;
-
- return !illegal;
- }
-
- // Normal moves
-
// The destination square cannot be occupied by a friendly piece
if (pos.color_of_piece_on(to) == us)
return false;
}
-/// Another version of move_is_legal(), which takes only a position and a move
-/// as input. This function does not require that the side to move is not in
-/// check. It is not optimized for speed, and is only used for verifying move
-/// legality when building a PV from the transposition table.
-
-bool move_is_legal(const Position& pos, const Move m) {
-
- Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
- if (!pos.is_check())
- return move_is_legal(pos, m, pinned);
- else
- {
- Position p(pos);
- MoveStack mlist[64];
- MoveStack* last = generate_evasions(p, mlist, pinned);
- for (MoveStack* cur = mlist; cur != last; cur++)
- if (cur->move == m)
- return true;
-
- return false;
- }
-}
-
-
namespace {
template<PieceType Piece>
return mlist;
}
- template<Color Us>
- MoveStack* generate_pawn_noncaptures(const Position& pos, MoveStack* mlist) {
+ template<Color Us, bool GenerateChecks>
+ MoveStack* generate_pawn_noncaptures(const Position& pos, MoveStack* mlist, Bitboard dc, Square ksq) {
// Calculate our parametrized parameters at compile time
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
const Bitboard TRank8BB = (Us == WHITE ? Rank8BB : Rank1BB);
const Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB);
const Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
const SquareDelta TDELTA_NW = (Us == WHITE ? DELTA_NW : DELTA_SW);
const SquareDelta TDELTA_N = (Us == WHITE ? DELTA_N : DELTA_S);
- Bitboard b1, b2;
+ Bitboard b1, b2, dcPawns1, dcPawns2;
Square to;
Bitboard pawns = pos.pieces(PAWN, Us);
Bitboard emptySquares = pos.empty_squares();
if (pawns & TRank7BB) // There is some promotion candidate ?
{
- Bitboard enemyPieces = pos.pieces_of_color(opposite_color(Us));
+ // When generating checks consider under-promotion moves (both captures
+ // and non captures) only if can give a discovery check.
+ Bitboard pp = GenerateChecks ? pawns & dc : pawns;
+ Bitboard enemyPieces = pos.pieces_of_color(opposite_color(Us));
// Underpromotion captures in the a1-h8 (a8-h1 for black) direction
- b1 = move_pawns<Us, DELTA_NE>(pawns) & ~FileABB & enemyPieces & TRank8BB;
+ b1 = move_pawns<Us, DELTA_NE>(pp) & ~FileABB & enemyPieces & TRank8BB;
while (b1)
{
to = pop_1st_bit(&b1);
}
// Underpromotion captures in the h1-a8 (h8-a1 for black) direction
- b1 = move_pawns<Us, DELTA_NW>(pawns) & ~FileHBB & enemyPieces & TRank8BB;
+ b1 = move_pawns<Us, DELTA_NW>(pp) & ~FileHBB & enemyPieces & TRank8BB;
while (b1)
{
to = pop_1st_bit(&b1);
}
// Underpromotion pawn pushes
- b1 = move_pawns<Us, DELTA_N>(pawns) & emptySquares & TRank8BB;
+ b1 = move_pawns<Us, DELTA_N>(pp) & emptySquares & TRank8BB;
while (b1)
{
to = pop_1st_bit(&b1);
}
}
- // Single pawn pushes
- b2 = b1 = move_pawns<Us, DELTA_N>(pawns) & emptySquares & ~TRank8BB;
- SERIALIZE_MOVES_D(b2, -TDELTA_N);
-
- // Double pawn pushes
- b2 = move_pawns<Us, DELTA_N>(b1 & TRank3BB) & emptySquares;
- SERIALIZE_MOVES_D(b2, -TDELTA_N -TDELTA_N);
- return mlist;
- }
-
-
- template<Color Us>
- MoveStack* generate_pawn_checks(const Position& pos, Bitboard dc, Square ksq, MoveStack* mlist)
- {
- // Calculate our parametrized parameters at compile time
- const Color Them = (Us == WHITE ? BLACK : WHITE);
- const Bitboard TRank8BB = (Us == WHITE ? Rank8BB : Rank1BB);
- const Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
- const SquareDelta TDELTA_N = (Us == WHITE ? DELTA_N : DELTA_S);
- const SquareDelta TDELTA_S = (Us == WHITE ? DELTA_S : DELTA_N);
-
- Square to;
- Bitboard b1, b2, b3;
- Bitboard pawns = pos.pieces(PAWN, Us);
-
- if (dc & pawns)
+ dcPawns1 = dcPawns2 = EmptyBoardBB;
+ if (GenerateChecks && (dc & pawns))
{
- Bitboard empty = pos.empty_squares();
-
// Pawn moves which gives discovered check. This is possible only if the
// pawn is not on the same file as the enemy king, because we don't
// generate captures.
- b1 = pawns & ~file_bb(ksq);
-
- // Discovered checks, single pawn pushes, no promotions
- b2 = b3 = move_pawns<Us, DELTA_N>(b1 & dc) & empty & ~TRank8BB;
- SERIALIZE_MOVES_D(b3, -TDELTA_N);
-
- // Discovered checks, double pawn pushes
- b3 = move_pawns<Us, DELTA_N>(b2 & TRank3BB) & empty;
- SERIALIZE_MOVES_D(b3, -TDELTA_N -TDELTA_N);
+ dcPawns1 = move_pawns<Us, DELTA_N>(pawns & dc & ~file_bb(ksq)) & emptySquares & ~TRank8BB;
+ dcPawns2 = move_pawns<Us, DELTA_N>(dcPawns1 & TRank3BB) & emptySquares;
}
- // Direct checks. These are possible only for pawns on neighboring files
- // and in the two ranks that, after the push, are in front of the enemy king.
- b1 = pawns & neighboring_files_bb(ksq) & ~dc;
-
- // We can get false positives if (ksq + x) is not in [0,63] range but
- // is not a problem, they will be filtered out later.
- b2 = b1 & (rank_bb(ksq + 2 * TDELTA_S) | rank_bb(ksq + 3 * TDELTA_S));
- if (!b2)
- return mlist;
-
- // Direct checks, single pawn pushes
- Bitboard empty = pos.empty_squares();
- b2 = move_pawns<Us, DELTA_N>(b1) & empty;
- b3 = b2 & pos.attacks_from<PAWN>(ksq, Them);
- SERIALIZE_MOVES_D(b3, -TDELTA_N);
+ // Single pawn pushes
+ b1 = move_pawns<Us, DELTA_N>(pawns) & emptySquares & ~TRank8BB;
+ b2 = GenerateChecks ? (b1 & pos.attacks_from<PAWN>(ksq, Them)) | dcPawns1 : b1;
+ SERIALIZE_MOVES_D(b2, -TDELTA_N);
- // Direct checks, double pawn pushes
- b3 = move_pawns<Us, DELTA_N>(b2 & TRank3BB) & empty & pos.attacks_from<PAWN>(ksq, Them);
- SERIALIZE_MOVES_D(b3, -TDELTA_N -TDELTA_N);
+ // Double pawn pushes
+ b1 = move_pawns<Us, DELTA_N>(b1 & TRank3BB) & emptySquares;
+ b2 = GenerateChecks ? (b1 & pos.attacks_from<PAWN>(ksq, Them)) | dcPawns2 : b1;
+ SERIALIZE_MOVES_D(b2, -TDELTA_N -TDELTA_N);
return mlist;
}
projects / stockfish / blobdiff