enum MoveType {
CAPTURE,
- NON_CAPTURE
+ NON_CAPTURE,
+ CHECK,
+ EVASION
};
// Functions
// Helper templates
template<CastlingSide Side>
- MoveStack* generate_castle_moves(const Position& pos, MoveStack* mlist);
+ MoveStack* generate_castle_moves(const Position&, MoveStack*);
- template<Color Us>
- MoveStack* generate_pawn_blocking_evasions(const Position&, Bitboard, Bitboard, MoveStack*);
+ template<Color Us, MoveType Type>
+ MoveStack* generate_pawn_moves(const Position&, MoveStack*, Bitboard = EmptyBoardBB,
+ Square = SQ_NONE, Bitboard = EmptyBoardBB);
- template<Color Us>
- MoveStack* generate_pawn_captures(const Position& pos, MoveStack* mlist);
+ // Template generate_piece_moves (captures and non-captures) with specializations and overloads
+ template<PieceType>
+ MoveStack* generate_piece_moves(const Position&, MoveStack*, Color, Bitboard);
- template<Color Us, SquareDelta Diagonal>
- MoveStack* generate_pawn_captures_diagonal(MoveStack* mlist, Bitboard pawns, Bitboard enemyPieces, bool promotion);
+ template<>
+ MoveStack* generate_piece_moves<KING>(const Position&, MoveStack*, Color, Bitboard);
- template<Color Us, bool Checks>
- MoveStack* generate_pawn_noncaptures(const Position& pos, MoveStack* mlist, Bitboard dc = EmptyBoardBB, Square ksq = SQ_NONE);
+ template<PieceType Piece, MoveType Type>
+ inline MoveStack* generate_piece_moves(const Position& p, MoveStack* m, Color us) {
- template<Color Us, SquareDelta Direction>
- inline Bitboard move_pawns(Bitboard p) {
+ assert(Piece == PAWN);
+ assert(Type == CAPTURE || Type == NON_CAPTURE);
- if (Direction == DELTA_N)
- return Us == WHITE ? p << 8 : p >> 8;
- else if (Direction == DELTA_NE)
- return Us == WHITE ? p << 9 : p >> 7;
- else if (Direction == DELTA_NW)
- return Us == WHITE ? p << 7 : p >> 9;
- else
- return p;
+ return (us == WHITE ? generate_pawn_moves<WHITE, Type>(p, m)
+ : generate_pawn_moves<BLACK, Type>(p, m));
}
- // Template generate_piece_checks() with specializations
+ // Template generate_piece_checks with specializations
template<PieceType>
MoveStack* generate_piece_checks(const Position&, MoveStack*, Color, Bitboard, Square);
template<>
inline MoveStack* generate_piece_checks<PAWN>(const Position& p, MoveStack* m, Color us, Bitboard dc, Square ksq) {
- 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
- template<PieceType>
- MoveStack* generate_piece_moves(const Position&, MoveStack*, Color us, Bitboard);
-
- template<>
- MoveStack* generate_piece_moves<KING>(const Position&, MoveStack*, Color, Bitboard);
-
- template<PieceType Piece, MoveType Type>
- inline MoveStack* generate_piece_moves(const Position& p, MoveStack* m, Color us) {
-
- assert(Piece == PAWN);
-
- if (Type == CAPTURE)
- return (us == WHITE ? generate_pawn_captures<WHITE>(p, m)
- : generate_pawn_captures<BLACK>(p, m));
- else
- return (us == WHITE ? generate_pawn_noncaptures<WHITE, false>(p, m)
- : generate_pawn_noncaptures<BLACK, false>(p, m));
+ return (us == WHITE ? generate_pawn_moves<WHITE, CHECK>(p, m, dc, ksq)
+ : generate_pawn_moves<BLACK, CHECK>(p, m, dc, ksq));
}
+ // Template generate_piece_evasions with specializations
template<PieceType>
- MoveStack* generate_piece_moves(const Position&, MoveStack*, Color us, Bitboard, Bitboard);
+ MoveStack* generate_piece_evasions(const Position&, MoveStack*, Color, Bitboard, Bitboard);
template<>
- inline MoveStack* generate_piece_moves<PAWN>(const Position& p, MoveStack* m,
- Color us, Bitboard t, Bitboard pnd) {
+ inline MoveStack* generate_piece_evasions<PAWN>(const Position& p, MoveStack* m,
+ Color us, Bitboard t, Bitboard pnd) {
- return (us == WHITE ? generate_pawn_blocking_evasions<WHITE>(p, pnd, t, m)
- : generate_pawn_blocking_evasions<BLACK>(p, pnd, t, m));
+ return (us == WHITE ? generate_pawn_moves<WHITE, EVASION>(p, m, pnd, SQ_NONE, t)
+ : generate_pawn_moves<BLACK, EVASION>(p, m, pnd, SQ_NONE, t));
}
}
////
-/// generate_captures generates() all pseudo-legal captures and queen
+/// generate_captures() generates all pseudo-legal captures and queen
/// promotions. Returns a pointer to the end of the move list.
MoveStack* generate_captures(const Position& pos, MoveStack* mlist) {
}
-/// generate_non_capture_checks() generates all pseudo-legal non-capturing,
-/// non-promoting checks. Returns a pointer to the end of the move list.
+/// generate_non_capture_checks() generates all pseudo-legal non-captures and
+/// underpromotions that give check. Returns a pointer to the end of the move list.
MoveStack* generate_non_capture_checks(const Position& pos, MoveStack* mlist, Bitboard dc) {
Bitboard b_noKing = pos.occupied_squares();
clear_bit(&b_noKing, ksq);
- // Find squares attacked by slider checkers, we will
- // remove them from king evasions set so to avoid a couple
+ // Find squares attacked by slider checkers, we will remove
+ // them from the king evasions set so to avoid a couple
// of cycles in the slow king evasions legality check loop
// and to be able to use attackers_to().
Bitboard b = checkers & pos.pieces(BISHOP, QUEEN);
sliderAttacks |= rook_attacks_bb(from, b_noKing);
}
- // Generate evasions for king, both captures and non captures
- Bitboard b1 = pos.attacks_from<KING>(ksq) & ~pos.pieces_of_color(us) & ~sliderAttacks;
+ // Generate evasions for king, capture and non capture moves
Bitboard enemy = pos.pieces_of_color(them);
+ Bitboard b1 = pos.attacks_from<KING>(ksq) & ~pos.pieces_of_color(us) & ~sliderAttacks;
while (b1)
{
+ // Note that we can use attackers_to() only because we have already
+ // removed from b1 the squares attacked by slider checkers.
to = pop_1st_bit(&b1);
- // Note that we can use attackers_to() only because we
- // have already removed slider checkers attacked squares.
if (!(pos.attackers_to(to) & enemy))
(*mlist++).move = make_move(ksq, to);
}
if (blockSquares)
{
- mlist = generate_piece_moves<PAWN>(pos, mlist, us, blockSquares, pinned);
- mlist = generate_piece_moves<KNIGHT>(pos, mlist, us, blockSquares, pinned);
- mlist = generate_piece_moves<BISHOP>(pos, mlist, us, blockSquares, pinned);
- mlist = generate_piece_moves<ROOK>(pos, mlist, us, blockSquares, pinned);
- mlist = generate_piece_moves<QUEEN>(pos, mlist, us, blockSquares, pinned);
+ mlist = generate_piece_evasions<PAWN>(pos, mlist, us, blockSquares, pinned);
+ mlist = generate_piece_evasions<KNIGHT>(pos, mlist, us, blockSquares, pinned);
+ mlist = generate_piece_evasions<BISHOP>(pos, mlist, us, blockSquares, pinned);
+ mlist = generate_piece_evasions<ROOK>(pos, mlist, us, blockSquares, pinned);
+ mlist = generate_piece_evasions<QUEEN>(pos, mlist, us, blockSquares, pinned);
}
}
}
-/// 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 non time-critical paths.
-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 in 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
+/// bitboard of pinned pieces 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();
+ Color them = opposite_color(us);
Square from = move_from(m);
+ Square to = move_to(m);
Piece pc = pos.piece_on(from);
// If the from square is not occupied by a piece belonging to the side to
if (color_of_piece(pc) != us)
return false;
- 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;
- // Proceed according to the type of the moving piece.
+ // Handle the special case of a pawn move
if (type_of_piece(pc) == PAWN)
{
// Move direction must be compatible with pawn color
if ((us == WHITE) != (direction > 0))
return false;
- // If the destination square is on the 8/1th rank, the move must
- // be a promotion.
- if ( ( (square_rank(to) == RANK_8 && us == WHITE)
- ||(square_rank(to) == RANK_1 && us != WHITE))
- && !move_is_promotion(m))
+ // A pawn move is a promotion iff the destination square is
+ // on the 8/1th rank.
+ if (( (square_rank(to) == RANK_8 && us == WHITE)
+ ||(square_rank(to) == RANK_1 && us != WHITE)) != bool(move_is_promotion(m)))
return false;
- // Proceed according to the square delta between the source and
- // destionation squares.
+ // Proceed according to the square delta between the origin and
+ // destination squares.
switch (direction)
{
case DELTA_NW:
}
-/// 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>
Square from;
Bitboard b;
+ const Square* ptr = pos.piece_list_begin(us, Piece);
- for (int i = 0, e = pos.piece_count(us, Piece); i < e; i++)
+ while ((from = *ptr++) != SQ_NONE)
{
- from = pos.piece_list(us, Piece, i);
b = pos.attacks_from<Piece>(from) & target;
SERIALIZE_MOVES(b);
}
return mlist;
}
+ template<>
+ MoveStack* generate_piece_moves<KING>(const Position& pos, MoveStack* mlist, Color us, Bitboard target) {
+
+ Bitboard b;
+ Square from = pos.king_square(us);
+
+ b = pos.attacks_from<KING>(from) & target;
+ SERIALIZE_MOVES(b);
+ return mlist;
+ }
+
template<PieceType Piece>
- MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist,
- Color us, Bitboard target, Bitboard pinned) {
+ MoveStack* generate_piece_evasions(const Position& pos, MoveStack* mlist,
+ Color us, Bitboard target, Bitboard pinned) {
Square from;
Bitboard b;
+ const Square* ptr = pos.piece_list_begin(us, Piece);
- for (int i = 0, e = pos.piece_count(us, Piece); i < e; i++)
+ while ((from = *ptr++) != SQ_NONE)
{
- from = pos.piece_list(us, Piece, i);
if (pinned && bit_is_set(pinned, from))
continue;
return mlist;
}
- template<>
- MoveStack* generate_piece_moves<KING>(const Position& pos, MoveStack* mlist, Color us, Bitboard target) {
-
- Bitboard b;
- Square from = pos.king_square(us);
+ template<Color Us, SquareDelta Direction>
+ inline Bitboard move_pawns(Bitboard p) {
- b = pos.attacks_from<KING>(from) & target;
- SERIALIZE_MOVES(b);
- return mlist;
+ if (Direction == DELTA_N)
+ return Us == WHITE ? p << 8 : p >> 8;
+ else if (Direction == DELTA_NE)
+ return Us == WHITE ? p << 9 : p >> 7;
+ else if (Direction == DELTA_NW)
+ return Us == WHITE ? p << 7 : p >> 9;
+ else
+ return p;
}
template<Color Us, SquareDelta Diagonal>
- MoveStack* generate_pawn_captures_diagonal(MoveStack* mlist, Bitboard pawns, Bitboard enemyPieces, bool promotion) {
+ MoveStack* generate_pawn_diagonal_captures(MoveStack* mlist, Bitboard pawns, Bitboard enemyPieces, bool promotion) {
// Calculate our parametrized parameters at compile time
const Bitboard TRank8BB = (Us == WHITE ? Rank8BB : Rank1BB);
return mlist;
}
- template<Color Us>
- MoveStack* generate_pawn_captures(const Position& pos, MoveStack* mlist) {
+ template<Color Us, MoveType Type>
+ MoveStack* generate_pawn_moves(const Position& pos, MoveStack* mlist, Bitboard dcp,
+ Square ksq, Bitboard blockSquares) {
// 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_NE = (Us == WHITE ? DELTA_NE : DELTA_SE);
+ const SquareDelta TDELTA_NW = (Us == WHITE ? DELTA_NW : DELTA_SW);
const SquareDelta TDELTA_N = (Us == WHITE ? DELTA_N : DELTA_S);
+ Bitboard b1, b2, dcPawns1, dcPawns2;
Square to;
- Bitboard pawns = pos.pieces(PAWN, Us);
- Bitboard enemyPieces = pos.pieces_of_color(opposite_color(Us));
- bool possiblePromotion = (pawns & TRank7BB);
+ Bitboard pawns = (Type == EVASION ? pos.pieces(PAWN, Us) & ~dcp : pos.pieces(PAWN, Us));
+ bool possiblePromotion = pawns & TRank7BB;
- // Standard captures and capturing promotions in both directions
- mlist = generate_pawn_captures_diagonal<Us, DELTA_NE>(mlist, pawns, enemyPieces, possiblePromotion);
- mlist = generate_pawn_captures_diagonal<Us, DELTA_NW>(mlist, pawns, enemyPieces, possiblePromotion);
+ if (Type == CAPTURE)
+ {
+ // Standard captures and capturing promotions in both directions
+ Bitboard enemyPieces = pos.pieces_of_color(opposite_color(Us));
+ mlist = generate_pawn_diagonal_captures<Us, DELTA_NE>(mlist, pawns, enemyPieces, possiblePromotion);
+ mlist = generate_pawn_diagonal_captures<Us, DELTA_NW>(mlist, pawns, enemyPieces, possiblePromotion);
+ }
- // Non-capturing promotions
if (possiblePromotion)
{
- Bitboard b1 = move_pawns<Us, DELTA_N>(pawns) & pos.empty_squares() & TRank8BB;
- while (b1)
+ // When generating checks consider under-promotion moves (both captures
+ // and non captures) only if can give a discovery check. Note that dcp
+ // is dc bitboard or pinned bitboard when Type == EVASION.
+ Bitboard pp = (Type == CHECK ? pawns & dcp : pawns);
+
+ if (Type != EVASION && Type != CAPTURE)
{
- to = pop_1st_bit(&b1);
- (*mlist++).move = make_promotion_move(to - TDELTA_N, to, QUEEN);
+ 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>(pp) & ~FileABB & enemyPieces & TRank8BB;
+ while (b1)
+ {
+ to = pop_1st_bit(&b1);
+ (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, ROOK);
+ (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, BISHOP);
+ (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, KNIGHT);
+ }
+
+ // Underpromotion captures in the h1-a8 (h8-a1 for black) direction
+ b1 = move_pawns<Us, DELTA_NW>(pp) & ~FileHBB & enemyPieces & TRank8BB;
+ while (b1)
+ {
+ to = pop_1st_bit(&b1);
+ (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, ROOK);
+ (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, BISHOP);
+ (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, KNIGHT);
+ }
}
- }
- // En passant captures
- if (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);
-
- Bitboard b1 = pawns & pos.attacks_from<PAWN>(pos.ep_square(), Them);
- assert(b1 != EmptyBoardBB);
+ // Underpromotion pawn pushes. Also queen promotions for evasions and captures.
+ b1 = move_pawns<Us, DELTA_N>(pp) & TRank8BB;
+ b1 &= (Type == EVASION ? blockSquares : pos.empty_squares());
while (b1)
{
to = pop_1st_bit(&b1);
- (*mlist++).move = make_ep_move(to, pos.ep_square());
+ if (Type == EVASION || Type == CAPTURE)
+ (*mlist++).move = make_promotion_move(to - TDELTA_N, to, QUEEN);
+
+ if (Type != CAPTURE)
+ {
+ (*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);
+ }
}
}
- return 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_NE = (Us == WHITE ? DELTA_NE : DELTA_SE);
- const SquareDelta TDELTA_NW = (Us == WHITE ? DELTA_NW : DELTA_SW);
- const SquareDelta TDELTA_N = (Us == WHITE ? DELTA_N : DELTA_S);
- 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 ?
+ if (Type != CAPTURE)
{
- // When generating checks consider under-promotion moves (both captures
- // and non captures) only if can give a discovery check.
- Bitboard pp = GenerateChecks ? pawns & dc & EmptyBoardBB: 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>(pp) & ~FileABB & enemyPieces & TRank8BB;
- while (b1)
+ Bitboard emptySquares = pos.empty_squares();
+ dcPawns1 = dcPawns2 = EmptyBoardBB;
+ if (Type == CHECK && (pawns & dcp))
{
- to = pop_1st_bit(&b1);
- (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, ROOK);
- (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, BISHOP);
- (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, KNIGHT);
+ // 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.
+ dcPawns1 = move_pawns<Us, DELTA_N>(pawns & dcp & ~file_bb(ksq)) & emptySquares & ~TRank8BB;
+ dcPawns2 = move_pawns<Us, DELTA_N>(dcPawns1 & TRank3BB) & emptySquares;
}
- // Underpromotion captures in the h1-a8 (h8-a1 for black) direction
- b1 = move_pawns<Us, DELTA_NW>(pp) & ~FileHBB & enemyPieces & TRank8BB;
- while (b1)
- {
- to = pop_1st_bit(&b1);
- (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, ROOK);
- (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, BISHOP);
- (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, KNIGHT);
- }
+ // Single pawn pushes
+ b1 = move_pawns<Us, DELTA_N>(pawns) & emptySquares & ~TRank8BB;
+ b2 = (Type == CHECK ? (b1 & pos.attacks_from<PAWN>(ksq, Them)) | dcPawns1 :
+ (Type == EVASION ? b1 & blockSquares : b1));
+ SERIALIZE_MOVES_D(b2, -TDELTA_N);
+
+ // Double pawn pushes
+ b1 = move_pawns<Us, DELTA_N>(b1 & TRank3BB) & emptySquares;
+ b2 = (Type == CHECK ? (b1 & pos.attacks_from<PAWN>(ksq, Them)) | dcPawns2 :
+ (Type == EVASION ? b1 & blockSquares : b1));
+ SERIALIZE_MOVES_D(b2, -TDELTA_N -TDELTA_N);
+ }
+ else if (pos.ep_square() != SQ_NONE) // En passant captures
+ {
+ assert(Us != WHITE || square_rank(pos.ep_square()) == RANK_6);
+ assert(Us != BLACK || square_rank(pos.ep_square()) == RANK_3);
+
+ b1 = pawns & pos.attacks_from<PAWN>(pos.ep_square(), Them);
+ assert(b1 != EmptyBoardBB);
- // Underpromotion pawn pushes
- b1 = move_pawns<Us, DELTA_N>(pp) & emptySquares & TRank8BB;
while (b1)
{
to = pop_1st_bit(&b1);
- (*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);
+ (*mlist++).move = make_ep_move(to, pos.ep_square());
}
}
-
- dcPawns1 = dcPawns2 = EmptyBoardBB;
- if (GenerateChecks && (dc & pawns))
- {
- // 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.
- dcPawns1 = move_pawns<Us, DELTA_N>(pawns & dc & ~file_bb(ksq)) & emptySquares & ~TRank8BB;
- dcPawns2 = move_pawns<Us, DELTA_N>(dcPawns1 & TRank3BB) & emptySquares;
- }
-
- // 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);
-
- // 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;
}
Bitboard target = pos.pieces(Piece, us);
- // Discovered checks
+ // Discovered non-capture checks
Bitboard b = target & dc;
+
+ assert(Piece != QUEEN || !b);
+
while (b)
{
Square from = pop_1st_bit(&b);
SERIALIZE_MOVES(bb);
}
- // Direct checks
+ // Direct non-capture checks
b = target & ~dc;
Bitboard checkSqs = pos.attacks_from<Piece>(ksq) & pos.empty_squares();
- if (Piece == KING || !checkSqs)
- return mlist;
-
- while (b)
+ if (Piece != KING && checkSqs)
{
- Square from = pop_1st_bit(&b);
- if ( (Piece == QUEEN && !(QueenPseudoAttacks[from] & checkSqs))
- || (Piece == ROOK && !(RookPseudoAttacks[from] & checkSqs))
- || (Piece == BISHOP && !(BishopPseudoAttacks[from] & checkSqs)))
- continue;
-
- Bitboard bb = pos.attacks_from<Piece>(from) & checkSqs;
- SERIALIZE_MOVES(bb);
- }
- return mlist;
- }
-
- template<Color Us>
- MoveStack* generate_pawn_blocking_evasions(const Position& pos, Bitboard pinned,
- Bitboard blockSquares, MoveStack* mlist) {
-
- // Calculate our parametrized parameters at compile time
- const Rank TRANK_8 = (Us == WHITE ? RANK_8 : RANK_1);
- const Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
- const SquareDelta TDELTA_N = (Us == WHITE ? DELTA_N : DELTA_S);
-
- Square to;
-
- // Find non-pinned pawns and push them one square
- Bitboard b1 = move_pawns<Us, DELTA_N>(pos.pieces(PAWN, Us) & ~pinned);
-
- // We don't have to AND with empty squares here,
- // because the blocking squares will always be empty.
- Bitboard b2 = b1 & blockSquares;
- while (b2)
- {
- to = pop_1st_bit(&b2);
-
- assert(pos.piece_on(to) == EMPTY);
-
- if (square_rank(to) == TRANK_8)
+ while (b)
{
- (*mlist++).move = make_promotion_move(to - TDELTA_N, to, QUEEN);
- (*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);
- } else
- (*mlist++).move = make_move(to - TDELTA_N, to);
- }
-
- // Double pawn pushes
- b2 = b1 & pos.empty_squares() & TRank3BB;
- b2 = move_pawns<Us, DELTA_N>(b2) & blockSquares;
- while (b2)
- {
- to = pop_1st_bit(&b2);
-
- assert(pos.piece_on(to) == EMPTY);
- assert(Us != WHITE || square_rank(to) == RANK_4);
- assert(Us != BLACK || square_rank(to) == RANK_5);
-
- (*mlist++).move = make_move(to - TDELTA_N - TDELTA_N, to);
+ Square from = pop_1st_bit(&b);
+ if ( (Piece == QUEEN && !(QueenPseudoAttacks[from] & checkSqs))
+ || (Piece == ROOK && !(RookPseudoAttacks[from] & checkSqs))
+ || (Piece == BISHOP && !(BishopPseudoAttacks[from] & checkSqs)))
+ continue;
+
+ Bitboard bb = pos.attacks_from<Piece>(from) & checkSqs;
+ SERIALIZE_MOVES(bb);
+ }
}
return mlist;
}