#include <cassert>
+#include "bitcount.h"
#include "movegen.h"
// Simple macro to wrap a very common while loop, no facny, no flexibility,
/// generate_captures generates() all pseudo-legal captures and queen
-/// promotions. The return value is the number of moves generated.
+/// promotions. The return value is the number of moves generated.
int generate_captures(const Position& pos, MoveStack* mlist) {
assert(pinned == pos.pinned_pieces(pos.side_to_move()));
Color us = pos.side_to_move();
- Color them = opposite_color(us);
Square from = move_from(m);
Piece pc = pos.piece_on(from);
if (color_of_piece(pc) != us)
return false;
+ Color them = opposite_color(us);
Square to = move_to(m);
// En passant moves
// be a promotion.
if ( ( (square_rank(to) == RANK_8 && us == WHITE)
||(square_rank(to) == RANK_1 && us != WHITE))
- && !move_promotion(m))
+ && !move_is_promotion(m))
return false;
// Proceed according to the square delta between the source and
// Luckly we can handle all the other pieces in one go
return ( pos.piece_attacks_square(pos.piece_on(from), from, to)
&& pos.pl_move_is_legal(m, pinned)
- && !move_promotion(m));
+ && !move_is_promotion(m));
}
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);
Bitboard b1, b2, b3;
- Bitboard empty = pos.empty_squares();
Bitboard pawns = pos.pawns(Us);
if (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.
}
// Direct checks. These are possible only for pawns on neighboring files
- // of the enemy king.
+ // 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.pawn_attacks(Them, ksq);
while (b3)
// Direct checks
b = target & ~dc;
- if (Piece == KING || !b)
- return mlist;
-
- Bitboard checkSqs = pos.piece_attacks<Piece>(ksq) & pos.empty_squares();
- if (!checkSqs)
- return mlist;
-
- while (b)
+ if (Piece != KING || b)
{
- Square from = pop_1st_bit(&b);
- if ( (Piece == QUEEN && !(QueenPseudoAttacks[from] & checkSqs))
- || (Piece == ROOK && !(RookPseudoAttacks[from] & checkSqs))
- || (Piece == BISHOP && !(BishopPseudoAttacks[from] & checkSqs)))
- continue;
+ Bitboard checkSqs = pos.piece_attacks<Piece>(ksq) & pos.empty_squares();
+ if (!checkSqs)
+ return mlist;
- Bitboard bb = pos.piece_attacks<Piece>(from) & checkSqs;
- SERIALIZE_MOVES(bb);
+ while (b)
+ {
+ 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.piece_attacks<Piece>(from) & checkSqs;
+ SERIALIZE_MOVES(bb);
+ }
}
return mlist;
}
Bitboard blockSquares, MoveStack* mlist) {
// Calculate our parametrized parameters at compile time
- const Bitboard TRank8BB = (Us == WHITE ? Rank8BB : Rank1BB);
+ 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);
assert(pos.piece_on(to) == EMPTY);
- if (square_rank(to) == TRank8BB)
+ if (square_rank(to) == TRANK_8)
{
(*mlist++).move = make_promotion_move(to - TDELTA_N, to, QUEEN);
(*mlist++).move = make_promotion_move(to - TDELTA_N, to, ROOK);