prefetch((char*)TT.first_entry(k));
// Move the piece
- Bitboard from_to_bb = SquareBB[from] | SquareBB[to];
+ Bitboard from_to_bb = SquareBB[from] ^ SquareBB[to];
byTypeBB[ALL_PIECES] ^= from_to_bb;
byTypeBB[pt] ^= from_to_bb;
byColorBB[us] ^= from_to_bb;
}
// Put the piece back at the source square
- Bitboard from_to_bb = SquareBB[from] | SquareBB[to];
+ Bitboard from_to_bb = SquareBB[from] ^ SquareBB[to];
byTypeBB[ALL_PIECES] ^= from_to_bb;
byTypeBB[pt] ^= from_to_bb;
byColorBB[us] ^= from_to_bb;
assert(piece_on(kfrom) == make_piece(us, KING));
assert(piece_on(rfrom) == make_piece(us, ROOK));
- // Remove pieces from source squares
- byTypeBB[ALL_PIECES] ^= kfrom;
- byTypeBB[KING] ^= kfrom;
- byColorBB[us] ^= kfrom;
- byTypeBB[ALL_PIECES] ^= rfrom;
- byTypeBB[ROOK] ^= rfrom;
- byColorBB[us] ^= rfrom;
-
- // Put pieces on destination squares
- byTypeBB[ALL_PIECES] |= kto;
- byTypeBB[KING] |= kto;
- byColorBB[us] |= kto;
- byTypeBB[ALL_PIECES] |= rto;
- byTypeBB[ROOK] |= rto;
- byColorBB[us] |= rto;
+ // Move the pieces, with some care; in chess960 could be kto == rfrom
+ Bitboard k_from_to_bb = SquareBB[kfrom] ^ SquareBB[kto];
+ Bitboard r_from_to_bb = SquareBB[rfrom] ^ SquareBB[rto];
+ byTypeBB[KING] ^= k_from_to_bb;
+ byTypeBB[ROOK] ^= r_from_to_bb;
+ byTypeBB[ALL_PIECES] ^= k_from_to_bb ^ r_from_to_bb;
+ byColorBB[us] ^= k_from_to_bb ^ r_from_to_bb;
// Update board
Piece king = make_piece(us, KING);