- Color us = sideToMove;
- 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;
-
- // Could be from == to, so first set NO_PIECE then KING and ROOK
- board[kfrom] = board[rfrom] = NO_PIECE;
- board[kto] = make_piece(us, KING);
- board[rto] = make_piece(us, ROOK);
-
- // Could be kfrom == rto, so use a 'tmp' variable
- int tmp = index[kfrom];
- index[rto] = index[rfrom];
- index[kto] = tmp;
- pieceList[us][KING][index[kto]] = kto;
- pieceList[us][ROOK][index[rto]] = rto;
+ // Remove both pieces first since squares could overlap in Chess960
+ remove_piece(kfrom, sideToMove, KING);
+ remove_piece(rfrom, sideToMove, ROOK);
+ board[kfrom] = board[rfrom] = NO_PIECE; // Since remove_piece doesn't do it for us
+ put_piece(kto, sideToMove, KING);
+ put_piece(rto, sideToMove, ROOK);