add_round_key
add_round_key(q, skey);
add_round_key(q, skey + (u << 3));
add_round_key(q, skey + (num_rounds << 3));
add_round_key(q, skey + (num_rounds << 3));
add_round_key(q, skey + (u << 3));
add_round_key(q, skey);