You can't apply that rule to all instructions. For example, movslq becomes move_sign_extended_double_word. ARM instruction QADD16 would be signed_saturating_p

You can't apply that rule to all instructions. For example, movslq becomes move_sign_extended_double_word. ARM instruction QADD16 would be signed_saturating_parallel_halfword_wise_addition. QASX: signed_saturating_parallel_add_and_subtract_halfwords _with_exchange.