Hi,

On 13/06/2019 18:26, Wilco Dijkstra wrote:
> Wouldn't it be easier to just do exact_log2 (real_to_integer (&r0))
> and then check the range is in 1..31?
I've revised this section.
> --- a/gcc/config/aarch64/aarch64.md
> +++ b/gcc/config/aarch64/aarch64.md
> @@ -6016,6 +6016,40 @@
>     [(set_attr "type" "f_cvtf2i")]
>   )
>   
> +(define_insn "*aarch64_<su_optab>cvtf_<fcvt_target>_<GPF:mode>2_mult"
> +  [(set (match_operand:GPF 0 "register_operand" "=w,w")
> +	(mult:GPF (FLOATUORS:GPF
> +		   (match_operand:<FCVT_TARGET> 1 "register_operand" "w,?r"))
> +		   (match_operand 2 "aarch64_fp_pow2_recip""Dt,Dt")))]
>
> We should add a comment before both define_insn similar to the other
> conversions, explaining what they do and why there are 2 separate patterns
> (the default versions of the conversions appear to be missing a comment too).
I've added comments to the new and existing patterns