[Bug rtl-optimization/70873] [7 Regressio] 20% performance regression at 482.sphinx3 after r235442 with -O2 -m32 on Haswell.

[bernds at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70873

--- Comment #19 from Bernd Schmidt <bernds at gcc dot gnu.org> ---
> This splitter is placed before the one we want.  We have quite
> a few similar splitters far apart and we lose the track.  This
> patch:
> 
> diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
> index 940dc20..dc46b16 100644
> --- a/gcc/config/i386/i386.md
> +++ b/gcc/config/i386/i386.md
> @@ -3615,6 +3615,35 @@
>      FAIL;
>  })
>  
> +;; Break partial reg stall for cvtss2sd.
> +
> +(define_split
> +  [(set (match_operand:DF 0 "register_operand")
> +        (float_extend:DF
...]

> works for me.

Did you mean to move the existing one rather than add a copy?

I don't know what you're trying to tell me with the two followup messages after
this.