Re: [PATCH] rs6000: fmr gets used instead of faster xxlor [PR93571]

[Andrew Pinski <pinskia@gmail.com>]

On Fri, Feb 17, 2023 at 8:59 AM Ajit Agarwal via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
>
> Hello All:
>
> This patch replaces fmr instruction (6 cycles) with xxlor instruction ( 2 cycles)
> Bootstrapped and regtested on powerpc64-linux-gnu.

I don't think this can be unconditionally replaced.
xxlor only exists in newer Power ISA.

Thanks,
Andrew Pinski

>
> copyright assignment form is still in the process of being sent.
>
> Thanks & Regards
> Ajit
>
>         rs6000: fmr gets used instead of faster xxlor [PR93571]
>
>         This patch replaces 6 cycles fmr instruction with xxlor
>         2 cycles.
>
>         2023-02-17  Ajit Kumar Agarwal  <aagarwa1@linux.ibm.com>
>
> gcc/ChangeLog:
>
>         * config/rs6000/rs6000.md (*movdf_hardfloat64): Replace fmr with xxlor instruction.
> ---
>  gcc/config/rs6000/rs6000.md | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md
> index 4a7812fa592..dfd6c73ffcb 100644
> --- a/gcc/config/rs6000/rs6000.md
> +++ b/gcc/config/rs6000/rs6000.md
> @@ -8436,7 +8436,7 @@
>    "@
>     stfd%U0%X0 %1,%0
>     lfd%U1%X1 %0,%1
> -   fmr %0,%1
> +   xxlor %0,%1,%1
>     lxsd %0,%1
>     stxsd %1,%0
>     lxsdx %x0,%y1
> --
> 2.31.1
>
>