[PATCH][Aarch64] Fix vec_perm cost for thunderx2t99

[Kyrylo Tkachov]

Hi Andrew, Anton,

On 11/1/19 11:22 PM, Andrew Pinski wrote:
> On Fri, Nov 1, 2019 at 7:03 AM Anton Youdkevitch
> <anton.youdkevitch@bell-sw.com> wrote:
> >
> > Hello,
> >
> > Here is the one-liner that fixes the incorrect
> > vec_perm cost for thunderx2t99 chip.
> > With the patch applied 526.blender of CPU2017
> > gets ~5% improvement with no measurable changes
> > for other benchmarks.
> >
> > Bootstrapped OK on aarch64-linux-gnu.
> >
> > OK for trunk?
>
> Maybe the big question is vec_perm used for both 1 input and 2 input
> cases?  If so maybe splitting the two cases would be important too.
> Otherwise this is ok from my point of view but I can't approve it.
>
I'd be interested to see a testcase/demonstration where this would would 
be beneficial.

In the meantime this patch is ok if it helps thunderx2t99 performance.

2019-11-01 Anton Youdkevitch <anton.youdkevitch@bell-sw.com>

         * gcc/config/aarch64/aarch64.c (thunderx2t99_vector_cost):
         change vec_perm field

ChangeLog nits:

* Two spaces between name and date+email

* No gcc/ prefix as the relevant ChangeLog file lives in gcc/

* End entry with full stop.

Anton, do you need someone to commit this for you?

Thanks,

Kyrill



>
> Thanks,
> Andrew Pinski
>
> >
> > 2019-11-01 Anton Youdkevitch <anton.youdkevitch@bell-sw.com>
> >
> >         * gcc/config/aarch64/aarch64.c (thunderx2t99_vector_cost):
> >         change vec_perm field
> >
> > --
> >   Thanks,
> >   Anton