[PATCH] Increase rtx_cost of sse_to_integer in skylake_cost.

[Hongtao Liu]

On Thu, Sep 17, 2020 at 12:10 PM Jeff Law <law@redhat.com> wrote:
>
>
> On 9/15/20 9:20 PM, Hongtao Liu via Gcc-patches wrote:
> > Hi:
> >   Rtx cost of sse_to_integer would be used by pass_stv as a
> > measurement for the scalar-to-vector transformation. As
> > https://gcc.gnu.org/pipermail/gcc-patches/2019-August/528839.html
> > indicates, movement between sse regs and gprs should be much expensive
> > than movement inside gprs(which is 2 as default). This patch would
> > also fix "pr96861".
> >
> >   Bootstrap is ok, regression test is ok for both "i386.exp=*
> > --target_board='unix{-m32,}'" and "i386.exp=*
> > --target_board='unix{-m32\ -march=cascadelake,-m64\
> > -march=cascadelake}"".
> >   No big impact on SPEC2017.
> >   Ok for trunk?
> >
> > gcc/ChangeLog
> >
> >         PR target/96861
> >         * config/i386/x86-tune-costs.h (skylake_cost): increase rtx
> >         cost of sse_to_integer from 2 to 6.
> >
> > gcc/testsuite
> >
> >         * gcc.target/i386/pr95021-3.c: Add -mtune=generic.
>
> I'll defer to HJ's judgement here.  If he's OK with it, then it's fine
> by me.
>

I've talked to H.J and he agrees on this patch.
So i'm going to check in this patch.

>
> jeff
>
>


-- 
BR,
Hongtao