On Tue, May 25, 2021 at 2:29 PM Andrew Pinski <pins...@gmail.com> wrote:
>
> On Mon, May 24, 2021 at 11:23 PM Hongtao Liu <crazy...@gmail.com> wrote:
> >
> > On Tue, May 25, 2021 at 2:11 PM Andrew Pinski <pins...@gmail.com> wrote:
> > >
> > > On Mon, May 24, 2021 at 11:03 PM Hongtao Liu via Gcc-patches
> > > <gcc-patches@gcc.gnu.org> wrote:
> > > >
> > > > Hi:
> > > > This patch is about to do transformation like below.
> > > > Bootstrapped and regtested on x86_64-linux-gnu{-m32,}.
> > > > Ok for trunk?
> > > >
> > > > from
> > > > notl %edi
> > > > vpbroadcastd %edi, %xmm0
> > > > vpand %xmm1, %xmm0, %xmm0
> > > > to
> > > > vpbroadcastd %edi, %xmm0
> > > > vpandn %xmm1, %xmm0, %xmm0
> > > >
> > > > gcc/ChangeLog:
> > > >
> > > > PR target/100711
> > > > * config/i386/sse.md (*andnot<mode>3): New combine splitter
> > > > after it.
> > > >
> > > > gcc/testsuite/ChangeLog:
> > > >
> > > > PR target/100711
> > > > * gcc.target/i386/avx2-pr100711.c: New test.
> > > > * gcc.target/i386/avx512bw-pr100711.c: New test.
> > > >
> > >
> > >
> > > Does it make sense to make this more generic and have combine/simplify
> > > rtx instead try:
> > > (vec_dup (not)) to (not (vec_dup))
> >
> > Even w/ that, a combine splitter is still needed since we don't have
> > any pandn patterns which contain op1 as vec_duplicate or "not" pattern
> > for vector mode, generic simplification only helps combine/forprop to
> > match more possibilities, but not split pattern by itself.
>
> Huh? This is a 3->2 combining which definitely just happen.
Oh, I don't know that, thanks for the classification, I thought
combine only does n->1.
> You don't need a "not" pattern for the vector mode for this to happen
> since the combining happens without an insn defined.
>
> Thanks,
> Andrew Pinski
>
> >
> > >
> > > Thanks,
> > > Andrew Pinski
> >
> >
> >
> > --
> > BR,
> > Hongtao
--
BR,
Hongtao
