RE: [PATCH v3] x86: make VPTERNLOG* usable on less than 512-bit operands with just AVX512F

["Liu, Hongtao" <hongtao.liu@intel.com>]

> -----Original Message-----
> From: Jan Beulich <jbeulich@suse.com>
> Sent: Tuesday, July 4, 2023 11:30 PM
> To: Hongtao Liu <crazylht@gmail.com>
> Cc: gcc-patches@gcc.gnu.org; Kirill Yukhin <kirill.yukhin@gmail.com>; Liu,
> Hongtao <hongtao.liu@intel.com>
> Subject: Re: [PATCH v3] x86: make VPTERNLOG* usable on less than 512-bit
> operands with just AVX512F
> 
> On 27.06.2023 07:11, Hongtao Liu wrote:
> > On Tue, Jun 20, 2023 at 5:34 PM Hongtao Liu <crazylht@gmail.com> wrote:
> >>
> >> On Tue, Jun 20, 2023 at 5:03 PM Jan Beulich <jbeulich@suse.com> wrote:
> >>>
> >>> On 20.06.2023 10:33, Hongtao Liu wrote:
> >>>> On Tue, Jun 20, 2023 at 3:07 PM Jan Beulich via Gcc-patches
> >>>> <gcc-patches@gcc.gnu.org> wrote:
> >>>>>
> >>>>> I guess the underlying pattern, going along the lines of what
> >>>>> <mask_codefor>one_cmpl<mode>2<mask_name> uses, can be
> applied
> >>>>> elsewhere as well.
> >>>> That should be guarded with !TARGET_PREFER_AVX256, let's handle
> >>>> that in a separate patch.
> >>>
> >>> Sure, and as indicated there are more places where similar things
> >>> could be done.
> >>>
> >>>>> --- /dev/null
> >>>>> +++ b/gcc/testsuite/gcc.target/i386/avx512f-copysign.c
> >>>>> @@ -0,0 +1,32 @@
> >>>>> +/* { dg-do compile } */
> >>>>> +/* { dg-options "-mavx512f -mno-avx512vl -O2" } */
> >>>> Please explicitly add -mprefer-vector-width=512, our tester will
> >>>> also test unix{-m32 \-march=cascadelake,\ -march=cascadelake} which
> >>>> set the
> >>>> - mprefer-vector-width=256, -mprefer-vector-width=512 in dg-options
> >>>> can overwrite that.
> >>>
> >>> Oh, I see. Will do. And I expect I then also need to adjust the
> >>> newly added avx512f-dupv2di.c from the earlier patch. I guess I
> >>> could commit that option addition there as obvious?
> >> Still need to send out the patch, and commit as an obvious fix.
> >>>
> >>>> Others LGTM.
> >>>
> >>> May I take this as "okay with that change", or should I submit v4?
> >> Okay. no need for a v4 version.
> >>>
> > avx512f-copysign.c failed for -m32, we need to add -mfpmath=sse to dg-
> options.
> 
> Oh, of course. I will take care of this, but it may take me a couple of days, as I
> just came back from a week of vacation. One question though:
> Elsewhere such tests are simply suppressed for 32-bit. Personally I'd prefer
> going that route, but if you think adding -mfpmath=sse is indeed better, I'll
> follow your request.
Either is ok.
> 
> Jan