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

[Jan Beulich <jbeulich@suse.com>]

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.

Jan