[FFmpeg-devel] [PATCH 2/3] swscale/x86/yuv2yuvX: Add yuv2yuvX avx512

[James Almer]

On 7/14/2023 11:57 AM, Kieran Kunhya wrote:
> On Fri, 14 Jul 2023 at 14:03, James Almer <jamrial at gmail.com> wrote:
> 
>> On 7/14/2023 9:59 AM, Kieran Kunhya wrote:
>>>> +#if ARCH_X86_64 && HAVE_AVX512_EXTERNAL
>>>> +        if (EXTERNAL_AVX512(cpu_flags))
>>>> +            c->yuv2planeX = yuv2yuvX_avx512;
>>>>    #endif
>>>>
>>>
>>>    You want EXTERNAL_AVX512ICL here.
>>
>> vpermt2q with zmm registers is avx512f and not any of the extensions, so
>> that check is fine.
>>
> 
> We still support Skylake and we don't want downclocking on that platform.
> At least that was my understanding of the intention of AVX512 vs AVX512ICL.
> It appears I'm the only one following this convention though.

Ah, no opinion in that regard. I was following the use of the checks in 
the strict technical sense of instruction availability.