Re: [PATCH v3 2/2] util: add util function buffer_zero_avx512()

[Richard Henderson]

On 2/27/20 6:24 PM, Robert Hoo wrote:
>              if ((bv & 6) == 6 && (b & bit_AVX2)) {
>                  cache |= CACHE_AVX2;
>              }
> +            if ((bv & 6) == 6 && (b & bit_AVX512F)) {
> +                cache |= CACHE_AVX512F;
> +            }

Oh, one more thing I missed -- we have to ensure that the 512-bit registers are
enabled.  I believe the minimum is bits 6 and 7 enabled (ZMM_Hi256, Hi16_ZMM),
since we don't know that the compiler won't allocate registers from zmm16-31.

So: (bv & 0xc6) == 0xc6.

You'd be right that some comments would be helpful on these lines.  :-P

With that,
Reviewed-by: Richard Henderson <address@hidden>


r~