Re: [PATCH v4 2/2] util: add util function buffer_zero_avx512()

[Richard Henderson]

On 2/29/20 4:34 AM, Robert Hoo wrote:
> And intialize buffer_is_zero() with it, when Intel AVX512F is
> available on host.
> 
> This function utilizes Intel AVX512 fundamental instructions which
> is faster than its implementation with AVX2 (in my unit test, with
> 4K buffer, on CascadeLake SP, ~36% faster, buffer_zero_avx512() V.S.
> buffer_zero_avx2()).
> 
> Signed-off-by: Robert Hoo <address@hidden>
> ---
>  include/qemu/cpuid.h |  3 +++
>  util/bufferiszero.c  | 74 
> +++++++++++++++++++++++++++++++++++++++++++++-------
>  2 files changed, 67 insertions(+), 10 deletions(-)

Reviewed-by: Richard Henderson <address@hidden>


r~