[PATCH] x86-64: Add memcmp/wmemcmp optimized with AVX2

[Florian Weimer]

On 06/02/2017 12:29 AM, H.J. Lu wrote:
> +	/* Use overlapping loads and bswap to avoid branches.  */

This comment is outdated.  I think the commit message needs a bit of
rewording, too.

Have you benchmarked this version against the original one?

> +	HAS_ARCH_FEATURE (Prefer_No_VZEROUPPER)
> +	jnz	1f
> +	HAS_ARCH_FEATURE (AVX2_Usable)
> +	jz	1f
> +	HAS_CPU_FEATURE (MOVBE)
> +	jz	1f
> +	HAS_ARCH_FEATURE (AVX_Fast_Unaligned_Load)
> +	jz	1f
> +	leaq	__memcmp_avx2_movbe(%rip), %rax
> +	ret

Do the IFUNC resolvers have to check for the BMI feature, too?

Thanks,
Florian