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Re: [PATCH v2] x86-64: AVX2 Optimize strcat/strcpy/stpcpy routines
On Thu, 2018-12-06 at 10:05 +0100, Florian Weimer wrote:
> * leonardo sandoval gonzalez:
>
> > Optimize strcat/strcpy/stpcpy routines and its max-offset versions
> > with
> > AVX2. It uses vector comparison as much as possible. Observed
> > speedups
> > compared to sse2_unaligned:
>
> Shouldn't we keep the stpcpy specialization from the original
> patch? Or
> at least call the new strcpy from a wrapper function? The generic
> function uses strlen plus memcpy, which I believe is slower than
> calling
> strcpy and recomputing the return value.
benchmarks numbers between old and new are basically the same, so I
rather stick with this version. The latter applies also so str?cat.
>
> How does this new strcpy compare against the old one for short
> strings?
strcpy did not change between versions, so we have the same numbers.
strcpy code density was decrease considerably on this version because
all preprocessor macros for non-strcpy functions were removed but
strcpy code remains the same.
Leo
>
> Thanks,
> Florian