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Re: [PATCH] Don't use SSE4_2 instructions on Intel Silvermont Micro Architecture.


On Mon, Jun 17, 2013 at 10:56 AM, Dmitrieva Liubov
<liubov.dmitrieva@gmail.com> wrote:
> I checked that functions.
> In case of strspn/strcspn/strpbrk to switch SSE4_2 off is bad because
> there are no optimized sse2 versions to call instead.
> Default versions are not sse there.
>
> So, it seems we need to create a new flag for Silvermont like
> "slowPcmpistri" and fix switches in functions where optimized sse2
> exist.
>
> Or implement optimized sse2 strspn/strcspn/strpbrk and switch SSE4_2 completely.
>

We can add bit_Prefer_SSE2_for_stringop.  When it is set, we
will use SSE2 version if it is available.  Otherwise, we use
SSE4_2 version if it is available.


H.J.


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