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Re: [PATCH] Rename __memcmp_sse4_2 to __memcmp_sse4_1.
- From: Matt Turner <mattst88 at gmail dot com>
- To: "H.J. Lu" <hjl dot tools at gmail dot com>
- Cc: Andreas Jaeger <aj at suse dot com>, GNU C Library <libc-alpha at sourceware dot org>, Liubov Dmitrieva <liubov dot dmitrieva at gmail dot com>
- Date: Wed, 10 Jul 2013 10:41:51 -0700
- Subject: Re: [PATCH] Rename __memcmp_sse4_2 to __memcmp_sse4_1.
- References: <CAMe9rOreowCOEH+6zRaRNk_p9sYe3T2bhwPRbKpybW9cO0BhJA at mail dot gmail dot com> <1373419029-19125-1-git-send-email-mattst88 at gmail dot com> <51DCE51F dot 7000001 at suse dot com> <CAMe9rOqb3_DnhSh0jPh9=suJo5c+WjegxfDh1+1go6pY+7+PLA at mail dot gmail dot com>
On Wed, Jul 10, 2013 at 8:30 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Tue, Jul 9, 2013 at 9:37 PM, Andreas Jaeger <aj@suse.com> wrote:
>> On 07/10/2013 03:17 AM, Matt Turner wrote:
>>> It uses SSE 4.1 instructions (ptest) but no SSE 4.2 instructions.
>>
>> There are two parts to this: It should only run on cpus with those
>> instructions but we also need to ensure that it gives a better
>> performance on such cpus. HJ, Matt, please do run performance tests on a
>> variety of affected cpus to show that this change really helps in all cases,
>>
>> Andreas
>
> Only Penryn has SSE4.1 without SSE4.2. Liubov, can
> you compare performance of memcmp-sse4.S vs
> memcmp-ssse3.S on Penryn?
Is it also the case that this path would now be used on Silvermont?