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Re: [PATCH] Don't use SSE4_2 instructions on Intel Silvermont Micro Architecture.
- From: Dmitrieva Liubov <liubov dot dmitrieva at gmail dot com>
- To: "Carlos O'Donell" <carlos at redhat dot com>
- Cc: Ondřej Bílka <neleai at seznam dot cz>, "H.J. Lu" <hjl dot tools at gmail dot com>, GNU C Library <libc-alpha at sourceware dot org>
- Date: Thu, 20 Jun 2013 17:10:13 +0400
- Subject: Re: [PATCH] Don't use SSE4_2 instructions on Intel Silvermont Micro Architecture.
- References: <CAHjhQ93=uegeZg9iTqoJ+PFuUrvn8e2mA8tZ96Jy4CaV6aPbWg at mail dot gmail dot com> <20130617163729 dot GA15981 at domone dot kolej dot mff dot cuni dot cz> <CAHjhQ93zmP525hqW-2RnHBREc_949XLnm7sE-CSv3Nj8PQgUig at mail dot gmail dot com> <CAMe9rOqT31AFq1S3V0Krh2CZnHu=FiyXqhg840fimRtfU4_hXQ at mail dot gmail dot com> <20130618064910 dot GA19972 at domone dot kolej dot mff dot cuni dot cz> <CAHjhQ90Fc0kdZfQrUwLwpKbz2va4X9rzf1EkGD-s-RH-iF7guQ at mail dot gmail dot com> <CAHjhQ92qfjdKZthqAwxCVuCnLqDr2stdEbQpne5rKhzJPeN_cQ at mail dot gmail dot com> <51C23583 dot 1070307 at redhat dot com>
What benchmarks do you mean? string/test-str** unit tests?
--
Liubov Dmitrieva
On Thu, Jun 20, 2013 at 2:49 AM, Carlos O'Donell <carlos@redhat.com> wrote:
> On 06/19/2013 03:44 PM, Dmitrieva Liubov wrote:
>> My patch is ready. Ok to commit?
>>
>> Change Log.
>>
>> 2013-06-19 Liubov Dmitrieva <liubov.dmitrieva@intel.com>
>>
>> * sysdeps/x86_64/multiarch/init-arch.c (__init_cpu_features):
>> Set bit_Slow_SSE4_2 for Intel Silvermont architecture.
>> Set bit_Prefer_PMINUB_for_stringop for Intel Silvermont.
>> * sysdeps/x86_64/multiarch/init-arch.h: Define
>> bit_Slow_SSE4_2 and index_Slow_SSE4_2.
>> Define index_Prefer_PMINUB_for_stringop which was undefined.
>> * sysdeps/x86_64/multiarch/strchr.S: Use SSE2 version if
>> bit_Slow_SSE4_2 is on.
>> * sysdeps/x86_64/multiarch/strrchr.S: Use SSE2 version if
>> bit_Slow_SSE4_2 is on.
>> * sysdeps/x86_64/multiarch/strcmp.S: Use SSSE3 or SSE2 version if
>> bit_Slow_SSE4_2 is on.
>
> We have string operations in the glibc microbenchmark.
>
> Can you show that this patch makes a performance improvement on Silvermont?
>
> What are the string op numbers before and after your patch?
>
> Cheers,
> Carlos.
>