[PATCH RFC] Imporve 64bit memset performance for Haswell CPU with AVX2 instruction

[H.J. Lu]

On Sun, Apr 27, 2014 at 4:45 AM, Ling Ma <ling.ma.program@gmail.com> wrote:
> Any comments ?
>
> 2014-04-21 12:52 GMT+08:00, ling.ma.program@gmail.com
> <ling.ma.program@gmail.com>:
>> From: Ling Ma <ling.ml@alibaba-inc.com>
>>
>> In this patch we take advantage of HSW memory bandwidth, manage to
>> reduce miss branch prediction by avoiding using branch instructions and
>> force destination to be aligned with avx & avx2 instruction.
>>
>> The CPU2006 403.gcc benchmark indicates this patch improves performance
>> from 23.7% to 57%.
>>
>> This version is based on latest ChangeLog, Appreciate your comments.
>> ---
>>  ChangeLog                              |   9 ++
>>  sysdeps/x86_64/multiarch/Makefile      |   4 +-
>>  sysdeps/x86_64/multiarch/memset-avx2.S | 198
>> +++++++++++++++++++++++++++++++++
>>  sysdeps/x86_64/multiarch/memset.S      |  58 ++++++++++
>>  sysdeps/x86_64/multiarch/memset_chk.S  |  43 +++++++
>>  5 files changed, 311 insertions(+), 1 deletion(-)
>>  create mode 100644 sysdeps/x86_64/multiarch/memset-avx2.S
>>  create mode 100644 sysdeps/x86_64/multiarch/memset.S
>>  create mode 100644 sysdeps/x86_64/multiarch/memset_chk.S
>>
>> diff --git a/ChangeLog b/ChangeLog
>> index e09fdc6..9bb48ab 100644
>> --- a/ChangeLog
>> +++ b/ChangeLog
>> @@ -1,3 +1,12 @@
>> +2014-04-21  Ling Ma  <ling.ml@alibaba-inc.com>
>> +
>> +     * sysdeps/x86_64/multiarch/Makefile: Add memset-avx2
>> +     * sysdeps/x86_64/multiarch/memset-avx2.S: New file for AVX2 memset
>> +     * sysdeps/x86_64/multiarch/memset.S: New file for multiple memset
>> +     versions
>> +     * sysdeps/x86_64/multiarch/memset_chk.S: New file for multiple memset_chk
>> +     versions
>> +

I didn't see the original patch in the libc-alpha mailing list archive at

https://sourceware.org/ml/libc-alpha/

Can you resubmit it and make sure that it shows up in the libc-alpha
mailing list archive?

Thanks.

-- 
H.J.