[PATCH] x86_64: Remove 9 REX bytes from memchr.S

[H.J. Lu]

On Wed, May 24, 2017 at 7:55 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Sat, May 20, 2017 at 12:58 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
>> On Sat, May 20, 2017 at 7:59 AM, Zack Weinberg <zackw@panix.com> wrote:
>>> On Sat, May 20, 2017 at 10:50 AM, H.J. Lu <hongjiu.lu@intel.com> wrote:
>>>> There is no need to use 64-bit registers when only the lower 32 bits
>>>> are non-zero.
>>>
>>> This code is used generically for x86-64, not for a specific
>>> microarchitecture. Is there a reason why this will never cause partial
>>> register stalls, now or in the future?
>>
>> By x86-64 specification, 32-bit destination registers in these instructions
>> are zero-extended to 64 bits and there is register stall at all.
>>
>
> Here is the updated patch with one more REX byte removed.
>
> Any other comments?
>

This is the patch I am checking in.

-- 
H.J.
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