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Re: PATCH: 32bit memcmp/strcmp/strncmp optimized for SSSE3/SSS4.2
- From: "H.J. Lu" <hjl dot tools at gmail dot com>
- To: Ulrich Drepper <drepper at redhat dot com>
- Cc: libc-alpha at sourceware dot org
- Date: Mon, 15 Feb 2010 18:08:32 -0800
- Subject: Re: PATCH: 32bit memcmp/strcmp/strncmp optimized for SSSE3/SSS4.2
- References: <20100213000156.GA17503@lucon.org> <4B79B7A2.60405@redhat.com>
On Mon, Feb 15, 2010 at 1:07 PM, Ulrich Drepper <drepper@redhat.com> wrote:
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> On 02/12/2010 04:01 PM, H.J. Lu wrote:
>> Here is a patch to provide 32bit memcmp/strcmp/strncmp optimized for
>> SSSE3/SSS4.2. ?It can improve memcmp by up to 3X, strcmp by up
>> to 7X, strncmp by up to 5X.
>
> I added the code but had to fix a lot of bugs in it. ?Take a look at the
> changes. ?You didn't handle unwind info correctly.
I will update my version and verify unwind info. Then I will
compare it against glibc.
> Another bug: at the end of strcmp-sse4.S you had a conditional jump
> without anything following it. ?From what I can see the last test isn't
> necessary. ?Please confirm.
>
That is correct.
Thanks.
--
H.J.