[COMMITED] faster memcpy on x64.

[Liubov Dmitrieva]

And also it is look very confusing that we don't have same unaligned
version for mempcpy and still use ssse3 version.
It is very easy to support mempcpy in memcpy-sse2-unaligned.S file.

--
Liubov

On Thu, Aug 29, 2013 at 6:45 PM, Liubov Dmitrieva
<liubov.dmitrieva@gmail.com> wrote:
> It looks like there is a confusion in the merged patch, I think it is
> supposed to be (at least looks more logical) the different flag, you
> only need to turn it on for Buldozer or whatever AMD machines the
> version is also good.
>
> diff --git a/sysdeps/x86_64/multiarch/memcpy.S
> b/sysdeps/x86_64/multiarch/memcpy.S
> index a1e5031..f6a44d2 100644
> --- a/sysdeps/x86_64/multiarch/memcpy.S
> +++ b/sysdeps/x86_64/multiarch/memcpy.S
> @@ -33,8 +33,8 @@ ENTRY(__new_memcpy)
>         jne     1f
>         call    __init_cpu_features
>  1:     leaq    __memcpy_sse2(%rip), %rax
> -       testl   $bit_Slow_BSF,
> __cpu_features+FEATURE_OFFSET+index_Slow_BSF(%rip)
> -       jnz     2f
> +       testl   $bit_Fast_Unaligned_Load,
> __cpu_features+FEATURE_OFFSET+index_Fast_Unaligned_Load(%rip)
> +       jz      2f
>         leaq    __memcpy_sse2_unaligned(%rip), %rax
>         ret
>  2:     testl   $bit_SSSE3, __cpu_features+CPUID_OFFSET+index_SSSE3(%rip)
>
>
> And you forgot to remove the version which is never used now as memcpy
> from the ifunc-impl-list:
>
>
> diff --git a/sysdeps/x86_64/multiarch/ifunc-impl-list.c
> b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
> index 28d3579..d6a7f4f 100644
> --- a/sysdeps/x86_64/multiarch/ifunc-impl-list.c
> +++ b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
> @@ -224,8 +224,6 @@ __libc_ifunc_impl_list (const char *name, struct
> libc_ifunc_impl *array,
>
>    /* Support sysdeps/x86_64/multiarch/memcpy.S.  */
>    IFUNC_IMPL (i, name, memcpy,
> -             IFUNC_IMPL_ADD (array, i, memcpy, HAS_SSSE3,
> -                             __memcpy_ssse3_back)
>               IFUNC_IMPL_ADD (array, i, memcpy, HAS_SSSE3, __memcpy_ssse3)
>               IFUNC_IMPL_ADD (array, i, memcpy, 1, __memcpy_sse2_unaligned)
>               IFUNC_IMPL_ADD (array, i, memcpy, 1, __memcpy_sse2))
>
>
> --
> Liubov
>
> On Mon, May 20, 2013 at 12:14 PM, Ondřej Bílka <neleai@seznam.cz> wrote:
>> Commited.