[COMMITED] faster memcpy on x64.

[Ondřej Bílka]

On Thu, Aug 29, 2013 at 06:54:21PM +0400, Liubov Dmitrieva wrote:
> 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.
>

Thats added in
http://www.sourceware.org/ml/libc-alpha/2013-08/msg00280.html


> --
> 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.

-- 

Insert coin for new game