Re: [PATCH] x86-64: Define __memcmpeq in ld.so

Re: [PATCH] x86-64: Define __memcmpeq in ld.so

[Sunil Pandey]

On Mon, Feb 14, 2022 at 5:20 PM Noah Goldstein via Libc-alpha
<libc-alpha@sourceware.org> wrote:
>
> On Mon, Feb 14, 2022 at 7:50 AM H.J. Lu <hjl.tools@gmail.com> wrote:
> >
> > On Mon, Feb 14, 2022 at 1:18 AM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
> > >
> > > On Sun, Feb 13, 2022 at 8:46 PM H.J. Lu <hjl.tools@gmail.com> wrote:
> > > >
> > > > Define __memcmpeq in ld.so so that compiler can generate __memcmpeq call
> > > > when compiling for ld.so.
> > > > ---
> > > >  sysdeps/x86_64/multiarch/memcmpeq-sse2.S | 4 +++-
> > > >  1 file changed, 3 insertions(+), 1 deletion(-)
> > > >
> > > > diff --git a/sysdeps/x86_64/multiarch/memcmpeq-sse2.S b/sysdeps/x86_64/multiarch/memcmpeq-sse2.S
> > > > index b80a29d4b0..de7f5a7525 100644
> > > > --- a/sysdeps/x86_64/multiarch/memcmpeq-sse2.S
> > > > +++ b/sysdeps/x86_64/multiarch/memcmpeq-sse2.S
> > > > @@ -16,8 +16,10 @@
> > > >     License along with the GNU C Library; if not, see
> > > >     <https://www.gnu.org/licenses/>.  */
> > > >
> > > > -#ifndef memcmp
> > > > +#if IS_IN (libc)
> > > >  # define memcmp        __memcmpeq_sse2
> > > > +#else
> > > > +# define memcmp        __memcmpeq
> > > >  #endif
> > > >  #define USE_AS_MEMCMPEQ        1
> > > >  #include "memcmp-sse2.S"
> > >
> > > How can I test this patch?
> >
> > Please build this GCC branch:
> >
> > https://gitlab.com/x86-gcc/gcc/-/commits/users/hjl/memcmpeq/master
> >
> > and use it to build glibc with
> >
> > CC="gcc -fextra-libc-function=memcmpeq"
> >
> > It will call __memcmpeq when possible.
>
> LGTM.
> >
> > --
> > H.J.

I would like to backport this patch to release branches.
Any comments or objections?

--Sunil