[PATCH v1 3/6] x86: Remove mem{move|cpy}-ssse3

[Noah Goldstein]

On Mon, Mar 28, 2022 at 9:51 PM Mayshao-oc <Mayshao-oc@zhaoxin.com> wrote:
>
> On Mon, Mar 28, 2022 at  9:07 PM H.J. Lu <hjl.tools@gmail.com> wrote:
>
>
> > On Mon, Mar 28, 2022 at 1:10 AM Mayshao-oc <Mayshao-oc@zhaoxin.com> wrote:
> > >
> > > On Fri, Mar 25, 2022 at 6:36 PM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
> > >
> > > > With SSE2, SSE4.1, AVX2, and EVEX versions very few targets prefer
> > > > SSSE3. As a result its no longer with the code size cost.
> > > > ---
> > > > sysdeps/x86_64/multiarch/Makefile          |    2 -
> > > > sysdeps/x86_64/multiarch/ifunc-impl-list.c |   15 -
> > > > sysdeps/x86_64/multiarch/ifunc-memmove.h   |   18 +-
> > > > sysdeps/x86_64/multiarch/memcpy-ssse3.S    | 3151 --------------------
> > > > sysdeps/x86_64/multiarch/memmove-ssse3.S   |    4 -
> > > > 5 files changed, 7 insertions(+), 3183 deletions(-)
> > > > delete mode 100644 sysdeps/x86_64/multiarch/memcpy-ssse3.S
> > > > delete mode 100644 sysdeps/x86_64/multiarch/memmove-ssse3.S
> > >
> > > > On some platforms, such as Zhaoxin, the memcpy performance of SSSE3
> > > is better than that of AVX2, and the current computer system has sufficient
> > > disk capacity and memory capacity.
> >
> > How does the SSSE3 version compare against the SSE2 version?
>
> On some Zhaoxin processors, the overall performance of SSSE3 is about
> 10% higher than that of SSE2.
>
>
> Best Regards,
> May Shao

Any chance you can post the result from running `bench-memset` or some
equivalent benchmark? Curious where the regressions are. Ideally we would
fix the SSE2 version so its optimal.
>
> > > It is strongly recommended to keep the SSSE3 version.
> > >
> >
> >
> > --
> > H.J.