[PATCH v2 1/2] x86: Move mem{p}{mov|cpy}_{chk_}erms to its own file

[Noah Goldstein]

On Wed, Jun 29, 2022 at 3:20 PM H.J. Lu <hjl.tools@gmail.com> wrote:
>
> On Wed, Jun 29, 2022 at 3:13 PM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
> >
> > The primary memmove_{impl}_unaligned_erms implementations don't
> > interact with this function. Putting them in same file both
> > wastes space and unnecessarily bloats a hot code section.
> > ---
> >  sysdeps/x86_64/multiarch/Makefile             |  1 +
> >  sysdeps/x86_64/multiarch/memmove-erms.S       | 53 +++++++++++++++++++
> >  .../multiarch/memmove-vec-unaligned-erms.S    | 50 -----------------
> >  3 files changed, 54 insertions(+), 50 deletions(-)
> >  create mode 100644 sysdeps/x86_64/multiarch/memmove-erms.S
> >
> > diff --git a/sysdeps/x86_64/multiarch/Makefile b/sysdeps/x86_64/multiarch/Makefile
> > index 666ee4d5d6..62a4d96fb8 100644
> > --- a/sysdeps/x86_64/multiarch/Makefile
> > +++ b/sysdeps/x86_64/multiarch/Makefile
> > @@ -18,6 +18,7 @@ sysdep_routines += \
> >    memmove-avx-unaligned-erms-rtm \
> >    memmove-avx512-no-vzeroupper \
> >    memmove-avx512-unaligned-erms \
> > +  memmove-erms \
> >    memmove-evex-unaligned-erms \
> >    memmove-sse2-unaligned-erms \
> >    memmove-ssse3 \
> > diff --git a/sysdeps/x86_64/multiarch/memmove-erms.S b/sysdeps/x86_64/multiarch/memmove-erms.S
> > new file mode 100644
> > index 0000000000..d98d21644b
> > --- /dev/null
> > +++ b/sysdeps/x86_64/multiarch/memmove-erms.S
> > @@ -0,0 +1,53 @@
>
> Need copyright notice.

Fixed in V3.
>
> > +#include <sysdep.h>
> > +
> > +#if defined USE_MULTIARCH && IS_IN (libc)
> > +       .text
> > +ENTRY (__mempcpy_chk_erms)
> > +       cmp     %RDX_LP, %RCX_LP
> > +       jb      HIDDEN_JUMPTARGET (__chk_fail)
> > +END (__mempcpy_chk_erms)
> > +
> > +/* Only used to measure performance of REP MOVSB.  */
> > +ENTRY (__mempcpy_erms)
> > +       mov     %RDI_LP, %RAX_LP
> > +       /* Skip zero length.  */
> > +       test    %RDX_LP, %RDX_LP
> > +       jz      2f
> > +       add     %RDX_LP, %RAX_LP
> > +       jmp     L(start_movsb)
> > +END (__mempcpy_erms)
> > +
> > +ENTRY (__memmove_chk_erms)
> > +       cmp     %RDX_LP, %RCX_LP
> > +       jb      HIDDEN_JUMPTARGET (__chk_fail)
> > +END (__memmove_chk_erms)
> > +
> > +ENTRY (__memmove_erms)
> > +       movq    %rdi, %rax
> > +       /* Skip zero length.  */
> > +       test    %RDX_LP, %RDX_LP
> > +       jz      2f
> > +L(start_movsb):
> > +       mov     %RDX_LP, %RCX_LP
> > +       cmp     %RSI_LP, %RDI_LP
> > +       jb      1f
> > +       /* Source == destination is less common.  */
> > +       je      2f
> > +       lea     (%rsi,%rcx), %RDX_LP
> > +       cmp     %RDX_LP, %RDI_LP
> > +       jb      L(movsb_backward)
> > +1:
> > +       rep movsb
> > +2:
> > +       ret
> > +L(movsb_backward):
> > +       leaq    -1(%rdi,%rcx), %rdi
> > +       leaq    -1(%rsi,%rcx), %rsi
> > +       std
> > +       rep movsb
> > +       cld
> > +       ret
> > +END (__memmove_erms)
> > +strong_alias (__memmove_erms, __memcpy_erms)
> > +strong_alias (__memmove_chk_erms, __memcpy_chk_erms)
> > +#endif
> > diff --git a/sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S b/sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S
> > index d1518b8bab..04747133b7 100644
> > --- a/sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S
> > +++ b/sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S
> > @@ -239,56 +239,6 @@ L(start):
> >  #endif
> >  #if defined USE_MULTIARCH && IS_IN (libc)
> >  END (MEMMOVE_SYMBOL (__memmove, unaligned))
> > -# if VEC_SIZE == 16
> > -ENTRY (__mempcpy_chk_erms)
> > -       cmp     %RDX_LP, %RCX_LP
> > -       jb      HIDDEN_JUMPTARGET (__chk_fail)
> > -END (__mempcpy_chk_erms)
> > -
> > -/* Only used to measure performance of REP MOVSB.  */
> > -ENTRY (__mempcpy_erms)
> > -       mov     %RDI_LP, %RAX_LP
> > -       /* Skip zero length.  */
> > -       test    %RDX_LP, %RDX_LP
> > -       jz      2f
> > -       add     %RDX_LP, %RAX_LP
> > -       jmp     L(start_movsb)
> > -END (__mempcpy_erms)
> > -
> > -ENTRY (__memmove_chk_erms)
> > -       cmp     %RDX_LP, %RCX_LP
> > -       jb      HIDDEN_JUMPTARGET (__chk_fail)
> > -END (__memmove_chk_erms)
> > -
> > -ENTRY (__memmove_erms)
> > -       movq    %rdi, %rax
> > -       /* Skip zero length.  */
> > -       test    %RDX_LP, %RDX_LP
> > -       jz      2f
> > -L(start_movsb):
> > -       mov     %RDX_LP, %RCX_LP
> > -       cmp     %RSI_LP, %RDI_LP
> > -       jb      1f
> > -       /* Source == destination is less common.  */
> > -       je      2f
> > -       lea     (%rsi,%rcx), %RDX_LP
> > -       cmp     %RDX_LP, %RDI_LP
> > -       jb      L(movsb_backward)
> > -1:
> > -       rep movsb
> > -2:
> > -       ret
> > -L(movsb_backward):
> > -       leaq    -1(%rdi,%rcx), %rdi
> > -       leaq    -1(%rsi,%rcx), %rsi
> > -       std
> > -       rep movsb
> > -       cld
> > -       ret
> > -END (__memmove_erms)
> > -strong_alias (__memmove_erms, __memcpy_erms)
> > -strong_alias (__memmove_chk_erms, __memcpy_chk_erms)
> > -# endif
> >
> >  # ifdef SHARED
> >  ENTRY (MEMMOVE_CHK_SYMBOL (__mempcpy_chk, unaligned_erms))
> > --
> > 2.34.1
> >
>
>
> --
> H.J.