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

[H.J. Lu]

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.

> +#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.