[PATCH] powerpc: Improve memcmp performance for POWER8

[Tulio Magno Quites Machado Filho]

Rajalakshmi Srinivasaraghavan <raji@linux.vnet.ibm.com> writes:

> diff --git a/sysdeps/powerpc/powerpc64/multiarch/memcmp-power8.S b/sysdeps/powerpc/powerpc64/multiarch/memcmp-power8.S
> new file mode 100644
> index 0000000..a568be4
> --- /dev/null
> +++ b/sysdeps/powerpc/powerpc64/multiarch/memcmp-power8.S
> @@ -0,0 +1,42 @@
> +/* Optimized memcmp implementation for PowerPC64/POWER8.
> +   Copyright (C) 2017 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#include <sysdep.h>
> +
> +#undef EALIGN
> +#define EALIGN(name, alignt, words)				\
> +  .section ".text";						\
> +  ENTRY_2(__memcmp_power8)					\
> +  .align ALIGNARG(alignt);					\
> +  EALIGN_W_##words;						\
> +  BODY_LABEL(__memcmp_power8):					\
> +  cfi_startproc;						\
> +  LOCALENTRY(__memcmp_power8)
> +
> +#undef END
> +#define END(name)						\
> +  cfi_endproc;							\
> +  TRACEBACK(__memcmp_power8)					\
> +  END_2(__memcmp_power8)
> +
> +#undef libc_hidden_builtin_def
> +#define libc_hidden_builtin_def(name)
> +#undef weak_alias
> +#define weak_alias(name,alias)
> +
> +#include <sysdeps/powerpc/powerpc64/power8/memcmp.S>

The patch LGTM in overall, except for this file.
I think it should be implemented as in commit b6a66222096c.

LGTM with that change.

-- 
Tulio Magno