Re: [PATCH] Fast catenation for Power7.

[Adhemerval Zanella <azanella at linux dot vnet dot ibm dot com>]

Hi Vidya,

Patch looks ok in general, some comments below


On 06-06-2014 11:55, vidya@linux.vnet.ibm.com wrote:
> From: Vidya Ranganathan <vidya@linux.vnet.ibm.com>
>
> An IFUNC version for POWER7 to call __strlen_power7/__strcpy_power7 following
> logic at glibc-git/sysdeps/powerpc/strcat.c has been created. __strlen_power7
> and __strcpy_power7 performs aligned memory access and improves performance
> significantly.

For future patch it is usual to describe in which platform you have tested it.

>
> Change log:
>         * string/strcat.c: Using macro to redefine symbol name.
>         * sysdeps/powerpc/strcat.c: Using macro to redefine symbol name.

Usually for such entry, that address macros and defines, it is usual to put the symbol
between '[' and ']', as:

	* sysdeps/powerpc/strcat.c [STRCAT]: Using macro to redefine symbol
	name.

>         * sysdeps/powerpc/powerpc64/multiarch/Makefile: Add strcat multiarch
> 	optimizations.
>         * sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c:
>         (__libc_ifunc_impl_list): Likewise.
>         * sysdeps/powerpc/powerpc64/multiarch/strcat.c: New file:
>         multiarch strcat for PPC64.
>         * sysdeps/powerpc/powerpc64/multiarch/strcat-ppc64.c: New file
>         * sysdeps/powerpc/powerpc64/multiarch/strcat-power7.c: New file
>
> Signed-off-by: Vidya Ranganathan <vidya@linux.vnet.ibm.com>
> ---
>  string/strcat.c                                    |  7 +++--
>  sysdeps/powerpc/powerpc64/multiarch/Makefile       |  2 +-
>  .../powerpc/powerpc64/multiarch/ifunc-impl-list.c  |  8 ++++++
>  .../powerpc/powerpc64/multiarch/strcat-power7.c    | 28 +++++++++++++++++++
>  sysdeps/powerpc/powerpc64/multiarch/strcat-ppc64.c | 29 ++++++++++++++++++++
>  sysdeps/powerpc/powerpc64/multiarch/strcat.c       | 31 ++++++++++++++++++++++
>  sysdeps/powerpc/strcat.c                           |  9 ++++---
>  7 files changed, 108 insertions(+), 6 deletions(-)
>  create mode 100644 sysdeps/powerpc/powerpc64/multiarch/strcat-power7.c
>  create mode 100644 sysdeps/powerpc/powerpc64/multiarch/strcat-ppc64.c
>  create mode 100644 sysdeps/powerpc/powerpc64/multiarch/strcat.c
>
> diff --git a/string/strcat.c b/string/strcat.c
> index 2cbe8b3..14d311c 100644
> --- a/string/strcat.c
> +++ b/string/strcat.c
> @@ -17,11 +17,14 @@
>
>  #include <string.h>
>
> -#undef strcat
> +#ifndef STRCAT
> +# undef strcat
> +# define STRCAT  strcat
> +#endif
>
>  /* Append SRC on the end of DEST.  */
>  char *
> -strcat (char *dest, const char *src)
> +STRCAT (char *dest, const char *src)
>  {
>    char *s1 = dest;
>    const char *s2 = src;

I see the patch does not require this modification, since it uses powerpc one version
at sysdeps/powerpc.  Please remove this modification.

> diff --git a/sysdeps/powerpc/powerpc64/multiarch/Makefile b/sysdeps/powerpc/powerpc64/multiarch/Makefile
> index 35020a7..e5670b1 100644
> --- a/sysdeps/powerpc/powerpc64/multiarch/Makefile
> +++ b/sysdeps/powerpc/powerpc64/multiarch/Makefile
> @@ -17,7 +17,7 @@ sysdep_routines += memcpy-power7 memcpy-a2 memcpy-power6 memcpy-cell \
>  		   strrchr-power7 strrchr-ppc64 strncat-power7 strncat-ppc64 \
>  		   strspn-power7 strspn-ppc64 strcspn-power7 strcspn-ppc64 \
>  		   strpbrk-power7 strpbrk-ppc64 strncpy-power7 strncpy-ppc64 \
> -		   stpncpy-power7 stpncpy-ppc64
> +		   stpncpy-power7 stpncpy-ppc64 strcat-power7 strcat-ppc64
>
>  CFLAGS-strncase-power7.c += -mcpu=power7 -funroll-loops
>  CFLAGS-strncase_l-power7.c += -mcpu=power7 -funroll-loops
> diff --git a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
> index d8578fb..747180a 100644
> --- a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
> +++ b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
> @@ -294,5 +294,13 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
>  	      IFUNC_IMPL_ADD (array, i, stpncpy, 1,
>  			     __stpncpy_ppc))
>
> +  /* Support sysdeps/powerpc/powerpc64/multiarch/strcat.c.  */
> +  IFUNC_IMPL (i, name, strcat,
> +	      IFUNC_IMPL_ADD (array, i, strcat,
> +			      hwcap & PPC_FEATURE_HAS_VSX,
> +			      __strcat_power7)
> +	      IFUNC_IMPL_ADD (array, i, strcat, 1,
> +			     __strcat_ppc))
> +
>    return i;
>  }
> diff --git a/sysdeps/powerpc/powerpc64/multiarch/strcat-power7.c b/sysdeps/powerpc/powerpc64/multiarch/strcat-power7.c
> new file mode 100644
> index 0000000..ba9a460
> --- /dev/null
> +++ b/sysdeps/powerpc/powerpc64/multiarch/strcat-power7.c
> @@ -0,0 +1,28 @@
> +/* Copyright (C) 2014 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 <string.h>
> +
> +#define STRCAT __strcat_power7
> +
> +#undef libc_hidden_def
> +#define libc_hidden_def(name)
> +
> +#define strcpy __strcpy_power7
> +#define strlen __strlen_power7
> +
> +#include <sysdeps/powerpc/strcat.c>
> diff --git a/sysdeps/powerpc/powerpc64/multiarch/strcat-ppc64.c b/sysdeps/powerpc/powerpc64/multiarch/strcat-ppc64.c
> new file mode 100644
> index 0000000..1245764
> --- /dev/null
> +++ b/sysdeps/powerpc/powerpc64/multiarch/strcat-ppc64.c
> @@ -0,0 +1,29 @@
> +/* Copyright (C) 2014 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 <string.h>
> +
> +#define STRCAT __strcat_ppc
> +#ifdef SHARED
> +# undef libc_hidden_builtin_def
> +# define libc_hidden_builtin_def(name) \
> +  __hidden_ver1 (__strcat_ppc, __GI_strcat, __strcat_ppc);
> +#endif
> +
> +extern __typeof (strcat) __strcat_ppc attribute_hidden;
> +
> +#include <sysdeps/powerpc/strcat.c>
> diff --git a/sysdeps/powerpc/powerpc64/multiarch/strcat.c b/sysdeps/powerpc/powerpc64/multiarch/strcat.c
> new file mode 100644
> index 0000000..847a62d
> --- /dev/null
> +++ b/sysdeps/powerpc/powerpc64/multiarch/strcat.c
> @@ -0,0 +1,31 @@
> +/* Multiple versions of strcat. PowerPC64 version.
> +   Copyright (C) 2014 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/>.  */
> +
> +#ifndef NOT_IN_libc
> +# include <string.h>
> +# include <shlib-compat.h>
> +# include "init-arch.h"
> +
> +extern __typeof (strcat) __strcat_ppc attribute_hidden;
> +extern __typeof (strcat) __strcat_power7 attribute_hidden;
> +
> +libc_ifunc (strcat,
> +            (hwcap & PPC_FEATURE_HAS_VSX)
> +            ? __strcat_power7
> +            : __strcat_ppc);
> +#endif
> diff --git a/sysdeps/powerpc/strcat.c b/sysdeps/powerpc/strcat.c
> index 06ceca7..4ff37ea 100644
> --- a/sysdeps/powerpc/strcat.c
> +++ b/sysdeps/powerpc/strcat.c
> @@ -18,13 +18,16 @@
>
>  #include <string.h>
>
> -#undef strcat
> +#ifndef STRCAT
> +# undef strcat
> +# define STRCAT  strcat
> +#endif
>
>  /* Append SRC on the end of DEST.  */
>  char *
> -strcat (char *dest, const char *src)
> +STRCAT(char *dest, const char *src)
>  {
>    strcpy (dest + strlen (dest), src);
>    return dest;
>  }
> -libc_hidden_builtin_def (strcat)
> +libc_hidden_builtin_def (STRCAT)