powerpc: Remove power8 strcasestr optimization

Similar to strstr (1e9a550ba4), power8 strcasestr does not show much
improvement compared to the generic implementation.  The geomean
on bench-strcasestr shows:

            __strcasestr_power8  __strcasestr_ppc
  power10                  1159              1120
  power9                   1640              1469
  power8                   1787              1904

The strcasestr uses the same 'trick' as power7 strstr to detect
potential quadradic behavior, which only adds overheads for input
that trigger quadradic behavior and it is really a hack.

Checked on powerpc64le-linux-gnu.
Reviewed-by: DJ Delorie <dj@redhat.com>

5 files changed, 1 insertions, 115 deletions

diff --git a/sysdeps/powerpc/powerpc64/multiarch/Makefile b/sysdeps/powerpc/powerpc64/multiarch/Makefile
index 5624249fe2..a38ff46448 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/Makefile
+++ b/sysdeps/powerpc/powerpc64/multiarch/Makefile
@@ -26,7 +26,7 @@ sysdep_routines += memcpy-power8-cached memcpy-power7 memcpy-a2 memcpy-power6 \
 		   memmove-power7 memmove-ppc64 wordcopy-ppc64 \
 		   strncpy-power8 \
 		   strspn-power8 strspn-ppc64 strcspn-power8 strcspn-ppc64 \
-		   strlen-power8 strcasestr-power8 strcasestr-ppc64 \
+		   strlen-power8 \
 		   strcasecmp-ppc64 strcasecmp-power8 strncase-ppc64 \
 		   strncase-power8
 
diff --git a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
index e3e6f5fd10..30fd89e109 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
@@ -432,14 +432,5 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
              IFUNC_IMPL_ADD (array, i, strcspn, 1,
                              __strcspn_ppc))
 
-  /* Support sysdeps/powerpc/powerpc64/multiarch/strcasestr.c.  */
-  IFUNC_IMPL (i, name, strcasestr,
-	      IFUNC_IMPL_ADD (array, i, strcasestr,
-			      hwcap2 & PPC_FEATURE2_ARCH_2_07
-			      && hwcap & PPC_FEATURE_HAS_ALTIVEC,
-			      __strcasestr_power8)
-             IFUNC_IMPL_ADD (array, i, strcasestr, 1,
-                             __strcasestr_ppc))
-
   return 0;
 }
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strcasestr-power8.S b/sysdeps/powerpc/powerpc64/multiarch/strcasestr-power8.S
deleted file mode 100644
index 4670d03aaa..0000000000
--- a/sysdeps/powerpc/powerpc64/multiarch/strcasestr-power8.S
+++ /dev/null
@@ -1,33 +0,0 @@
-/* Optimized strcasestr implementation for POWER8.
-   Copyright (C) 2016-2024 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
-   <https://www.gnu.org/licenses/>.  */
-
-#define STRCASESTR __strcasestr_power8
-
-#undef libc_hidden_builtin_def
-#define libc_hidden_builtin_def(name)
-
-/* The following definitions are used in strcasestr optimization.  */
-
-/* strlen is used to calculate len of r4.  */
-#define STRLEN __strlen_power8
-/* strnlen is used to check if len of r3 is more than r4.  */
-#define STRNLEN __strnlen_power8
-/* strchr is used to check if first char of r4 is present in r3.  */
-#define STRCHR __strchr_power8
-
-#include <sysdeps/powerpc/powerpc64/power8/strcasestr.S>
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strcasestr-ppc64.c b/sysdeps/powerpc/powerpc64/multiarch/strcasestr-ppc64.c
deleted file mode 100644
index 073d8beaff..0000000000
--- a/sysdeps/powerpc/powerpc64/multiarch/strcasestr-ppc64.c
+++ /dev/null
@@ -1,34 +0,0 @@
-/* PowerPC64 default implementation of strcasestr.
-   Copyright (C) 2016-2024 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
-   <https://www.gnu.org/licenses/>.  */
-
-#include <string.h>
-
-#define STRCASESTR  __strcasestr_ppc
-#if IS_IN (libc) && defined(SHARED)
-# undef libc_hidden_builtin_def
-# define libc_hidden_builtin_def(name) \
-  __hidden_ver1(__strcasestr_ppc, __GI_strcasestr, __strcasestr_ppc);
-#endif
-
-
-#undef weak_alias
-#define weak_alias(a,b)
-
-extern __typeof (strcasestr) __strcasestr_ppc attribute_hidden;
-
-#include <string/strcasestr.c>
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strcasestr.c b/sysdeps/powerpc/powerpc64/multiarch/strcasestr.c
deleted file mode 100644
index d2bda3f487..0000000000
--- a/sysdeps/powerpc/powerpc64/multiarch/strcasestr.c
+++ /dev/null
@@ -1,38 +0,0 @@
-/* Multiple versions of strcasestr.
-   Copyright (C) 2016-2024 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
-   <https://www.gnu.org/licenses/>.  */
-
-#if IS_IN (libc)
-# include <string.h>
-# include <shlib-compat.h>
-# include "init-arch.h"
-
-extern __typeof (__strcasestr) __strcasestr_ppc attribute_hidden;
-extern __typeof (__strcasestr) __strcasestr_power8 attribute_hidden;
-
-/* Avoid DWARF definition DIE on ifunc symbol so that GDB can handle
-   ifunc symbol properly.  */
-libc_ifunc (__strcasestr,
-		(hwcap2 & PPC_FEATURE2_ARCH_2_07
-		 && hwcap & PPC_FEATURE_HAS_ALTIVEC)
-		? __strcasestr_power8
-		: __strcasestr_ppc);
-
-weak_alias (__strcasestr, strcasestr)
-#else
-#include <string/strcasestr.c>
-#endif