powerpc: Optimize memrchr for power8

Vectorized loops are used for sizes greater than 32B to improve
performance over power7 optimization.  This shows as an average
of 25% improvement depending on the position of search
character.  The performance is same for shorter strings.

4 files changed, 47 insertions, 3 deletions

diff --git a/sysdeps/powerpc/powerpc64/multiarch/Makefile b/sysdeps/powerpc/powerpc64/multiarch/Makefile
index f6491a2dc6..dea49acff5 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/Makefile
+++ b/sysdeps/powerpc/powerpc64/multiarch/Makefile
@@ -6,8 +6,9 @@ sysdep_routines += memcpy-power7 memcpy-a2 memcpy-power6 memcpy-cell \
 		   memset-ppc64 memset-power8 \
 		   mempcpy-power7 mempcpy-ppc64 \
 		   memchr-power8 memchr-power7 memchr-ppc64 \
-		   memrchr-power7 memrchr-ppc64 rawmemchr-power7 \
-		   rawmemchr-ppc64 strlen-power7 strlen-ppc64 \
+		   memrchr-power8 memrchr-power7 memrchr-ppc64 \
+		   rawmemchr-power7 rawmemchr-ppc64 \
+		   strlen-power7 strlen-ppc64 \
 		   strnlen-power8 strnlen-power7 strnlen-ppc64 \
 		   strcasecmp-power7 strcasecmp_l-power7 \
 		   strncase-power7 strncase_l-power7 \
diff --git a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
index a1d3ca0088..6a88536c98 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
@@ -194,6 +194,9 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
   /* Support sysdeps/powerpc/powerpc64/multiarch/memrchr.c.  */
   IFUNC_IMPL (i, name, memrchr,
 	      IFUNC_IMPL_ADD (array, i, memrchr,
+			      hwcap2 & PPC_FEATURE2_ARCH_2_07,
+			      __memrchr_power8)
+	      IFUNC_IMPL_ADD (array, i, memrchr,
 			      hwcap & PPC_FEATURE_HAS_VSX,
 			      __memrchr_power7)
 	      IFUNC_IMPL_ADD (array, i, memrchr, 1,
diff --git a/sysdeps/powerpc/powerpc64/multiarch/memrchr-power8.S b/sysdeps/powerpc/powerpc64/multiarch/memrchr-power8.S
new file mode 100644
index 0000000000..0dcb9e75f3
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/memrchr-power8.S
@@ -0,0 +1,28 @@
+/* Optimized memrchr 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>
+
+#define MEMRCHR __memrchr_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/memrchr.S>
diff --git a/sysdeps/powerpc/powerpc64/multiarch/memrchr-ppc64.c b/sysdeps/powerpc/powerpc64/multiarch/memrchr-ppc64.c
index 2fc706db71..be24689336 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/memrchr-ppc64.c
+++ b/sysdeps/powerpc/powerpc64/multiarch/memrchr-ppc64.c
@@ -16,4 +16,16 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <sysdeps/powerpc/powerpc32/power4/multiarch/memrchr-ppc32.c>
+#include <string.h>
+
+#define MEMRCHR  __memrchr_ppc
+
+#undef weak_alias
+#define weak_alias(a, b)
+
+#undef libc_hidden_builtin_def
+#define libc_hidden_builtin_def(name)
+
+extern __typeof (memrchr) __memrchr_ppc attribute_hidden;
+
+#include <string/memrchr.c>