powerpc64: strrchr optimization for power8

P7 code is used for <=32B strings and for > 32B vectorized loops are used.
This shows as an average 25% improvement depending on the position of search
character.  The performance is same for shorter strings.
Tested on ppc64 and ppc64le.

4 files changed, 46 insertions, 1 deletions

diff --git a/sysdeps/powerpc/powerpc64/multiarch/Makefile b/sysdeps/powerpc/powerpc64/multiarch/Makefile
index 0eb3d0710d..7d4f35cb1c 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/Makefile
+++ b/sysdeps/powerpc/powerpc64/multiarch/Makefile
@@ -15,7 +15,7 @@ sysdep_routines += memcpy-power7 memcpy-a2 memcpy-power6 memcpy-cell \
 		   strchrnul-power8 strchrnul-power7 strchrnul-ppc64 \
 		   strcpy-power8 strcpy-power7 strcpy-ppc64 stpcpy-power8 \
 		   stpcpy-power7 stpcpy-ppc64 \
-		   strrchr-power7 strrchr-ppc64 \
+		   strrchr-power8 strrchr-power7 strrchr-ppc64 \
 		   strncat-power8 strncat-power7 strncat-ppc64 \
 		   strncpy-power7 strncpy-ppc64 \
 		   stpncpy-power8 stpncpy-power7 stpncpy-ppc64 \
diff --git a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
index bddec1a6f8..107ffe6416 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
@@ -284,6 +284,9 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
   /* Support sysdeps/powerpc/powerpc64/multiarch/strrchr.c.  */
   IFUNC_IMPL (i, name, strrchr,
 	      IFUNC_IMPL_ADD (array, i, strrchr,
+			      hwcap2 & PPC_FEATURE2_ARCH_2_07,
+			      __strrchr_power8)
+	      IFUNC_IMPL_ADD (array, i, strrchr,
 			      hwcap & PPC_FEATURE_HAS_VSX,
 			      __strrchr_power7)
 	      IFUNC_IMPL_ADD (array, i, strrchr, 1,
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strrchr-power8.S b/sysdeps/powerpc/powerpc64/multiarch/strrchr-power8.S
new file mode 100644
index 0000000000..23365a1446
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strrchr-power8.S
@@ -0,0 +1,39 @@
+/* Optimized strrchr implementation for 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 ENTRY
+#define ENTRY(name)						\
+  .section ".text";						\
+  ENTRY_2(__strrchr_power8)					\
+  .align ALIGNARG(2);						\
+  BODY_LABEL(__strrchr_power8):					\
+  cfi_startproc;						\
+  LOCALENTRY(__strrchr_power8)
+
+#undef END
+#define END(name)						\
+  cfi_endproc;							\
+  TRACEBACK(__strrchr_power8)					\
+  END_2(__strrchr_power8)
+
+#undef libc_hidden_builtin_def
+#define libc_hidden_builtin_def(name)
+
+#include <sysdeps/powerpc/powerpc64/power8/strrchr.S>
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strrchr.c b/sysdeps/powerpc/powerpc64/multiarch/strrchr.c
index dc1d3d0bb7..0f94c9d6a1 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/strrchr.c
+++ b/sysdeps/powerpc/powerpc64/multiarch/strrchr.c
@@ -25,11 +25,14 @@
 
 extern __typeof (strrchr) __strrchr_ppc attribute_hidden;
 extern __typeof (strrchr) __strrchr_power7 attribute_hidden;
+extern __typeof (strrchr) __strrchr_power8 attribute_hidden;
 #undef strrchr
 
 /* Avoid DWARF definition DIE on ifunc symbol so that GDB can handle
    ifunc symbol properly.  */
 libc_ifunc_redirected (__redirect_strrchr, strrchr,
+		       (hwcap2 & PPC_FEATURE2_ARCH_2_07)
+		       ? __strrchr_power8 :
 		       (hwcap & PPC_FEATURE_HAS_VSX)
 		       ? __strrchr_power7
 		       : __strrchr_ppc);