powerpc: Optimization for strlen for POWER8.

This implementation takes advantage of vectorization to improve performance of
the loop over the current strlen implementation for POWER7.

4 files changed, 48 insertions, 4 deletions

diff --git a/sysdeps/powerpc/powerpc64/multiarch/Makefile b/sysdeps/powerpc/powerpc64/multiarch/Makefile
index 7ed56bf292..57abe8ff3c 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/Makefile
+++ b/sysdeps/powerpc/powerpc64/multiarch/Makefile
@@ -20,7 +20,7 @@ sysdep_routines += memcpy-power7 memcpy-a2 memcpy-power6 memcpy-cell \
 		   strcat-power8 strcat-power7 strcat-ppc64 \
 		   memmove-power7 memmove-ppc64 wordcopy-ppc64 bcopy-ppc64 \
 		   strncpy-power8 strstr-power7 strstr-ppc64 \
-		   strspn-power8 strspn-ppc64
+		   strspn-power8 strspn-ppc64 strlen-power8
 
 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 3e1f099d71..d30a661caf 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
@@ -101,6 +101,8 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 
   /* Support sysdeps/powerpc/powerpc64/multiarch/strlen.c.  */
   IFUNC_IMPL (i, name, strlen,
+	      IFUNC_IMPL_ADD (array, i, strlen, hwcap2 & PPC_FEATURE2_ARCH_2_07,
+			      __strlen_power8)
 	      IFUNC_IMPL_ADD (array, i, strlen, hwcap & PPC_FEATURE_HAS_VSX,
 			      __strlen_power7)
 	      IFUNC_IMPL_ADD (array, i, strlen, 1,
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strlen-power8.S b/sysdeps/powerpc/powerpc64/multiarch/strlen-power8.S
new file mode 100644
index 0000000000..686dc3d7f6
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strlen-power8.S
@@ -0,0 +1,39 @@
+/* Optimized strlen implementation for POWER8.
+   Copyright (C) 2016 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(__strlen_power8)					\
+  .align ALIGNARG(alignt);					\
+  EALIGN_W_##words;						\
+  BODY_LABEL(__strlen_power8):					\
+  cfi_startproc;						\
+  LOCALENTRY(__strlen_power8)
+#undef END
+#define END(name)						\
+  cfi_endproc;							\
+  TRACEBACK(__strlen_power8)					\
+  END_2(__strlen_power8)
+
+#undef libc_hidden_builtin_def
+#define libc_hidden_builtin_def(name)
+
+#include <sysdeps/powerpc/powerpc64/power8/strlen.S>
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strlen.c b/sysdeps/powerpc/powerpc64/multiarch/strlen.c
index 94501fdf2f..609a87ec9f 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/strlen.c
+++ b/sysdeps/powerpc/powerpc64/multiarch/strlen.c
@@ -29,11 +29,14 @@ extern __typeof (__redirect_strlen) __libc_strlen;
 
 extern __typeof (__redirect_strlen) __strlen_ppc attribute_hidden;
 extern __typeof (__redirect_strlen) __strlen_power7 attribute_hidden;
+extern __typeof (__redirect_strlen) __strlen_power8 attribute_hidden;
 
 libc_ifunc (__libc_strlen,
-            (hwcap & PPC_FEATURE_HAS_VSX)
-            ? __strlen_power7
-            : __strlen_ppc);
+	    (hwcap2 & PPC_FEATURE2_ARCH_2_07)
+	    ? __strlen_power8 :
+	      (hwcap & PPC_FEATURE_HAS_VSX)
+	      ? __strlen_power7
+	      : __strlen_ppc);
 
 #undef strlen
 strong_alias (__libc_strlen, strlen)