powerpc: Optimized st{r,p}cpy for POWER8/PPC64

This patch adds an optimized POWER8 strcpy using unaligned accesses.
For strings up to 16 bytes the implementation first calculate the
string size, like strlen, and issues a memcpy.  For larger strings,
source is first aligned to 16 bytes and then tested over a loop that
reads 16 bytes am combine the cmpb results for speedup.  Special case is
added for page cross reads.

It shows 30%-60% improvement over the optimized POWER7 one that uses
only aligned accesses.

5 files changed, 91 insertions, 3 deletions

diff --git a/sysdeps/powerpc/powerpc64/multiarch/Makefile b/sysdeps/powerpc/powerpc64/multiarch/Makefile
index 39e441b9a0..f170551b44 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/Makefile
+++ b/sysdeps/powerpc/powerpc64/multiarch/Makefile
@@ -13,7 +13,8 @@ sysdep_routines += memcpy-power7 memcpy-a2 memcpy-power6 memcpy-cell \
 		   wcschr-power6 wcschr-ppc64 wcsrchr-power7 wcsrchr-power6 \
 		   wcsrchr-ppc64 wcscpy-power7 wcscpy-power6 wcscpy-ppc64 \
 		   wordcopy-power7 wordcopy-power6 wordcopy-ppc64 \
-		   strcpy-power7 strcpy-ppc64 stpcpy-power7 stpcpy-ppc64 \
+		   strcpy-power8 strcpy-power7 strcpy-ppc64 stpcpy-power8 \
+		   stpcpy-power7 stpcpy-ppc64 \
 		   strrchr-power7 strrchr-ppc64 strncat-power7 strncat-ppc64 \
 		   strncpy-power7 strncpy-ppc64 \
 		   stpncpy-power7 stpncpy-ppc64 strcmp-power7 strcmp-ppc64 \
diff --git a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
index 47e33981f6..88c8234ff4 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
@@ -83,6 +83,8 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 
   /* Support sysdeps/powerpc/powerpc64/multiarch/strcpy.c.  */
   IFUNC_IMPL (i, name, strcpy,
+	      IFUNC_IMPL_ADD (array, i, strcpy, hwcap2 & PPC_FEATURE2_ARCH_2_07,
+			      __strcpy_power8)
 	      IFUNC_IMPL_ADD (array, i, strcpy, hwcap & PPC_FEATURE_HAS_VSX,
 			      __strcpy_power7)
 	      IFUNC_IMPL_ADD (array, i, strcpy, 1,
@@ -90,6 +92,8 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 
   /* Support sysdeps/powerpc/powerpc64/multiarch/stpcpy.c.  */
   IFUNC_IMPL (i, name, stpcpy,
+	      IFUNC_IMPL_ADD (array, i, stpcpy, hwcap2 & PPC_FEATURE2_ARCH_2_07,
+			      __stpcpy_power8)
 	      IFUNC_IMPL_ADD (array, i, stpcpy, hwcap & PPC_FEATURE_HAS_VSX,
 			      __stpcpy_power7)
 	      IFUNC_IMPL_ADD (array, i, stpcpy, 1,
diff --git a/sysdeps/powerpc/powerpc64/multiarch/stpcpy-power8.S b/sysdeps/powerpc/powerpc64/multiarch/stpcpy-power8.S
new file mode 100644
index 0000000000..66e6f708bd
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/stpcpy-power8.S
@@ -0,0 +1,40 @@
+/* Optimized stpcpy implementation for POWER8/PPC64.
+   Copyright (C) 2015 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(__stpcpy_power8)					\
+  .align ALIGNARG(alignt);					\
+  EALIGN_W_##words;						\
+  BODY_LABEL(__stpcpy_power8):					\
+  cfi_startproc;						\
+  LOCALENTRY(__stpcpy_power8)
+
+#undef END
+#define END(name)						\
+  cfi_endproc;							\
+  TRACEBACK(__stpcpy_power8)					\
+  END_2(__stpcpy_power8)
+
+#undef libc_hidden_builtin_def
+#define libc_hidden_builtin_def(name)
+
+#include <sysdeps/powerpc/powerpc64/power8/stpcpy.S>
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strcpy-power8.S b/sysdeps/powerpc/powerpc64/multiarch/strcpy-power8.S
new file mode 100644
index 0000000000..64cbc163a4
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strcpy-power8.S
@@ -0,0 +1,40 @@
+/* Optimized strcpy implementation for POWER8/PPC64.
+   Copyright (C) 2015 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(__strcpy_power8)					\
+  .align ALIGNARG(alignt);					\
+  EALIGN_W_##words;						\
+  BODY_LABEL(__strcpy_power8):					\
+  cfi_startproc;						\
+  LOCALENTRY(__strcpy_power8)
+
+#undef END
+#define END(name)						\
+  cfi_endproc;							\
+  TRACEBACK(__strcpy_power8)					\
+  END_2(__strcpy_power8)
+
+#undef libc_hidden_builtin_def
+#define libc_hidden_builtin_def(name)
+
+#include <sysdeps/powerpc/powerpc64/power8/strcpy.S>
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strcpy.c b/sysdeps/powerpc/powerpc64/multiarch/strcpy.c
index cd47bf6713..fd0afd408a 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/strcpy.c
+++ b/sysdeps/powerpc/powerpc64/multiarch/strcpy.c
@@ -23,9 +23,12 @@
 
 extern __typeof (strcpy) __strcpy_ppc attribute_hidden;
 extern __typeof (strcpy) __strcpy_power7 attribute_hidden;
+extern __typeof (strcpy) __strcpy_power8 attribute_hidden;
 
 libc_ifunc (strcpy,
-            (hwcap & PPC_FEATURE_HAS_VSX)
-            ? __strcpy_power7
+            (hwcap2 & PPC_FEATURE2_ARCH_2_07)
+            ? __strcpy_power8 :
+              (hwcap & PPC_FEATURE_HAS_VSX)
+              ? __strcpy_power7
             : __strcpy_ppc);
 #endif