powerpc: strcasestr optmization for power8

This patch optimizes strcasestr function for power >= 8 systems.  The average
improvement of this optimization is ~40% and compares 16 bytes at a time
using vector instructions.  This patch is tested on powerpc64 and powerpc64le.

5 files changed, 130 insertions, 1 deletions

diff --git a/sysdeps/powerpc/powerpc64/multiarch/Makefile b/sysdeps/powerpc/powerpc64/multiarch/Makefile
index 57abe8ff3c..7f70ceb717 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/Makefile
+++ b/sysdeps/powerpc/powerpc64/multiarch/Makefile
@@ -20,7 +20,8 @@ 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 strlen-power8
+		   strspn-power8 strspn-ppc64 strlen-power8 \
+		   strcasestr-power8 strcasestr-ppc64
 
 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 d30a661caf..c834f8f6db 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
@@ -341,5 +341,13 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
                              __strstr_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,
+			      __strcasestr_power8)
+             IFUNC_IMPL_ADD (array, i, strcasestr, 1,
+                             __strcasestr_ppc))
+
   return i;
 }
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strcasestr-power8.S b/sysdeps/powerpc/powerpc64/multiarch/strcasestr-power8.S
new file mode 100644
index 0000000000..c77ff9f9ee
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strcasestr-power8.S
@@ -0,0 +1,49 @@
+/* Optimized strcasestr 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(__strcasestr_power8)					\
+  .align ALIGNARG(alignt);					\
+  EALIGN_W_##words;						\
+  BODY_LABEL(__strcasestr_power8):				\
+  cfi_startproc;						\
+  LOCALENTRY(__strcasestr_power8)
+
+#undef END
+#define END(name)						\
+  cfi_endproc;							\
+  TRACEBACK(__strcasestr_power8)				\
+  END_2(__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_power7
+/* strchr is used to check if first char of r4 is present in r3.  */
+#define STRCHR __strchr_power7
+
+#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
new file mode 100644
index 0000000000..7f7bb9eea3
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strcasestr-ppc64.c
@@ -0,0 +1,34 @@
+/* PowerPC64 default implementation of strcasestr.
+   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 <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
new file mode 100644
index 0000000000..17ba1882ad
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strcasestr.c
@@ -0,0 +1,37 @@
+/* Multiple versions of strcasestr.
+   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/>.  */
+
+#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)
+		? __strcasestr_power8
+		: __strcasestr_ppc);
+
+weak_alias (__strcasestr, strcasestr)
+#else
+#include <string/strcasestr.c>
+#endif