PowerPC: strrchr optimization for POWER7/PPC64

This patch optimizes strrchr() for ppc64. It uses aligned memory
access along with cmpb instruction and CPU prefetch to avoid
cache misses for speed improvement.

5 files changed, 117 insertions, 1 deletions

diff --git a/sysdeps/powerpc/powerpc64/multiarch/Makefile b/sysdeps/powerpc/powerpc64/multiarch/Makefile
index 3c47316bda..d09f2e3e5d 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-power7 strcpy-ppc64 stpcpy-power7 stpcpy-ppc64 \
+		   strrchr-power7 strrchr-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 6bbdd4ebba..8789483780 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
@@ -238,5 +238,13 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 	      IFUNC_IMPL_ADD (array, i, wcscpy, 1,
 			      __wcscpy_ppc))
 
+  /* Support sysdeps/powerpc/powerpc64/multiarch/strrchr.c.  */
+  IFUNC_IMPL (i, name, strrchr,
+	      IFUNC_IMPL_ADD (array, i, strrchr,
+			      hwcap & PPC_FEATURE_HAS_VSX,
+			      __strrchr_power7)
+	      IFUNC_IMPL_ADD (array, i, strrchr, 1,
+			      __strrchr_ppc))
+
   return i;
 }
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strrchr-power7.S b/sysdeps/powerpc/powerpc64/multiarch/strrchr-power7.S
new file mode 100644
index 0000000000..78e15e3d87
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strrchr-power7.S
@@ -0,0 +1,39 @@
+/* Optimized strrchr implementation for POWER7.
+   Copyright (C) 2014 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_power7)					\
+  .align ALIGNARG(2);						\
+  BODY_LABEL(__strrchr_power7):					\
+  cfi_startproc;						\
+  LOCALENTRY(__strrchr_power7)
+
+#undef END
+#define END(name)						\
+  cfi_endproc;							\
+  TRACEBACK(__strrchr_power7)					\
+  END_2(__strrchr_power7)
+
+#undef libc_hidden_builtin_def
+#define libc_hidden_builtin_def(name)
+
+#include <sysdeps/powerpc/powerpc64/power7/strrchr.S>
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strrchr-ppc64.c b/sysdeps/powerpc/powerpc64/multiarch/strrchr-ppc64.c
new file mode 100644
index 0000000000..5633a9f003
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strrchr-ppc64.c
@@ -0,0 +1,33 @@
+/* Copyright (C) 2014 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 STRRCHR __strrchr_ppc
+#undef weak_alias
+#define weak_alias(name, aliasname) \
+  extern __typeof (__strrchr_ppc) aliasname \
+    __attribute__ ((weak, alias ("__strrchr_ppc")));
+#if !defined(NOT_IN_libc) && defined(SHARED)
+# undef libc_hidden_builtin_def
+# define libc_hidden_builtin_def(name) \
+  __hidden_ver1(__strrchr_ppc, __GI_strrchr, __strrchr_ppc);
+#endif
+
+extern __typeof (strrchr) __strrchr_ppc attribute_hidden;
+
+#include <string/strrchr.c>
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strrchr.c b/sysdeps/powerpc/powerpc64/multiarch/strrchr.c
new file mode 100644
index 0000000000..046162f2d7
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strrchr.c
@@ -0,0 +1,35 @@
+/* Multiple versions of strrchr. PowerPC64 version.
+   Copyright (C) 2014 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/>.  */
+
+/* Define multiple versions only for definition in libc.  */
+#ifndef NOT_IN_libc
+# include <string.h>
+# include <shlib-compat.h>
+# include "init-arch.h"
+
+extern __typeof (strrchr) __strrchr_ppc attribute_hidden;
+extern __typeof (strrchr) __strrchr_power7 attribute_hidden;
+
+/* Avoid DWARF definition DIE on ifunc symbol so that GDB can handle
+   ifunc symbol properly.  */
+libc_ifunc (strrchr,
+            (hwcap & PPC_FEATURE_HAS_VSX)
+            ? __strrchr_power7
+            : __strrchr_ppc);
+weak_alias (strrchr, rindex)
+#endif