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.

1 files changed, 29 insertions, 0 deletions

diff --git a/sysdeps/powerpc/powerpc64/power8/strcasestr-ppc64.c b/sysdeps/powerpc/powerpc64/power8/strcasestr-ppc64.c
new file mode 100644
index 0000000000..09a07b0a90
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/power8/strcasestr-ppc64.c
@@ -0,0 +1,29 @@
+/* Optimized strcasestr implementation for PowerPC64/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 <string.h>
+
+#define STRCASESTR __strcasestr_ppc
+#undef libc_hidden_builtin_def
+#define libc_hidden_builtin_def(__name)
+
+#undef weak_alias
+#define weak_alias(a,b)
+extern __typeof (strcasestr) __strcasestr_ppc attribute_hidden;
+
+#include <string/strcasestr.c>