Add versions of wcscpy, wcschr, wcsrchr for power6/power7.

Initially based on the versions found in wcsmbs/* ; these files have
been changed by hand unrolling, and adding some additional variables
to allow some read-ahead to occur, which then relieves some of the
wait-for-increment/wait-for-load/wait-for-compare-results pressure
that was slowing down every iteration through the while-loop.

For 64-bit Power7, These changes give an approx 20% throughput boost
for the wcschr and wcsrchr functions; and approx 40% boost for the
wcscpy function.  32-bit improvements appear to be slightly better
with ~ %30 and ~ %45 respectively.  Results for Power6 closely match
those for power7.

1 files changed, 88 insertions, 0 deletions

diff --git a/sysdeps/powerpc/powerpc32/power6/wcsrchr.c b/sysdeps/powerpc/powerpc32/power6/wcsrchr.c
new file mode 100644
index 0000000000..f9db8f8b53
--- /dev/null
+++ b/sysdeps/powerpc/powerpc32/power6/wcsrchr.c
@@ -0,0 +1,88 @@
+/* wcsrchr.c - Wide Character Reverse Search for powerpc32/power6.
+   Copyright (C) 2012 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; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <wchar.h>
+
+
+/* Find the last occurrence of WC in WCS.  */
+wchar_t *
+wcsrchr (wcs, wc)
+     register const wchar_t *wcs;
+     register const wchar_t wc;
+{
+  register const wchar_t *wcs2 = wcs + 1;
+  const wchar_t *retval = NULL;
+
+  if (*wcs == wc)
+    retval = wcs;
+
+  if (*wcs == L'\0') return (wchar_t *) retval;
+
+  do
+    {
+    wcs+=2;
+
+    if (*wcs2 == wc)
+      retval = wcs2;
+    if (*wcs2 == L'\0')
+      return (wchar_t *) retval;
+    wcs2+=2;
+
+    if (*wcs == wc)
+      retval = wcs;
+    if (*wcs == L'\0')
+      return (wchar_t *) retval;
+    wcs+=2;
+
+    if (*wcs2 == wc)
+      retval = wcs2;
+    if (*wcs2 == L'\0')
+      return (wchar_t *) retval;
+    wcs2+=2;
+
+    if (*wcs == wc)
+      retval = wcs;
+    if (*wcs == L'\0')
+      return (wchar_t *) retval;
+    wcs+=2;
+
+    if (*wcs2 == wc)
+      retval = wcs2;
+    if (*wcs2 == L'\0')
+      return (wchar_t *) retval;
+    wcs2+=2;
+
+    if (*wcs == wc)
+      retval = wcs;
+    if (*wcs == L'\0')
+      return (wchar_t *) retval;
+    wcs+=2;
+
+    if (*wcs2 == wc)
+      retval = wcs2;
+    if (*wcs2 == L'\0')
+      return (wchar_t *) retval;
+    wcs2+=2;
+
+    if (*wcs == wc)
+      retval = wcs;
+    }
+  while (*wcs != L'\0');
+
+  return (wchar_t *) retval;
+}