PowerPC: optimized memmove for POWER7/PPC64

This patch adds an optimized memmove optimization for POWER7/powerpc64.
Basically the idea is to use the memcpy for POWER7 on non-overlapped
memory regions and a optimized backward memcpy for memory regions
that overlap (similar to the idea of string/memmove.c).

The backward memcpy algorithm used is similar the one use for memcpy for
POWER7, with adjustments done for alignment.  The difference is memory
is always aligned to 16 bytes before using VSX/altivec instructions.

1 files changed, 29 insertions, 0 deletions

diff --git a/sysdeps/powerpc/powerpc64/multiarch/bcopy.c b/sysdeps/powerpc/powerpc64/multiarch/bcopy.c
new file mode 100644
index 0000000000..0688907629
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/bcopy.c
@@ -0,0 +1,29 @@
+/* PowerPC64 multiarch bcopy.
+   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>
+#include "init-arch.h"
+
+extern __typeof (bcopy) __bcopy_ppc attribute_hidden;
+/* __bcopy_power7 symbol is implemented at memmove-power7.S  */
+extern __typeof (bcopy) __bcopy_power7 attribute_hidden;
+
+libc_ifunc (bcopy,
+            (hwcap & PPC_FEATURE_HAS_VSX)
+            ? __bcopy_power7
+            : __bcopy_ppc);