S390: Optimize memrchr.

This patch provides optimized version of memrchr with the z13 vector
instructions.

ChangeLog:

	* sysdeps/s390/multiarch/memrchr-c.c: New File.
	* sysdeps/s390/multiarch/memrchr-vx.S: Likewise.
	* sysdeps/s390/multiarch/memrchr.c: Likewise.
	* sysdeps/s390/multiarch/Makefile
	(sysdep_routines): Add memrchr functions.
	* sysdeps/s390/multiarch/ifunc-impl-list-common.c
	(__libc_ifunc_impl_list_common): Add ifunc test for memrchr.

1 files changed, 25 insertions, 0 deletions

diff --git a/sysdeps/s390/multiarch/memrchr-c.c b/sysdeps/s390/multiarch/memrchr-c.c
new file mode 100644
index 0000000..ac481fd
--- /dev/null
+++ b/sysdeps/s390/multiarch/memrchr-c.c
@@ -0,0 +1,25 @@
+/* Default memrchr implementation for S/390.
+   Copyright (C) 2015 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 defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)
+# define MEMRCHR  __memrchr_c
+
+# include <string.h>
+extern __typeof (__memrchr) __memrchr_c;
+# include <string/memrchr.c>
+#endif