S390: Add z13 memmove ifunc variant.

This patch introduces a z13 specific ifunc variant for memmove.
As the common code implementation, it checks if we can copy from
the beginning to the end - with z196 memcpy implementation - or
if we have to copy from the end to the beginning.
The latter case is done by using vector load/store instructions.

If vector instructions are not available, the common-code is
used as fallback.  Therefore it is implemented in memmove-c with
a different name.
Furthermore the ifunc logic decides if we need the common-code
implementation at all.  If vector instructions are supported
due to the minimum architecture level set we can skip the
common-code ifunc variant.

ChangeLog:

	* sysdeps/s390/Makefile (sysdep_routines): Add memmove-c.
	* sysdeps/s390/ifunc-memcpy.h (HAVE_MEMMOVE_IFUNC,
	HAVE_MEMMOVE_IFUNC_AND_VX_SUPPORT, MEMMOVE_DEFAULT,
	HAVE_MEMMOVE_C, MEMMOVE_C,  HAVE_MEMMOVE_Z13, MEMMOVE_Z13):
	New defines.
	* sysdeps/s390/memcpy-z900.S: Add z13 memmove implementation.
	* sysdeps/s390/memmove-c.c: New file.
	* sysdeps/s390/memmove.c: Likewise.
	* sysdeps/s390/multiarch/ifunc-impl-list.c
	(__libc_ifunc_impl_list): Add ifunc variants for memmove.

1 files changed, 37 insertions, 0 deletions

diff --git a/sysdeps/s390/memmove-c.c b/sysdeps/s390/memmove-c.c
new file mode 100644
index 0000000..be57109
--- /dev/null
+++ b/sysdeps/s390/memmove-c.c
@@ -0,0 +1,37 @@
+/* Fallback C version of memmove.
+   Copyright (C) 2018 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 <ifunc-memcpy.h>
+
+#if HAVE_MEMMOVE_C
+# if HAVE_MEMMOVE_IFUNC
+/* If we use ifunc, then the memmove symbol is defined
+   in sysdeps/s390/memmove.c and we use a different name here.
+   Otherwise, we have to define memmove here or in
+   sysdeps/s390/memcpy.S depending on the used default implementation.  */
+#  define MEMMOVE MEMMOVE_C
+#  if defined SHARED && IS_IN (libc)
+/* Define the internal symbol.  */
+#   undef libc_hidden_builtin_def
+#   define libc_hidden_builtin_def(name)			\
+  __hidden_ver1 (__memmove_c, __GI_memmove, __memmove_c);
+#  endif
+# endif
+
+# include <string/memmove.c>
+#endif