S390: Refactor wcsnlen ifunc handling.

The ifunc handling for wcsnlen is adjusted in order to omit ifunc
if the minimum architecture level already supports newer CPUs by default.
Unfortunately the c ifunc variant can't be omitted at all as it is used
by the z13 ifunc variant as fallback if the pointers are not 4-byte aligned.
Glibc internal calls will use the "newer" ifunc variant.

ChangeLog:

	* sysdeps/s390/multiarch/Makefile
	(sysdep_routines): Remove wcsnlen variants.
	* sysdeps/s390/Makefile (sysdep_routines): Add wcsnlen variants.
	* sysdeps/s390/multiarch/ifunc-impl-list.c
	(__libc_ifunc_impl_list): Refactor ifunc handling for wcsnlen.
	* sysdeps/s390/multiarch/wcsnlen-c.c: Move to ...
	* sysdeps/s390/wcsnlen-c.c: ... here and adjust ifunc handling.
	* sysdeps/s390/multiarch/wcsnlen-vx.S: Move to ...
	* sysdeps/s390/wcsnlen-vx.S: ... here and adjust ifunc handling.
	* sysdeps/s390/multiarch/wcsnlen.c: Move to ...
	* sysdeps/s390/wcsnlen.c: ... here and adjust ifunc handling.
	* sysdeps/s390/ifunc-wcsnlen.h: New file.

1 files changed, 39 insertions, 0 deletions

diff --git a/sysdeps/s390/wcsnlen.c b/sysdeps/s390/wcsnlen.c
new file mode 100644
index 0000000..b5c8ad9
--- /dev/null
+++ b/sysdeps/s390/wcsnlen.c
@@ -0,0 +1,39 @@
+/* Multiple versions of wcsnlen.
+   Copyright (C) 2015-2018 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-wcsnlen.h>
+
+#if HAVE_WCSNLEN_IFUNC
+# include <wchar.h>
+# include <ifunc-resolve.h>
+
+# if HAVE_WCSNLEN_C
+extern __typeof (__wcsnlen) WCSNLEN_C attribute_hidden;
+# endif
+
+# if HAVE_WCSNLEN_Z13
+extern __typeof (__wcsnlen) WCSNLEN_Z13 attribute_hidden;
+# endif
+
+s390_libc_ifunc_expr (__wcsnlen, __wcsnlen,
+		      (HAVE_WCSNLEN_Z13 && (hwcap & HWCAP_S390_VX))
+		      ? WCSNLEN_Z13
+		      : WCSNLEN_DEFAULT
+		      )
+weak_alias (__wcsnlen, wcsnlen)
+#endif