S390: Refactor wcschrnul ifunc handling.

The ifunc handling for wcschrnul 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.

ChangeLog:

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

7 files changed, 103 insertions, 20 deletions

diff --git a/sysdeps/s390/Makefile b/sysdeps/s390/Makefile
index 982e5abfb2..a8cd264521 100644
--- a/sysdeps/s390/Makefile
+++ b/sysdeps/s390/Makefile
@@ -93,5 +93,6 @@ sysdep_routines += wcslen wcslen-vx wcslen-c \
 		   wcsncat wcsncat-vx wcsncat-c \
 		   wcscmp wcscmp-vx wcscmp-c \
 		   wcsncmp wcsncmp-vx wcsncmp-c \
-		   wcschr wcschr-vx wcschr-c
+		   wcschr wcschr-vx wcschr-c \
+		   wcschrnul wcschrnul-vx wcschrnul-c
 endif
diff --git a/sysdeps/s390/ifunc-wcschrnul.h b/sysdeps/s390/ifunc-wcschrnul.h
new file mode 100644
index 0000000000..39d4120eb3
--- /dev/null
+++ b/sysdeps/s390/ifunc-wcschrnul.h
@@ -0,0 +1,53 @@
+/* wcschrnul variant information on S/390 version.
+   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/>.  */
+
+#if defined USE_MULTIARCH && IS_IN (libc)		\
+  && ! defined HAVE_S390_MIN_Z13_ZARCH_ASM_SUPPORT
+# define HAVE_WCSCHRNUL_IFUNC	1
+#else
+# define HAVE_WCSCHRNUL_IFUNC	0
+#endif
+
+#ifdef HAVE_S390_VX_ASM_SUPPORT
+# define HAVE_WCSCHRNUL_IFUNC_AND_VX_SUPPORT HAVE_WCSCHRNUL_IFUNC
+#else
+# define HAVE_WCSCHRNUL_IFUNC_AND_VX_SUPPORT 0
+#endif
+
+#if defined HAVE_S390_MIN_Z13_ZARCH_ASM_SUPPORT
+# define WCSCHRNUL_DEFAULT	WCSCHRNUL_Z13
+/* The z13 ifunc variant is using the common code variant as fallback!  */
+# define HAVE_WCSCHRNUL_C	1
+# define HAVE_WCSCHRNUL_Z13	1
+#else
+# define WCSCHRNUL_DEFAULT	WCSCHRNUL_C
+# define HAVE_WCSCHRNUL_C	1
+# define HAVE_WCSCHRNUL_Z13	HAVE_WCSCHRNUL_IFUNC_AND_VX_SUPPORT
+#endif
+
+#if HAVE_WCSCHRNUL_C
+# define WCSCHRNUL_C		__wcschrnul_c
+#else
+# define WCSCHRNUL_C		NULL
+#endif
+
+#if HAVE_WCSCHRNUL_Z13
+# define WCSCHRNUL_Z13		__wcschrnul_vx
+#else
+# define WCSCHRNUL_Z13		NULL
+#endif
diff --git a/sysdeps/s390/multiarch/Makefile b/sysdeps/s390/multiarch/Makefile
index b282613b47..0eb01d5d84 100644
--- a/sysdeps/s390/multiarch/Makefile
+++ b/sysdeps/s390/multiarch/Makefile
@@ -1,6 +1,5 @@
 ifeq ($(subdir),wcsmbs)
-sysdep_routines += wcschrnul wcschrnul-vx wcschrnul-c \
-		   wcsrchr wcsrchr-vx wcsrchr-c \
+sysdep_routines += wcsrchr wcsrchr-vx wcsrchr-c \
 		   wcsspn wcsspn-vx wcsspn-c \
 		   wcspbrk wcspbrk-vx wcspbrk-c \
 		   wcscspn wcscspn-vx wcscspn-c \
diff --git a/sysdeps/s390/multiarch/ifunc-impl-list.c b/sysdeps/s390/multiarch/ifunc-impl-list.c
index c69165465d..553a76c39e 100644
--- a/sysdeps/s390/multiarch/ifunc-impl-list.c
+++ b/sysdeps/s390/multiarch/ifunc-impl-list.c
@@ -57,6 +57,7 @@
 #include <ifunc-wcscmp.h>
 #include <ifunc-wcsncmp.h>
 #include <ifunc-wcschr.h>
+#include <ifunc-wcschrnul.h>
 
 /* Maximum number of IFUNC implementations.  */
 #define MAX_IFUNC	3
@@ -567,6 +568,18 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 		)
 #endif /* HAVE_WCSCHR_IFUNC  */
 
+#if HAVE_WCSCHRNUL_IFUNC
+    IFUNC_IMPL (i, name, wcschrnul,
+# if HAVE_WCSCHRNUL_Z13
+		IFUNC_IMPL_ADD (array, i, wcschrnul,
+				dl_hwcap & HWCAP_S390_VX, WCSCHRNUL_Z13)
+# endif
+# if HAVE_WCSCHRNUL_C
+		IFUNC_IMPL_ADD (array, i, wcschrnul, 1, WCSCHRNUL_C)
+# endif
+		)
+#endif /* HAVE_WCSCHRNUL_IFUNC  */
+
 #ifdef HAVE_S390_VX_ASM_SUPPORT
 
 # define IFUNC_VX_IMPL(FUNC)						\
@@ -575,8 +588,6 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 			      __##FUNC##_vx)				\
 	      IFUNC_IMPL_ADD (array, i, FUNC, 1, __##FUNC##_c))
 
-  IFUNC_VX_IMPL (wcschrnul);
-
   IFUNC_VX_IMPL (wcsrchr);
 
   IFUNC_VX_IMPL (wcsspn);
diff --git a/sysdeps/s390/multiarch/wcschrnul-c.c b/sysdeps/s390/wcschrnul-c.c
index 00e776a3ad..410cee1399 100644
--- a/sysdeps/s390/multiarch/wcschrnul-c.c
+++ b/sysdeps/s390/wcschrnul-c.c
@@ -16,10 +16,12 @@
    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 WCSCHRNUL  __wcschrnul_c
+#include <ifunc-wcschrnul.h>
+
+#if HAVE_WCSCHRNUL_C
+# if HAVE_WCSCHRNUL_IFUNC || HAVE_WCSCHRNUL_Z13
+#  define WCSCHRNUL WCSCHRNUL_C
+# endif
 
-# include <wchar.h>
-extern __typeof (__wcschrnul) __wcschrnul_c;
 # include <wcsmbs/wcschrnul.c>
 #endif
diff --git a/sysdeps/s390/multiarch/wcschrnul-vx.S b/sysdeps/s390/wcschrnul-vx.S
index ebcd32b870..4ffb937c6b 100644
--- a/sysdeps/s390/multiarch/wcschrnul-vx.S
+++ b/sysdeps/s390/wcschrnul-vx.S
@@ -16,7 +16,8 @@
    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)
+#include <ifunc-wcschrnul.h>
+#if HAVE_WCSCHRNUL_Z13
 
 # include "sysdep.h"
 # include "asm-syntax.h"
@@ -35,7 +36,7 @@
    -v16=part of s
    -v18=vector with c replicated in every byte
 */
-ENTRY(__wcschrnul_vx)
+ENTRY(WCSCHRNUL_Z13)
 	.machine "z13"
 	.machinemode "zarch_nohighgprs"
 
@@ -92,6 +93,11 @@ ENTRY(__wcschrnul_vx)
 .Lend:
 	br	%r14
 .Lfallback:
-	jg	__wcschrnul_c
-END(__wcschrnul_vx)
-#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */
+	jg	WCSCHRNUL_C
+END(WCSCHRNUL_Z13)
+
+# if ! HAVE_WCSCHRNUL_IFUNC
+strong_alias (WCSCHRNUL_Z13, __wcschrnul)
+weak_alias (__wcschrnul, wcschrnul)
+# endif
+#endif
diff --git a/sysdeps/s390/multiarch/wcschrnul.c b/sysdeps/s390/wcschrnul.c
index 807d7ee089..ab5aaf0402 100644
--- a/sysdeps/s390/multiarch/wcschrnul.c
+++ b/sysdeps/s390/wcschrnul.c
@@ -16,13 +16,24 @@
    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)
+#include <ifunc-wcschrnul.h>
+
+#if HAVE_WCSCHRNUL_IFUNC
 # include <wchar.h>
 # include <ifunc-resolve.h>
 
-s390_vx_libc_ifunc (__wcschrnul)
-weak_alias (__wcschrnul, wcschrnul)
+# if HAVE_WCSCHRNUL_C
+extern __typeof (__wcschrnul) WCSCHRNUL_C attribute_hidden;
+# endif
 
-#else
-# include <wcsmbs/wcschrnul.c>
-#endif /* !(defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)) */
+# if HAVE_WCSCHRNUL_Z13
+extern __typeof (__wcschrnul) WCSCHRNUL_Z13 attribute_hidden;
+# endif
+
+s390_libc_ifunc_expr (__wcschrnul, __wcschrnul,
+		      (HAVE_WCSCHRNUL_Z13 && (hwcap & HWCAP_S390_VX))
+		      ? WCSCHRNUL_Z13
+		      : WCSCHRNUL_DEFAULT
+		      )
+weak_alias (__wcschrnul, wcschrnul)
+#endif