S390: Refactor wcscspn ifunc handling.

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

7 files changed, 100 insertions, 19 deletions

diff --git a/sysdeps/s390/Makefile b/sysdeps/s390/Makefile
index 4decbf8f0a..a9058047a9 100644
--- a/sysdeps/s390/Makefile
+++ b/sysdeps/s390/Makefile
@@ -97,5 +97,6 @@ sysdep_routines += wcslen wcslen-vx wcslen-c \
 		   wcschrnul wcschrnul-vx wcschrnul-c \
 		   wcsrchr wcsrchr-vx wcsrchr-c \
 		   wcsspn wcsspn-vx wcsspn-c \
-		   wcspbrk wcspbrk-vx wcspbrk-c
+		   wcspbrk wcspbrk-vx wcspbrk-c \
+		   wcscspn wcscspn-vx wcscspn-c
 endif
diff --git a/sysdeps/s390/ifunc-wcscspn.h b/sysdeps/s390/ifunc-wcscspn.h
new file mode 100644
index 0000000000..23f3667ba3
--- /dev/null
+++ b/sysdeps/s390/ifunc-wcscspn.h
@@ -0,0 +1,53 @@
+/* wcscspn 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_WCSCSPN_IFUNC	1
+#else
+# define HAVE_WCSCSPN_IFUNC	0
+#endif
+
+#ifdef HAVE_S390_VX_ASM_SUPPORT
+# define HAVE_WCSCSPN_IFUNC_AND_VX_SUPPORT HAVE_WCSCSPN_IFUNC
+#else
+# define HAVE_WCSCSPN_IFUNC_AND_VX_SUPPORT 0
+#endif
+
+#if defined HAVE_S390_MIN_Z13_ZARCH_ASM_SUPPORT
+# define WCSCSPN_DEFAULT	WCSCSPN_Z13
+/* The z13 ifunc variant is using the common code variant as fallback!  */
+# define HAVE_WCSCSPN_C		1
+# define HAVE_WCSCSPN_Z13	1
+#else
+# define WCSCSPN_DEFAULT	WCSCSPN_C
+# define HAVE_WCSCSPN_C		1
+# define HAVE_WCSCSPN_Z13	HAVE_WCSCSPN_IFUNC_AND_VX_SUPPORT
+#endif
+
+#if HAVE_WCSCSPN_C
+# define WCSCSPN_C		__wcscspn_c
+#else
+# define WCSCSPN_C		NULL
+#endif
+
+#if HAVE_WCSCSPN_Z13
+# define WCSCSPN_Z13		__wcscspn_vx
+#else
+# define WCSCSPN_Z13		NULL
+#endif
diff --git a/sysdeps/s390/multiarch/Makefile b/sysdeps/s390/multiarch/Makefile
index e1e2d9dc74..5be6355423 100644
--- a/sysdeps/s390/multiarch/Makefile
+++ b/sysdeps/s390/multiarch/Makefile
@@ -1,6 +1,5 @@
 ifeq ($(subdir),wcsmbs)
-sysdep_routines += wcscspn wcscspn-vx wcscspn-c \
-		   wmemchr wmemchr-vx wmemchr-c \
+sysdep_routines += wmemchr wmemchr-vx wmemchr-c \
 		   wmemset wmemset-vx wmemset-c \
 		   wmemcmp wmemcmp-vx wmemcmp-c
 endif
diff --git a/sysdeps/s390/multiarch/ifunc-impl-list.c b/sysdeps/s390/multiarch/ifunc-impl-list.c
index 89d6e8ad7e..7d8031a069 100644
--- a/sysdeps/s390/multiarch/ifunc-impl-list.c
+++ b/sysdeps/s390/multiarch/ifunc-impl-list.c
@@ -61,6 +61,7 @@
 #include <ifunc-wcsrchr.h>
 #include <ifunc-wcsspn.h>
 #include <ifunc-wcspbrk.h>
+#include <ifunc-wcscspn.h>
 
 /* Maximum number of IFUNC implementations.  */
 #define MAX_IFUNC	3
@@ -619,6 +620,18 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 		)
 #endif /* HAVE_WCSPBRK_IFUNC  */
 
+#if HAVE_WCSCSPN_IFUNC
+    IFUNC_IMPL (i, name, wcscspn,
+# if HAVE_WCSCSPN_Z13
+		IFUNC_IMPL_ADD (array, i, wcscspn,
+				dl_hwcap & HWCAP_S390_VX, WCSCSPN_Z13)
+# endif
+# if HAVE_WCSCSPN_C
+		IFUNC_IMPL_ADD (array, i, wcscspn, 1, WCSCSPN_C)
+# endif
+		)
+#endif /* HAVE_WCSCSPN_IFUNC  */
+
 #ifdef HAVE_S390_VX_ASM_SUPPORT
 
 # define IFUNC_VX_IMPL(FUNC)						\
@@ -627,8 +640,6 @@ __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 (wcscspn);
-
   IFUNC_VX_IMPL (wmemchr);
 
   IFUNC_VX_IMPL (wmemset);
diff --git a/sysdeps/s390/multiarch/wcscspn-c.c b/sysdeps/s390/wcscspn-c.c
index 161e52e686..d47cb6b75b 100644
--- a/sysdeps/s390/multiarch/wcscspn-c.c
+++ b/sysdeps/s390/wcscspn-c.c
@@ -16,11 +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 WCSCSPN  __wcscspn_c
+#include <ifunc-wcscspn.h>
 
-# include <wchar.h>
-extern __typeof (wcscspn) __wcscspn_c;
+#if HAVE_WCSCSPN_C
+# if HAVE_WCSCSPN_IFUNC || HAVE_WCSCSPN_Z13
+#  define WCSCSPN WCSCSPN_C
+# endif
 
 # include <wcsmbs/wcscspn.c>
 #endif
diff --git a/sysdeps/s390/multiarch/wcscspn-vx.S b/sysdeps/s390/wcscspn-vx.S
index 06bc4e25d0..882cb93fb8 100644
--- a/sysdeps/s390/multiarch/wcscspn-vx.S
+++ b/sysdeps/s390/wcscspn-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-wcscspn.h>
+#if HAVE_WCSCSPN_Z13
 
 # include "sysdep.h"
 # include "asm-syntax.h"
@@ -57,7 +58,7 @@
 			otherwise =0;
    r9:  loaded byte count of vlbb reject-string
 */
-ENTRY(__wcscspn_vx)
+ENTRY(WCSCSPN_Z13)
 	.machine "z13"
 	.machinemode "zarch_nohighgprs"
 
@@ -288,6 +289,10 @@ ENTRY(__wcscspn_vx)
 	vlgvg	%r9,%v31,1
 	br	%r14
 .Lfallback:
-	jg	__wcscspn_c
-END(__wcscspn_vx)
-#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */
+	jg	WCSCSPN_C
+END(WCSCSPN_Z13)
+
+# if ! HAVE_WCSCSPN_IFUNC
+strong_alias (WCSCSPN_Z13, wcscspn)
+# endif
+#endif
diff --git a/sysdeps/s390/multiarch/wcscspn.c b/sysdeps/s390/wcscspn.c
index 707327522a..0ce31b8aab 100644
--- a/sysdeps/s390/multiarch/wcscspn.c
+++ b/sysdeps/s390/wcscspn.c
@@ -16,12 +16,23 @@
    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-wcscspn.h>
+
+#if HAVE_WCSCSPN_IFUNC
 # include <wchar.h>
 # include <ifunc-resolve.h>
 
-s390_vx_libc_ifunc2 (__wcscspn, wcscspn)
+# if HAVE_WCSCSPN_C
+extern __typeof (wcscspn) WCSCSPN_C attribute_hidden;
+# endif
+
+# if HAVE_WCSCSPN_Z13
+extern __typeof (wcscspn) WCSCSPN_Z13 attribute_hidden;
+# endif
 
-#else
-# include <wcsmbs/wcscspn.c>
-#endif /* !(defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)) */
+s390_libc_ifunc_expr (wcscspn, wcscspn,
+		      (HAVE_WCSCSPN_Z13 && (hwcap & HWCAP_S390_VX))
+		      ? WCSCSPN_Z13
+		      : WCSCSPN_DEFAULT
+		      )
+#endif