S390: Refactor wcschr ifunc handling.

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

7 files changed, 126 insertions, 32 deletions

diff --git a/sysdeps/s390/Makefile b/sysdeps/s390/Makefile
index e1253c04be..982e5abfb2 100644
--- a/sysdeps/s390/Makefile
+++ b/sysdeps/s390/Makefile
@@ -92,5 +92,6 @@ sysdep_routines += wcslen wcslen-vx wcslen-c \
 		   wcscat wcscat-vx wcscat-c \
 		   wcsncat wcsncat-vx wcsncat-c \
 		   wcscmp wcscmp-vx wcscmp-c \
-		   wcsncmp wcsncmp-vx wcsncmp-c
+		   wcsncmp wcsncmp-vx wcsncmp-c \
+		   wcschr wcschr-vx wcschr-c
 endif
diff --git a/sysdeps/s390/ifunc-wcschr.h b/sysdeps/s390/ifunc-wcschr.h
new file mode 100644
index 0000000000..2fe9110f7c
--- /dev/null
+++ b/sysdeps/s390/ifunc-wcschr.h
@@ -0,0 +1,53 @@
+/* wcschr 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_WCSCHR_IFUNC	1
+#else
+# define HAVE_WCSCHR_IFUNC	0
+#endif
+
+#ifdef HAVE_S390_VX_ASM_SUPPORT
+# define HAVE_WCSCHR_IFUNC_AND_VX_SUPPORT HAVE_WCSCHR_IFUNC
+#else
+# define HAVE_WCSCHR_IFUNC_AND_VX_SUPPORT 0
+#endif
+
+#if defined HAVE_S390_MIN_Z13_ZARCH_ASM_SUPPORT
+# define WCSCHR_DEFAULT		WCSCHR_Z13
+/* The z13 ifunc variant is using the common code variant as fallback!  */
+# define HAVE_WCSCHR_C		1
+# define HAVE_WCSCHR_Z13	1
+#else
+# define WCSCHR_DEFAULT		WCSCHR_C
+# define HAVE_WCSCHR_C		1
+# define HAVE_WCSCHR_Z13	HAVE_WCSCHR_IFUNC_AND_VX_SUPPORT
+#endif
+
+#if HAVE_WCSCHR_C
+# define WCSCHR_C		__wcschr_c
+#else
+# define WCSCHR_C		NULL
+#endif
+
+#if HAVE_WCSCHR_Z13
+# define WCSCHR_Z13		__wcschr_vx
+#else
+# define WCSCHR_Z13		NULL
+#endif
diff --git a/sysdeps/s390/multiarch/Makefile b/sysdeps/s390/multiarch/Makefile
index d1740fa8e4..b282613b47 100644
--- a/sysdeps/s390/multiarch/Makefile
+++ b/sysdeps/s390/multiarch/Makefile
@@ -1,6 +1,5 @@
 ifeq ($(subdir),wcsmbs)
-sysdep_routines += wcschr wcschr-vx wcschr-c \
-		   wcschrnul wcschrnul-vx wcschrnul-c \
+sysdep_routines += wcschrnul wcschrnul-vx wcschrnul-c \
 		   wcsrchr wcsrchr-vx wcsrchr-c \
 		   wcsspn wcsspn-vx wcsspn-c \
 		   wcspbrk wcspbrk-vx wcspbrk-c \
diff --git a/sysdeps/s390/multiarch/ifunc-impl-list.c b/sysdeps/s390/multiarch/ifunc-impl-list.c
index 8c9e788ae5..c69165465d 100644
--- a/sysdeps/s390/multiarch/ifunc-impl-list.c
+++ b/sysdeps/s390/multiarch/ifunc-impl-list.c
@@ -56,6 +56,7 @@
 #include <ifunc-wcsncat.h>
 #include <ifunc-wcscmp.h>
 #include <ifunc-wcsncmp.h>
+#include <ifunc-wcschr.h>
 
 /* Maximum number of IFUNC implementations.  */
 #define MAX_IFUNC	3
@@ -554,6 +555,18 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 		)
 #endif /* HAVE_WCSNCMP_IFUNC  */
 
+#if HAVE_WCSCHR_IFUNC
+    IFUNC_IMPL (i, name, wcschr,
+# if HAVE_WCSCHR_Z13
+		IFUNC_IMPL_ADD (array, i, wcschr,
+				dl_hwcap & HWCAP_S390_VX, WCSCHR_Z13)
+# endif
+# if HAVE_WCSCHR_C
+		IFUNC_IMPL_ADD (array, i, wcschr, 1, WCSCHR_C)
+# endif
+		)
+#endif /* HAVE_WCSCHR_IFUNC  */
+
 #ifdef HAVE_S390_VX_ASM_SUPPORT
 
 # define IFUNC_VX_IMPL(FUNC)						\
@@ -562,8 +575,6 @@ __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 (wcschr);
-
   IFUNC_VX_IMPL (wcschrnul);
 
   IFUNC_VX_IMPL (wcsrchr);
diff --git a/sysdeps/s390/multiarch/wcschr-c.c b/sysdeps/s390/wcschr-c.c
index 8d6679c7f2..4908492a0a 100644
--- a/sysdeps/s390/multiarch/wcschr-c.c
+++ b/sysdeps/s390/wcschr-c.c
@@ -16,22 +16,29 @@
    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 WCSCHR  __wcschr_c
-
-# include <wchar.h>
-extern __typeof (__wcschr) __wcschr_c;
-# undef weak_alias
-# define weak_alias(name, alias)
-# ifdef SHARED
-#  undef libc_hidden_def
-#  define libc_hidden_def(name)					\
-  __hidden_ver1 (__wcschr_c, __GI_wcschr, __wcschr_c);		\
-  strong_alias (__wcschr_c, __wcschr_c_1);			\
+#include <ifunc-wcschr.h>
+
+#if HAVE_WCSCHR_C
+# if HAVE_WCSCHR_IFUNC || HAVE_WCSCHR_Z13
+#  define WCSCHR WCSCHR_C
+
+#  undef weak_alias
+#  define weak_alias(name, alias)
+
+#  if defined SHARED && IS_IN (libc)
+#   undef libc_hidden_weak
+#   define libc_hidden_weak(name)
+#   undef libc_hidden_def
+#   if ! defined HAVE_S390_MIN_Z13_ZARCH_ASM_SUPPORT
+#    define libc_hidden_def(name)					\
+  __hidden_ver1 (__wcschr_c, __GI_wcschr, __wcschr_c)  __attribute__((weak)); \
+  strong_alias (__wcschr_c, __wcschr_c_1);				\
   __hidden_ver1 (__wcschr_c_1, __GI___wcschr, __wcschr_c_1);
-#  undef libc_hidden_weak
-#  define libc_hidden_weak(name)
-# endif /* SHARED */
+#   else
+#    define libc_hidden_def(name)
+#   endif
+#  endif
+# endif
 
 # include <wcsmbs/wcschr.c>
-#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */
+#endif
diff --git a/sysdeps/s390/multiarch/wcschr-vx.S b/sysdeps/s390/wcschr-vx.S
index 94e5df7f36..dd24998390 100644
--- a/sysdeps/s390/multiarch/wcschr-vx.S
+++ b/sysdeps/s390/wcschr-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-wcschr.h>
+#if HAVE_WCSCHR_Z13
 
 # include "sysdep.h"
 # include "asm-syntax.h"
@@ -36,7 +37,7 @@
    -v17=index of unequal
    -v18=replicated c
 */
-ENTRY(__wcschr_vx)
+ENTRY(WCSCHR_Z13)
 	.machine "z13"
 	.machinemode "zarch_nohighgprs"
 
@@ -98,6 +99,17 @@ ENTRY(__wcschr_vx)
 	lghi	%r2,0		/* Return null if character not found.  */
 	br	%r14
 .Lfallback:
-	jg	__wcschr_c
-END(__wcschr_vx)
-#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */
+	jg	WCSCHR_C
+END(WCSCHR_Z13)
+
+# if ! HAVE_WCSCHR_IFUNC
+strong_alias (WCSCHR_Z13, __wcschr)
+weak_alias (__wcschr, wcschr)
+# endif
+
+# if defined HAVE_S390_MIN_Z13_ZARCH_ASM_SUPPORT \
+	&& defined SHARED && IS_IN (libc)
+strong_alias (WCSCHR_Z13, __GI___wcschr)
+weak_alias (WCSCHR_Z13, __GI_wcschr)
+# endif
+#endif
diff --git a/sysdeps/s390/multiarch/wcschr.c b/sysdeps/s390/wcschr.c
index f44138f771..9923864ff8 100644
--- a/sysdeps/s390/multiarch/wcschr.c
+++ b/sysdeps/s390/wcschr.c
@@ -16,7 +16,9 @@
    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-wcschr.h>
+
+#if HAVE_WCSCHR_IFUNC
 # define wcschr __redirect_wcschr
 # define __wcschr __redirect___wcschr
 # include <wchar.h>
@@ -24,9 +26,18 @@
 # undef __wcschr
 # include <ifunc-resolve.h>
 
-s390_vx_libc_ifunc_redirected (__redirect___wcschr, __wcschr)
-weak_alias (__wcschr, wcschr)
+# if HAVE_WCSCHR_C
+extern __typeof (__redirect___wcschr) WCSCHR_C attribute_hidden;
+# endif
 
-#else
-# include <wcsmbs/wcschr.c>
-#endif /* !(defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)) */
+# if HAVE_WCSCHR_Z13
+extern __typeof (__redirect___wcschr) WCSCHR_Z13 attribute_hidden;
+# endif
+
+s390_libc_ifunc_expr (__redirect___wcschr, __wcschr,
+		      (HAVE_WCSCHR_Z13 && (hwcap & HWCAP_S390_VX))
+		      ? WCSCHR_Z13
+		      : WCSCHR_DEFAULT
+		      )
+weak_alias (__wcschr, wcschr)
+#endif