S390: Refactor wcsrchr ifunc handling.

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

7 files changed, 101 insertions, 19 deletions

diff --git a/sysdeps/s390/Makefile b/sysdeps/s390/Makefile
index a8cd264521..a2c641e81f 100644
--- a/sysdeps/s390/Makefile
+++ b/sysdeps/s390/Makefile
@@ -94,5 +94,6 @@ sysdep_routines += wcslen wcslen-vx wcslen-c \
 		   wcscmp wcscmp-vx wcscmp-c \
 		   wcsncmp wcsncmp-vx wcsncmp-c \
 		   wcschr wcschr-vx wcschr-c \
-		   wcschrnul wcschrnul-vx wcschrnul-c
+		   wcschrnul wcschrnul-vx wcschrnul-c \
+		   wcsrchr wcsrchr-vx wcsrchr-c
 endif
diff --git a/sysdeps/s390/ifunc-wcsrchr.h b/sysdeps/s390/ifunc-wcsrchr.h
new file mode 100644
index 0000000000..4eec0c1707
--- /dev/null
+++ b/sysdeps/s390/ifunc-wcsrchr.h
@@ -0,0 +1,53 @@
+/* wcsrchr 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_WCSRCHR_IFUNC	1
+#else
+# define HAVE_WCSRCHR_IFUNC	0
+#endif
+
+#ifdef HAVE_S390_VX_ASM_SUPPORT
+# define HAVE_WCSRCHR_IFUNC_AND_VX_SUPPORT HAVE_WCSRCHR_IFUNC
+#else
+# define HAVE_WCSRCHR_IFUNC_AND_VX_SUPPORT 0
+#endif
+
+#if defined HAVE_S390_MIN_Z13_ZARCH_ASM_SUPPORT
+# define WCSRCHR_DEFAULT	WCSRCHR_Z13
+/* The z13 ifunc variant is using the common code variant as fallback!  */
+# define HAVE_WCSRCHR_C		1
+# define HAVE_WCSRCHR_Z13	1
+#else
+# define WCSRCHR_DEFAULT	WCSRCHR_C
+# define HAVE_WCSRCHR_C		1
+# define HAVE_WCSRCHR_Z13	HAVE_WCSRCHR_IFUNC_AND_VX_SUPPORT
+#endif
+
+#if HAVE_WCSRCHR_C
+# define WCSRCHR_C		__wcsrchr_c
+#else
+# define WCSRCHR_C		NULL
+#endif
+
+#if HAVE_WCSRCHR_Z13
+# define WCSRCHR_Z13		__wcsrchr_vx
+#else
+# define WCSRCHR_Z13		NULL
+#endif
diff --git a/sysdeps/s390/multiarch/Makefile b/sysdeps/s390/multiarch/Makefile
index 0eb01d5d84..3d72cbb5f3 100644
--- a/sysdeps/s390/multiarch/Makefile
+++ b/sysdeps/s390/multiarch/Makefile
@@ -1,6 +1,5 @@
 ifeq ($(subdir),wcsmbs)
-sysdep_routines += wcsrchr wcsrchr-vx wcsrchr-c \
-		   wcsspn wcsspn-vx wcsspn-c \
+sysdep_routines += wcsspn wcsspn-vx wcsspn-c \
 		   wcspbrk wcspbrk-vx wcspbrk-c \
 		   wcscspn wcscspn-vx wcscspn-c \
 		   wmemchr wmemchr-vx wmemchr-c \
diff --git a/sysdeps/s390/multiarch/ifunc-impl-list.c b/sysdeps/s390/multiarch/ifunc-impl-list.c
index 553a76c39e..ffb4d5b687 100644
--- a/sysdeps/s390/multiarch/ifunc-impl-list.c
+++ b/sysdeps/s390/multiarch/ifunc-impl-list.c
@@ -58,6 +58,7 @@
 #include <ifunc-wcsncmp.h>
 #include <ifunc-wcschr.h>
 #include <ifunc-wcschrnul.h>
+#include <ifunc-wcsrchr.h>
 
 /* Maximum number of IFUNC implementations.  */
 #define MAX_IFUNC	3
@@ -580,6 +581,18 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 		)
 #endif /* HAVE_WCSCHRNUL_IFUNC  */
 
+#if HAVE_WCSRCHR_IFUNC
+    IFUNC_IMPL (i, name, wcsrchr,
+# if HAVE_WCSRCHR_Z13
+		IFUNC_IMPL_ADD (array, i, wcsrchr,
+				dl_hwcap & HWCAP_S390_VX, WCSRCHR_Z13)
+# endif
+# if HAVE_WCSRCHR_C
+		IFUNC_IMPL_ADD (array, i, wcsrchr, 1, WCSRCHR_C)
+# endif
+		)
+#endif /* HAVE_WCSRCHR_IFUNC  */
+
 #ifdef HAVE_S390_VX_ASM_SUPPORT
 
 # define IFUNC_VX_IMPL(FUNC)						\
@@ -588,8 +601,6 @@ __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 (wcsrchr);
-
   IFUNC_VX_IMPL (wcsspn);
 
   IFUNC_VX_IMPL (wcspbrk);
diff --git a/sysdeps/s390/multiarch/wcsrchr-c.c b/sysdeps/s390/wcsrchr-c.c
index 615250358b..65164a897f 100644
--- a/sysdeps/s390/multiarch/wcsrchr-c.c
+++ b/sysdeps/s390/wcsrchr-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 WCSRCHR  __wcsrchr_c
+#include <ifunc-wcsrchr.h>
+
+#if HAVE_WCSRCHR_C
+# if HAVE_WCSRCHR_IFUNC || HAVE_WCSRCHR_Z13
+#  define WCSRCHR WCSRCHR_C
+# endif
 
-# include <wchar.h>
-extern __typeof (wcsrchr) __wcsrchr_c;
 # include <wcsmbs/wcsrchr.c>
 #endif
diff --git a/sysdeps/s390/multiarch/wcsrchr-vx.S b/sysdeps/s390/wcsrchr-vx.S
index e40a554e5d..c7b6585bea 100644
--- a/sysdeps/s390/multiarch/wcsrchr-vx.S
+++ b/sysdeps/s390/wcsrchr-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-wcsrchr.h>
+#if HAVE_WCSRCHR_Z13
 
 # include "sysdep.h"
 # include "asm-syntax.h"
@@ -39,7 +40,7 @@
    -v19=part of s with last occurence of c.
    -v20=permute pattern
 */
-ENTRY(__wcsrchr_vx)
+ENTRY(WCSRCHR_Z13)
 	.machine "z13"
 	.machinemode "zarch_nohighgprs"
 
@@ -185,6 +186,10 @@ ENTRY(__wcsrchr_vx)
 	.byte	0x0C,0x0D,0x0E,0x0F,0x08,0x09,0x0A,0x0B
 	.byte	0x04,0x05,0x06,0x07,0x00,0x01,0x02,0x03
 .Lfallback:
-	jg	__wcsrchr_c
-END(__wcsrchr_vx)
-#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */
+	jg	WCSRCHR_C
+END(WCSRCHR_Z13)
+
+# if ! HAVE_WCSRCHR_IFUNC
+strong_alias (WCSRCHR_Z13, wcsrchr)
+# endif
+#endif
diff --git a/sysdeps/s390/multiarch/wcsrchr.c b/sysdeps/s390/wcsrchr.c
index aa0b8a8f82..eb70f27038 100644
--- a/sysdeps/s390/multiarch/wcsrchr.c
+++ b/sysdeps/s390/wcsrchr.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-wcsrchr.h>
+
+#if HAVE_WCSRCHR_IFUNC
 # include <wchar.h>
 # include <ifunc-resolve.h>
 
-s390_vx_libc_ifunc2 (__wcsrchr, wcsrchr)
+# if HAVE_WCSRCHR_C
+extern __typeof (wcsrchr) WCSRCHR_C attribute_hidden;
+# endif
+
+# if HAVE_WCSRCHR_Z13
+extern __typeof (wcsrchr) WCSRCHR_Z13 attribute_hidden;
+# endif
 
-#else
-# include <wcsmbs/wcsrchr.c>
-#endif /* !(defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)) */
+s390_libc_ifunc_expr (wcsrchr, wcsrchr,
+		      (HAVE_WCSRCHR_Z13 && (hwcap & HWCAP_S390_VX))
+		      ? WCSRCHR_Z13
+		      : WCSRCHR_DEFAULT
+		      )
+#endif