S390: Refactor wcslen ifunc handling.

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

7 files changed, 105 insertions, 19 deletions

diff --git a/sysdeps/s390/Makefile b/sysdeps/s390/Makefile
index 0e86242c5d..10c0e1bea0 100644
--- a/sysdeps/s390/Makefile
+++ b/sysdeps/s390/Makefile
@@ -81,3 +81,7 @@ sysdep_routines += bzero memset memset-z900 \
 		   memccpy memccpy-vx memccpy-c \
 		   memrchr memrchr-vx memrchr-c
 endif
+
+ifeq ($(subdir),wcsmbs)
+sysdep_routines += wcslen wcslen-vx wcslen-c
+endif
diff --git a/sysdeps/s390/ifunc-wcslen.h b/sysdeps/s390/ifunc-wcslen.h
new file mode 100644
index 0000000000..50d879caf2
--- /dev/null
+++ b/sysdeps/s390/ifunc-wcslen.h
@@ -0,0 +1,53 @@
+/* wcslen 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_WCSLEN_IFUNC	1
+#else
+# define HAVE_WCSLEN_IFUNC	0
+#endif
+
+#ifdef HAVE_S390_VX_ASM_SUPPORT
+# define HAVE_WCSLEN_IFUNC_AND_VX_SUPPORT HAVE_WCSLEN_IFUNC
+#else
+# define HAVE_WCSLEN_IFUNC_AND_VX_SUPPORT 0
+#endif
+
+#if defined HAVE_S390_MIN_Z13_ZARCH_ASM_SUPPORT
+# define WCSLEN_DEFAULT		WCSLEN_Z13
+/* The z13 ifunc variant is using the common code variant as fallback!  */
+# define HAVE_WCSLEN_C		1
+# define HAVE_WCSLEN_Z13	1
+#else
+# define WCSLEN_DEFAULT		WCSLEN_C
+# define HAVE_WCSLEN_C		1
+# define HAVE_WCSLEN_Z13	HAVE_WCSLEN_IFUNC_AND_VX_SUPPORT
+#endif
+
+#if HAVE_WCSLEN_C
+# define WCSLEN_C		__wcslen_c
+#else
+# define WCSLEN_C		NULL
+#endif
+
+#if HAVE_WCSLEN_Z13
+# define WCSLEN_Z13		__wcslen_vx
+#else
+# define WCSLEN_Z13		NULL
+#endif
diff --git a/sysdeps/s390/multiarch/Makefile b/sysdeps/s390/multiarch/Makefile
index 260b514936..421d40d020 100644
--- a/sysdeps/s390/multiarch/Makefile
+++ b/sysdeps/s390/multiarch/Makefile
@@ -1,6 +1,5 @@
 ifeq ($(subdir),wcsmbs)
-sysdep_routines += wcslen wcslen-vx wcslen-c \
-		   wcsnlen wcsnlen-vx wcsnlen-c \
+sysdep_routines += wcsnlen wcsnlen-vx wcsnlen-c \
 		   wcscpy wcscpy-vx wcscpy-c \
 		   wcpcpy wcpcpy-vx wcpcpy-c \
 		   wcsncpy wcsncpy-vx wcsncpy-c \
diff --git a/sysdeps/s390/multiarch/ifunc-impl-list.c b/sysdeps/s390/multiarch/ifunc-impl-list.c
index 0f01b99691..7bf5f14c01 100644
--- a/sysdeps/s390/multiarch/ifunc-impl-list.c
+++ b/sysdeps/s390/multiarch/ifunc-impl-list.c
@@ -46,6 +46,7 @@
 #include <ifunc-rawmemchr.h>
 #include <ifunc-memccpy.h>
 #include <ifunc-memrchr.h>
+#include <ifunc-wcslen.h>
 
 /* Maximum number of IFUNC implementations.  */
 #define MAX_IFUNC	3
@@ -424,6 +425,18 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 		)
 #endif /* HAVE_MEMRCHR_IFUNC  */
 
+#if HAVE_WCSLEN_IFUNC
+    IFUNC_IMPL (i, name, wcslen,
+# if HAVE_WCSLEN_Z13
+		IFUNC_IMPL_ADD (array, i, wcslen,
+				dl_hwcap & HWCAP_S390_VX, WCSLEN_Z13)
+# endif
+# if HAVE_WCSLEN_C
+		IFUNC_IMPL_ADD (array, i, wcslen, 1, WCSLEN_C)
+# endif
+		)
+#endif /* HAVE_WCSLEN_IFUNC  */
+
 #ifdef HAVE_S390_VX_ASM_SUPPORT
 
 # define IFUNC_VX_IMPL(FUNC)						\
@@ -432,8 +445,6 @@ __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 (wcslen);
-
   IFUNC_VX_IMPL (wcsnlen);
 
   IFUNC_VX_IMPL (wcscpy);
diff --git a/sysdeps/s390/multiarch/wcslen-c.c b/sysdeps/s390/wcslen-c.c
index 32a23e206d..45399cff3a 100644
--- a/sysdeps/s390/multiarch/wcslen-c.c
+++ b/sysdeps/s390/wcslen-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 WCSLEN  __wcslen_c
+#include <ifunc-wcslen.h>
+
+#if HAVE_WCSLEN_C
+# if HAVE_WCSLEN_IFUNC || HAVE_WCSLEN_Z13
+#  define WCSLEN WCSLEN_C
+# endif
 
-# include <wchar.h>
-extern __typeof (__wcslen) __wcslen_c;
 # include <wcsmbs/wcslen.c>
 #endif
diff --git a/sysdeps/s390/multiarch/wcslen-vx.S b/sysdeps/s390/wcslen-vx.S
index 337cbed6ec..114f7ef743 100644
--- a/sysdeps/s390/multiarch/wcslen-vx.S
+++ b/sysdeps/s390/wcslen-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-wcslen.h>
+#if HAVE_WCSLEN_Z13
 
 # include "sysdep.h"
 # include "asm-syntax.h"
@@ -34,7 +35,7 @@
    -r5=current_len and return_value
    -v16=part of s
 */
-ENTRY(__wcslen_vx)
+ENTRY(WCSLEN_Z13)
 	.machine "z13"
 	.machinemode "zarch_nohighgprs"
 
@@ -86,6 +87,11 @@ ENTRY(__wcslen_vx)
 	srlg	%r2,%r2,2	/* Convert byte-count to character-count.  */
 	br	%r14
 .Lfallback:
-	jg	__wcslen_c
-END(__wcslen_vx)
-#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */
+	jg	WCSLEN_C
+END(WCSLEN_Z13)
+
+# if ! HAVE_WCSLEN_IFUNC
+strong_alias (WCSLEN_Z13, __wcslen)
+weak_alias (__wcslen, wcslen)
+# endif
+#endif
diff --git a/sysdeps/s390/multiarch/wcslen.c b/sysdeps/s390/wcslen.c
index 3a1d1a32c9..a5eee83f6c 100644
--- a/sysdeps/s390/multiarch/wcslen.c
+++ b/sysdeps/s390/wcslen.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-wcslen.h>
+
+#if HAVE_WCSLEN_IFUNC
 # include <wchar.h>
 # include <ifunc-resolve.h>
 
-s390_vx_libc_ifunc (__wcslen)
-weak_alias (__wcslen, wcslen)
+# if HAVE_WCSLEN_C
+extern __typeof (__wcslen) WCSLEN_C attribute_hidden;
+# endif
 
-#else
-# include <wcsmbs/wcslen.c>
-#endif /* !(defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)) */
+# if HAVE_WCSLEN_Z13
+extern __typeof (__wcslen) WCSLEN_Z13 attribute_hidden;
+# endif
+
+s390_libc_ifunc_expr (__wcslen, __wcslen,
+		      (HAVE_WCSLEN_Z13 && (hwcap & HWCAP_S390_VX))
+		      ? WCSLEN_Z13
+		      : WCSLEN_DEFAULT
+		      )
+weak_alias (__wcslen, wcslen)
+#endif