S390: Refactor strspn ifunc handling.

The ifunc handling for strspn is adjusted in order to omit ifunc
variants if those will never be used as the minimum architecture level
already supports newer CPUs by default.
Glibc internal calls will then also use the "newer" ifunc variant.

ChangeLog:

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

7 files changed, 110 insertions, 20 deletions

diff --git a/sysdeps/s390/Makefile b/sysdeps/s390/Makefile
index c423c80a43..604ca68ef1 100644
--- a/sysdeps/s390/Makefile
+++ b/sysdeps/s390/Makefile
@@ -72,5 +72,6 @@ sysdep_routines += bzero memset memset-z900 \
 		   strncmp strncmp-vx strncmp-c \
 		   strchr strchr-vx strchr-c \
 		   strchrnul strchrnul-vx strchrnul-c \
-		   strrchr strrchr-vx strrchr-c
+		   strrchr strrchr-vx strrchr-c \
+		   strspn strspn-vx strspn-c
 endif
diff --git a/sysdeps/s390/ifunc-strspn.h b/sysdeps/s390/ifunc-strspn.h
new file mode 100644
index 0000000000..1152ba1f3d
--- /dev/null
+++ b/sysdeps/s390/ifunc-strspn.h
@@ -0,0 +1,52 @@
+/* strspn 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_STRSPN_IFUNC	1
+#else
+# define HAVE_STRSPN_IFUNC	0
+#endif
+
+#ifdef HAVE_S390_VX_ASM_SUPPORT
+# define HAVE_STRSPN_IFUNC_AND_VX_SUPPORT HAVE_STRSPN_IFUNC
+#else
+# define HAVE_STRSPN_IFUNC_AND_VX_SUPPORT 0
+#endif
+
+#if defined HAVE_S390_MIN_Z13_ZARCH_ASM_SUPPORT
+# define STRSPN_DEFAULT		STRSPN_Z13
+# define HAVE_STRSPN_C		0
+# define HAVE_STRSPN_Z13	1
+#else
+# define STRSPN_DEFAULT		STRSPN_C
+# define HAVE_STRSPN_C		1
+# define HAVE_STRSPN_Z13	HAVE_STRSPN_IFUNC_AND_VX_SUPPORT
+#endif
+
+#if HAVE_STRSPN_C
+# define STRSPN_C		__strspn_c
+#else
+# define STRSPN_C		NULL
+#endif
+
+#if HAVE_STRSPN_Z13
+# define STRSPN_Z13		__strspn_vx
+#else
+# define STRSPN_Z13		NULL
+#endif
diff --git a/sysdeps/s390/multiarch/Makefile b/sysdeps/s390/multiarch/Makefile
index c826755558..9b141e338c 100644
--- a/sysdeps/s390/multiarch/Makefile
+++ b/sysdeps/s390/multiarch/Makefile
@@ -1,6 +1,5 @@
 ifeq ($(subdir),string)
-sysdep_routines += strspn strspn-vx strspn-c \
-		   strpbrk strpbrk-vx strpbrk-c \
+sysdep_routines += strpbrk strpbrk-vx strpbrk-c \
 		   strcspn strcspn-vx strcspn-c \
 		   memchr memchr-vx \
 		   rawmemchr rawmemchr-vx rawmemchr-c \
diff --git a/sysdeps/s390/multiarch/ifunc-impl-list.c b/sysdeps/s390/multiarch/ifunc-impl-list.c
index 60cd705ffa..c39e1f793a 100644
--- a/sysdeps/s390/multiarch/ifunc-impl-list.c
+++ b/sysdeps/s390/multiarch/ifunc-impl-list.c
@@ -39,6 +39,7 @@
 #include <ifunc-strchr.h>
 #include <ifunc-strchrnul.h>
 #include <ifunc-strrchr.h>
+#include <ifunc-strspn.h>
 
 /* Maximum number of IFUNC implementations.  */
 #define MAX_IFUNC	3
@@ -333,6 +334,18 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 		)
 #endif /* HAVE_STRRCHR_IFUNC  */
 
+#if HAVE_STRSPN_IFUNC
+    IFUNC_IMPL (i, name, strspn,
+# if HAVE_STRSPN_Z13
+		IFUNC_IMPL_ADD (array, i, strspn,
+				dl_hwcap & HWCAP_S390_VX, STRSPN_Z13)
+# endif
+# if HAVE_STRSPN_C
+		IFUNC_IMPL_ADD (array, i, strspn, 1, STRSPN_C)
+# endif
+		)
+#endif /* HAVE_STRSPN_IFUNC  */
+
 #ifdef HAVE_S390_VX_ASM_SUPPORT
 
 # define IFUNC_VX_IMPL(FUNC)						\
@@ -367,7 +380,6 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 
   IFUNC_VX_IMPL (wcsrchr);
 
-  IFUNC_VX_IMPL (strspn);
   IFUNC_VX_IMPL (wcsspn);
 
   IFUNC_VX_IMPL (strpbrk);
diff --git a/sysdeps/s390/multiarch/strspn-c.c b/sysdeps/s390/strspn-c.c
index 0efe61bfb2..506f668321 100644
--- a/sysdeps/s390/multiarch/strspn-c.c
+++ b/sysdeps/s390/strspn-c.c
@@ -16,13 +16,17 @@
    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 STRSPN  __strspn_c
-# ifdef SHARED
-#  undef libc_hidden_builtin_def
-#  define libc_hidden_builtin_def(name)				\
+#include <ifunc-strspn.h>
+
+#if HAVE_STRSPN_C
+# if HAVE_STRSPN_IFUNC
+#  define STRSPN STRSPN_C
+#  if defined SHARED && IS_IN (libc)
+#   undef libc_hidden_builtin_def
+#   define libc_hidden_builtin_def(name)			\
      __hidden_ver1 (__strspn_c, __GI_strspn, __strspn_c);
-# endif /* SHARED */
+#  endif
+# endif
 
 # include <string/strspn.c>
-#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */
+#endif
diff --git a/sysdeps/s390/multiarch/strspn-vx.S b/sysdeps/s390/strspn-vx.S
index 6aa823e63b..ae5529b567 100644
--- a/sysdeps/s390/multiarch/strspn-vx.S
+++ b/sysdeps/s390/strspn-vx.S
@@ -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-strspn.h>
+
+#if HAVE_STRSPN_Z13
 
 # include "sysdep.h"
 # include "asm-syntax.h"
@@ -57,7 +59,7 @@
 	otherwise =0;
    r9: loaded byte count of vlbb accept-string
 */
-ENTRY(__strspn_vx)
+ENTRY(STRSPN_Z13)
 	.machine "z13"
 	.machinemode "zarch_nohighgprs"
 
@@ -252,5 +254,14 @@ ENTRY(__strspn_vx)
 				   Check for zero is in jump-target.  */
 	j	.Lslow_next_acc_notonbb /* ... and search for zero in
 					    fully loaded vreg again.  */
-END(__strspn_vx)
-#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */
+END(STRSPN_Z13)
+
+# if ! HAVE_STRSPN_IFUNC
+strong_alias (STRSPN_Z13, strspn)
+# endif
+
+# if ! HAVE_STRSPN_C && defined SHARED && IS_IN (libc)
+strong_alias (STRSPN_Z13, __GI_strspn)
+# endif
+
+#endif /* HAVE_STRSPN_Z13  */
diff --git a/sysdeps/s390/multiarch/strspn.c b/sysdeps/s390/strspn.c
index bedbe98cfc..91401fdaf8 100644
--- a/sysdeps/s390/multiarch/strspn.c
+++ b/sysdeps/s390/strspn.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-strspn.h>
+
+#if HAVE_STRSPN_IFUNC
 # define strspn __redirect_strspn
 /* Omit the strspn inline definitions because it would redefine strspn.  */
 # define __NO_STRING_INLINES
@@ -24,8 +26,17 @@
 # undef strspn
 # include <ifunc-resolve.h>
 
-s390_vx_libc_ifunc2_redirected (__redirect_strspn, __strspn, strspn)
+# if HAVE_STRSPN_C
+extern __typeof (__redirect_strspn) STRSPN_C attribute_hidden;
+# endif
+
+# if HAVE_STRSPN_Z13
+extern __typeof (__redirect_strspn) STRSPN_Z13 attribute_hidden;
+# endif
 
-#else
-# include <string/strspn.c>
-#endif /* !(defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)) */
+s390_libc_ifunc_expr (__redirect_strspn, strspn,
+		      (HAVE_STRSPN_Z13 && (hwcap & HWCAP_S390_VX))
+		      ? STRSPN_Z13
+		      : STRSPN_DEFAULT
+		      )
+#endif /* HAVE_STRSPN_IFUNC  */