S390: Refactor strcspn ifunc handling.

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

7 files changed, 111 insertions, 21 deletions

diff --git a/sysdeps/s390/Makefile b/sysdeps/s390/Makefile
index df1f858e28..c163969652 100644
--- a/sysdeps/s390/Makefile
+++ b/sysdeps/s390/Makefile
@@ -74,5 +74,6 @@ sysdep_routines += bzero memset memset-z900 \
 		   strchrnul strchrnul-vx strchrnul-c \
 		   strrchr strrchr-vx strrchr-c \
 		   strspn strspn-vx strspn-c \
-		   strpbrk strpbrk-vx strpbrk-c
+		   strpbrk strpbrk-vx strpbrk-c \
+		   strcspn strcspn-vx strcspn-c
 endif
diff --git a/sysdeps/s390/ifunc-strcspn.h b/sysdeps/s390/ifunc-strcspn.h
new file mode 100644
index 0000000000..9b7032509a
--- /dev/null
+++ b/sysdeps/s390/ifunc-strcspn.h
@@ -0,0 +1,52 @@
+/* strcspn 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_STRCSPN_IFUNC	1
+#else
+# define HAVE_STRCSPN_IFUNC	0
+#endif
+
+#ifdef HAVE_S390_VX_ASM_SUPPORT
+# define HAVE_STRCSPN_IFUNC_AND_VX_SUPPORT HAVE_STRCSPN_IFUNC
+#else
+# define HAVE_STRCSPN_IFUNC_AND_VX_SUPPORT 0
+#endif
+
+#if defined HAVE_S390_MIN_Z13_ZARCH_ASM_SUPPORT
+# define STRCSPN_DEFAULT	STRCSPN_Z13
+# define HAVE_STRCSPN_C		0
+# define HAVE_STRCSPN_Z13	1
+#else
+# define STRCSPN_DEFAULT	STRCSPN_C
+# define HAVE_STRCSPN_C		1
+# define HAVE_STRCSPN_Z13	HAVE_STRCSPN_IFUNC_AND_VX_SUPPORT
+#endif
+
+#if HAVE_STRCSPN_C
+# define STRCSPN_C		__strcspn_c
+#else
+# define STRCSPN_C		NULL
+#endif
+
+#if HAVE_STRCSPN_Z13
+# define STRCSPN_Z13		__strcspn_vx
+#else
+# define STRCSPN_Z13		NULL
+#endif
diff --git a/sysdeps/s390/multiarch/Makefile b/sysdeps/s390/multiarch/Makefile
index 1a3fed9fc8..1578f21af4 100644
--- a/sysdeps/s390/multiarch/Makefile
+++ b/sysdeps/s390/multiarch/Makefile
@@ -1,6 +1,5 @@
 ifeq ($(subdir),string)
-sysdep_routines += strcspn strcspn-vx strcspn-c \
-		   memchr memchr-vx \
+sysdep_routines += memchr memchr-vx \
 		   rawmemchr rawmemchr-vx rawmemchr-c \
 		   memccpy memccpy-vx memccpy-c \
 		   memrchr memrchr-vx memrchr-c
diff --git a/sysdeps/s390/multiarch/ifunc-impl-list.c b/sysdeps/s390/multiarch/ifunc-impl-list.c
index 8e23416730..2d48c99c8d 100644
--- a/sysdeps/s390/multiarch/ifunc-impl-list.c
+++ b/sysdeps/s390/multiarch/ifunc-impl-list.c
@@ -41,6 +41,7 @@
 #include <ifunc-strrchr.h>
 #include <ifunc-strspn.h>
 #include <ifunc-strpbrk.h>
+#include <ifunc-strcspn.h>
 
 /* Maximum number of IFUNC implementations.  */
 #define MAX_IFUNC	3
@@ -359,6 +360,18 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 		)
 #endif /* HAVE_STRPBRK_IFUNC  */
 
+#if HAVE_STRCSPN_IFUNC
+    IFUNC_IMPL (i, name, strcspn,
+# if HAVE_STRCSPN_Z13
+		IFUNC_IMPL_ADD (array, i, strcspn,
+				dl_hwcap & HWCAP_S390_VX, STRCSPN_Z13)
+# endif
+# if HAVE_STRCSPN_C
+		IFUNC_IMPL_ADD (array, i, strcspn, 1, STRCSPN_C)
+# endif
+		)
+#endif /* HAVE_STRCSPN_IFUNC  */
+
 #ifdef HAVE_S390_VX_ASM_SUPPORT
 
 # define IFUNC_VX_IMPL(FUNC)						\
@@ -397,7 +410,6 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 
   IFUNC_VX_IMPL (wcspbrk);
 
-  IFUNC_VX_IMPL (strcspn);
   IFUNC_VX_IMPL (wcscspn);
 
   IFUNC_VX_IMPL (memchr);
diff --git a/sysdeps/s390/multiarch/strcspn-c.c b/sysdeps/s390/strcspn-c.c
index 7b454f5b56..9f51f92bdb 100644
--- a/sysdeps/s390/multiarch/strcspn-c.c
+++ b/sysdeps/s390/strcspn-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 STRCSPN  __strcspn_c
-# ifdef SHARED
-#  undef libc_hidden_builtin_def
-#  define libc_hidden_builtin_def(name)				\
-     __hidden_ver1 (__strcspn_c, __GI_strcspn, __strcspn_c);
-# endif /* SHARED */
+#include <ifunc-strcspn.h>
+
+#if HAVE_STRCSPN_C
+# if HAVE_STRCSPN_IFUNC
+#  define STRCSPN STRCSPN_C
+#  if defined SHARED && IS_IN (libc)
+#   undef libc_hidden_builtin_def
+#   define libc_hidden_builtin_def(name)			\
+  __hidden_ver1 (__strcspn_c, __GI_strcspn, __strcspn_c);
+#  endif
+# endif
 
 # include <string/strcspn.c>
-#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */
+#endif
diff --git a/sysdeps/s390/multiarch/strcspn-vx.S b/sysdeps/s390/strcspn-vx.S
index ea1668742b..ff5b1be549 100644
--- a/sysdeps/s390/multiarch/strcspn-vx.S
+++ b/sysdeps/s390/strcspn-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-strcspn.h>
+
+#if HAVE_STRCSPN_Z13
 
 # include "sysdep.h"
 # include "asm-syntax.h"
@@ -58,7 +60,7 @@
 			otherwise =0;
    r9:  loaded byte count of vlbb reject-string
 */
-ENTRY(__strcspn_vx)
+ENTRY(STRCSPN_Z13)
 	.machine "z13"
 	.machinemode "zarch_nohighgprs"
 
@@ -277,5 +279,14 @@ ENTRY(__strcspn_vx)
 	vlgvg	%r8,%v31,0
 	vlgvg	%r9,%v31,1
 	br	%r14
-END(__strcspn_vx)
-#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */
+END(STRCSPN_Z13)
+
+# if ! HAVE_STRCSPN_IFUNC
+strong_alias (STRCSPN_Z13, strcspn)
+# endif
+
+# if ! HAVE_STRCSPN_C && defined SHARED && IS_IN (libc)
+strong_alias (STRCSPN_Z13, __GI_strcspn)
+# endif
+
+#endif /* HAVE_STRCSPN_Z13  */
diff --git a/sysdeps/s390/multiarch/strcspn.c b/sysdeps/s390/strcspn.c
index 418ffcdded..a3f35d39c5 100644
--- a/sysdeps/s390/multiarch/strcspn.c
+++ b/sysdeps/s390/strcspn.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-strcspn.h>
+
+#if HAVE_STRCSPN_IFUNC
 # define strcspn __redirect_strcspn
 /* Omit the strcspn inline definitions because it would redefine strcspn.  */
 # define __NO_STRING_INLINES
@@ -24,8 +26,17 @@
 # undef strcspn
 # include <ifunc-resolve.h>
 
-s390_vx_libc_ifunc2_redirected (__redirect_strcspn, __strcspn, strcspn)
+# if HAVE_STRCSPN_C
+extern __typeof (__redirect_strcspn) STRCSPN_C attribute_hidden;
+# endif
+
+# if HAVE_STRCSPN_Z13
+extern __typeof (__redirect_strcspn) STRCSPN_Z13 attribute_hidden;
+# endif
 
-#else
-# include <string/strcspn.c>
-#endif /* !(defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)) */
+s390_libc_ifunc_expr (__redirect_strcspn, strcspn,
+		      (HAVE_STRCSPN_Z13 && (hwcap & HWCAP_S390_VX))
+		      ? STRCSPN_Z13
+		      : STRCSPN_DEFAULT
+		      )
+#endif /* HAVE_STRCSPN_IFUNC  */