S390: Refactor stpcpy ifunc handling.

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

7 files changed, 118 insertions, 26 deletions

diff --git a/sysdeps/s390/Makefile b/sysdeps/s390/Makefile
index af9482adc3..96f1538cfd 100644
--- a/sysdeps/s390/Makefile
+++ b/sysdeps/s390/Makefile
@@ -62,5 +62,6 @@ sysdep_routines += bzero memset memset-z900 \
 		   memmem memmem-vx memmem-c \
 		   strlen strlen-vx strlen-c \
 		   strnlen strnlen-vx strnlen-c \
-		   strcpy strcpy-vx strcpy-z900
+		   strcpy strcpy-vx strcpy-z900 \
+		   stpcpy stpcpy-vx stpcpy-c
 endif
diff --git a/sysdeps/s390/ifunc-stpcpy.h b/sysdeps/s390/ifunc-stpcpy.h
new file mode 100644
index 0000000000..9a70cd7c8c
--- /dev/null
+++ b/sysdeps/s390/ifunc-stpcpy.h
@@ -0,0 +1,52 @@
+/* stpcpy 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_STPCPY_IFUNC	1
+#else
+# define HAVE_STPCPY_IFUNC	0
+#endif
+
+#ifdef HAVE_S390_VX_ASM_SUPPORT
+# define HAVE_STPCPY_IFUNC_AND_VX_SUPPORT HAVE_STPCPY_IFUNC
+#else
+# define HAVE_STPCPY_IFUNC_AND_VX_SUPPORT 0
+#endif
+
+#if defined HAVE_S390_MIN_Z13_ZARCH_ASM_SUPPORT
+# define STPCPY_DEFAULT		STPCPY_Z13
+# define HAVE_STPCPY_C		0
+# define HAVE_STPCPY_Z13	1
+#else
+# define STPCPY_DEFAULT		STPCPY_C
+# define HAVE_STPCPY_C		1
+# define HAVE_STPCPY_Z13	HAVE_STPCPY_IFUNC_AND_VX_SUPPORT
+#endif
+
+#if HAVE_STPCPY_C
+# define STPCPY_C		__stpcpy_c
+#else
+# define STPCPY_C		NULL
+#endif
+
+#if HAVE_STPCPY_Z13
+# define STPCPY_Z13		__stpcpy_vx
+#else
+# define STPCPY_Z13		NULL
+#endif
diff --git a/sysdeps/s390/multiarch/Makefile b/sysdeps/s390/multiarch/Makefile
index 50f7f0b78d..9517417dcb 100644
--- a/sysdeps/s390/multiarch/Makefile
+++ b/sysdeps/s390/multiarch/Makefile
@@ -1,6 +1,5 @@
 ifeq ($(subdir),string)
-sysdep_routines += stpcpy stpcpy-vx stpcpy-c \
-		   strncpy strncpy-vx \
+sysdep_routines += strncpy strncpy-vx \
 		   stpncpy stpncpy-vx stpncpy-c \
 		   strcat strcat-vx strcat-c \
 		   strncat strncat-vx strncat-c \
diff --git a/sysdeps/s390/multiarch/ifunc-impl-list.c b/sysdeps/s390/multiarch/ifunc-impl-list.c
index 1784372db9..678ed13833 100644
--- a/sysdeps/s390/multiarch/ifunc-impl-list.c
+++ b/sysdeps/s390/multiarch/ifunc-impl-list.c
@@ -29,6 +29,7 @@
 #include <ifunc-strlen.h>
 #include <ifunc-strnlen.h>
 #include <ifunc-strcpy.h>
+#include <ifunc-stpcpy.h>
 
 /* Maximum number of IFUNC implementations.  */
 #define MAX_IFUNC	3
@@ -203,6 +204,18 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 		)
 #endif /* HAVE_STRCPY_IFUNC  */
 
+#if HAVE_STPCPY_IFUNC
+    IFUNC_IMPL (i, name, stpcpy,
+# if HAVE_STPCPY_Z13
+		IFUNC_IMPL_ADD (array, i, stpcpy,
+				dl_hwcap & HWCAP_S390_VX, STPCPY_Z13)
+# endif
+# if HAVE_STPCPY_C
+		IFUNC_IMPL_ADD (array, i, stpcpy, 1, STPCPY_C)
+# endif
+		)
+#endif /* HAVE_STPCPY_IFUNC  */
+
 #ifdef HAVE_S390_VX_ASM_SUPPORT
 
 # define IFUNC_VX_IMPL(FUNC)						\
@@ -217,7 +230,6 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 
   IFUNC_VX_IMPL (wcscpy);
 
-  IFUNC_VX_IMPL (stpcpy);
   IFUNC_VX_IMPL (wcpcpy);
 
   IFUNC_VX_IMPL (strncpy);
diff --git a/sysdeps/s390/multiarch/stpcpy-c.c b/sysdeps/s390/stpcpy-c.c
index 4a1c3e5832..76ec884627 100644
--- a/sysdeps/s390/multiarch/stpcpy-c.c
+++ b/sysdeps/s390/stpcpy-c.c
@@ -16,20 +16,25 @@
    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 STPCPY  __stpcpy_c
-# undef weak_alias
-# define weak_alias(a, b)
-# ifdef SHARED
-#  undef libc_hidden_def
-#  define libc_hidden_def(name)					\
+#include <ifunc-stpcpy.h>
+
+#if HAVE_STPCPY_C
+# if HAVE_STPCPY_IFUNC
+#  define STPCPY STPCPY_C
+
+#  undef weak_alias
+#  define weak_alias(a, b)
+
+#  if defined SHARED && IS_IN (libc)
+#   undef libc_hidden_def
+#   define libc_hidden_def(name)				\
   __hidden_ver1 (__stpcpy_c, __GI___stpcpy, __stpcpy_c);
-#  undef libc_hidden_builtin_def
-#  define libc_hidden_builtin_def(name)				\
+#   undef libc_hidden_builtin_def
+#   define libc_hidden_builtin_def(name)			\
   strong_alias (__stpcpy_c, __stpcpy_c_1);			\
   __hidden_ver1 (__stpcpy_c_1, __GI_stpcpy, __stpcpy_c_1);
-# endif /* SHARED */
-
+#  endif
+# endif
 
 # include <string/stpcpy.c>
-#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */
+#endif
diff --git a/sysdeps/s390/multiarch/stpcpy-vx.S b/sysdeps/s390/stpcpy-vx.S
index 6c17def0fc..d2db02d0cd 100644
--- a/sysdeps/s390/multiarch/stpcpy-vx.S
+++ b/sysdeps/s390/stpcpy-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-stpcpy.h>
+
+#if HAVE_STPCPY_Z13
 
 # include "sysdep.h"
 # include "asm-syntax.h"
@@ -36,7 +38,7 @@
    -v17=index of zero
    -v18=part of src
 */
-ENTRY(__stpcpy_vx)
+ENTRY(STPCPY_Z13)
 	.machine "z13"
 	.machinemode "zarch_nohighgprs"
 
@@ -100,5 +102,15 @@ ENTRY(__stpcpy_vx)
 	vstl	%v16,%r5,0(%r2)	/* Copy characters including zero.  */
 	la	%r2,0(%r5,%r2)	/* Return pointer to zero.  */
 	br	%r14
-END(__stpcpy_vx)
-#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */
+END(STPCPY_Z13)
+
+# if ! HAVE_STPCPY_IFUNC
+strong_alias (STPCPY_Z13, __stpcpy)
+weak_alias (__stpcpy, stpcpy)
+# endif
+
+# if ! HAVE_STPCPY_C && defined SHARED && IS_IN (libc)
+strong_alias (STPCPY_Z13, __GI_stpcpy)
+strong_alias (STPCPY_Z13, __GI___stpcpy)
+# endif
+#endif
diff --git a/sysdeps/s390/multiarch/stpcpy.c b/sysdeps/s390/stpcpy.c
index 654f9dfbef..670604e2de 100644
--- a/sysdeps/s390/multiarch/stpcpy.c
+++ b/sysdeps/s390/stpcpy.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-stpcpy.h>
+
+#if HAVE_STPCPY_IFUNC
 # define stpcpy __redirect_stpcpy
 # define __stpcpy __redirect___stpcpy
 /* Omit the stpcpy inline definitions because it would redefine stpcpy.  */
@@ -27,9 +29,18 @@
 # undef __stpcpy
 # include <ifunc-resolve.h>
 
-s390_vx_libc_ifunc_redirected (__redirect___stpcpy, __stpcpy);
-weak_alias (__stpcpy, stpcpy)
+# if HAVE_STPCPY_C
+extern __typeof (__redirect_stpcpy) STPCPY_C attribute_hidden;
+# endif
 
-#else
-# include <string/stpcpy.c>
-#endif /* !(defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)) */
+# if HAVE_STPCPY_Z13
+extern __typeof (__redirect_stpcpy) STPCPY_Z13 attribute_hidden;
+# endif
+
+s390_libc_ifunc_expr (__redirect___stpcpy, __stpcpy,
+		      (HAVE_STPCPY_Z13 && (hwcap & HWCAP_S390_VX))
+		      ? STPCPY_Z13
+		      : STPCPY_DEFAULT
+		      )
+weak_alias (__stpcpy, stpcpy)
+#endif