S390: Refactor memccpy ifunc handling.

The ifunc handling for memccpy 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.

ChangeLog:

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

7 files changed, 105 insertions, 19 deletions

diff --git a/sysdeps/s390/Makefile b/sysdeps/s390/Makefile
index a181eeac8a..649f29adc2 100644
--- a/sysdeps/s390/Makefile
+++ b/sysdeps/s390/Makefile
@@ -77,5 +77,6 @@ sysdep_routines += bzero memset memset-z900 \
 		   strpbrk strpbrk-vx strpbrk-c \
 		   strcspn strcspn-vx strcspn-c \
 		   memchr memchr-vx memchr-z900 \
-		   rawmemchr rawmemchr-vx rawmemchr-c
+		   rawmemchr rawmemchr-vx rawmemchr-c \
+		   memccpy memccpy-vx memccpy-c
 endif
diff --git a/sysdeps/s390/ifunc-memccpy.h b/sysdeps/s390/ifunc-memccpy.h
new file mode 100644
index 0000000000..8f7a1d0f9f
--- /dev/null
+++ b/sysdeps/s390/ifunc-memccpy.h
@@ -0,0 +1,52 @@
+/* memccpy 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_MEMCCPY_IFUNC	1
+#else
+# define HAVE_MEMCCPY_IFUNC	0
+#endif
+
+#ifdef HAVE_S390_VX_ASM_SUPPORT
+# define HAVE_MEMCCPY_IFUNC_AND_VX_SUPPORT HAVE_MEMCCPY_IFUNC
+#else
+# define HAVE_MEMCCPY_IFUNC_AND_VX_SUPPORT 0
+#endif
+
+#if defined HAVE_S390_MIN_Z13_ZARCH_ASM_SUPPORT
+# define MEMCCPY_DEFAULT	MEMCCPY_Z13
+# define HAVE_MEMCCPY_C		0
+# define HAVE_MEMCCPY_Z13	1
+#else
+# define MEMCCPY_DEFAULT	MEMCCPY_C
+# define HAVE_MEMCCPY_C		1
+# define HAVE_MEMCCPY_Z13	HAVE_MEMCCPY_IFUNC_AND_VX_SUPPORT
+#endif
+
+#if HAVE_MEMCCPY_C
+# define MEMCCPY_C		__memccpy_c
+#else
+# define MEMCCPY_C		NULL
+#endif
+
+#if HAVE_MEMCCPY_Z13
+# define MEMCCPY_Z13		__memccpy_vx
+#else
+# define MEMCCPY_Z13		NULL
+#endif
diff --git a/sysdeps/s390/multiarch/memccpy-c.c b/sysdeps/s390/memccpy-c.c
index 1f4c548199..2b2f81eb9c 100644
--- a/sysdeps/s390/multiarch/memccpy-c.c
+++ b/sysdeps/s390/memccpy-c.c
@@ -16,10 +16,14 @@
    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 MEMCCPY  __memccpy_c
+#include <ifunc-memccpy.h>
+
+#if HAVE_MEMCCPY_C
+# if HAVE_MEMCCPY_IFUNC
+#  define MEMCCPY MEMCCPY_C
+#  undef weak_alias
+#  define weak_alias(a, b)
+#endif
 
-# include <string.h>
-extern __typeof (__memccpy) __memccpy_c;
 # include <string/memccpy.c>
 #endif
diff --git a/sysdeps/s390/multiarch/memccpy-vx.S b/sysdeps/s390/memccpy-vx.S
index 150aa0e4a4..44f7bc5824 100644
--- a/sysdeps/s390/multiarch/memccpy-vx.S
+++ b/sysdeps/s390/memccpy-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-memccpy.h>
+
+#if HAVE_MEMCCPY_Z13
 
 # include "sysdep.h"
 # include "asm-syntax.h"
@@ -42,7 +44,7 @@
    -v19=part #2 of s
    -v31=save area for r6
 */
-ENTRY(__memccpy_vx)
+ENTRY(MEMCCPY_Z13)
 	.machine "z13"
 	.machinemode "zarch_nohighgprs"
 
@@ -152,5 +154,11 @@ ENTRY(__memccpy_vx)
 	vlgvg	%r7,%v31,1
 	lghi	%r2,0		/* Return null.  */
 	br	%r14
-END(__memccpy_vx)
-#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */
+END(MEMCCPY_Z13)
+
+# if ! HAVE_MEMCCPY_IFUNC
+strong_alias (MEMCCPY_Z13, __memccpy)
+weak_alias (__memccpy, memccpy)
+# endif
+
+#endif /* HAVE_MEMCCPY_Z13  */
diff --git a/sysdeps/s390/multiarch/memccpy.c b/sysdeps/s390/memccpy.c
index 30aae82321..bcfeb31e86 100644
--- a/sysdeps/s390/multiarch/memccpy.c
+++ b/sysdeps/s390/memccpy.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-memccpy.h>
+
+#if HAVE_MEMCCPY_IFUNC
 # include <string.h>
 # include <ifunc-resolve.h>
 
-s390_vx_libc_ifunc (__memccpy)
-weak_alias (__memccpy, memccpy)
+# if HAVE_MEMCCPY_C
+extern __typeof (__memccpy) MEMCCPY_C attribute_hidden;
+# endif
 
-#else
-# include <string/memccpy.c>
-#endif /* !(defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)) */
+# if HAVE_MEMCCPY_Z13
+extern __typeof (__memccpy) MEMCCPY_Z13 attribute_hidden;
+# endif
+
+s390_libc_ifunc_expr (__memccpy, __memccpy,
+		      (HAVE_MEMCCPY_Z13 && (hwcap & HWCAP_S390_VX))
+		      ? MEMCCPY_Z13
+		      : MEMCCPY_DEFAULT
+		      )
+weak_alias (__memccpy, memccpy)
+#endif /* HAVE_MEMCCPY_IFUNC  */
diff --git a/sysdeps/s390/multiarch/Makefile b/sysdeps/s390/multiarch/Makefile
index ac6cfcf9c7..d5a32fc309 100644
--- a/sysdeps/s390/multiarch/Makefile
+++ b/sysdeps/s390/multiarch/Makefile
@@ -1,6 +1,5 @@
 ifeq ($(subdir),string)
-sysdep_routines += memccpy memccpy-vx memccpy-c \
-		   memrchr memrchr-vx memrchr-c
+sysdep_routines += memrchr memrchr-vx memrchr-c
 endif
 
 ifeq ($(subdir),wcsmbs)
diff --git a/sysdeps/s390/multiarch/ifunc-impl-list.c b/sysdeps/s390/multiarch/ifunc-impl-list.c
index bf3b40e111..b8917747f0 100644
--- a/sysdeps/s390/multiarch/ifunc-impl-list.c
+++ b/sysdeps/s390/multiarch/ifunc-impl-list.c
@@ -44,6 +44,7 @@
 #include <ifunc-strcspn.h>
 #include <ifunc-memchr.h>
 #include <ifunc-rawmemchr.h>
+#include <ifunc-memccpy.h>
 
 /* Maximum number of IFUNC implementations.  */
 #define MAX_IFUNC	3
@@ -398,6 +399,18 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 		)
 #endif /* HAVE_RAWMEMCHR_IFUNC  */
 
+#if HAVE_MEMCCPY_IFUNC
+    IFUNC_IMPL (i, name, memccpy,
+# if HAVE_MEMCCPY_Z13
+		IFUNC_IMPL_ADD (array, i, memccpy,
+				dl_hwcap & HWCAP_S390_VX, MEMCCPY_Z13)
+# endif
+# if HAVE_MEMCCPY_C
+		IFUNC_IMPL_ADD (array, i, memccpy, 1, MEMCCPY_C)
+# endif
+		)
+#endif /* HAVE_MEMCCPY_IFUNC  */
+
 #ifdef HAVE_S390_VX_ASM_SUPPORT
 
 # define IFUNC_VX_IMPL(FUNC)						\
@@ -440,8 +453,6 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 
   IFUNC_VX_IMPL (wmemchr);
 
-  IFUNC_VX_IMPL (memccpy);
-
   IFUNC_VX_IMPL (wmemset);
 
   IFUNC_VX_IMPL (wmemcmp);