S390: Refactor memchr ifunc handling.

The ifunc handling for memchr 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.

Note: The fallback s390-32/s390-64 ifunc variants with srst instruction
are now moved to the unified memchr-z900.S file which can be used for
31/64bit. The s390-32/s390-64 files multiarch/memchr.c and memchr.S
are deleted.

ChangeLog:

	* sysdeps/s390/multiarch/Makefile
	(sysdep_routines): Remove memchr variants.
	* sysdeps/s390/Makefile (sysdep_routines): Add memchr variants.
	* sysdeps/s390/multiarch/ifunc-impl-list.c
	(__libc_ifunc_impl_list): Refactor ifunc handling for memchr.
	* sysdeps/s390/multiarch/memchr-vx.S: Move to ...
	* sysdeps/s390/memchr-vx.S: ... here and adjust ifunc handling.
	* sysdeps/s390/multiarch/memchr.c: Move to ...
	* sysdeps/s390/memchr.c: ... here and adjust ifunc handling.
	* sysdeps/s390/ifunc-memchr.h: New file.
	* sysdeps/s390/s390-64/memchr.S: Move to ...
	* sysdeps/s390/memchr-z900.S: ... here and adjust to be usable
	for 31/64bit and ifunc handling.
	* sysdeps/s390/s390-32/multiarch/memchr.c: Delete file.
	* sysdeps/s390/s390-64/multiarch/memchr.c: Likewise.
	* sysdeps/s390/s390-32/memchr.S: Likewise.

10 files changed, 127 insertions, 105 deletions

diff --git a/sysdeps/s390/Makefile b/sysdeps/s390/Makefile
index c163969652..8f11ed5463 100644
--- a/sysdeps/s390/Makefile
+++ b/sysdeps/s390/Makefile
@@ -75,5 +75,6 @@ sysdep_routines += bzero memset memset-z900 \
 		   strrchr strrchr-vx strrchr-c \
 		   strspn strspn-vx strspn-c \
 		   strpbrk strpbrk-vx strpbrk-c \
-		   strcspn strcspn-vx strcspn-c
+		   strcspn strcspn-vx strcspn-c \
+		   memchr memchr-vx memchr-z900
 endif
diff --git a/sysdeps/s390/ifunc-memchr.h b/sysdeps/s390/ifunc-memchr.h
new file mode 100644
index 0000000000..5d1327b453
--- /dev/null
+++ b/sysdeps/s390/ifunc-memchr.h
@@ -0,0 +1,52 @@
+/* memchr 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_MEMCHR_IFUNC	1
+#else
+# define HAVE_MEMCHR_IFUNC	0
+#endif
+
+#ifdef HAVE_S390_VX_ASM_SUPPORT
+# define HAVE_MEMCHR_IFUNC_AND_VX_SUPPORT HAVE_MEMCHR_IFUNC
+#else
+# define HAVE_MEMCHR_IFUNC_AND_VX_SUPPORT 0
+#endif
+
+#if defined HAVE_S390_MIN_Z13_ZARCH_ASM_SUPPORT
+# define MEMCHR_DEFAULT		MEMCHR_Z13
+# define HAVE_MEMCHR_Z900_G5	0
+# define HAVE_MEMCHR_Z13	1
+#else
+# define MEMCHR_DEFAULT		MEMCHR_Z900_G5
+# define HAVE_MEMCHR_Z900_G5	1
+# define HAVE_MEMCHR_Z13	HAVE_MEMCHR_IFUNC_AND_VX_SUPPORT
+#endif
+
+#if HAVE_MEMCHR_Z900_G5
+# define MEMCHR_Z900_G5		__memchr_default
+#else
+# define MEMCHR_Z900_G5		NULL
+#endif
+
+#if HAVE_MEMCHR_Z13
+# define MEMCHR_Z13		__memchr_vx
+#else
+# define MEMCHR_Z13		NULL
+#endif
diff --git a/sysdeps/s390/multiarch/memchr-vx.S b/sysdeps/s390/memchr-vx.S
index 77d31e0036..274e7971ca 100644
--- a/sysdeps/s390/multiarch/memchr-vx.S
+++ b/sysdeps/s390/memchr-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-memchr.h>
+#if HAVE_MEMCHR_Z13
 
 # include "sysdep.h"
 # include "asm-syntax.h"
@@ -38,7 +39,7 @@
    -v17=index of found c
    -v18=c replicated
 */
-ENTRY(__memchr_vx)
+ENTRY(MEMCHR_Z13)
 
 	.machine "z13"
 	.machinemode "zarch_nohighgprs"
@@ -149,11 +150,14 @@ ENTRY(__memchr_vx)
 	clgrjl	%r0,%r4,.Lloop64
 
 	j	.Llt64
-END(__memchr_vx)
+END(MEMCHR_Z13)
 
-# define memchr __memchr_c
-# undef libc_hidden_builtin_def
-# define libc_hidden_builtin_def(name) strong_alias(__memchr_c, __GI_memchr)
-#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */
+# if ! HAVE_MEMCHR_IFUNC
+strong_alias (MEMCHR_Z13, __memchr)
+weak_alias (__memchr, memchr)
+# endif
 
-#include <memchr.S>
+# if ! HAVE_MEMCHR_Z900_G5 && defined SHARED && IS_IN (libc)
+strong_alias (MEMCHR_Z13, __GI_memchr)
+# endif
+#endif
diff --git a/sysdeps/s390/s390-64/memchr.S b/sysdeps/s390/memchr-z900.S
index a19fcafa14..c016bc41c6 100644
--- a/sysdeps/s390/s390-64/memchr.S
+++ b/sysdeps/s390/memchr-z900.S
@@ -1,4 +1,4 @@
-/* Search a character in a block of memory.  64 bit S/390 version.
+/* Search a character in a block of memory.  31/64 bit S/390 version.
    Copyright (C) 2001-2018 Free Software Foundation, Inc.
    Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
    This file is part of the GNU C Library.
@@ -22,19 +22,42 @@
      %r3 = character to find
      %r4 = number of bytes to search.  */
 
+#include <ifunc-memchr.h>
 #include "sysdep.h"
 #include "asm-syntax.h"
 
+#if HAVE_MEMCHR_Z900_G5
+# if defined __s390x__
+#  define SLGR	slgr
+#  define LGHI	lghi
+#  define NGR	ngr
+#  define LGR	lgr
+# else
+#  define SLGR	slr
+#  define LGHI	lhi
+#  define NGR	nr
+#  define LGR	lr
+# endif /* ! defined __s390x__  */
+
 	.text
-ENTRY(memchr)
-	lghi  %r0,0xff
-	ngr   %r0,%r3
-	lgr   %r1,%r2
+ENTRY(MEMCHR_Z900_G5)
+	LGHI  %r0,0xff
+	NGR   %r0,%r3
+	LGR   %r1,%r2
 	la    %r2,0(%r4,%r1)
 0:	srst  %r2,%r1
 	jo    0b
 	brc   13,1f
-	slgr  %r2,%r2
+	SLGR  %r2,%r2
 1:	br    %r14
-END(memchr)
-libc_hidden_builtin_def (memchr)
+END(MEMCHR_Z900_G5)
+
+# if ! HAVE_MEMCHR_IFUNC
+strong_alias (MEMCHR_Z900_G5, __memchr)
+weak_alias (__memchr, memchr)
+# endif
+
+# if defined SHARED && IS_IN (libc)
+strong_alias (MEMCHR_Z900_G5, __GI_memchr)
+# endif
+#endif
diff --git a/sysdeps/s390/multiarch/memchr.c b/sysdeps/s390/memchr.c
index 3885ebaa4d..490f1b6600 100644
--- a/sysdeps/s390/multiarch/memchr.c
+++ b/sysdeps/s390/memchr.c
@@ -16,12 +16,26 @@
    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-memchr.h>
+
+#if HAVE_MEMCHR_IFUNC
 # define memchr __redirect_memchr
 # include <string.h>
 # undef memchr
 # include <ifunc-resolve.h>
 
-s390_vx_libc_ifunc2_redirected (__redirect_memchr, __memchr, memchr)
+# if HAVE_MEMCHR_Z900_G5
+extern __typeof (__redirect_memchr) MEMCHR_Z900_G5 attribute_hidden;
+# endif
+
+# if HAVE_MEMCHR_Z13
+extern __typeof (__redirect_memchr) MEMCHR_Z13 attribute_hidden;
+# endif
 
+s390_libc_ifunc_expr (__redirect_memchr, __memchr,
+		      (HAVE_MEMCHR_Z13 && (hwcap & HWCAP_S390_VX))
+		      ? MEMCHR_Z13
+		      : MEMCHR_DEFAULT
+		      )
+weak_alias (__memchr, memchr)
 #endif
diff --git a/sysdeps/s390/multiarch/Makefile b/sysdeps/s390/multiarch/Makefile
index 1578f21af4..fa1f7b81db 100644
--- a/sysdeps/s390/multiarch/Makefile
+++ b/sysdeps/s390/multiarch/Makefile
@@ -1,6 +1,5 @@
 ifeq ($(subdir),string)
-sysdep_routines += memchr memchr-vx \
-		   rawmemchr rawmemchr-vx rawmemchr-c \
+sysdep_routines += rawmemchr rawmemchr-vx rawmemchr-c \
 		   memccpy memccpy-vx memccpy-c \
 		   memrchr memrchr-vx memrchr-c
 endif
diff --git a/sysdeps/s390/multiarch/ifunc-impl-list.c b/sysdeps/s390/multiarch/ifunc-impl-list.c
index 2d48c99c8d..b4be014042 100644
--- a/sysdeps/s390/multiarch/ifunc-impl-list.c
+++ b/sysdeps/s390/multiarch/ifunc-impl-list.c
@@ -42,6 +42,7 @@
 #include <ifunc-strspn.h>
 #include <ifunc-strpbrk.h>
 #include <ifunc-strcspn.h>
+#include <ifunc-memchr.h>
 
 /* Maximum number of IFUNC implementations.  */
 #define MAX_IFUNC	3
@@ -372,6 +373,18 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 		)
 #endif /* HAVE_STRCSPN_IFUNC  */
 
+#if HAVE_MEMCHR_IFUNC
+    IFUNC_IMPL (i, name, memchr,
+# if HAVE_MEMCHR_Z13
+		IFUNC_IMPL_ADD (array, i, memchr,
+				dl_hwcap & HWCAP_S390_VX, MEMCHR_Z13)
+# endif
+# if HAVE_MEMCHR_Z900_G5
+		IFUNC_IMPL_ADD (array, i, memchr, 1, MEMCHR_Z900_G5)
+# endif
+		)
+#endif /* HAVE_MEMCHR_IFUNC  */
+
 #ifdef HAVE_S390_VX_ASM_SUPPORT
 
 # define IFUNC_VX_IMPL(FUNC)						\
@@ -412,7 +425,6 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 
   IFUNC_VX_IMPL (wcscspn);
 
-  IFUNC_VX_IMPL (memchr);
   IFUNC_VX_IMPL (wmemchr);
   IFUNC_VX_IMPL (rawmemchr);
 
diff --git a/sysdeps/s390/s390-32/memchr.S b/sysdeps/s390/s390-32/memchr.S
deleted file mode 100644
index 54f9b85f57..0000000000
--- a/sysdeps/s390/s390-32/memchr.S
+++ /dev/null
@@ -1,41 +0,0 @@
-/* Search a character in a block of memory.  For IBM S390
-   Copyright (C) 2000-2018 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
-
-   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/>.  */
-
-/*
- * R2 = address to memory area
- * R3 = character to find
- * R4 = number of bytes to search
- */
-
-#include "sysdep.h"
-#include "asm-syntax.h"
-
-	.text
-ENTRY(memchr)
-	lhi   %r0,0xff
-	nr    %r0,%r3
-	lr    %r1,%r2
-	la    %r2,0(%r4,%r1)
-0:      srst  %r2,%r1
-	jo    0b
-	brc   13,1f
-	slr   %r2,%r2
-1:      br    %r14
-END(memchr)
-libc_hidden_builtin_def (memchr)
diff --git a/sysdeps/s390/s390-32/multiarch/memchr.c b/sysdeps/s390/s390-32/multiarch/memchr.c
deleted file mode 100644
index 5e1610afa4..0000000000
--- a/sysdeps/s390/s390-32/multiarch/memchr.c
+++ /dev/null
@@ -1,21 +0,0 @@
-/* Multiple versions of memchr.
-   Copyright (C) 2015-2018 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/>.  */
-
-/* This wrapper-file is needed, because otherwise file
-   sysdeps/s390/s390-[32|64]/memchr.S will be used.  */
-#include <sysdeps/s390/multiarch/memchr.c>
diff --git a/sysdeps/s390/s390-64/multiarch/memchr.c b/sysdeps/s390/s390-64/multiarch/memchr.c
deleted file mode 100644
index 5e1610afa4..0000000000
--- a/sysdeps/s390/s390-64/multiarch/memchr.c
+++ /dev/null
@@ -1,21 +0,0 @@
-/* Multiple versions of memchr.
-   Copyright (C) 2015-2018 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/>.  */
-
-/* This wrapper-file is needed, because otherwise file
-   sysdeps/s390/s390-[32|64]/memchr.S will be used.  */
-#include <sysdeps/s390/multiarch/memchr.c>