S390: Refactor memset ifunc handling.

This patch moves all ifunc variants for memset
to sysdeps/s390/memset-z900.S. The configure-check/preprocessor logic
in sysdeps/s390/ifunc-memset.h decides if ifunc is needed at all
and which ifunc variants should be available.
E.g. if the compiler/assembler already supports z196 by default,
the older ifunc variants are not included.
If we only need the newest ifunc variant,
then we can skip ifunc at all.

Therefore the ifunc-resolvers and __libc_ifunc_impl_list are adjusted
in order to handle only the available ifunc variants.

ChangeLog:

	* sysdeps/s390/ifunc-memset.h: New File.
	* sysdeps/s390/memset.S: Move to ...
	* sysdeps/s390/memset-z900.S ... here.
	Move implementations from memset-s390x.s to here.
	* sysdeps/s390/multiarch/memset-s390x.S: Delete File.
	* sysdeps/s390/multiarch/Makefile (sysdep_routines):
	Remove memset variants.
	* sysdeps/s390/Makefile (sysdep_routines):
	Add memset variants.
	* sysdeps/s390/multiarch/ifunc-impl-list.c
	(__libc_ifunc_impl_list): Adjust ifunc variants for
	memset.
	* sysdeps/s390/multiarch/memset.c: Move ifunc resolver
	to ...
	* sysdeps/s390/memset.c: ... here.
	Adjust ifunc variants for memset.

7 files changed, 215 insertions, 146 deletions

diff --git a/sysdeps/s390/Makefile b/sysdeps/s390/Makefile
index 496ab51973..f90a41d3ae 100644
--- a/sysdeps/s390/Makefile
+++ b/sysdeps/s390/Makefile
@@ -52,3 +52,7 @@ tst-dl-runtime-profile-noaudit-ENV = $(env-profile)
 tst-dl-runtime-profile-audit-ENV = $(env-profile) $(env-audit)
 endif
 endif
+
+ifeq ($(subdir),string)
+sysdep_routines += memset memset-z900
+endif
diff --git a/sysdeps/s390/ifunc-memset.h b/sysdeps/s390/ifunc-memset.h
new file mode 100644
index 0000000000..9a13b1001f
--- /dev/null
+++ b/sysdeps/s390/ifunc-memset.h
@@ -0,0 +1,65 @@
+/* memset 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_Z196_ZARCH_ASM_SUPPORT
+# define HAVE_MEMSET_IFUNC	1
+#else
+# define HAVE_MEMSET_IFUNC	0
+#endif
+
+#if defined HAVE_S390_MIN_Z196_ZARCH_ASM_SUPPORT
+# define MEMSET_DEFAULT		MEMSET_Z196
+# define HAVE_MEMSET_Z900_G5	0
+# define HAVE_MEMSET_Z10	0
+# define HAVE_MEMSET_Z196	1
+#elif defined HAVE_S390_MIN_Z10_ZARCH_ASM_SUPPORT
+# define MEMSET_DEFAULT		MEMSET_Z10
+# define HAVE_MEMSET_Z900_G5	0
+# define HAVE_MEMSET_Z10	1
+# define HAVE_MEMSET_Z196	HAVE_MEMSET_IFUNC
+#else
+# define MEMSET_DEFAULT		MEMSET_Z900_G5
+# define HAVE_MEMSET_Z900_G5	1
+# define HAVE_MEMSET_Z10	HAVE_MEMSET_IFUNC
+# define HAVE_MEMSET_Z196	HAVE_MEMSET_IFUNC
+#endif
+
+#if HAVE_MEMSET_Z10 || HAVE_MEMSET_Z196
+# define HAVE_MEMSET_MVCLE	1
+#else
+# define HAVE_MEMSET_MVCLE	0
+#endif
+
+#if HAVE_MEMSET_Z900_G5
+# define MEMSET_Z900_G5		__memset_default
+#else
+# define MEMSET_Z900_G5		NULL
+#endif
+
+#if HAVE_MEMSET_Z10
+# define MEMSET_Z10		__memset_z10
+#else
+# define MEMSET_Z10		NULL
+#endif
+
+#if HAVE_MEMSET_Z196
+# define MEMSET_Z196		__memset_z196
+#else
+# define MEMSET_Z196		NULL
+#endif
diff --git a/sysdeps/s390/multiarch/memset-s390x.S b/sysdeps/s390/memset-z900.S
index aca3ac3fda..eaf13402bd 100644
--- a/sysdeps/s390/multiarch/memset-s390x.S
+++ b/sysdeps/s390/memset-z900.S
@@ -1,5 +1,6 @@
 /* Set a block of memory to some byte value.  31/64 bit S/390 version.
-   Copyright (C) 2012-2018 Free Software Foundation, Inc.
+   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.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -17,8 +18,9 @@
    <http://www.gnu.org/licenses/>.  */
 
 
-#include "sysdep.h"
+#include <sysdep.h>
 #include "asm-syntax.h"
+#include <ifunc-memset.h>
 
 /* INPUT PARAMETERS
      %r2 = address of memory area
@@ -27,43 +29,68 @@
 
        .text
 
-#if IS_IN (libc)
+#if HAVE_MEMSET_Z900_G5
+# if defined __s390x__
+#  define LTGR	ltgr
+#  define CGHI	cghi
+#  define LGR	lgr
+#  define AGHI	aghi
+#  define BRCTG	brctg
+# else
+#  define LTGR	ltr
+#  define CGHI	chi
+#  define LGR	lr
+#  define AGHI	ahi
+#  define BRCTG	brct
+# endif /* ! defined __s390x__  */
 
-ENTRY(__memset_z196)
-	.machine "z196"
-	.machinemode "zarch_nohighgprs"
-# if !defined __s390x__
-	llgfr	%r4,%r4
-# endif /* !defined __s390x__  */
-	ltgr    %r4,%r4
-	je      .L_Z196_4
+ENTRY(MEMSET_Z900_G5)
+#if defined __s390x__
+	.machine "z900"
+#else
+	.machine "g5"
+#endif /* ! defined __s390x__  */
+	LTGR    %r4,%r4
+	je      .L_Z900_G5_4
 	stc     %r3,0(%r2)
-	lgr     %r1,%r2
-	cghi    %r4,1
-	je      .L_Z196_4
-	aghi    %r4,-2
-	srlg    %r5,%r4,8
-	ltgr    %r5,%r5
-	jne     .L_Z196_1
-.L_Z196_3:
-	exrl    %r4,.L_Z196_17
-.L_Z196_4:
+	CGHI    %r4,1
+	LGR     %r1,%r2
+	je      .L_Z900_G5_4
+	AGHI    %r4,-2
+#if defined __s390x__
+	larl    %r5,.L_Z900_G5_18
+	srlg    %r3,%r4,8
+# define Z900_G5_EX_D 0
+#else
+	basr    %r5,0
+.L_Z900_G5_19:
+# define Z900_G5_EX_D .L_Z900_G5_18-.L_Z900_G5_19
+	lr      %r3,%r4
+	srl     %r3,8
+#endif /* ! defined __s390x__  */
+	LTGR    %r3,%r3
+	jne     .L_Z900_G5_14
+.L_Z900_G5_3:
+	ex      %r4,Z900_G5_EX_D(%r5)
+.L_Z900_G5_4:
 	br      %r14
-.L_Z196_1:
-	cgfi	%r5,1048576
-	jh	__memset_mvcle	   # Switch to mvcle for >256MB
-.L_Z196_2:
-	pfd     2,1024(%r1)
+.L_Z900_G5_14:
 	mvc     1(256,%r1),0(%r1)
-	aghi    %r5,-1
 	la      %r1,256(%r1)
-	jne     .L_Z196_2
-	j       .L_Z196_3
-.L_Z196_17:
+	BRCTG   %r3,.L_Z900_G5_14
+	j       .L_Z900_G5_3
+.L_Z900_G5_18:
 	mvc     1(1,%r1),0(%r1)
-END(__memset_z196)
+END(MEMSET_Z900_G5)
+# undef LTGR
+# undef CGHI
+# undef LGR
+# undef AGHI
+# undef BRCTG
+#endif /*  HAVE_MEMSET_Z900_G5  */
 
-ENTRY(__memset_z10)
+#if HAVE_MEMSET_Z10
+ENTRY(MEMSET_Z10)
 	.machine "z10"
 	.machinemode "zarch_nohighgprs"
 # if !defined __s390x__
@@ -91,8 +118,46 @@ ENTRY(__memset_z10)
 	j       .L_Z10_3
 .L_Z10_18:
 	mvc     1(1,%r1),0(%r1)
-END(__memset_z10)
+END(MEMSET_Z10)
+#endif /* HAVE_MEMSET_Z10  */
+
+#if HAVE_MEMSET_Z196
+ENTRY(MEMSET_Z196)
+	.machine "z196"
+	.machinemode "zarch_nohighgprs"
+# if !defined __s390x__
+	llgfr	%r4,%r4
+# endif /* !defined __s390x__  */
+	ltgr    %r4,%r4
+	je      .L_Z196_4
+	stc     %r3,0(%r2)
+	lgr     %r1,%r2
+	cghi    %r4,1
+	je      .L_Z196_4
+	aghi    %r4,-2
+	srlg    %r5,%r4,8
+	ltgr    %r5,%r5
+	jne     .L_Z196_1
+.L_Z196_3:
+	exrl    %r4,.L_Z196_17
+.L_Z196_4:
+	br      %r14
+.L_Z196_1:
+	cgfi	%r5,1048576
+	jh	__memset_mvcle	   # Switch to mvcle for >256MB
+.L_Z196_2:
+	pfd     2,1024(%r1)
+	mvc     1(256,%r1),0(%r1)
+	aghi    %r5,-1
+	la      %r1,256(%r1)
+	jne     .L_Z196_2
+	j       .L_Z196_3
+.L_Z196_17:
+	mvc     1(1,%r1),0(%r1)
+END(MEMSET_Z196)
+#endif /* HAVE_MEMSET_Z196  */
 
+#if HAVE_MEMSET_MVCLE
 ENTRY(__memset_mvcle)
 	aghi	%r4,2               # take back the change done by the caller
 	lgr	%r0,%r2		    # save source address
@@ -106,15 +171,16 @@ ENTRY(__memset_mvcle)
 .L1:
 	br	%r14
 END(__memset_mvcle)
+#endif /* HAVE_MEMSET_MVCLE  */
 
-#endif /* IS_IN (libc) */
-
-#include "../memset.S"
+#if ! HAVE_MEMSET_IFUNC
+/* If we don't use ifunc, define an alias for memset here.
+   Otherwise see sysdeps/s390/memset.c.  */
+strong_alias (MEMSET_DEFAULT, memset)
+#endif
 
-#if !IS_IN (libc)
-.globl   memset
-.set     memset,__memset_default
-#elif defined SHARED && IS_IN (libc)
-.globl   __GI_memset
-.set     __GI_memset,__memset_default
+#if defined SHARED && IS_IN (libc)
+/* Defines the internal symbol.
+   Compare to libc_hidden_builtin_def (memset) in string/memset.c.  */
+strong_alias (MEMSET_DEFAULT, __GI_memset)
 #endif
diff --git a/sysdeps/s390/memset.S b/sysdeps/s390/memset.S
deleted file mode 100644
index 72e7c5a42e..0000000000
--- a/sysdeps/s390/memset.S
+++ /dev/null
@@ -1,97 +0,0 @@
-/* Set a block of memory to some byte value.  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.
-
-   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/>.  */
-
-
-#include <sysdep.h>
-#include "asm-syntax.h"
-
-/* INPUT PARAMETERS
-     %r2 = address of memory area
-     %r3 = byte to fill memory with
-     %r4 = number of bytes to fill.  */
-
-       .text
-
-#if defined __s390x__
-# define LTGR	ltgr
-# define CGHI	cghi
-# define LGR	lgr
-# define AGHI	aghi
-# define BRCTG	brctg
-#else
-# define LTGR	ltr
-# define CGHI	chi
-# define LGR	lr
-# define AGHI	ahi
-# define BRCTG	brct
-#endif /* ! defined __s390x__  */
-
-#ifdef USE_MULTIARCH
-ENTRY(__memset_default)
-#else
-ENTRY(memset)
-#endif
-#if defined __s390x__
-	.machine "z900"
-#else
-	.machine "g5"
-#endif /* ! defined __s390x__  */
-	LTGR    %r4,%r4
-	je      .L_Z900_G5_4
-	stc     %r3,0(%r2)
-	CGHI    %r4,1
-	LGR     %r1,%r2
-	je      .L_Z900_G5_4
-	AGHI    %r4,-2
-#if defined __s390x__
-	larl    %r5,.L_Z900_G5_18
-	srlg    %r3,%r4,8
-# define Z900_G5_EX_D 0
-#else
-	basr    %r5,0
-.L_Z900_G5_19:
-# define Z900_G5_EX_D .L_Z900_G5_18-.L_Z900_G5_19
-	lr      %r3,%r4
-	srl     %r3,8
-#endif /* ! defined __s390x__  */
-	LTGR    %r3,%r3
-	jne     .L_Z900_G5_14
-.L_Z900_G5_3:
-	ex      %r4,Z900_G5_EX_D(%r5)
-.L_Z900_G5_4:
-	br      %r14
-.L_Z900_G5_14:
-	mvc     1(256,%r1),0(%r1)
-	la      %r1,256(%r1)
-	BRCTG   %r3,.L_Z900_G5_14
-	j       .L_Z900_G5_3
-.L_Z900_G5_18:
-	mvc     1(1,%r1),0(%r1)
-#ifdef USE_MULTIARCH
-END(__memset_default)
-#else
-END(memset)
-libc_hidden_builtin_def (memset)
-#endif
-
-#undef LTGR
-#undef CGHI
-#undef LGR
-#undef AGHI
-#undef BRCTG
diff --git a/sysdeps/s390/multiarch/memset.c b/sysdeps/s390/memset.c
index 760b3e9df2..57a35aebc7 100644
--- a/sysdeps/s390/multiarch/memset.c
+++ b/sysdeps/s390/memset.c
@@ -16,11 +16,33 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#if IS_IN (libc)
+#include <ifunc-memset.h>
+#if HAVE_MEMSET_IFUNC
 # define memset __redirect_memset
 # include <string.h>
 # undef memset
 # include <ifunc-resolve.h>
 
-s390_libc_ifunc (__redirect_memset, __memset, memset)
+# if HAVE_MEMSET_Z900_G5
+extern __typeof (__redirect_memset) MEMSET_Z900_G5 attribute_hidden;
+# endif
+
+# if HAVE_MEMSET_Z10
+extern __typeof (__redirect_memset) MEMSET_Z10 attribute_hidden;
+# endif
+
+# if HAVE_MEMSET_Z196
+extern __typeof (__redirect_memset) MEMSET_Z196 attribute_hidden;
+# endif
+
+s390_libc_ifunc_expr (__redirect_memset, memset,
+		      ({
+			s390_libc_ifunc_init ();
+			(HAVE_MEMSET_Z196 && S390_IS_Z196 (stfle_bits))
+			  ? MEMSET_Z196
+			  : (HAVE_MEMSET_Z10 && S390_IS_Z10 (stfle_bits))
+			  ? MEMSET_Z10
+			  : MEMSET_DEFAULT;
+		      })
+		      )
 #endif
diff --git a/sysdeps/s390/multiarch/Makefile b/sysdeps/s390/multiarch/Makefile
index 93ad21bfa2..c893ebc565 100644
--- a/sysdeps/s390/multiarch/Makefile
+++ b/sysdeps/s390/multiarch/Makefile
@@ -19,8 +19,7 @@ sysdep_routines += strlen strlen-vx strlen-c \
 		   rawmemchr rawmemchr-vx rawmemchr-c \
 		   memccpy memccpy-vx memccpy-c \
 		   memrchr memrchr-vx memrchr-c \
-		   mempcpy \
-		   memset memset-s390x
+		   mempcpy
 endif
 
 ifeq ($(subdir),wcsmbs)
diff --git a/sysdeps/s390/multiarch/ifunc-impl-list.c b/sysdeps/s390/multiarch/ifunc-impl-list.c
index ec3373ae26..2f671eac1f 100644
--- a/sysdeps/s390/multiarch/ifunc-impl-list.c
+++ b/sysdeps/s390/multiarch/ifunc-impl-list.c
@@ -21,6 +21,7 @@
 #include <wchar.h>
 #include <ifunc-impl-list.h>
 #include <ifunc-resolve.h>
+#include <ifunc-memset.h>
 
 /* Maximum number of IFUNC implementations.  */
 #define MAX_IFUNC	3
@@ -46,12 +47,21 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
       S390_STORE_STFLE (stfle_bits);
     }
 
+#if HAVE_MEMSET_IFUNC
   IFUNC_IMPL (i, name, memset,
+# if HAVE_MEMSET_Z196
 	      IFUNC_IMPL_ADD (array, i, memset,
-			      S390_IS_Z196 (stfle_bits), __memset_z196)
+			      S390_IS_Z196 (stfle_bits), MEMSET_Z196)
+# endif
+# if HAVE_MEMSET_Z10
 	      IFUNC_IMPL_ADD (array, i, memset,
-			      S390_IS_Z10 (stfle_bits), __memset_z10)
-	      IFUNC_IMPL_ADD (array, i, memset, 1, __memset_default))
+			      S390_IS_Z10 (stfle_bits), MEMSET_Z10)
+# endif
+# if HAVE_MEMSET_Z900_G5
+	      IFUNC_IMPL_ADD (array, i, memset, 1, MEMSET_Z900_G5)
+# endif
+	      )
+#endif /* HAVE_MEMSET_IFUNC */
 
   IFUNC_IMPL (i, name, memcmp,
 	      IFUNC_IMPL_ADD (array, i, memcmp,