S390: Optimize wmemset.

This patch provides optimized version of wmemset with the z13 vector
instructions.

ChangeLog:

	* sysdeps/s390/multiarch/wmemset-c.c: New File.
	* sysdeps/s390/multiarch/wmemset-vx.S: Likewise.
	* sysdeps/s390/multiarch/wmemset.c: Likewise.
	* sysdeps/s390/multiarch/Makefile
	(sysdep_routines): Add wmemset functions.
	* sysdeps/s390/multiarch/ifunc-impl-list-common.c
	(__libc_ifunc_impl_list_common): Add ifunc test for wmemset.
	* wcsmbs/wmemset.c: Use WMEMSET if defined.
	* string/test-memset.c: Add wmemset support.
	* wcsmbs/test-wmemset.c: New File.
	* wcsmbs/Makefile (strop-tests): Add wmemset.
	* benchtests/bench-memset.c: Add wmemset support.
	* benchtests/bench-wmemset.c: New File.
	* benchtests/Makefile (wcsmbs-bench): Add wmemset.

13 files changed, 373 insertions, 56 deletions

diff --git a/ChangeLog b/ChangeLog
index 3354f1d58c..76fc7c2c2f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,22 @@
 2015-08-26  Stefan Liebler  <stli@linux.vnet.ibm.com>
 
+	* sysdeps/s390/multiarch/wmemset-c.c: New File.
+	* sysdeps/s390/multiarch/wmemset-vx.S: Likewise.
+	* sysdeps/s390/multiarch/wmemset.c: Likewise.
+	* sysdeps/s390/multiarch/Makefile
+	(sysdep_routines): Add wmemset functions.
+	* sysdeps/s390/multiarch/ifunc-impl-list-common.c
+	(__libc_ifunc_impl_list_common): Add ifunc test for wmemset.
+	* wcsmbs/wmemset.c: Use WMEMSET if defined.
+	* string/test-memset.c: Add wmemset support.
+	* wcsmbs/test-wmemset.c: New File.
+	* wcsmbs/Makefile (strop-tests): Add wmemset.
+	* benchtests/bench-memset.c: Add wmemset support.
+	* benchtests/bench-wmemset.c: New File.
+	* benchtests/Makefile (wcsmbs-bench): Add wmemset.
+
+2015-08-26  Stefan Liebler  <stli@linux.vnet.ibm.com>
+
 	* sysdeps/s390/multiarch/memccpy-c.c: New File.
 	* sysdeps/s390/multiarch/memccpy-vx.S: Likewise.
 	* sysdeps/s390/multiarch/memccpy.c: Likewise.
diff --git a/benchtests/Makefile b/benchtests/Makefile
index 95712a32ae..28a517060b 100644
--- a/benchtests/Makefile
+++ b/benchtests/Makefile
@@ -38,7 +38,7 @@ string-bench := bcopy bzero memccpy memchr memcmp memcpy memmem memmove \
 		strcoll
 wcsmbs-bench := wcslen wcsnlen wcscpy wcpcpy wcsncpy wcpncpy wcscat wcsncat \
 		wcscmp wcsncmp wcschr wcschrnul wcsrchr wcsspn wcspbrk wcscspn \
-		wmemchr
+		wmemchr wmemset
 string-bench-all := $(string-bench) ${wcsmbs-bench}
 
 # We have to generate locales
diff --git a/benchtests/bench-memset.c b/benchtests/bench-memset.c
index 9786ce71d1..66c3c45c72 100644
--- a/benchtests/bench-memset.c
+++ b/benchtests/bench-memset.c
@@ -20,12 +20,29 @@
 #ifdef TEST_BZERO
 # define TEST_NAME "bzero"
 #else
-# define TEST_NAME "memset"
-#endif
+# ifndef WIDE
+#  define TEST_NAME "memset"
+# else
+#  define TEST_NAME "wmemset"
+# endif /* WIDE */
+#endif /* !TEST_BZERO */
 #define MIN_PAGE_SIZE 131072
 #include "bench-string.h"
 
-char *simple_memset (char *, int, size_t);
+#ifndef WIDE
+# define MEMSET memset
+# define CHAR char
+# define SIMPLE_MEMSET simple_memset
+# define MEMCMP memcmp
+#else
+# include <wchar.h>
+# define MEMSET wmemset
+# define CHAR wchar_t
+# define SIMPLE_MEMSET simple_wmemset
+# define MEMCMP wmemcmp
+#endif /* WIDE */
+
+CHAR *SIMPLE_MEMSET (CHAR *, int, size_t);
 
 #ifdef TEST_BZERO
 typedef void (*proto_t) (char *, size_t);
@@ -39,7 +56,7 @@ IMPL (bzero, 1)
 void
 simple_bzero (char *s, size_t n)
 {
-  simple_memset (s, 0, n);
+  SIMPLE_MEMSET (s, 0, n);
 }
 
 void
@@ -48,46 +65,50 @@ builtin_bzero (char *s, size_t n)
   __builtin_bzero (s, n);
 }
 #else
-typedef char *(*proto_t) (char *, int, size_t);
-char *builtin_memset (char *, int, size_t);
+typedef CHAR *(*proto_t) (CHAR *, int, size_t);
 
-IMPL (simple_memset, 0)
+IMPL (SIMPLE_MEMSET, 0)
+# ifndef WIDE
+char *builtin_memset (char *, int, size_t);
 IMPL (builtin_memset, 0)
-IMPL (memset, 1)
+# endif /* !WIDE */
+IMPL (MEMSET, 1)
 
+# ifndef WIDE
 char *
 builtin_memset (char *s, int c, size_t n)
 {
   return __builtin_memset (s, c, n);
 }
-#endif
+# endif /* !WIDE */
+#endif /* !TEST_BZERO */
 
-char *
+CHAR *
 inhibit_loop_to_libcall
-simple_memset (char *s, int c, size_t n)
+SIMPLE_MEMSET (CHAR *s, int c, size_t n)
 {
-  char *r = s, *end = s + n;
+  CHAR *r = s, *end = s + n;
   while (r < end)
     *r++ = c;
   return s;
 }
 
 static void
-do_one_test (impl_t *impl, char *s, int c __attribute ((unused)), size_t n)
+do_one_test (impl_t *impl, CHAR *s, int c __attribute ((unused)), size_t n)
 {
   size_t i, iters = INNER_LOOP_ITERS;
   timing_t start, stop, cur;
-  char tstbuf[n];
+  CHAR tstbuf[n];
 #ifdef TEST_BZERO
   simple_bzero (tstbuf, n);
   CALL (impl, s, n);
   if (memcmp (s, tstbuf, n) != 0)
 #else
-  char *res = CALL (impl, s, c, n);
+  CHAR *res = CALL (impl, s, c, n);
   if (res != s
-      || simple_memset (tstbuf, c, n) != tstbuf
-      || memcmp (s, tstbuf, n) != 0)
-#endif
+      || SIMPLE_MEMSET (tstbuf, c, n) != tstbuf
+      || MEMCMP (s, tstbuf, n) != 0)
+#endif /* !TEST_BZERO */
     {
       error (0, 0, "Wrong result in function %s", impl->name);
       ret = 1;
@@ -101,7 +122,7 @@ do_one_test (impl_t *impl, char *s, int c __attribute ((unused)), size_t n)
       CALL (impl, s, n);
 #else
       CALL (impl, s, c, n);
-#endif
+#endif /* !TEST_BZERO */
     }
   TIMING_NOW (stop);
 
@@ -114,13 +135,13 @@ static void
 do_test (size_t align, int c, size_t len)
 {
   align &= 7;
-  if (align + len > page_size)
+  if ((align + len) * sizeof (CHAR) > page_size)
     return;
 
   printf ("Length %4zd, alignment %2zd, c %2d:", len, align, c);
 
   FOR_EACH_IMPL (impl, 0)
-    do_one_test (impl, (char *) buf1 + align, c, len);
+    do_one_test (impl, (CHAR *) (buf1) + align, c, len);
 
   putchar ('\n');
 }
diff --git a/benchtests/bench-wmemset.c b/benchtests/bench-wmemset.c
new file mode 100644
index 0000000000..540829cd89
--- /dev/null
+++ b/benchtests/bench-wmemset.c
@@ -0,0 +1,20 @@
+/* Measure wmemset functions.
+   Copyright (C) 2015 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/>.  */
+
+#define WIDE 1
+#include "bench-memset.c"
diff --git a/string/test-memset.c b/string/test-memset.c
index 9f3af468b0..79b298333c 100644
--- a/string/test-memset.c
+++ b/string/test-memset.c
@@ -1,4 +1,4 @@
-/* Test and measure memset functions.
+/* Test memset functions.
    Copyright (C) 1999-2015 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Written by Jakub Jelinek <jakub@redhat.com>, 1999.
@@ -21,12 +21,33 @@
 #ifdef TEST_BZERO
 # define TEST_NAME "bzero"
 #else
-# define TEST_NAME "memset"
-#endif
+# ifndef WIDE
+#  define TEST_NAME "memset"
+# else
+#  define TEST_NAME "wmemset"
+# endif /* WIDE */
+#endif /* !TEST_BZERO */
 #define MIN_PAGE_SIZE 131072
 #include "test-string.h"
 
-char *simple_memset (char *, int, size_t);
+#ifndef WIDE
+# define MEMSET memset
+# define CHAR char
+# define UCHAR unsigned char
+# define SIMPLE_MEMSET simple_memset
+# define MEMCMP memcmp
+# define BIG_CHAR CHAR_MAX
+#else
+# include <wchar.h>
+# define MEMSET wmemset
+# define CHAR wchar_t
+# define UCHAR wchar_t
+# define SIMPLE_MEMSET simple_wmemset
+# define MEMCMP wmemcmp
+# define BIG_CHAR WCHAR_MAX
+#endif /* WIDE */
+
+CHAR *SIMPLE_MEMSET (CHAR *, int, size_t);
 
 #ifdef TEST_BZERO
 typedef void (*proto_t) (char *, size_t);
@@ -40,7 +61,7 @@ IMPL (bzero, 1)
 void
 simple_bzero (char *s, size_t n)
 {
-  simple_memset (s, 0, n);
+  SIMPLE_MEMSET (s, 0, n);
 }
 
 void
@@ -49,44 +70,48 @@ builtin_bzero (char *s, size_t n)
   __builtin_bzero (s, n);
 }
 #else
-typedef char *(*proto_t) (char *, int, size_t);
-char *builtin_memset (char *, int, size_t);
+typedef CHAR *(*proto_t) (CHAR *, int, size_t);
 
-IMPL (simple_memset, 0)
+IMPL (SIMPLE_MEMSET, 0)
+# ifndef WIDE
+char *builtin_memset (char *, int, size_t);
 IMPL (builtin_memset, 0)
-IMPL (memset, 1)
+# endif /* !WIDE */
+IMPL (MEMSET, 1)
 
+# ifndef WIDE
 char *
 builtin_memset (char *s, int c, size_t n)
 {
   return __builtin_memset (s, c, n);
 }
-#endif
+# endif /* !WIDE */
+#endif /* !TEST_BZERO */
 
-char *
+CHAR *
 inhibit_loop_to_libcall
-simple_memset (char *s, int c, size_t n)
+SIMPLE_MEMSET (CHAR *s, int c, size_t n)
 {
-  char *r = s, *end = s + n;
+  CHAR *r = s, *end = s + n;
   while (r < end)
     *r++ = c;
   return s;
 }
 
 static void
-do_one_test (impl_t *impl, char *s, int c __attribute ((unused)), size_t n)
+do_one_test (impl_t *impl, CHAR *s, int c __attribute ((unused)), size_t n)
 {
-  char tstbuf[n];
+  CHAR tstbuf[n];
 #ifdef TEST_BZERO
   simple_bzero (tstbuf, n);
   CALL (impl, s, n);
   if (memcmp (s, tstbuf, n) != 0)
 #else
-  char *res = CALL (impl, s, c, n);
+  CHAR *res = CALL (impl, s, c, n);
   if (res != s
-      || simple_memset (tstbuf, c, n) != tstbuf
-      || memcmp (s, tstbuf, n) != 0)
-#endif
+      || SIMPLE_MEMSET (tstbuf, c, n) != tstbuf
+      || MEMCMP (s, tstbuf, n) != 0)
+#endif /* !TEST_BZERO */
     {
       error (0, 0, "Wrong result in function %s", impl->name);
       ret = 1;
@@ -98,11 +123,11 @@ static void
 do_test (size_t align, int c, size_t len)
 {
   align &= 7;
-  if (align + len > page_size)
+  if ((align + len) * sizeof (CHAR) > page_size)
     return;
 
   FOR_EACH_IMPL (impl, 0)
-    do_one_test (impl, (char *) buf1 + align, c, len);
+    do_one_test (impl, (CHAR *) (buf1) + align, c, len);
 }
 
 #ifndef TEST_BZERO
@@ -111,18 +136,19 @@ do_random_tests (void)
 {
   size_t i, j, k, n, align, len, size;
   int c, o;
-  unsigned char *p, *res;
+  UCHAR *p, *res;
+  UCHAR *p2 = (UCHAR *) buf2;
 
-  for (i = 0; i < 65536; ++i)
-    buf2[i] = random () & 255;
+  for (i = 0; i < 65536 / sizeof (CHAR); ++i)
+    p2[i] = random () & BIG_CHAR;
 
   for (n = 0; n < ITERATIONS; n++)
     {
       if ((random () & 31) == 0)
-	size = 65536;
+	size = 65536 / sizeof (CHAR);
       else
 	size = 512;
-      p = buf1 + page_size - size;
+      p = (UCHAR *) (buf1 + page_size) - size;
       len = random () & (size - 1);
       align = size - len - (random () & 31);
       if (align > size)
@@ -132,10 +158,10 @@ do_random_tests (void)
       if ((random () & 7) == 0)
 	c = 0;
       else
-	c = random () & 255;
-      o = random () & 255;
+	c = random () & BIG_CHAR;
+      o = random () & BIG_CHAR;
       if (o == c)
-        o = (c + 1) & 255;
+	o = (c + 1) & BIG_CHAR;
       j = len + align + 128;
       if (j > size)
 	j = size;
@@ -152,11 +178,11 @@ do_random_tests (void)
 	{
 	  for (i = 0; i < len; ++i)
 	    {
-	      p[i + align] = buf2[i];
+	      p[i + align] = p2[i];
 	      if (p[i + align] == c)
 		p[i + align] = o;
 	    }
-	  res = (unsigned char *) CALL (impl, (char *) p + align, c, len);
+	  res = (UCHAR *) CALL (impl, (CHAR *) p + align, c, len);
 	  if (res != p + align)
 	    {
 	      error (0, 0, "Iteration %zd - wrong result in function %s (%zd, %d, %zd) %p != %p",
@@ -190,7 +216,7 @@ do_random_tests (void)
 	}
     }
 }
-#endif
+#endif /* !TEST_BZERO */
 
 int
 test_main (void)
diff --git a/sysdeps/s390/multiarch/Makefile b/sysdeps/s390/multiarch/Makefile
index 87dff0f71d..eac88e0255 100644
--- a/sysdeps/s390/multiarch/Makefile
+++ b/sysdeps/s390/multiarch/Makefile
@@ -37,5 +37,6 @@ sysdep_routines += wcslen wcslen-vx wcslen-c \
 		   wcsspn wcsspn-vx wcsspn-c \
 		   wcspbrk wcspbrk-vx wcspbrk-c \
 		   wcscspn wcscspn-vx wcscspn-c \
-		   wmemchr wmemchr-vx wmemchr-c
+		   wmemchr wmemchr-vx wmemchr-c \
+		   wmemset wmemset-vx wmemset-c
 endif
diff --git a/sysdeps/s390/multiarch/ifunc-impl-list.c b/sysdeps/s390/multiarch/ifunc-impl-list.c
index c90fb6b6c7..93789acbbe 100644
--- a/sysdeps/s390/multiarch/ifunc-impl-list.c
+++ b/sysdeps/s390/multiarch/ifunc-impl-list.c
@@ -133,6 +133,7 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 
   IFUNC_VX_IMPL (memccpy);
 
+  IFUNC_VX_IMPL (wmemset);
 #endif /* HAVE_S390_VX_ASM_SUPPORT */
 
   return i;
diff --git a/sysdeps/s390/multiarch/wmemset-c.c b/sysdeps/s390/multiarch/wmemset-c.c
new file mode 100644
index 0000000000..cec2339c20
--- /dev/null
+++ b/sysdeps/s390/multiarch/wmemset-c.c
@@ -0,0 +1,37 @@
+/* Default wmemset implementation for S/390.
+   Copyright (C) 2015 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 HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)
+# define WMEMSET  __wmemset_c
+
+# include <wchar.h>
+extern __typeof (__wmemset) __wmemset_c;
+# undef weak_alias
+# define weak_alias(name, alias)
+# ifdef SHARED
+#  undef libc_hidden_def
+#  define libc_hidden_def(name)					\
+  __hidden_ver1 (__wmemset_c, __GI___wmemset, __wmemset_c);
+#  undef libc_hidden_weak
+#  define libc_hidden_weak(name)					\
+  strong_alias (__wmemset_c, __wmemset_c_1);				\
+  __hidden_ver1 (__wmemset_c_1, __GI_wmemset, __wmemset_c_1);
+# endif /* SHARED */
+
+# include <wcsmbs/wmemset.c>
+#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */
diff --git a/sysdeps/s390/multiarch/wmemset-vx.S b/sysdeps/s390/multiarch/wmemset-vx.S
new file mode 100644
index 0000000000..22bddcd3a3
--- /dev/null
+++ b/sysdeps/s390/multiarch/wmemset-vx.S
@@ -0,0 +1,142 @@
+/* Vector Optimized 32/64 bit S/390 version of wmemset.
+   Copyright (C) 2015 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 HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)
+
+# include "sysdep.h"
+# include "asm-syntax.h"
+
+	.text
+
+/* wchar_t *wmemset(wchar_t *dest, wchar_t wc, size_t n)
+   Fill an array of wide-characters with a constant wide character
+   and returns dest.
+
+   Register usage:
+   -r0=tmp
+   -r1=tmp
+   -r2=dest or current-pointer
+   -r3=wc
+   -r4=n
+   -r5=tmp
+   -v16=replicated wc
+   -v17,v18,v19=copy of v16 for vstm
+   -v31=saved dest for return
+*/
+ENTRY(__wmemset_vx)
+	.machine "z13"
+	.machinemode "zarch_nohighgprs"
+
+# if !defined __s390x__
+	llgfr	%r4,%r4
+# endif /* !defined __s390x__ */
+
+	vlvgg	%v31,%r2,0	/* Save destination pointer for return.  */
+	clgije	%r4,0,.Lend
+
+	vlvgf	%v16,%r3,0	/* Generate vector with wchar_t wc.  */
+	vrepf	%v16,%v16,0
+
+	/* Check range of maxlen and convert to byte-count.  */
+# ifdef __s390x__
+	tmhh	%r4,49152	/* Test bit 0 or 1 of maxlen.  */
+	lghi	%r5,-4		/* Max byte-count is 18446744073709551612.  */
+# else
+	tmlh	%r4,49152	/* Test bit 0 or 1 of maxlen.  */
+	llilf	%r5,4294967292	/* Max byte-count is 4294967292.  */
+# endif /* !__s390x__ */
+	sllg	%r4,%r4,2	/* Convert character-count to byte-count.  */
+	locgrne	%r4,%r5		/* Use max byte-count, if bit 0/1 was one.  */
+
+	/* Align dest to 16 byte.  */
+	risbg	%r0,%r2,60,128+63,0 /* Test if s is aligned and
+				       %r3 = bits 60-63 'and' 15.  */
+	je	.Lpreloop	/* If s is aligned, loop aligned.  */
+	tmll	%r2,3		/* Test if s is 4-byte aligned?  */
+	jne	.Lfallback	/* And use common-code variant if not.  */
+	lghi	%r1,16
+	slr	%r1,%r0		/* Compute byte count to load (16-x).  */
+	clgr	%r1,%r4
+	locgrh	%r1,%r4		/* min (byte count, n)  */
+	aghik	%r5,%r1,-1	/* vstl needs highest index.  */
+	vstl	%v16,%r5,0(%r2)	/* Store remaining bytes.  */
+	clgrje	%r1,%r4,.Lend	/* Return if n bytes where set.  */
+	slgr	%r4,%r1		/* Compute remaining byte count.  */
+	la	%r2,0(%r1,%r2)
+
+.Lpreloop:
+	/* Now we are 16-byte aligned.  */
+	clgijl	%r4,17,.Lremaining
+	srlg	%r1,%r4,8	/* Split into 256byte blocks */
+	clgije	%r1,0,.Lpreloop64
+	vlr	%v17,%v16
+	vlr	%v18,%v16
+	vlr	%v19,%v16
+
+.Lloop256:
+	vstm	%v16,%v19,0(%r2)
+	vstm	%v16,%v19,64(%r2)
+	vstm	%v16,%v19,128(%r2)
+	vstm	%v16,%v19,192(%r2)
+	la	%r2,256(%r2)
+	brctg	%r1,.Lloop256	/* Loop until all blocks are processed.  */
+
+	llgfr	%r4,%r4
+	nilf	%r4,255		/* Get remaining bytes */
+	je	.Lend		/* Skip store remaining bytes if zero.  */
+
+.Lpreloop64:
+	clgijl	%r4,17,.Lremaining
+	clgijl	%r4,33,.Lpreloop16
+	srlg	%r1,%r4,5	/* Split into 32byte blocks */
+
+.Lloop32:
+	vst	%v16,0(%r2)
+	vst	%v16,16(%r2)
+	la	%r2,32(%r2)
+	brctg	%r1,.Lloop32	/* Loop until all blocks are processed.  */
+
+	llgfr	%r4,%r4
+	nilf	%r4,31		/* Get remaining bytes */
+	je	.Lend		/* Skip store remaining bytes if zero.  */
+
+.Lpreloop16:
+	clgijl	%r4,17,.Lremaining
+	srlg	%r1,%r4,4	/* Split into 16byte blocks */
+
+.Lloop16:
+	vst	%v16,0(%r2)
+	la	%r2,16(%r2)
+	brctg	%r1,.Lloop16	/* Loop until all blocks are processed.  */
+
+	llgfr	%r4,%r4
+	nilf	%r4,15		/* Get remaining bytes */
+	je	.Lend		/* Skip store remaining bytes if zero.  */
+
+.Lremaining:
+	aghi	%r4,-1		/* vstl needs highest index.  */
+	vstl	%v16,%r4,0(%r2)
+
+.Lend:
+	vlgvg	%r2,%v31,0	/* Load saved dest for return value.  */
+	br	%r14
+.Lfallback:
+	srlg	%r4,%r4,2	/* Convert byte-count to character-count.  */
+	jg	__wmemset_c
+END(__wmemset_vx)
+#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */
diff --git a/sysdeps/s390/multiarch/wmemset.c b/sysdeps/s390/multiarch/wmemset.c
new file mode 100644
index 0000000000..884fea932c
--- /dev/null
+++ b/sysdeps/s390/multiarch/wmemset.c
@@ -0,0 +1,29 @@
+/* Multiple versions of wmemset.
+   Copyright (C) 2015 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 HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)
+# include <wchar.h>
+# include <ifunc-resolve.h>
+
+s390_vx_libc_ifunc (__wmemset)
+weak_alias (__wmemset, wmemset)
+libc_hidden_weak (wmemset)
+
+#else
+# include <wcsmbs/wmemset.c>
+#endif /* !(defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)) */
diff --git a/wcsmbs/Makefile b/wcsmbs/Makefile
index e8ce57969d..dc72ba4ad5 100644
--- a/wcsmbs/Makefile
+++ b/wcsmbs/Makefile
@@ -44,7 +44,7 @@ routines := wcscat wcschr wcscmp wcscpy wcscspn wcsdup wcslen wcsncat \
 
 strop-tests :=  wcscmp wcsncmp wmemcmp wcslen wcschr wcsrchr wcscpy wcsnlen \
 		wcpcpy wcsncpy wcpncpy wcscat wcsncat wcschrnul wcsspn wcspbrk \
-		wcscspn wmemchr
+		wcscspn wmemchr wmemset
 tests := tst-wcstof wcsmbs-tst1 tst-wcsnlen tst-btowc tst-mbrtowc \
 	 tst-wcrtomb tst-wcpncpy tst-mbsrtowcs tst-wchar-h tst-mbrtowc2 \
 	 tst-c16c32-1 wcsatcliff $(addprefix test-,$(strop-tests))
diff --git a/wcsmbs/test-wmemset.c b/wcsmbs/test-wmemset.c
new file mode 100644
index 0000000000..c03c759d9f
--- /dev/null
+++ b/wcsmbs/test-wmemset.c
@@ -0,0 +1,20 @@
+/* Test wmemset functions.
+   Copyright (C) 2015 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/>.  */
+
+#define WIDE 1
+#include "../string/test-memset.c"
diff --git a/wcsmbs/wmemset.c b/wcsmbs/wmemset.c
index 88fc015802..1eb6b2bc4e 100644
--- a/wcsmbs/wmemset.c
+++ b/wcsmbs/wmemset.c
@@ -18,6 +18,9 @@
 
 #include <wchar.h>
 
+#ifdef WMEMSET
+# define __wmemset WMEMSET
+#endif
 
 wchar_t *
 __wmemset (s, c, n)