Index: testsuite/gcc.target/i386/sse4_1-set-v16qi-3.c
===================================================================
--- testsuite/gcc.target/i386/sse4_1-set-v16qi-3.c	(revision 0)
+++ testsuite/gcc.target/i386/sse4_1-set-v16qi-3.c	(revision 0)
@@ -0,0 +1,8 @@
+/* { dg-do run } */
+/* { dg-require-effective-target sse4 } */
+/* { dg-options "-O2 -msse4.1" } */
+
+#define CHECK_H "sse4_1-check.h"
+#define TEST sse4_1_test
+
+#include "set-v16qi-3.h"
Index: testsuite/gcc.target/i386/sse2-set-v16qi-3.c
===================================================================
--- testsuite/gcc.target/i386/sse2-set-v16qi-3.c	(revision 0)
+++ testsuite/gcc.target/i386/sse2-set-v16qi-3.c	(revision 0)
@@ -0,0 +1,7 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -msse2" } */
+
+#define CHECK_H "sse2-check.h"
+#define TEST sse2_test
+
+#include "set-v16qi-3.h"
Index: testsuite/gcc.target/i386/m128-check.h
===================================================================
--- testsuite/gcc.target/i386/m128-check.h	(revision 135731)
+++ testsuite/gcc.target/i386/m128-check.h	(working copy)
@@ -37,6 +37,10 @@ typedef union
   double a[2];
 } union128d;
 
+#ifndef ARRAY_SIZE
+#define ARRAY_SIZE(A) (sizeof (A) / sizeof ((A)[0]))
+#endif
+
 #ifdef DEBUG
 #define PRINTF printf
 #else
@@ -51,7 +55,7 @@ check_##UINON_TYPE (UINON_TYPE u, const 
   int i;						\
   int err = 0;						\
 							\
-  for (i = 0; i < sizeof (u.a) / sizeof (u.a[0]); i++)	\
+  for (i = 0; i < ARRAY_SIZE (u.a); i++)		\
     if (u.a[i] != v[i])					\
       {							\
 	err++;						\
Index: testsuite/gcc.target/i386/set-v16qi-3.h
===================================================================
--- testsuite/gcc.target/i386/set-v16qi-3.h	(revision 0)
+++ testsuite/gcc.target/i386/set-v16qi-3.h	(revision 0)
@@ -0,0 +1,63 @@
+#include CHECK_H
+
+static __m128i
+__attribute__((noinline))
+foo (char x, int i)
+{
+  switch (i)
+    {
+    case 15:
+      return _mm_set_epi8 (x, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1);
+    case 14:
+      return _mm_set_epi8 (1, x, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1);
+    case 13:
+      return _mm_set_epi8 (1, 1, x, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1);
+    case 12:
+      return _mm_set_epi8 (1, 1, 1, x, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1);
+    case 11:
+      return _mm_set_epi8 (1, 1, 1, 1, x, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1);
+    case 10:
+      return _mm_set_epi8 (1, 1, 1, 1, 1, x, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1);
+    case 9:
+      return _mm_set_epi8 (1, 1, 1, 1, 1, 1, x, 1, 1, 1, 1, 1, 1, 1, 1, 1);
+    case 8:
+      return _mm_set_epi8 (1, 1, 1, 1, 1, 1, 1, x, 1, 1, 1, 1, 1, 1, 1, 1);
+    case 7:
+      return _mm_set_epi8 (1, 1, 1, 1, 1, 1, 1, 1, x, 1, 1, 1, 1, 1, 1, 1);
+    case 6:
+      return _mm_set_epi8 (1, 1, 1, 1, 1, 1, 1, 1, 1, x, 1, 1, 1, 1, 1, 1);
+    case 5:
+      return _mm_set_epi8 (1, 1, 1, 1, 1, 1, 1, 1, 1, 1, x, 1, 1, 1, 1, 1);
+    case 4:
+      return _mm_set_epi8 (1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, x, 1, 1, 1, 1);
+    case 3:
+      return _mm_set_epi8 (1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, x, 1, 1, 1);
+    case 2:
+      return _mm_set_epi8 (1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, x, 1, 1);
+    case 1:
+      return _mm_set_epi8 (1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, x, 1);
+    case 0:
+      return _mm_set_epi8 (1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, x);
+    default:
+      abort ();
+    }
+}
+
+static void
+TEST (void)
+{
+  char e = 0x13;
+  char v[16];
+  union128i_b u;
+  int i, j;
+
+  for (i = 0; i < ARRAY_SIZE (v); i++)
+    {
+      for (j = 0; j < ARRAY_SIZE (v); j++)
+	v[j] = 1;
+      v[i] = e;
+      u.x = foo (e, i);
+      if (check_union128i_b (u, v))
+	abort ();
+    }
+}
Index: config/i386/i386.c
===================================================================
--- config/i386/i386.c	(revision 135732)
+++ config/i386/i386.c	(working copy)
@@ -23818,6 +23818,8 @@ ix86_expand_vector_init_one_var (bool mm
       break;
 
     case V16QImode:
+      if (TARGET_SSE4_1)
+	break;
       wmode = V8HImode;
       goto widen;
     case V8QImode: