pr66174.c: New test.

	* gcc.target/i386/pr66174.c: New test.

From-SVN: r223275

gcc/testsuite/gcc.target/i386/pr66174.c

+/* { dg-do compile } */
+/* { dg-options "-O -ftree-vectorize -mavx512f" } */
+
+extern void abort (void);
+
+typedef struct {
+   unsigned int a;
+   unsigned int b;
+} ii;
+
+void foo (unsigned short *arr, ii *iarr)
+{
+  ii *iptr = iarr;
+  unsigned short res[128];
+  ii ires[128];
+  int i;
+  for (i = 0; i < 128; i++)
+    {
+      ires[i].a = iptr->b - iptr->a;
+      ires[i].b = iptr->b + iptr->a;
+      iptr++;
+    }
+  for (i = 0; i < 128; i++)
+    {
+      if (res[i] != arr[i]
+          || ires[i].a != iarr[i].b - iarr[i].a
+          || ires[i].b != iarr[i].b + iarr[i].a)
+        abort ();
+    }
+}