re PR tree-optimization/78558 (Incorrect loop optimization leads to crash)

	PR tree-optimization/78558
	* gcc.dg/vect/pr78558.c: New test.

From-SVN: r253661

gcc/testsuite/ChangeLog

 2017-10-11  Jakub Jelinek  <jakub@redhat.com>
 
+	PR tree-optimization/78558
+	* gcc.dg/vect/pr78558.c: New test.
+
 	PR c++/82414
 	* g++.dg/lto/pr82414_0.C: New test.
 

gcc/testsuite/gcc.dg/vect/pr78558.c

+/* PR tree-optimization/78558 */
+
+#include "tree-vect.h"
+
+struct S
+{
+  char p[48];
+  unsigned long long q, r, s;
+} s[50];
+
+struct D
+{
+  unsigned long long q, r;
+} d[50];
+
+void
+foo (void)
+{
+  unsigned long i;
+  for (i = 0; i < 50; ++i)
+    {
+      d[i].q = s[i].q;
+      d[i].r = s[i].r;
+    }
+}
+
+int
+main ()
+{
+  check_vect ();
+  unsigned long i;
+  for (i = 0; i < 50; ++i)
+    {
+      s[i].q = i;
+      s[i].r = 50 * i;
+    }
+  asm volatile ("" : : "g" (s), "g" (d) : "memory");
+  foo ();
+  asm volatile ("" : : "g" (s), "g" (d) : "memory");
+  for (i = 0; i < 50; ++i)
+    if (d[i].q != i || d[i].r != 50 * i)
+      abort ();
+  return 0;
+}