Add a testcase for PR tree-optimization/67077

	PR tree-optimization/67077
	* gcc.dg/pr67077.c: New test.

From-SVN: r226518

gcc/testsuite/ChangeLog

+2015-08-03  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR tree-optimization/67077
+	* gcc.dg/pr67077.c: New test.
+
 2015-08-03  Jeff Law  <law@redhat.com>
 
 	PR middle-end/66314

gcc/testsuite/gcc.dg/pr67077.c

+/* { dg-do compile } */
+/* { dg-options "-Wall -O2" } */
+
+unsigned char buffer[8];
+unsigned long
+foo (void)
+{
+  unsigned long i;
+  i = buffer[0];
+  if (i >= 8)
+    return i - 7;
+  i++;
+  while (i > 8)
+    {
+      if (buffer[i-1] != 0)
+        return 0;
+      i--;
+    }
+  return 1;
+}