re PR tree-optimization/79007 (gcc.dg/tree-ssa/dse-points-to.c fails starting with r244067)

	PR tree-optimization/79007
	PR tree-optimization/67955
	* tree-ssa-alias.c (same_addr_size_stores_p): Only need to be
	conservative for pt.null when flag_non_call_exceptions is on.

From-SVN: r244247

gcc/ChangeLog

+2017-01-04  Jeff Law  <law@redhat.com>
+
+	PR tree-optimization/79007
+	PR tree-optimization/67955
+	* tree-ssa-alias.c (same_addr_size_stores_p): Only need to be
+	conservative for pt.null when flag_non_call_exceptions is on.
+
 2017-01-09  Jakub Jelinek  <jakub@redhat.com>
 
 	PR translation/79019

gcc/tree-ssa-alias.c

@@ -2373,9 +2373,9 @@ same_addr_size_stores_p (tree base1, HOST_WIDE_INT offset1, HOST_WIDE_INT size1,
       || !pt_solution_singleton_or_null_p (&pi->pt, &pt_uid))
     return false;
 
-  /* If the solution has a singleton and NULL, then we can not
-     be sure that the two stores hit the same address.  */
-  if (pi->pt.null)
+  /* Be conservative with non-call exceptions when the address might
+     be NULL.  */
+  if (flag_non_call_exceptions && pi->pt.null)
     return false;
 
   /* Check that ptr points relative to obj.  */