tree-vrp.c (vrp_visit_assignment_or_call): Handle simplifications to SSA names…

tree-vrp.c (vrp_visit_assignment_or_call): Handle simplifications to SSA names via extract_range_from_ssa_name if allowed.

2016-11-28  Richard Biener  <rguenther@suse.de>

	* tree-vrp.c (vrp_visit_assignment_or_call): Handle
	simplifications to SSA names via extract_range_from_ssa_name
	if allowed.

From-SVN: r242921

gcc/ChangeLog

 2016-11-28  Richard Biener  <rguenther@suse.de>
 
+	* tree-vrp.c (vrp_visit_assignment_or_call): Handle
+	simplifications to SSA names via extract_range_from_ssa_name
+	if allowed.
+
+2016-11-28  Richard Biener  <rguenther@suse.de>
+
 	PR tree-optimization/78542
 	* tree-ssa-ccp.c (evaluate_stmt): Only valueize simplification
 	if allowed.

gcc/tree-vrp.c

@@ -7132,17 +7132,31 @@ vrp_visit_assignment_or_call (gimple *stmt, tree *output_p, value_range *vr)
 	   && TYPE_MAX_VALUE (TREE_TYPE (lhs)))
 	  || POINTER_TYPE_P (TREE_TYPE (lhs))))
     {
+      *output_p = lhs;
+
       /* Try folding the statement to a constant first.  */
       tree tem = gimple_fold_stmt_to_constant_1 (stmt, vrp_valueize,
 						 vrp_valueize_1);
-      if (tem && is_gimple_min_invariant (tem))
-	set_value_range_to_value (vr, tem, NULL);
+      if (tem)
+	{
+	  if (TREE_CODE (tem) == SSA_NAME
+	      && (SSA_NAME_IS_DEFAULT_DEF (tem)
+		  || ! prop_simulate_again_p (SSA_NAME_DEF_STMT (tem))))
+	    {
+	      extract_range_from_ssa_name (vr, tem);
+	      return;
+	    }
+	  else if (is_gimple_min_invariant (tem))
+	    {
+	      set_value_range_to_value (vr, tem, NULL);
+	      return;
+	    }
+	}
       /* Then dispatch to value-range extracting functions.  */
-      else if (code == GIMPLE_CALL)
+      if (code == GIMPLE_CALL)
 	extract_range_basic (vr, stmt);
       else
 	extract_range_from_assignment (vr, as_a <gassign *> (stmt));
-      *output_p = lhs;
     }
 }