tree-vrp.c (set_defs_to_varying): New helper avoiding writing to vr_const_varying.

2016-09-29  Richard Biener  <rguenther@suse.de>

	* tree-vrp.c (set_defs_to_varying): New helper avoiding
	writing to vr_const_varying.
	(vrp_initialize): Call it.
	(vrp_visit_stmt): Likewise.
	(evrp_dom_walker::before_dom_children): Likewise.

From-SVN: r240612

gcc/ChangeLog

 2016-09-29  Richard Biener  <rguenther@suse.de>
 
+	* tree-vrp.c (set_defs_to_varying): New helper avoiding
+	writing to vr_const_varying.
+	(vrp_initialize): Call it.
+	(vrp_visit_stmt): Likewise.
+	(evrp_dom_walker::before_dom_children): Likewise.
+
+2016-09-29  Richard Biener  <rguenther@suse.de>
+
 	* tree-vect-stmts.c (vectorizable_load): Avoid emitting vector
 	constructors with vector elements.
 

gcc/tree-vrp.c

@@ -710,6 +710,23 @@ get_value_range (const_tree var)
   return vr;
 }
 
+/* Set value-ranges of all SSA names defined by STMT to varying.  */
+
+static void
+set_defs_to_varying (gimple *stmt)
+{
+  ssa_op_iter i;
+  tree def;
+  FOR_EACH_SSA_TREE_OPERAND (def, stmt, i, SSA_OP_DEF)
+    {
+      value_range *vr = get_value_range (def);
+      /* Avoid writing to vr_const_varying get_value_range may return.  */
+      if (vr->type != VR_VARYING)
+	set_value_range_to_varying (vr);
+    }
+}
+
+
 /* Return true, if VAL1 and VAL2 are equal values for VRP purposes.  */
 
 static inline bool
@@ -7022,10 +7039,7 @@ vrp_initialize ()
 	    prop_set_simulate_again (stmt, true);
 	  else if (!stmt_interesting_for_vrp (stmt))
 	    {
-	      ssa_op_iter i;
-	      tree def;
-	      FOR_EACH_SSA_TREE_OPERAND (def, stmt, i, SSA_OP_DEF)
-		set_value_range_to_varying (get_value_range (def));
+	      set_defs_to_varying (stmt);
 	      prop_set_simulate_again (stmt, false);
 	    }
 	  else
@@ -7901,8 +7915,6 @@ vrp_visit_stmt (gimple *stmt, edge *taken_edge_p, tree *output_p)
 {
   value_range vr = VR_INITIALIZER;
   tree lhs = gimple_get_lhs (stmt);
-  tree def;
-  ssa_op_iter iter;
   extract_range_from_stmt (stmt, taken_edge_p, output_p, &vr);
 
   if (*output_p)
@@ -7997,8 +8009,7 @@ vrp_visit_stmt (gimple *stmt, edge *taken_edge_p, tree *output_p)
 
   /* All other statements produce nothing of interest for VRP, so mark
      their outputs varying and prevent further simulation.  */
-  FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_DEF)
-    set_value_range_to_varying (get_value_range (def));
+  set_defs_to_varying (stmt);
 
   return (*taken_edge_p) ? SSA_PROP_INTERESTING : SSA_PROP_VARYING;
 }
@@ -10726,12 +10737,7 @@ evrp_dom_walker::before_dom_children (basic_block bb)
 	      && (vr.type == VR_RANGE || vr.type == VR_ANTI_RANGE))
 	    update_value_range (output, &vr);
 	  else
-	    {
-	      tree def;
-	      ssa_op_iter iter;
-	      FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_DEF)
-		set_value_range_to_varying (get_value_range (def));
-	    }
+	    set_defs_to_varying (stmt);
 
 	  /* Try folding stmts with the VR discovered.  */
 	  bool did_replace
@@ -10780,12 +10786,7 @@ evrp_dom_walker::before_dom_children (basic_block bb)
 	    }
 	}
       else
-	{
-	  tree def;
-	  ssa_op_iter iter;
-	  FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_DEF)
-	    set_value_range_to_varying (get_value_range (def));
-	}
+	set_defs_to_varying (stmt);
     }
   bb->flags |= BB_VISITED;
   return NULL;