--- a/src/hotspot/share/opto/compile.hpp	Thu Mar 22 16:39:02 2018 -0700
+++ b/src/hotspot/share/opto/compile.hpp	Thu Mar 22 20:21:19 2018 -0700
@@ -416,6 +416,7 @@
   GrowableArray<Node*>* _predicate_opaqs;       // List of Opaque1 nodes for the loop predicates.
   GrowableArray<Node*>* _expensive_nodes;       // List of nodes that are expensive to compute and that we'd better not let the GVN freely common
   GrowableArray<Node*>* _range_check_casts;     // List of CastII nodes with a range check dependency
+  GrowableArray<Node*>* _opaque4_nodes;         // List of Opaque4 nodes that have a default value
   ConnectionGraph*      _congraph;
 #ifndef PRODUCT
   IdealGraphPrinter*    _printer;
@@ -810,6 +811,16 @@
   // Remove all range check dependent CastIINodes.
   void  remove_range_check_casts(PhaseIterGVN &igvn);
 
+  void add_opaque4_node(Node* n);
+  void remove_opaque4_node(Node* n) {
+    if (_opaque4_nodes->contains(n)) {
+      _opaque4_nodes->remove(n);
+    }
+  }
+  Node* opaque4_node(int idx) const { return _opaque4_nodes->at(idx);  }
+  int   opaque4_count()       const { return _opaque4_nodes->length(); }
+  void  remove_opaque4_nodes(PhaseIterGVN &igvn);
+
   // remove the opaque nodes that protect the predicates so that the unused checks and
   // uncommon traps will be eliminated from the graph.
   void cleanup_loop_predicates(PhaseIterGVN &igvn);