--- a/src/hotspot/share/gc/shared/c2/barrierSetC2.hpp	Tue Nov 06 10:10:18 2018 -0800
+++ b/src/hotspot/share/gc/shared/c2/barrierSetC2.hpp	Tue Nov 06 23:03:05 2018 +0100
@@ -245,6 +245,9 @@
                              Node*& fast_oop_ctrl, Node*& fast_oop_rawmem,
                              intx prefetch_lines) const;
 
+  virtual Node* ideal_node(PhaseGVN* phase, Node* n, bool can_reshape) const { return NULL; }
+  virtual Node* identity_node(PhaseGVN* phase, Node* n) const { return n; }
+
   // These are general helper methods used by C2
   enum ArrayCopyPhase {
     Parsing,