--- old/src/hotspot/share/opto/memnode.hpp	2018-07-19 11:58:49.938278432 +0100
+++ new/src/hotspot/share/opto/memnode.hpp	2018-07-19 11:58:49.667277616 +0100
@@ -1605,4 +1605,40 @@
   virtual const Type *bottom_type() const { return ( AllocatePrefetchStyle == 3 ) ? Type::MEMORY : Type::ABIO; }
 };
 
+// cachewb node for guaranteeing writeback of the cache line at a
+// given address to (persistent) storage
+class CacheWBNode : public Node {
+public:
+  CacheWBNode(Node *ctrl, Node *mem, Node *addr) : Node(ctrl, mem, addr) {}
+  virtual int Opcode() const;
+  virtual uint ideal_reg() const { return NotAMachineReg; }
+  virtual uint match_edge(uint idx) const { return (idx == 2); }
+  virtual const TypePtr *adr_type() const { return TypeRawPtr::BOTTOM; }
+  virtual const Type *bottom_type() const { return Type::MEMORY; }
+};
+
+// cachewb pre sync node for ensuring that writebacks are serialised
+// relative to preceding or following stores
+class CacheWBPreSyncNode : public Node {
+public:
+  CacheWBPreSyncNode(Node *ctrl, Node *mem) : Node(ctrl, mem) {}
+  virtual int Opcode() const;
+  virtual uint ideal_reg() const { return NotAMachineReg; }
+  virtual uint match_edge(uint idx) const { return false; }
+  virtual const TypePtr *adr_type() const { return TypeRawPtr::BOTTOM; }
+  virtual const Type *bottom_type() const { return Type::MEMORY; }
+};
+
+// cachewb pre sync node for ensuring that writebacks are serialised
+// relative to preceding or following stores
+class CacheWBPostSyncNode : public Node {
+public:
+  CacheWBPostSyncNode(Node *ctrl, Node *mem) : Node(ctrl, mem) {}
+  virtual int Opcode() const;
+  virtual uint ideal_reg() const { return NotAMachineReg; }
+  virtual uint match_edge(uint idx) const { return false; }
+  virtual const TypePtr *adr_type() const { return TypeRawPtr::BOTTOM; }
+  virtual const Type *bottom_type() const { return Type::MEMORY; }
+};
+
 #endif // SHARE_VM_OPTO_MEMNODE_HPP