src/hotspot/share/opto/memnode.hpp

*** 109,118 ****
--- 109,122 ----
  #else
      return 0;
  #endif
    }
  
+ #ifdef ASSERT
+   void set_adr_type(const TypePtr* adr_type) { _adr_type = adr_type; }
+ #endif
+   
    // Map a load or store opcode to its corresponding store opcode.
    // (Return -1 if unknown.)
    virtual int store_Opcode() const { return -1; }
  
    // What is the type of the value in memory?  (T_VOID mean "unspecified".)
*** 520,529 ****
--- 524,560 ----
    virtual const Type* Value(PhaseGVN* phase) const;
    virtual Node* Identity(PhaseGVN* phase);
    virtual bool depends_only_on_test() const { return true; }
  };
  
+ // Retrieve the null free property from an array klass. This is
+ // treated a bit like a field that would be read from the klass
+ // structure at runtime except, the implementation encodes the
+ // property as a bit in the klass header field of the array. This
+ // implementation detail is hidden under this node so it doesn't make
+ // a difference for high level optimizations. At final graph reshaping
+ // time, this node is turned into the actual logical operations that
+ // extract the property from the klass pointer. For this to work
+ // correctly, GetNullFreePropertyNode must take a LoadKlass/LoadNKlass
+ // input. The Ideal transformation splits the GetNullFreePropertyNode
+ // through phis, Value returns a constant if the node's input is a
+ // constant. These 2 should guarantee GetNullFreePropertyNode does
+ // indeed have a LoadKlass/LoadNKlass input at final graph reshaping
+ // time.
+ class GetNullFreePropertyNode : public Node {
+ public:
+   GetNullFreePropertyNode(Node* klass) : Node(NULL, klass) {}
+   virtual int Opcode() const;
+   virtual const Type* Value(PhaseGVN* phase) const;
+   virtual Node* Ideal(PhaseGVN *phase, bool can_reshape);
+   virtual const Type* bottom_type() const {
+     if (in(1)->bottom_type()->isa_klassptr()) {
+       return TypeLong::LONG;
+     }
+     return TypeInt::INT;
+   }
+ };
  
  //------------------------------StoreNode--------------------------------------
  // Store value; requires Store, Address and Value
  class StoreNode : public MemNode {
  private: