src/share/vm/opto/opaquenode.hpp

rev 12700 : 8176506: C2: loop unswitching and unsafe accesses cause crash
Reviewed-by:

*** 85,94 ****
--- 85,116 ----
    Opaque3Node(Compile* C, Node *n, int opt) : Opaque2Node(C, n), _opt(opt) {}
    virtual int Opcode() const;
    bool rtm_opt() const { return (_opt == RTM_OPT); }
  };
  
+ // Used by GraphKit::must_be_not_null(): input 1 is a check that we
+ // know implicitly is always true of false but the compiler has no way
+ // to prove. If during optimizations, that check becomes true of
+ // false, the Opaque4 node is replaced by that constant true or
+ // false. Input 2 is the constant value we know the test takes. After
+ // loop optimizations, we replace input 1 by input 2 so the control
+ // that depends on that test can be removed and there's no overhead at
+ // runtime.
+ class Opaque4Node : public Node {
+   public:
+   Opaque4Node(Compile* C, Node *tst, Node* final_tst) : Node(0, tst, final_tst) {
+     // Put it on the Macro nodes list to removed during macro nodes expansion.
+     init_flags(Flag_is_macro);
+     C->add_macro_node(this);
+   }
+   virtual int Opcode() const;
+   virtual const Type *bottom_type() const { return TypeInt::BOOL; }
+   virtual const Type* Value(PhaseGVN* phase) const;
+   virtual Node* Identity(PhaseGVN* phase);
+ };
+ 
+ 
  //------------------------------ProfileBooleanNode-------------------------------
  // A node represents value profile for a boolean during parsing.
  // Once parsing is over, the node goes away (during IGVN).
  // It is used to override branch frequencies from MDO (see has_injected_profile in parse2.cpp).
  class ProfileBooleanNode : public Node {