Improve representation inference for HUnknownOSRValue.

src/hydrogen-instructions.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 3405 matching lines @@
   DECLARE_CONCRETE_INSTRUCTION(CallStub)
 
  private:
   CodeStub::Major major_key_;
   TranscendentalCache::Type transcendental_type_;
 };
 
 
 class HUnknownOSRValue: public HTemplateInstruction<0> {
  public:
-  HUnknownOSRValue() { set_representation(Representation::Tagged()); }
+  HUnknownOSRValue()
+      : incoming_value_(NULL) {
+    set_representation(Representation::Tagged());
+  }
 
   virtual Representation RequiredInputRepresentation(int index) {
     return Representation::None();
   }
 
+  void set_incoming_value(HPhi* value) {
+    incoming_value_ = value;
+  }
+
+  HPhi* incoming_value() {
+    return incoming_value_;
+  }
+
   DECLARE_CONCRETE_INSTRUCTION(UnknownOSRValue)
+
+ private:
+  HPhi* incoming_value_;
 };
 
 
 class HLoadGlobalCell: public HTemplateInstruction<0> {
  public:
   HLoadGlobalCell(Handle<JSGlobalPropertyCell> cell, PropertyDetails details)
       : cell_(cell), details_(details) {
     set_representation(Representation::Tagged());
     SetFlag(kUseGVN);
     SetGVNFlag(kDependsOnGlobalVars);
@@ skipping 1364 matching lines @@
   DECLARE_CONCRETE_INSTRUCTION(LoadFieldByIndex);
 };
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_