Eagerly deoptimize on never-executed code-paths.

src/hydrogen-instructions.h

 // Copyright 2011 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 78 matching lines @@
   V(CheckSmi)                                  \
   V(ClampToUint8)                              \
   V(ClassOfTest)                               \
   V(Compare)                                   \
   V(CompareJSObjectEq)                         \
   V(CompareMap)                                \
   V(CompareSymbolEq)                           \
   V(Constant)                                  \
   V(Context)                                   \
   V(DeleteProperty)                            \
+  V(EagerDeoptimize)                           \

[danno, 2011/06/01 10:11:27]

My gut feeling is that  Eager vs. Lazy isn't the right distinction. I think I
would prefer this to be a "SoftDeoptimize" and the other one to be explicitly a
"HardDeoptimize". 

[fschneider, 2011/06/01 11:04:48]

Done.

   V(Deoptimize)                                \
   V(Div)                                       \
   V(EnterInlined)                              \
   V(ExternalArrayLength)                       \
   V(FixedArrayLength)                          \
   V(ToInt32)                                   \
   V(ForceRepresentation)                       \
   V(FunctionLiteral)                           \
   V(GetCachedArrayIndex)                       \
   V(GlobalObject)                              \
@@ skipping 729 matching lines @@
 class HBlockEntry: public HTemplateInstruction<0> {
  public:
   virtual Representation RequiredInputRepresentation(int index) const {
     return Representation::None();
   }
 
   DECLARE_CONCRETE_INSTRUCTION(BlockEntry)
 };
 
 
+class HEagerDeoptimize: public HTemplateInstruction<0> {
+ public:
+  virtual Representation RequiredInputRepresentation(int index) const {
+    return Representation::None();
+  }
+
+  DECLARE_CONCRETE_INSTRUCTION(EagerDeoptimize)
+};
+
+
 class HDeoptimize: public HControlInstruction {
  public:
   explicit HDeoptimize(int environment_length)
       : HControlInstruction(NULL, NULL),
         values_(environment_length) { }
 
   virtual Representation RequiredInputRepresentation(int index) const {
     return Representation::None();
   }
 
   virtual int OperandCount() { return values_.length(); }
   virtual HValue* OperandAt(int index) { return values_[index]; }
+  virtual void PrintDataTo(StringStream* stream);
 
   void AddEnvironmentValue(HValue* value) {
     values_.Add(NULL);
     SetOperandAt(values_.length() - 1, value);
   }
 
   DECLARE_CONCRETE_INSTRUCTION(Deoptimize)
 
   enum UseEnvironment {
     kNoUses,
@@ skipping 3130 matching lines @@
 
   DECLARE_CONCRETE_INSTRUCTION(In)
 };
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_