fix the compare nil ic

src/code-stubs.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 259 matching lines @@
 struct CodeStubInterfaceDescriptor {
   CodeStubInterfaceDescriptor();
   int register_param_count_;
   const Register* stack_parameter_count_;
   // if hint_stack_parameter_count_ > 0, the code stub can optimize the
   // return sequence. Default value is -1, which means it is ignored.
   int hint_stack_parameter_count_;
   StubFunctionMode function_mode_;
   Register* register_params_;
   Address deoptimization_handler_;
-  ExternalReference miss_handler_;
 
   int environment_length() const {
     if (stack_parameter_count_ != NULL) {
       return register_param_count_ + 1;
     }
     return register_param_count_;
   }
 
   bool initialized() const { return register_param_count_ >= 0; }
+
+  void SetMissHandler(ExternalReference handler) {
+    miss_handler_ = handler;
+    has_miss_handler_ = true;
+  }
+
+  ExternalReference miss_handler() {
+    ASSERT(has_miss_handler_);
+    return miss_handler_;
+  }
+
+  bool has_miss_handler() {
+    return has_miss_handler_;
+  }
+
+ private:
+  ExternalReference miss_handler_;
+  bool has_miss_handler_;
 };
 
 // A helper to make up for the fact that type Register is not fully
 // defined outside of the platform directories
 #define DESCRIPTOR_GET_PARAMETER_REGISTER(descriptor, index) \
   ((index) == (descriptor)->register_param_count_)           \
       ? *((descriptor)->stack_parameter_count_)              \
       : (descriptor)->register_params_[(index)]
 
 
 class HydrogenCodeStub : public CodeStub {
  public:
   enum InitializationState {
-    CODE_STUB_IS_NOT_MISS,
-    CODE_STUB_IS_MISS
+    UNINITIALIZED,
+    INITIALIZED
   };
 
-  explicit HydrogenCodeStub(InitializationState state) {
-    is_miss_ = (state == CODE_STUB_IS_MISS);
+  explicit HydrogenCodeStub(InitializationState state = INITIALIZED) {
+    is_uninitialized_ = (state == UNINITIALIZED);
   }
 
   virtual Code::Kind GetCodeKind() const { return Code::STUB; }
 
   CodeStubInterfaceDescriptor* GetInterfaceDescriptor(Isolate* isolate) {
     return isolate->code_stub_interface_descriptor(MajorKey());
   }
 
-  bool IsMiss() { return is_miss_; }
+  bool IsUninitialized() { return is_uninitialized_; }
 
   template<class SubClass>
   static Handle<Code> GetUninitialized(Isolate* isolate) {
     SubClass::GenerateAheadOfTime(isolate);
     return SubClass().GetCode(isolate);
   }
 
   virtual void InitializeInterfaceDescriptor(
       Isolate* isolate,
       CodeStubInterfaceDescriptor* descriptor) = 0;
 
   // Retrieve the code for the stub. Generate the code if needed.
   virtual Handle<Code> GenerateCode() = 0;
 
   virtual int NotMissMinorKey() = 0;
 
   Handle<Code> GenerateLightweightMissCode(Isolate* isolate);
 
  private:
   class MinorKeyBits: public BitField<int, 0, kStubMinorKeyBits - 1> {};
   class IsMissBits: public BitField<bool, kStubMinorKeyBits - 1, 1> {};
 
   void GenerateLightweightMiss(MacroAssembler* masm);
   virtual int MinorKey() {
-    return IsMissBits::encode(is_miss_) |
+    return IsMissBits::encode(is_uninitialized_) |
         MinorKeyBits::encode(NotMissMinorKey());
   }
 
-  bool is_miss_;
+  bool is_uninitialized_;
 };
 
 
 // Helper interface to prepare to/restore after making runtime calls.
 class RuntimeCallHelper {
  public:
   virtual ~RuntimeCallHelper() {}
 
   virtual void BeforeCall(MacroAssembler* masm) const = 0;
 
@@ skipping 152 matching lines @@
     COPY_ON_WRITE_ELEMENTS,
     CLONE_ANY_ELEMENTS,
     LAST_CLONE_MODE = CLONE_ANY_ELEMENTS
   };
 
   static const int kFastCloneModeCount = LAST_CLONE_MODE + 1;
 
   FastCloneShallowArrayStub(Mode mode,
                             AllocationSiteMode allocation_site_mode,
                             int length)
-      : HydrogenCodeStub(CODE_STUB_IS_NOT_MISS),
-        mode_(mode),
+      : mode_(mode),
         allocation_site_mode_(allocation_site_mode),
         length_((mode == COPY_ON_WRITE_ELEMENTS) ? 0 : length) {
     ASSERT_GE(length_, 0);
     ASSERT_LE(length_, kMaximumClonedLength);
   }
 
   Mode mode() const { return mode_; }
   int length() const { return length_; }
   AllocationSiteMode allocation_site_mode() const {
     return allocation_site_mode_;
@@ skipping 39 matching lines @@
   }
 };
 
 
 class FastCloneShallowObjectStub : public HydrogenCodeStub {
  public:
   // Maximum number of properties in copied object.
   static const int kMaximumClonedProperties = 6;
 
   explicit FastCloneShallowObjectStub(int length)
-      : HydrogenCodeStub(CODE_STUB_IS_NOT_MISS),
-        length_(length) {
+      : length_(length) {
     ASSERT_GE(length_, 0);
     ASSERT_LE(length_, kMaximumClonedProperties);
   }
 
   int length() const { return length_; }
 
   virtual Handle<Code> GenerateCode();
 
   virtual void InitializeInterfaceDescriptor(
       Isolate* isolate,
@@ skipping 164 matching lines @@
   virtual CodeStub::Major MajorKey() { return StoreArrayLength; }
 };
 
 
 class HICStub: public HydrogenCodeStub {
  public:
   virtual Code::Kind GetCodeKind() const { return kind(); }
   virtual InlineCacheState GetICState() { return MONOMORPHIC; }
 
  protected:
-  HICStub() : HydrogenCodeStub(CODE_STUB_IS_NOT_MISS) { }
+  HICStub() { }
   class KindBits: public BitField<Code::Kind, 0, 4> {};
   virtual Code::Kind kind() const = 0;
 };
 
 
 class HandlerStub: public HICStub {
  public:
   virtual Code::Kind GetCodeKind() const { return Code::STUB; }
   virtual int GetStubFlags() { return kind(); }
 
@@ skipping 285 matching lines @@
 
     static Types FullCompare() {
       Types set;
       set.Add(UNDEFINED);
       set.Add(NULL_TYPE);
       set.Add(UNDETECTABLE);
       return set;
     }
 
     void Print(StringStream* stream) const;
+    void TraceTransition(Types to) const;
   };
 
   // At most 6 different types can be distinguished, because the Code object
   // only has room for a single byte to hold a set and there are two more
   // boolean flags we need to store. :-P
   STATIC_ASSERT(NUMBER_OF_TYPES <= 6);
 
-  CompareNilICStub(EqualityKind kind, NilValue nil, Types types)
-      : HydrogenCodeStub(CODE_STUB_IS_NOT_MISS), types_(types) {
+  CompareNilICStub(EqualityKind kind, NilValue nil, Types types = Types())
+      : types_(types) {
     equality_kind_ = kind;
     nil_value_ = nil;
   }
 
-  explicit CompareNilICStub(Code::ExtraICState ic_state)
-      : HydrogenCodeStub(CODE_STUB_IS_NOT_MISS) {
+  CompareNilICStub(Code::ExtraICState ic_state,
+                   InitializationState init_state = INITIALIZED)
+      : HydrogenCodeStub(init_state) {
     equality_kind_ = EqualityKindField::decode(ic_state);
     nil_value_ = NilValueField::decode(ic_state);
     types_ = Types(ExtractTypesFromExtraICState(ic_state));
   }
 
   static Handle<Code> GetUninitialized(Isolate* isolate,
                                        EqualityKind kind,
                                        NilValue nil) {
-    return CompareNilICStub(kind, nil, CODE_STUB_IS_MISS).GetCode(isolate);
+    return CompareNilICStub(kind, nil, UNINITIALIZED).GetCode(isolate);
   }
 
   virtual void InitializeInterfaceDescriptor(
       Isolate* isolate,
       CodeStubInterfaceDescriptor* descriptor);
 
   static void InitializeForIsolate(Isolate* isolate) {
-    CompareNilICStub compare_stub(kStrictEquality, kNullValue,
-                                  CODE_STUB_IS_MISS);
+    CompareNilICStub compare_stub(kStrictEquality, kNullValue, UNINITIALIZED);
     compare_stub.InitializeInterfaceDescriptor(
         isolate,
         isolate->code_stub_interface_descriptor(CodeStub::CompareNilIC));
   }
 
   virtual InlineCacheState GetICState() {
     if (types_ == Types::FullCompare()) {
       return MEGAMORPHIC;
     } else if (types_.Contains(MONOMORPHIC_MAP)) {
       return MONOMORPHIC;
@@ skipping 26 matching lines @@
   void ClearTypes() { types_.RemoveAll(); }
   void SetKind(EqualityKind kind) { equality_kind_ = kind; }
 
   virtual void PrintName(StringStream* stream);
 
  private:
   friend class CompareNilIC;
 
   CompareNilICStub(EqualityKind kind, NilValue nil,
                    InitializationState init_state)
-      : HydrogenCodeStub(init_state), types_(0) {
+      : HydrogenCodeStub(init_state) {
     equality_kind_ = kind;
     nil_value_ = nil;
   }
 
-  CompareNilICStub(Code::ExtraICState ic_state, InitializationState init_state)
-      : HydrogenCodeStub(init_state) {
-    equality_kind_ = EqualityKindField::decode(ic_state);
-    nil_value_ = NilValueField::decode(ic_state);
-    types_ = Types(ExtractTypesFromExtraICState(ic_state));
-  }
-
   class EqualityKindField : public BitField<EqualityKind, NUMBER_OF_TYPES, 1> {
   };
   class NilValueField : public BitField<NilValue, NUMBER_OF_TYPES+1, 1> {};
 
   virtual CodeStub::Major MajorKey() { return CompareNilIC; }
   virtual int NotMissMinorKey() { return GetExtraICState(); }
 
   EqualityKind equality_kind_;
   NilValue nil_value_;
   Types types_;
@@ skipping 387 matching lines @@
  private:
   Major MajorKey() { return KeyedLoadElement; }
   int MinorKey() { return DICTIONARY_ELEMENTS; }
 
   DISALLOW_COPY_AND_ASSIGN(KeyedLoadDictionaryElementStub);
 };
 
 
 class KeyedLoadFastElementStub : public HydrogenCodeStub {
  public:
-  KeyedLoadFastElementStub(bool is_js_array, ElementsKind elements_kind)
-      : HydrogenCodeStub(CODE_STUB_IS_NOT_MISS) {
+  KeyedLoadFastElementStub(bool is_js_array, ElementsKind elements_kind) {
     bit_field_ = ElementsKindBits::encode(elements_kind) |
         IsJSArrayBits::encode(is_js_array);
   }
 
   bool is_js_array() const {
     return IsJSArrayBits::decode(bit_field_);
   }
 
   ElementsKind elements_kind() const {
     return ElementsKindBits::decode(bit_field_);
@@ skipping 14 matching lines @@
   int NotMissMinorKey() { return bit_field_; }
 
   DISALLOW_COPY_AND_ASSIGN(KeyedLoadFastElementStub);
 };
 
 
 class KeyedStoreFastElementStub : public HydrogenCodeStub {
  public:
   KeyedStoreFastElementStub(bool is_js_array,
                             ElementsKind elements_kind,
-                            KeyedAccessStoreMode mode)
-      : HydrogenCodeStub(CODE_STUB_IS_NOT_MISS) {
+                            KeyedAccessStoreMode mode) {
     bit_field_ = ElementsKindBits::encode(elements_kind) |
         IsJSArrayBits::encode(is_js_array) |
         StoreModeBits::encode(mode);
   }
 
   bool is_js_array() const {
     return IsJSArrayBits::decode(bit_field_);
   }
 
   ElementsKind elements_kind() const {
@@ skipping 19 matching lines @@
   Major MajorKey() { return KeyedStoreElement; }
   int NotMissMinorKey() { return bit_field_; }
 
   DISALLOW_COPY_AND_ASSIGN(KeyedStoreFastElementStub);
 };
 
 
 class TransitionElementsKindStub : public HydrogenCodeStub {
  public:
   TransitionElementsKindStub(ElementsKind from_kind,
-                             ElementsKind to_kind)
-      : HydrogenCodeStub(CODE_STUB_IS_NOT_MISS) {
+                             ElementsKind to_kind) {
     bit_field_ = FromKindBits::encode(from_kind) |
         ToKindBits::encode(to_kind);
   }
 
   ElementsKind from_kind() const {
     return FromKindBits::decode(bit_field_);
   }
 
   ElementsKind to_kind() const {
     return ToKindBits::decode(bit_field_);
@@ skipping 12 matching lines @@
 
   Major MajorKey() { return TransitionElementsKind; }
   int NotMissMinorKey() { return bit_field_; }
 
   DISALLOW_COPY_AND_ASSIGN(TransitionElementsKindStub);
 };
 
 
 class ArrayConstructorStubBase : public HydrogenCodeStub {
  public:
-  ArrayConstructorStubBase(ElementsKind kind, AllocationSiteMode mode)
-      : HydrogenCodeStub(CODE_STUB_IS_NOT_MISS) {
+  ArrayConstructorStubBase(ElementsKind kind, AllocationSiteMode mode) {
     bit_field_ = ElementsKindBits::encode(kind) |
         AllocationSiteModeBits::encode(mode == TRACK_ALLOCATION_SITE);
   }
 
   ElementsKind elements_kind() const {
     return ElementsKindBits::decode(bit_field_);
   }
 
   AllocationSiteMode mode() const {
     return AllocationSiteModeBits::decode(bit_field_)
@@ skipping 297 matching lines @@
 
   // The current function entry hook.
   static FunctionEntryHook entry_hook_;
 
   DISALLOW_COPY_AND_ASSIGN(ProfileEntryHookStub);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_CODE_STUBS_H_