Express LoadIC extra ic state with LoadIC::State

src/ic.h

Index: src/ic.h
diff --git a/src/ic.h b/src/ic.h
index 61845d1d69f6fca4024ba186cb0079f1edda6c4f..6ca416ac0a22cdde87acd911dc5089375c1a128a 100644
--- a/src/ic.h
+++ b/src/ic.h
@@ -380,9 +380,6 @@ OStream& operator<<(OStream& os, const CallIC::State& s);
 
 class LoadIC: public IC {
  public:
-  // ExtraICState bits
-  class ContextualModeBits: public BitField<ContextualMode, 0, 1> {};
-  STATIC_ASSERT(static_cast<int>(NOT_CONTEXTUAL) == 0);
 
   enum ParameterIndices {
     kReceiverIndex,
@@ -397,16 +394,38 @@ class LoadIC: public IC {
   static const Register SlotRegister();
   static const Register VectorRegister();
 
-  static ExtraICState ComputeExtraICState(ContextualMode contextual_mode) {
-    return ContextualModeBits::encode(contextual_mode);
+  class State V8_FINAL BASE_EMBEDDED {
+   public:
+    explicit State(ExtraICState extra_ic_state)
+        : typeof_state_(TypeofStateBits::decode(extra_ic_state)) {}
+
+    State(TypeofState typeof_state) : typeof_state_(typeof_state) {}
+
+    ExtraICState GetExtraICState() const {
+      return TypeofStateBits::encode(typeof_state_);
+    }
+
+    TypeofState typeof_state() const {
+      return typeof_state_;
+    }
+
+   private:
+    class TypeofStateBits: public BitField<TypeofState, 0, 1> {};
+    STATIC_ASSERT(static_cast<int>(INSIDE_TYPEOF) == 0);
+
+    const TypeofState typeof_state_;
+  };
+
+  static ExtraICState ComputeExtraICState(TypeofState typeof_state) {
+    return State(typeof_state).GetExtraICState();
   }
 
-  static ContextualMode GetContextualMode(ExtraICState state) {
-    return ContextualModeBits::decode(state);
+  static TypeofState GetTypeofState(ExtraICState state) {
+    return State(state).typeof_state();
   }
 
-  ContextualMode contextual_mode() const {
-    return ContextualModeBits::decode(extra_ic_state());
+  TypeofState typeof_state() const {
+    return GetTypeofState(extra_ic_state());
   }
 
   explicit LoadIC(FrameDepth depth, Isolate* isolate)
@@ -414,13 +433,13 @@ class LoadIC: public IC {
     ASSERT(IsLoadStub());
   }
 
-  // Returns if this IC is for contextual (no explicit receiver)
-  // access to properties.
+  // Returns true if the receiver is the global object accessed outside of a
+  // typeof scope.
   bool IsUndeclaredGlobal(Handle<Object> receiver) {
     if (receiver->IsGlobalObject()) {
-      return contextual_mode() == CONTEXTUAL;
+      return typeof_state() == NOT_INSIDE_TYPEOF;
     } else {
-      ASSERT(contextual_mode() != CONTEXTUAL);
+      ASSERT(typeof_state() == INSIDE_TYPEOF);
       return false;
     }
   }
@@ -445,9 +464,9 @@ class LoadIC: public IC {
   virtual Code::Kind kind() const { return Code::LOAD_IC; }
 
   void set_target(Code* code) {
-    // The contextual mode must be preserved across IC patching.
-    ASSERT(GetContextualMode(code->extra_ic_state()) ==
-           GetContextualMode(target()->extra_ic_state()));
+    // The typeof state must be preserved across IC patching.
+    ASSERT(GetTypeofState(code->extra_ic_state()) ==
+           GetTypeofState(target()->extra_ic_state()));
 
     IC::set_target(code);
   }