Refactor CallICStub to use a different stub for each customization.

src/ic.h

Index: src/ic.h
diff --git a/src/ic.h b/src/ic.h
index cb60bcb86a6de0a1e738d1318a68365cb5985495..92dd773198ae0144022b8dd655259d91def0a0b1 100644
--- a/src/ic.h
+++ b/src/ic.h
@@ -20,6 +20,7 @@ const int kMaxKeyedPolymorphism = 4;
   ICU(LoadIC_Miss)                                    \
   ICU(KeyedLoadIC_Miss)                               \
   ICU(CallIC_Miss)                                    \
+  ICU(CallIC_Customization_Miss)                      \
   ICU(StoreIC_Miss)                                   \
   ICU(StoreIC_ArrayLength)                            \
   ICU(StoreIC_Slow)                                   \
@@ -333,34 +334,16 @@ class IC_Utility {
 class CallIC: public IC {
  public:
   enum CallType { METHOD, FUNCTION };
-  enum StubType { DEFAULT, MONOMORPHIC_ARRAY };
 
   class State V8_FINAL BASE_EMBEDDED {
    public:
     explicit State(ExtraICState extra_ic_state);
 
-    static State MonomorphicArrayCallState(int argc, CallType call_type) {
-      return State(argc, call_type, MONOMORPHIC_ARRAY);
+    State(int argc, CallType call_type)
+        : argc_(argc), call_type_(call_type) {
     }
 
-    static State DefaultCallState(int argc, CallType call_type) {
-      return State(argc, call_type, DEFAULT);
-    }
-
-    // Transition from the current state to another.
-    State ToGenericState() const {
-      return DefaultCallState(arg_count(), call_type());
-    }
-
-    State ToMonomorphicArrayCallState() const {
-      return MonomorphicArrayCallState(arg_count(), call_type());
-    }
-
-    InlineCacheState GetICState() const {
-      return stub_type_ == CallIC::DEFAULT
-          ? ::v8::internal::GENERIC
-          : ::v8::internal::MONOMORPHIC;
-    }
+    InlineCacheState GetICState() const { return ::v8::internal::GENERIC; }
 
     ExtraICState GetExtraICState() const;
 
@@ -369,43 +352,25 @@ class CallIC: public IC {
 
     int arg_count() const { return argc_; }
     CallType call_type() const { return call_type_; }
-    StubType stub_type() const { return stub_type_; }
 
     bool CallAsMethod() const { return call_type_ == METHOD; }
 
     void Print(StringStream* stream) const;
 
-    bool operator==(const State& other_state) const {
-      return (argc_ == other_state.argc_ &&
-              call_type_ == other_state.call_type_ &&
-              stub_type_ == other_state.stub_type_);
-    }
-
-    bool operator!=(const State& other_state) const {
-      return !(*this == other_state);
-    }
-
    private:
-    State(int argc, CallType call_type, StubType stub_type)
-        : argc_(argc),
-        call_type_(call_type),
-        stub_type_(stub_type) {
-    }
-
     class ArgcBits: public BitField<int, 0, Code::kArgumentsBits> {};
     class CallTypeBits: public BitField<CallType, Code::kArgumentsBits, 1> {};
-    class StubTypeBits:
-        public BitField<StubType, Code::kArgumentsBits + 1, 1> {};  // NOLINT
 
     const int argc_;
     const CallType call_type_;
-    const StubType stub_type_;
   };
 
   explicit CallIC(Isolate* isolate)
       : IC(EXTRA_CALL_FRAME, isolate) {
   }
 
+  void PatchMegamorphic(Handle<FixedArray> vector, Handle<Smi> slot);
+
   void HandleMiss(Handle<Object> receiver,
                   Handle<Object> function,
                   Handle<FixedArray> vector,
@@ -416,7 +381,7 @@ class CallIC: public IC {
                        Handle<Object> function,
                        Handle<FixedArray> vector,
                        Handle<Smi> slot,
-                       const State& new_state);
+                       const State& state);
 
   // Code generator routines.
   static Handle<Code> initialize_stub(Isolate* isolate,