Implement a type recording ToBoolean IC.

src/code-stubs.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 882 matching lines @@
  private:
   bool is_js_array_;
   JSObject::ElementsKind elements_kind_;
 
   DISALLOW_COPY_AND_ASSIGN(KeyedStoreElementStub);
 };
 
 
 class ToBooleanStub: public CodeStub {
  public:
-  explicit ToBooleanStub(Register tos) : tos_(tos) { }
+  enum Type {
+    UNDEFINED,
+    BOOLEAN,
+    NULL_TYPE,
+    SMI,
+    UNDETECTABLE,
+    SPEC_OBJECT,
+    STRING,
+    HEAP_NUMBER,
+    INTERNAL_OBJECT,
+    NUMBER_OF_TYPES
+  };
+
+  class Types {
+   public:
+    Types() {}
+    explicit Types(int bits) : set_(bits) {}
+
+    bool IsEmpty() const { return set_.IsEmpty(); }
+    bool Contains(Type type) const { return set_.Contains(type); }
+    void Add(Type type) { set_.Add(type); }
+    int ToInt() const { return set_.ToIntegral(); }
+    void Print(StringStream* stream);
+    void TraceTransition(Types to);
+    bool Record(Handle<Object> object);
+
+   private:
+    EnumSet<Type> set_;
+  };
+
+  explicit ToBooleanStub(Register tos, Types types = Types())
+      : tos_(tos), types_(types) { }
 
   void Generate(MacroAssembler* masm);
+  virtual int GetCodeKind() { return Code::TO_BOOLEAN_IC; }
+  virtual void PrintName(StringStream* stream);
 
  private:
+  Major MajorKey() { return ToBoolean; }
+  int MinorKey() { return (tos_.code() << NUMBER_OF_TYPES) | types_.ToInt(); }
+
+  void CheckOddball(MacroAssembler* masm,
+                    Type type,
+                    Handle<Object> value,
+                    bool result,
+                    Label* patch);
+  void GenerateTypeTransition(MacroAssembler* masm);
+
   Register tos_;
-  Major MajorKey() { return ToBoolean; }
-  int MinorKey() { return tos_.code(); }
+  Types types_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_CODE_STUBS_H_