Extend ToBooleanStub to be able to return oddballs.

src/code-stubs.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_CODE_STUBS_H_
 #define V8_CODE_STUBS_H_
 
 #include "src/allocation.h"
 #include "src/assembler.h"
 #include "src/codegen.h"
@@ skipping 2297 matching lines @@
     BOOLEAN,
     NULL_TYPE,
     SMI,
     SPEC_OBJECT,
     STRING,
     SYMBOL,
     HEAP_NUMBER,
     NUMBER_OF_TYPES
   };
 
+  enum ResultMode {
+    RESULT_AS_SMI,             // For Smi(1) on truthy value, Smi(0) otherwise.
+    RESULT_AS_ODDBALL,         // For {true} on truthy value, {false} otherwise.
+    RESULT_AS_INVERSE_ODDBALL  // For {false} on truthy value, {true} otherwise.
+  };
+
   // At most 8 different types can be distinguished, because the Code object
   // only has room for a single byte to hold a set of these types. :-P
   STATIC_ASSERT(NUMBER_OF_TYPES <= 8);
 
   class Types : public EnumSet<Type, byte> {
    public:
     Types() : EnumSet<Type, byte>(0) {}
     explicit Types(byte bits) : EnumSet<Type, byte>(bits) {}
 
     byte ToByte() const { return ToIntegral(); }
     bool UpdateStatus(Handle<Object> object);
     bool NeedsMap() const;
     bool CanBeUndetectable() const;
     bool IsGeneric() const { return ToIntegral() == Generic().ToIntegral(); }
 
     static Types Generic() { return Types((1 << NUMBER_OF_TYPES) - 1); }
   };
 
-  ToBooleanStub(Isolate* isolate, Types types = Types())
-      : HydrogenCodeStub(isolate), types_(types) { }
+  ToBooleanStub(Isolate* isolate, ResultMode mode, Types types = Types())
+      : HydrogenCodeStub(isolate), types_(types), mode_(mode) {}
   ToBooleanStub(Isolate* isolate, ExtraICState state)
-      : HydrogenCodeStub(isolate), types_(static_cast<byte>(state)) { }
+      : HydrogenCodeStub(isolate),
+        types_(static_cast<byte>(state)),
+        mode_(RESULT_AS_SMI) {}
 
   bool UpdateStatus(Handle<Object> object);
   Types GetTypes() { return types_; }
+  ResultMode GetMode() { return mode_; }
 
   virtual Handle<Code> GenerateCode() V8_OVERRIDE;
   virtual void InitializeInterfaceDescriptor(
       CodeStubInterfaceDescriptor* descriptor) V8_OVERRIDE;
 
   virtual Code::Kind GetCodeKind() const { return Code::TO_BOOLEAN_IC; }
   virtual void PrintState(OStream& os) const V8_OVERRIDE;  // NOLINT
 
   virtual bool SometimesSetsUpAFrame() { return false; }
 
   static void InstallDescriptors(Isolate* isolate) {
-    ToBooleanStub stub(isolate);
+    ToBooleanStub stub(isolate, RESULT_AS_SMI);
     stub.InitializeInterfaceDescriptor(
         isolate->code_stub_interface_descriptor(CodeStub::ToBoolean));
   }
 
   static Handle<Code> GetUninitialized(Isolate* isolate) {
     return ToBooleanStub(isolate, UNINITIALIZED).GetCode();
   }
 
   virtual ExtraICState GetExtraICState() const { return types_.ToIntegral(); }
 
   virtual InlineCacheState GetICState() const {
     if (types_.IsEmpty()) {
       return ::v8::internal::UNINITIALIZED;
     } else {
       return MONOMORPHIC;
     }
   }
 
  private:
+  class TypesBits : public BitField<byte, 0, NUMBER_OF_TYPES> {};
+  class ResultModeBits : public BitField<ResultMode, NUMBER_OF_TYPES, 2> {};
+
   Major MajorKey() const { return ToBoolean; }
-  int NotMissMinorKey() const { return GetExtraICState(); }
+  int NotMissMinorKey() const {
+    return TypesBits::encode(types_.ToByte()) | ResultModeBits::encode(mode_);
+  }
 
-  ToBooleanStub(Isolate* isolate, InitializationState init_state) :
-      HydrogenCodeStub(isolate, init_state) {}
+  ToBooleanStub(Isolate* isolate, InitializationState init_state)
+      : HydrogenCodeStub(isolate, init_state), mode_(RESULT_AS_SMI) {}
 
   Types types_;
+  ResultMode mode_;
 };
 
 
 OStream& operator<<(OStream& os, const ToBooleanStub::Types& t);
 
 
 class ElementsTransitionAndStoreStub : public HydrogenCodeStub {
  public:
   ElementsTransitionAndStoreStub(Isolate* isolate,
                                  ElementsKind from_kind,
@@ skipping 119 matching lines @@
 
 
 class CallDescriptors {
  public:
   static void InitializeForIsolate(Isolate* isolate);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_CODE_STUBS_H_