1 // Copyright 2014 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #ifndef V8_TYPE_FEEDBACK_VECTOR_H_
6 #define V8_TYPE_FEEDBACK_VECTOR_H_
7 
8 #include "src/checks.h"
9 #include "src/elements-kind.h"
10 #include "src/heap/heap.h"
11 #include "src/isolate.h"
12 #include "src/objects.h"
13 
14 namespace v8 {
15 namespace internal {
16 
17 class TypeFeedbackVector : public FixedArray {
18  public:
19   // Casting.
cast(Object * obj)20   static TypeFeedbackVector* cast(Object* obj) {
21     DCHECK(obj->IsTypeFeedbackVector());
22     return reinterpret_cast<TypeFeedbackVector*>(obj);
23   }
24 
25   static Handle<TypeFeedbackVector> Copy(Isolate* isolate,
26                                          Handle<TypeFeedbackVector> vector);
27 
28   // The object that indicates an uninitialized cache.
29   static inline Handle<Object> UninitializedSentinel(Isolate* isolate);
30 
31   // The object that indicates a megamorphic state.
32   static inline Handle<Object> MegamorphicSentinel(Isolate* isolate);
33 
34   // The object that indicates a premonomorphic state.
35   static inline Handle<Object> PremonomorphicSentinel(Isolate* isolate);
36 
37   // The object that indicates a generic state.
38   static inline Handle<Object> GenericSentinel(Isolate* isolate);
39 
40   // The object that indicates a monomorphic state of Array with
41   // ElementsKind
42   static inline Handle<Object> MonomorphicArraySentinel(
43       Isolate* isolate, ElementsKind elements_kind);
44 
45   // A raw version of the uninitialized sentinel that's safe to read during
46   // garbage collection (e.g., for patching the cache).
47   static inline Object* RawUninitializedSentinel(Heap* heap);
48 
49  private:
50   DISALLOW_IMPLICIT_CONSTRUCTORS(TypeFeedbackVector);
51 };
52 }
53 }  // namespace v8::internal
54 
55 #endif  // V8_TRANSITIONS_H_
56