Type Feedback Vector lives in the closure

src/type-feedback-vector-inl.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_TYPE_FEEDBACK_VECTOR_INL_H_
 #define V8_TYPE_FEEDBACK_VECTOR_INL_H_
 
 #include "src/type-feedback-vector.h"
 
 namespace v8 {
@@ skipping 63 matching lines @@
 }
 
 
 FeedbackVectorSlotKind TypeFeedbackVector::GetKind(
     FeedbackVectorSlot slot) const {
   DCHECK(!is_empty());
   return metadata()->GetKind(slot);
 }
 
 
-int TypeFeedbackVector::GetIndex(FeedbackVectorSlot slot) const {
-  DCHECK(slot.ToInt() < slot_count());
+// static
+int TypeFeedbackVector::GetIndex(FeedbackVectorSlot slot) {
   return kReservedIndexCount + slot.ToInt();
 }
 
 
 // Conversion from an integer index to either a slot or an ic slot. The caller
 // should know what kind she expects.
-FeedbackVectorSlot TypeFeedbackVector::ToSlot(int index) const {
-  DCHECK(index >= kReservedIndexCount && index < length());
+// static
+FeedbackVectorSlot TypeFeedbackVector::ToSlot(int index) {
+  DCHECK(index >= kReservedIndexCount);
   return FeedbackVectorSlot(index - kReservedIndexCount);
 }
 
 
 Object* TypeFeedbackVector::Get(FeedbackVectorSlot slot) const {
   return get(GetIndex(slot));
 }
 
 
 void TypeFeedbackVector::Set(FeedbackVectorSlot slot, Object* value,
@@ skipping 77 matching lines @@
   int index = vector()->GetIndex(slot()) + 1;
   vector()->set(index, feedback_extra, mode);
 }
 
 
 Isolate* FeedbackNexus::GetIsolate() const { return vector()->GetIsolate(); }
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TYPE_FEEDBACK_VECTOR_INL_H_