Retain maps embedded in optimized code for several garbage collections.

src/objects-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.
 //
 // Review notes:
 //
 // - The use of macros in these inline functions may seem superfluous
 // but it is absolutely needed to make sure gcc generates optimal
 // code. gcc is not happy when attempting to inline too deep.
 //
@@ skipping 701 matching lines @@
 bool Object::IsJSWeakCollection() const {
   return IsJSWeakMap() || IsJSWeakSet();
 }
 
 
 bool Object::IsDescriptorArray() const {
   return IsFixedArray();
 }
 
 
+bool Object::IsArrayList() const { return IsFixedArray(); }
+
+
 bool Object::IsLayoutDescriptor() const {
   return IsSmi() || IsFixedTypedArrayBase();
 }
 
 
 bool Object::IsTransitionArray() const {
   return IsFixedArray();
 }
 
 
@@ skipping 1661 matching lines @@
 
 int WeakFixedArray::last_used_index() const {
   return Smi::cast(FixedArray::cast(this)->get(kLastUsedIndexIndex))->value();
 }
 
 
 void WeakFixedArray::set_last_used_index(int index) {
   FixedArray::cast(this)->set(kLastUsedIndexIndex, Smi::FromInt(index));
 }
 
 

[Hannes Payer (out of office), 2015/03/05 21:12:28]

Should we DCHECK for wrong input values? Negative values? The index should be
unsigned. I know, the functions above are similar'ish... As you like.

[ulan, 2015/03/06 10:16:34]

Fixed array getters and setters check the index.

+int ArrayList::Length() {
+  if (FixedArray::cast(this)->length() == 0) return 0;
+  return Smi::cast(FixedArray::cast(this)->get(kLengthIndex))->value();
+}
+
+
+void ArrayList::SetLength(int length) {
+  return FixedArray::cast(this)->set(kLengthIndex, Smi::FromInt(length));
+}
+
+
+Object* ArrayList::Get(int index) {
+  return FixedArray::cast(this)->get(kFirstIndex + index);
+}
+
+
+Object** ArrayList::Slot(int index) {
+  return data_start() + kFirstIndex + index;
+}
+
+
+void ArrayList::Set(int index, Object* obj) {
+  FixedArray::cast(this)->set(kFirstIndex + index, obj);
+}
+
+
+void ArrayList::Clear(int index, Object* undefined) {
+  DCHECK(undefined->IsUndefined());
+  FixedArray::cast(this)
+      ->set(kFirstIndex + index, undefined, SKIP_WRITE_BARRIER);
+}
+
+
 void ConstantPoolArray::NumberOfEntries::increment(Type type) {
   DCHECK(type < NUMBER_OF_TYPES);
   element_counts_[type]++;
 }
 
 
 int ConstantPoolArray::NumberOfEntries::equals(
     const ConstantPoolArray::NumberOfEntries& other) const {
   for (int i = 0; i < NUMBER_OF_TYPES; i++) {
     if (element_counts_[i] != other.element_counts_[i]) return false;
@@ skipping 878 matching lines @@
 void SeededNumberDictionary::set_requires_slow_elements() {
   set(kMaxNumberKeyIndex, Smi::FromInt(kRequiresSlowElementsMask));
 }
 
 
 // ------------------------------------
 // Cast operations
 
 
 CAST_ACCESSOR(AccessorInfo)
+CAST_ACCESSOR(ArrayList)
 CAST_ACCESSOR(ByteArray)
 CAST_ACCESSOR(Cell)
 CAST_ACCESSOR(Code)
 CAST_ACCESSOR(CodeCacheHashTable)
 CAST_ACCESSOR(CompilationCacheTable)
 CAST_ACCESSOR(ConsString)
 CAST_ACCESSOR(ConstantPoolArray)
 CAST_ACCESSOR(DeoptimizationInputData)
 CAST_ACCESSOR(DeoptimizationOutputData)
 CAST_ACCESSOR(DependentCode)
@@ skipping 4318 matching lines @@
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 #undef NOBARRIER_READ_BYTE_FIELD
 #undef NOBARRIER_WRITE_BYTE_FIELD
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_