Generalize map dependent codes array to allow multiple dependency groups.

src/objects-inl.h

 // Copyright 2012 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 3407 matching lines @@
          has_slow_elements_kind() || has_external_array_elements());
   set_bit_field3(IsObserved::update(bit_field3(), is_observed));
 }
 
 
 bool Map::is_observed() {
   return IsObserved::decode(bit_field3());
 }
 
 
-void Map::AddDependentCode(Handle<Code> code) {
+void Map::AddDependentCode(DependentCodes::DependencyGroup group,
+                           Handle<Code> code) {
   Handle<DependentCodes> codes =
-      DependentCodes::Append(Handle<DependentCodes>(dependent_codes()), code);
+      DependentCodes::Insert(Handle<DependentCodes>(dependent_codes()),
+                             group, code);
   if (*codes != dependent_codes()) {
     set_dependent_codes(*codes);
   }
 }
 
 
-int DependentCodes::number_of_codes() {
+int DependentCodes::number_of_codes(DependencyGroup group) {
   if (length() == 0) return 0;
-  return Smi::cast(get(kNumberOfCodesIndex))->value();
+  return Smi::cast(get(group))->value();
 }
 
 
-void DependentCodes::set_number_of_codes(int value) {
-  set(kNumberOfCodesIndex, Smi::FromInt(value));
+void DependentCodes::set_number_of_codes(DependencyGroup group, int value) {
+  set(group, Smi::FromInt(value));
 }
 
 
 Code* DependentCodes::code_at(int i) {
-  return Code::cast(get(kCodesIndex + i));
+  return Code::cast(get(kCodesStartIndex + i));
 }
 
 
 void DependentCodes::set_code_at(int i, Code* value) {
-  set(kCodesIndex + i, value);
+  set(kCodesStartIndex + i, value);
 }
 
 
 Object** DependentCodes::code_slot_at(int i) {
   return HeapObject::RawField(
-      this, FixedArray::OffsetOfElementAt(kCodesIndex + i));
+      this, FixedArray::OffsetOfElementAt(kCodesStartIndex + i));
 }
 
 
 void DependentCodes::clear_code_at(int i) {
-  set_undefined(kCodesIndex + i);
+  set_undefined(kCodesStartIndex + i);
 }
 
 
+void DependentCodes::ComputeGroupStartIndexes(GroupStartIndexes starts) {
+  starts[0] = 0;
+  for (int g = 1; g <= kGroupCount; g++) {
+    int count = number_of_codes(static_cast<DependencyGroup>(g - 1));
+    starts[g] = starts[g - 1] + count;
+  }
+}
+
+
+void DependentCodes::ExtendGroup(DependencyGroup group) {
+  GroupStartIndexes starts;
+  ComputeGroupStartIndexes(starts);
+  for (int g = kGroupCount - 2; g > group; g--) {
+    set_code_at(starts[g + 1], code_at(starts[g]));
+  }
+}
+
+
 void Code::set_flags(Code::Flags flags) {
   STATIC_ASSERT(Code::NUMBER_OF_KINDS <= KindField::kMax + 1);
   // Make sure that all call stubs have an arguments count.
   ASSERT((ExtractKindFromFlags(flags) != CALL_IC &&
           ExtractKindFromFlags(flags) != KEYED_CALL_IC) ||
          ExtractArgumentsCountFromFlags(flags) >= 0);
   WRITE_INT_FIELD(this, kFlagsOffset, flags);
 }
 
 
@@ skipping 2411 matching lines @@
 #undef WRITE_UINT32_FIELD
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_