Remove prototype checks for leaf maps in optimized code.

src/objects.cc

 // 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 3606 matching lines @@
   int instance_size_delta = map_of_this->instance_size() - new_instance_size;
   ASSERT(instance_size_delta >= 0);
   current_heap->CreateFillerObjectAt(this->address() + new_instance_size,
                                      instance_size_delta);
   if (Marking::IsBlack(Marking::MarkBitFrom(this))) {
     MemoryChunk::IncrementLiveBytesFromMutator(this->address(),
                                                -instance_size_delta);
   }
 
   set_map(new_map);
+  map_of_this->NotifyObjectLayoutChange();
 
   set_properties(dictionary);
 
   current_heap->isolate()->counters()->props_to_dictionary()->Increment();
 
 #ifdef DEBUG
   if (FLAG_trace_normalization) {
     PrintF("Object properties have been normalized:\n");
     Print();
   }
@@ skipping 1648 matching lines @@
   MaybeObject* maybe_result = RawCopy(instance_size());
   if (!maybe_result->To(&result)) return maybe_result;
 
   // Please note instance_type and instance_size are set when allocated.
   result->set_inobject_properties(inobject_properties());
   result->set_unused_property_fields(unused_property_fields());
 
   result->set_pre_allocated_property_fields(pre_allocated_property_fields());
   result->set_is_shared(false);
   result->ClearCodeCache(GetHeap());
+  NotifyObjectLayoutChange();
   return result;
 }
 
 
 MaybeObject* Map::ShareDescriptor(DescriptorArray* descriptors,
                                   Descriptor* descriptor) {
   // Sanity check. This path is only to be taken if the map owns its descriptor
   // array, implying that its NumberOfOwnDescriptors equals the number of
   // descriptors in the descriptor array.
   ASSERT(NumberOfOwnDescriptors() ==
@@ skipping 4189 matching lines @@
 
 
 void Map::ZapPrototypeTransitions() {
   FixedArray* proto_transitions = GetPrototypeTransitions();
   MemsetPointer(proto_transitions->data_start(),
                 GetHeap()->the_hole_value(),
                 proto_transitions->length());
 }
 
 
-Handle<DependentCodes> DependentCodes::Insert(Handle<DependentCodes> codes,
+DependentCode::GroupStartIndexes::GroupStartIndexes(DependentCode* codes) {
+  Recompute(codes);
+}
+
+
+void DependentCode::GroupStartIndexes::Recompute(DependentCode* codes) {
+  start_indexes_[0] = 0;
+  for (int g = 1; g <= kGroupCount; g++) {
+    int count = codes->number_of_codes(static_cast<DependencyGroup>(g - 1));
+    start_indexes_[g] = start_indexes_[g - 1] + count;
+  }
+}
+
+
+Handle<DependentCode> DependentCode::Insert(Handle<DependentCode> codes,
                                               DependencyGroup group,
                                               Handle<Code> value) {
-  GroupStartIndexes starts;
-  codes->ComputeGroupStartIndexes(starts);
-  int start = starts[group];
-  int end = starts[group + 1];
-  int number_of_codes = starts[kGroupCount];
+  GroupStartIndexes starts(*codes);
+  int start = starts.at(group);
+  int end = starts.at(group + 1);
+  int number_of_codes = starts.at(kGroupCount);
   if (start < end && codes->code_at(end - 1) == *value) {
     // Do not append the code if it is already in the array.
     // It is sufficient to just check only the last element because
     // we process embedded maps of an optimized code in one batch.
     return codes;
   }
   if (codes->length() < kCodesStartIndex + number_of_codes + 1) {
     Factory* factory = codes->GetIsolate()->factory();
     int capacity = kCodesStartIndex + number_of_codes + 1;
     if (capacity > 5) capacity = capacity * 5 / 4;
-    Handle<DependentCodes> new_codes = Handle<DependentCodes>::cast(
+    Handle<DependentCode> new_codes = Handle<DependentCode>::cast(
         factory->CopySizeFixedArray(codes, capacity));
     // The number of codes can change after GC.
-    codes->ComputeGroupStartIndexes(starts);
-    start = starts[group];
-    end = starts[group + 1];
-    number_of_codes = starts[kGroupCount];
+    starts.Recompute(*codes);
+    start = starts.at(group);
+    end = starts.at(group + 1);
+    number_of_codes = starts.at(kGroupCount);
     for (int i = 0; i < number_of_codes; i++) {
       codes->clear_code_at(i);
     }
     // If the old fixed array was empty, we need to reset counters of the
     // new array.
     if (number_of_codes == 0) {
       for (int g = 0; g < kGroupCount; g++) {
         new_codes->set_number_of_codes(static_cast<DependencyGroup>(g), 0);
       }
     }
     codes = new_codes;
   }
   codes->ExtendGroup(group);
   codes->set_code_at(end, *value);
   codes->set_number_of_codes(group, end + 1 - start);
   return codes;
 }
 
 
-bool DependentCodes::Contains(DependencyGroup group, Code* code) {
-  GroupStartIndexes starts;
-  ComputeGroupStartIndexes(starts);
-  int number_of_codes = starts[kGroupCount];
+bool DependentCode::Contains(DependencyGroup group, Code* code) {
+  GroupStartIndexes starts(this);
+  int number_of_codes = starts.at(kGroupCount);
   for (int i = 0; i < number_of_codes; i++) {
     if (code_at(i) == code) return true;
   }
   return false;
 }
 
 
+class DeoptimizeDependentCodeFilter : public OptimizedFunctionFilter {
+ public:
+  virtual bool TakeFunction(JSFunction* function) {
+    return function->code()->marked_for_deoptimization();
+  }
+};
+
+
+void Map::DeoptimizeDependentCode(DependentCode::DependencyGroup group) {
+  AssertNoAllocation no_allocation_scope;
+  DependentCode* codes = dependent_code();
+  DependentCode::GroupStartIndexes starts(codes);
+  int start = starts.at(group);
+  int end = starts.at(group + 1);
+  int number_of_codes = starts.at(DependentCode::kGroupCount);
+  if (start == end) return;
+  for (int i = start; i < end; i++) {
+    Code* code = codes->code_at(i);
+    code->set_marked_for_deoptimization(true);
+  }
+  for (int src = end, dst = start; src < number_of_codes; src++, dst++) {
+    codes->set_code_at(dst, codes->code_at(src));
+  }
+  codes->set_number_of_codes(group, 0);
+  DeoptimizeDependentCodeFilter filter;
+  Deoptimizer::DeoptimizeAllFunctionsWith(&filter);
+}
+
+
 MaybeObject* JSReceiver::SetPrototype(Object* value,
                                       bool skip_hidden_prototypes) {
 #ifdef DEBUG
   int size = Size();
 #endif
 
   Heap* heap = GetHeap();
   // Silently ignore the change if value is not a JSObject or null.
   // SpiderMonkey behaves this way.
   if (!value->IsJSReceiver() && !value->IsNull()) return value;
@@ skipping 4341 matching lines @@
   set_year(Smi::FromInt(year), SKIP_WRITE_BARRIER);
   set_month(Smi::FromInt(month), SKIP_WRITE_BARRIER);
   set_day(Smi::FromInt(day), SKIP_WRITE_BARRIER);
   set_weekday(Smi::FromInt(weekday), SKIP_WRITE_BARRIER);
   set_hour(Smi::FromInt(hour), SKIP_WRITE_BARRIER);
   set_min(Smi::FromInt(min), SKIP_WRITE_BARRIER);
   set_sec(Smi::FromInt(sec), SKIP_WRITE_BARRIER);
 }
 
 } }  // namespace v8::internal