Allocation site pretenuring.

src/objects.cc

 // Copyright 2013 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 9167 matching lines @@
     MemoryChunk::IncrementLiveBytesFromMutator(start_of_string, -delta);
   }
 
 
   if (new_length == 0) return heap->isolate()->factory()->empty_string();
   return string;
 }
 
 
 AllocationMemento* AllocationMemento::FindForHeapObject(HeapObject* object,
+                                                        Heap* heap,
                                                         bool in_GC) {
   // AllocationMemento objects are only allocated immediately after objects in
   // NewSpace. Detecting whether a memento is present involves carefully
   // checking the object immediately after the current object (if there is one)
   // to see if it's an AllocationMemento.
-  ASSERT(object->GetHeap()->InNewSpace(object));
+  ASSERT(heap->InNewSpace(object));
   Address ptr_end = (reinterpret_cast<Address>(object) - kHeapObjectTag) +
       object->Size();
   Address top;
   if (in_GC) {
-    top = object->GetHeap()->new_space()->FromSpacePageHigh();
+    top = heap->new_space()->FromSpacePageHigh();
   } else {
-    top = object->GetHeap()->NewSpaceTop();
+    top = heap->NewSpaceTop();
   }
   if ((ptr_end + AllocationMemento::kSize) <= top) {
     // There is room in newspace for allocation info. Do we have some?
     Map** possible_allocation_memento_map =
         reinterpret_cast<Map**>(ptr_end);
     if (*possible_allocation_memento_map ==
         object->GetHeap()->allocation_memento_map()) {
       AllocationMemento* memento = AllocationMemento::cast(
           reinterpret_cast<Object*>(ptr_end + kHeapObjectTag));
       if (memento->IsValid()) {
@@ skipping 3557 matching lines @@
 void JSObject::TransitionElementsKind(Handle<JSObject> object,
                                       ElementsKind to_kind) {
   CALL_HEAP_FUNCTION_VOID(object->GetIsolate(),
                           object->TransitionElementsKind(to_kind));
 }
 
 
 const double AllocationSite::kPretenureRatio = 0.60;
 
 
+void AllocationSite::ResetPretenureDecision() {
+  dependent_code()->DeoptimizeDependentCodeGroup(
+      GetIsolate(),
+      DependentCode::kAllocationSiteTenuringChangedGroup);
+  set_pretenure_decision(Smi::FromInt(kUndecided));
+  set_memento_found_count(Smi::FromInt(0));
+  set_memento_create_count(Smi::FromInt(0));
+}
+
+
+PretenureFlag AllocationSite::GetPretenureMode() {
+  int mode = pretenure_decision()->value();
+  // Zombie objects "decide" to be untenured.
+  return (mode == kTenure && GetHeap()->GetPretenureMode() == TENURED)
+      ? TENURED : NOT_TENURED;
+}
+
+
 bool AllocationSite::IsNestedSite() {
   ASSERT(FLAG_trace_track_allocation_sites);
   Object* current = GetHeap()->allocation_sites_list();
   while (current->IsAllocationSite()) {
     AllocationSite* current_site = AllocationSite::cast(current);
     if (current_site->nested_site() == this) {
       return true;
     }
     current = current_site->weak_next();
   }
@@ skipping 78 matching lines @@
   CALL_HEAP_FUNCTION_VOID(object->GetIsolate(),
       object->UpdateAllocationSite(to_kind));
 }
 
 
 MaybeObject* JSObject::UpdateAllocationSite(ElementsKind to_kind) {
   if (!IsJSArray()) {
     return this;
   }
 
-  if (!GetHeap()->InNewSpace(this)) return this;
+  Heap* heap = GetHeap();
+  if (!heap->InNewSpace(this)) return this;
 
-  AllocationMemento* memento = AllocationMemento::FindForHeapObject(this);
+  AllocationMemento* memento = AllocationMemento::FindForHeapObject(this, heap);
   if (memento == NULL || !memento->IsValid()) {
     return this;
   }
 
   // Walk through to the Allocation Site
   AllocationSite* site = memento->GetAllocationSite();
   return site->DigestTransitionFeedback(to_kind);
 }
 
 
@@ skipping 3751 matching lines @@
 #define ERROR_MESSAGES_TEXTS(C, T) T,
   static const char* error_messages_[] = {
       ERROR_MESSAGES_LIST(ERROR_MESSAGES_TEXTS)
   };
 #undef ERROR_MESSAGES_TEXTS
   return error_messages_[reason];
 }
 
 
 } }  // namespace v8::internal