Revert "Remove flag track-allocation-sites."

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 9173 matching lines @@
 }
 
 
 AllocationMemento* AllocationMemento::FindForHeapObject(HeapObject* object,
                                                         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));
-  Address ptr_end = (reinterpret_cast<Address>(object) - kHeapObjectTag) +
-      object->Size();
-  Address top;
-  if (in_GC) {
-    top = object->GetHeap()->new_space()->FromSpacePageHigh();
-  } else {
-    top = object->GetHeap()->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()) {
-        return memento;
+  if (FLAG_track_allocation_sites) {
+    Address ptr_end = (reinterpret_cast<Address>(object) - kHeapObjectTag) +
+        object->Size();
+    Address top;
+    if (in_GC) {
+      top = object->GetHeap()->new_space()->FromSpacePageHigh();
+    } else {
+      top = object->GetHeap()->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()) {
+          return memento;
+        }
       }
     }
   }
   return NULL;
 }
 
 
 uint32_t StringHasher::MakeArrayIndexHash(uint32_t value, int length) {
   // For array indexes mix the length into the hash as an array index could
   // be zero.
@@ skipping 3664 matching lines @@
 
 
 void JSObject::UpdateAllocationSite(Handle<JSObject> object,
                                     ElementsKind to_kind) {
   CALL_HEAP_FUNCTION_VOID(object->GetIsolate(),
       object->UpdateAllocationSite(to_kind));
 }
 
 
 MaybeObject* JSObject::UpdateAllocationSite(ElementsKind to_kind) {
-  if (!IsJSArray()) {
+  if (!FLAG_track_allocation_sites || !IsJSArray()) {
     return this;
   }
 
   if (!GetHeap()->InNewSpace(this)) return this;
 
   AllocationMemento* memento = AllocationMemento::FindForHeapObject(this);
   if (memento == NULL || !memento->IsValid()) {
     return this;
   }
 
@@ skipping 3757 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