Merged r19024, r19026 into trunk branch.

src/heap-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 475 matching lines @@
 }
 
 
 void Heap::UpdateAllocationSiteFeedback(HeapObject* object) {
   Heap* heap = object->GetHeap();
   ASSERT(heap->InFromSpace(object));
 
   if (!FLAG_allocation_site_pretenuring ||
       !AllocationSite::CanTrack(object->map()->instance_type())) return;
 
-  // Either object is the last object in the from space, or there is another
-  // object of at least word size (the header map word) following it, so
-  // suffices to compare ptr and top here.
-  Address ptr = object->address() + object->Size();
-  Address top = heap->new_space()->FromSpacePageHigh();
-  ASSERT(ptr == top || ptr + HeapObject::kHeaderSize <= top);
-  if (ptr == top) return;
+  // Check if there is potentially a memento behind the object. If
+  // the last word of the momento is on another page we return
+  // immediatelly. Note that we do not have to compare with the current
+  // top pointer of the from space page, since we always install filler
+  // objects above the top pointer of a from space page when performing
+  // a garbage collection.
+  Address object_address = object->address();
+  Address memento_address = object_address + object->Size();
+  Address last_memento_word_address = memento_address + kPointerSize;
+  if (!NewSpacePage::OnSamePage(object_address,
+                                last_memento_word_address)) {
+    return;
+  }
 
-  HeapObject* candidate = HeapObject::FromAddress(ptr);
+  HeapObject* candidate = HeapObject::FromAddress(memento_address);
   if (candidate->map() != heap->allocation_memento_map()) return;
 
   AllocationMemento* memento = AllocationMemento::cast(candidate);
   if (!memento->IsValid()) return;
 
   if (memento->GetAllocationSite()->IncrementMementoFoundCount() &&
       heap->allocation_sites_scratchpad_length <
       kAllocationSiteScratchpadSize) {
     heap->allocation_sites_scratchpad[
         heap->allocation_sites_scratchpad_length++] =
@@ skipping 318 matching lines @@
 #ifdef DEBUG
   Isolate* isolate = Isolate::Current();
   isolate->heap()->disallow_allocation_failure_ = old_state_;
 #endif
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_INL_H_