Merge bleeding_edge from version 2.1.3 up to revision 4205...

src/heap-inl.h

Index: src/heap-inl.h
===================================================================
--- src/heap-inl.h	(revision 4205)
+++ src/heap-inl.h	(working copy)
@@ -133,7 +133,8 @@
 #ifdef DEBUG
   if (!result->IsFailure()) {
     // Maps have their own alignment.
-    CHECK((OffsetFrom(result) & kMapAlignmentMask) == kHeapObjectTag);
+    CHECK((reinterpret_cast<intptr_t>(result) & kMapAlignmentMask) ==
+          static_cast<intptr_t>(kHeapObjectTag));
   }
 #endif
   return result;
@@ -273,6 +274,25 @@
 }
 
 
+Object* Heap::PrepareForCompare(String* str) {
+  // Always flatten small strings and force flattening of long strings
+  // after we have accumulated a certain amount we failed to flatten.
+  static const int kMaxAlwaysFlattenLength = 32;
+  static const int kFlattenLongThreshold = 16*KB;
+
+  const int length = str->length();
+  Object* obj = str->TryFlatten();
+  if (length <= kMaxAlwaysFlattenLength ||
+      unflattended_strings_length_ >= kFlattenLongThreshold) {
+    return obj;
+  }
+  if (obj->IsFailure()) {
+    unflattended_strings_length_ += length;
+  }
+  return str;
+}
+
+
 int Heap::AdjustAmountOfExternalAllocatedMemory(int change_in_bytes) {
   ASSERT(HasBeenSetup());
   int amount = amount_of_external_allocated_memory_ + change_in_bytes;