A change in the way we place TransitionElementKinds in the tree.

src/hydrogen.h

Index: src/hydrogen.h
diff --git a/src/hydrogen.h b/src/hydrogen.h
index 78ab571b5c52376549a07423a1dfcc2b9decd74f..0eb14b1c4cf8df1d2dbfa0afd84365322ac9f2e3 100644
--- a/src/hydrogen.h
+++ b/src/hydrogen.h
@@ -242,6 +242,8 @@ class HLoopInformation: public ZoneObject {
   HStackCheck* stack_check_;
 };
 
+
+class MarkedTransitionElementsGroup;

[danno, 2012/11/28 14:42:10]

Marked has a meaning in the GC space, "bookmarked" would be better.

 class BoundsCheckTable;
 class HGraph: public ZoneObject {
  public:
@@ -370,6 +372,11 @@ class HGraph: public ZoneObject {
     uint32_instructions_->Add(instr, zone());
   }
 
+  void AddMarkedTransitionElementsGroup(
+      MarkedTransitionElementsGroup* group) {
+    marked_transitions_.Add(group, zone());
+  }
+
  private:
   HConstant* GetConstant(SetOncePointer<HConstant>* pointer,
                          Handle<Object> value);
@@ -377,6 +384,7 @@ class HGraph: public ZoneObject {
                               int32_t integer_value);
 
   void MarkAsDeoptimizingRecursively(HBasicBlock* block);
+  void InsertElementsTransitions();
   void InsertTypeConversions(HInstruction* instr);
   void PropagateMinusZeroChecks(HValue* value, BitVector* visited);
   void RecursivelyMarkPhiDeoptimizeOnUndefined(HPhi* phi);
@@ -398,6 +406,7 @@ class HGraph: public ZoneObject {
   ZoneList<HValue*> values_;
   ZoneList<HPhi*>* phi_list_;
   ZoneList<HInstruction*>* uint32_instructions_;
+  ZoneList<MarkedTransitionElementsGroup*> marked_transitions_;
   SetOncePointer<HConstant> undefined_constant_;
   SetOncePointer<HConstant> constant_1_;
   SetOncePointer<HConstant> constant_minus1_;
@@ -1144,7 +1153,8 @@ class HGraphBuilder: public AstVisitor {
                                        HValue* val,
                                        HValue* dependency,
                                        ElementsKind elements_kind,
-                                       bool is_store);
+                                       bool is_store,
+                                       bool defer_initialization);
 
   HInstruction* TryBuildConsolidatedElementLoad(HValue* object,
                                                 HValue* key,
@@ -1152,18 +1162,20 @@ class HGraphBuilder: public AstVisitor {
                                                 SmallMapList* maps);
 
   HInstruction* BuildUncheckedMonomorphicElementAccess(HValue* object,
-                                                       HValue* key,
-                                                       HValue* val,
-                                                       HCheckMaps* mapcheck,
-                                                       Handle<Map> map,
-                                                       bool is_store);
+                                                   HValue* key,
+                                                   HValue* val,
+                                                   HCheckMaps* mapcheck,
+                                                   Handle<Map> map,
+                                                   bool is_store,
+                                                   bool defer_initialization);
 
   HInstruction* BuildMonomorphicElementAccess(HValue* object,
-                                              HValue* key,
-                                              HValue* val,
-                                              HValue* dependency,
-                                              Handle<Map> map,
-                                              bool is_store);
+                                          HValue* key,
+                                          HValue* val,
+                                          HValue* dependency,
+                                          Handle<Map> map,
+                                          bool is_store,
+                                          HCheckMaps** checkmap_instr = NULL);
 
   HValue* HandlePolymorphicElementAccess(HValue* object,
                                          HValue* key,