Revert "Refactor transitioning stores."

src/hydrogen-instructions.h

Index: src/hydrogen-instructions.h
diff --git a/src/hydrogen-instructions.h b/src/hydrogen-instructions.h
index 37f735a1a883c31a7f6ab99844f521b8833721c4..918229b1ae11f8e9141944139fdac15f0f7c813d 100644
--- a/src/hydrogen-instructions.h
+++ b/src/hydrogen-instructions.h
@@ -6656,7 +6656,7 @@ enum StoreFieldOrKeyedMode {
 };
 
 
-class HStoreNamedField V8_FINAL : public HTemplateInstruction<2> {
+class HStoreNamedField V8_FINAL : public HTemplateInstruction<3> {
  public:
   DECLARE_INSTRUCTION_FACTORY_P3(HStoreNamedField, HValue*,
                                  HObjectAccess, HValue*);
@@ -6706,12 +6706,30 @@ class HStoreNamedField V8_FINAL : public HTemplateInstruction<2> {
 
   HValue* object() const { return OperandAt(0); }
   HValue* value() const { return OperandAt(1); }
+  HValue* transition() const { return OperandAt(2); }
 
   HObjectAccess access() const { return access_; }
   HValue* new_space_dominator() const { return new_space_dominator_; }
+  bool has_transition() const { return has_transition_; }
   StoreFieldOrKeyedMode store_mode() const { return store_mode_; }
 
+  Handle<Map> transition_map() const {
+    if (has_transition()) {
+      return Handle<Map>::cast(
+          HConstant::cast(transition())->handle(Isolate::Current()));
+    } else {
+      return Handle<Map>();
+    }
+  }
+
+  void SetTransition(HConstant* transition) {
+    ASSERT(!has_transition());  // Only set once.
+    SetOperandAt(2, transition);
+    has_transition_ = true;
+  }
+
   bool NeedsWriteBarrier() {
+    ASSERT(!field_representation().IsDouble() || !has_transition());
     if (field_representation().IsDouble()) return false;
     if (field_representation().IsSmi()) return false;
     if (field_representation().IsInteger32()) return false;
@@ -6721,6 +6739,11 @@ class HStoreNamedField V8_FINAL : public HTemplateInstruction<2> {
                                         new_space_dominator());
   }
 
+  bool NeedsWriteBarrierForMap() {
+    return ReceiverObjectNeedsWriteBarrier(object(), transition(),
+                                           new_space_dominator());
+  }
+
   Representation field_representation() const {
     return access_.representation();
   }
@@ -6736,6 +6759,7 @@ class HStoreNamedField V8_FINAL : public HTemplateInstruction<2> {
                    StoreFieldOrKeyedMode store_mode = INITIALIZING_STORE)
       : access_(access),
         new_space_dominator_(NULL),
+        has_transition_(false),
         store_mode_(store_mode) {
     // Stores to a non existing in-object property are allowed only to the
     // newly allocated objects (via HAllocate or HInnerAllocatedObject).
@@ -6743,11 +6767,13 @@ class HStoreNamedField V8_FINAL : public HTemplateInstruction<2> {
            obj->IsAllocate() || obj->IsInnerAllocatedObject());
     SetOperandAt(0, obj);
     SetOperandAt(1, val);
+    SetOperandAt(2, obj);
     access.SetGVNFlags(this, STORE);
   }
 
   HObjectAccess access_;
   HValue* new_space_dominator_;
+  bool has_transition_ : 1;
   StoreFieldOrKeyedMode store_mode_ : 1;
 };