Revert "Refactor transitioning stores."

src/hydrogen-check-elimination.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "hydrogen-check-elimination.h"
 
 #include "hydrogen-alias-analysis.h"
 #include "hydrogen-flow-engine.h"
 
 #define GLOBAL 1
@@ skipping 433 matching lines @@
     HValue* value = instr->value()->ActualValue();
     if (Find(value) != NULL) {
       // If the object has known maps, it's definitely a heap object.
       instr->DeleteAndReplaceWith(value);
       INC_STAT(removed_cho_);
     }
   }
 
   void ReduceStoreNamedField(HStoreNamedField* instr) {
     HValue* object = instr->object()->ActualValue();
-    if (instr->access().IsMap()) {
+    if (instr->has_transition()) {
+      // This store transitions the object to a new map.
+      Kill(object);
+      HConstant* c_transition = HConstant::cast(instr->transition());
+      HCheckTableEntry::State state = c_transition->HasStableMapValue()
+          ? HCheckTableEntry::CHECKED_STABLE
+          : HCheckTableEntry::CHECKED;
+      Insert(object, NULL, c_transition->MapValue(), state);
+    } else if (instr->access().IsMap()) {
       // This is a store directly to the map field of the object.
       Kill(object);
       if (!instr->value()->IsConstant()) return;
       HConstant* c_value = HConstant::cast(instr->value());
       HCheckTableEntry::State state = c_value->HasStableMapValue()
           ? HCheckTableEntry::CHECKED_STABLE
           : HCheckTableEntry::CHECKED;
       Insert(object, NULL, c_value->MapValue(), state);
     } else {
       // If the instruction changes maps, it should be handled above.
@@ skipping 234 matching lines @@
   explicit HCheckMapsEffects(Zone* zone) : objects_(0, zone) { }
 
   // Effects are _not_ disabled.
   inline bool Disabled() const { return false; }
 
   // Process a possibly side-effecting instruction.
   void Process(HInstruction* instr, Zone* zone) {
     switch (instr->opcode()) {
       case HValue::kStoreNamedField: {
         HStoreNamedField* store = HStoreNamedField::cast(instr);
-        if (store->access().IsMap()) {
+        if (store->access().IsMap() || store->has_transition()) {
           objects_.Add(store->object(), zone);
         }
         break;
       }
       case HValue::kTransitionElementsKind: {
         objects_.Add(HTransitionElementsKind::cast(instr)->object(), zone);
         break;
       }
       default: {
         flags_.Add(instr->ChangesFlags());
@@ skipping 68 matching lines @@
   PRINT_STAT(removed_cho);
   PRINT_STAT(narrowed);
   PRINT_STAT(loads);
   PRINT_STAT(empty);
   PRINT_STAT(compares_true);
   PRINT_STAT(compares_false);
   PRINT_STAT(transitions);
 }
 
 } }  // namespace v8::internal