Version 4.2.77.8 (cherry-pick)

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 "src/hydrogen-check-elimination.h"
 
 #include "src/hydrogen-alias-analysis.h"
 #include "src/hydrogen-flow-engine.h"
 
 #define GLOBAL 1
@@ skipping 610 matching lines @@
     }
     instr->set_known_successor_index(succ);
     int unreachable_succ = 1 - succ;
     instr->block()->MarkSuccEdgeUnreachable(unreachable_succ);
   }
 
   void ReduceTransitionElementsKind(HTransitionElementsKind* instr) {
     HValue* object = instr->object()->ActualValue();
     HCheckTableEntry* entry = Find(object);
     // Can only learn more about an object that already has a known set of maps.
-    if (entry == NULL) return;
+    if (entry == NULL) {
+      Kill(object);
+      return;
+    }
     EnsureChecked(entry, object, instr);
     if (entry->maps_->Contains(instr->original_map())) {
       // If the object has the original map, it will be transitioned.
       UniqueSet<Map>* maps = entry->maps_->Copy(zone());
       maps->Remove(instr->original_map());
       maps->Add(instr->transitioned_map(), zone());
-      entry->maps_ = maps;
+      HCheckTableEntry::State state =
+          (entry->state_ == HCheckTableEntry::CHECKED_STABLE &&
+           instr->map_is_stable())
+              ? HCheckTableEntry::CHECKED_STABLE
+              : HCheckTableEntry::CHECKED;
+      Kill(object);
+      Insert(object, NULL, maps, state);
     } else {
       // Object does not have the given map, thus the transition is redundant.
       instr->DeleteAndReplaceWith(object);
       INC_STAT(transitions_);
     }
   }
 
   void EnsureChecked(HCheckTableEntry* entry,
                      HValue* value,
                      HInstruction* instr) {
@@ skipping 245 matching lines @@
   PRINT_STAT(removed_cit);
   PRINT_STAT(narrowed);
   PRINT_STAT(loads);
   PRINT_STAT(empty);
   PRINT_STAT(compares_true);
   PRINT_STAT(compares_false);
   PRINT_STAT(transitions);
 }
 
 } }  // namespace v8::internal