Elide hole checks on KeyedLoads of holey double arrays.

src/objects.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 4950 matching lines @@
     // deoptimized when the map is garbage collected.
     kWeaklyEmbeddedGroup,
     // Group of code that embed a transition to this map, and depend on being
     // deoptimized when the transition is replaced by a new version.
     kTransitionGroup,
     // Group of code that omit run-time prototype checks for prototypes
     // described by this map. The group is deoptimized whenever an object
     // described by this map changes shape (and transitions to a new map),
     // possibly invalidating the assumptions embedded in the code.
     kPrototypeCheckGroup,
-    kGroupCount = kPrototypeCheckGroup + 1
+    // Group of code that depends on elements not being added to objects with
+    // this map.
+    kElementsCantBeAddedGroup,
+    kGroupCount = kElementsCantBeAddedGroup + 1
   };
 
   // Array for holding the index of the first code object of each group.
   // The last element stores the total number of code objects.
   class GroupStartIndexes {
    public:
     explicit GroupStartIndexes(DependentCode* entries);
     void Recompute(DependentCode* entries);
     int at(int i) { return start_indexes_[i]; }
     int number_of_entries() { return start_indexes_[kGroupCount]; }
@@ skipping 511 matching lines @@
   // Fires when the layout of an object with a leaf map changes.
   // This includes adding transitions to the leaf map or changing
   // the descriptor array.
   inline void NotifyLeafMapLayoutChange();
 
   inline bool CanOmitPrototypeChecks();
 
   inline void AddDependentCode(DependentCode::DependencyGroup group,
                                Handle<Code> code);
 
+  bool IsMapInArrayPrototypeChain();
+
   // Dispatched behavior.
   DECLARE_PRINTER(Map)
   DECLARE_VERIFIER(Map)
 
 #ifdef VERIFY_HEAP
   void SharedMapVerify();
   void VerifyOmittedPrototypeChecks();
 #endif
 
   inline int visitor_id();
@@ skipping 4055 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_