Elements load depends on the type of the receiver.

src/hydrogen-instructions.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 2050 matching lines @@
   virtual bool DataEquals(HValue* other) {
     HUnaryMathOperation* b = HUnaryMathOperation::cast(other);
     return op_ == b->op();
   }
 
  private:
   BuiltinFunctionId op_;
 };
 
 
-class HLoadElements: public HUnaryOperation {
+class HLoadElements: public HTemplateInstruction<2> {
  public:
-  explicit HLoadElements(HValue* value) : HUnaryOperation(value) {
+  HLoadElements(HValue* value, HValue* typecheck) {
+    SetOperandAt(0, value);
+    SetOperandAt(1, typecheck);
     set_representation(Representation::Tagged());
     SetFlag(kUseGVN);
     SetGVNFlag(kDependsOnElementsPointer);
   }
 
+  HValue* value() { return OperandAt(0); }
+
   virtual Representation RequiredInputRepresentation(int index) {
     return Representation::Tagged();
   }
 
   DECLARE_CONCRETE_INSTRUCTION(LoadElements)
 
  protected:
   virtual bool DataEquals(HValue* other) { return true; }
 };
 
@@ skipping 3191 matching lines @@
   DECLARE_CONCRETE_INSTRUCTION(LoadFieldByIndex);
 };
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_