return UNCHANGED;
return DefUseEffect.UNCHANGED;
  private static byte objarrayStoreCheckNotNull(OPT_Instruction s){    OPT_Operand val = StoreCheck.getVal(s);    OPT_Operand ref = StoreCheck.getRef(s);    VM_TypeReference arrayTypeRef = ref.getType();    VM_Type typeOfIMElem = arrayTypeRef.getInnermostElementType().peekResolvedType();    if (typeOfIMElem != null) {      VM_Type typeOfVal = val.getType().peekResolvedType();      if ((typeOfIMElem == typeOfVal) &&          (typeOfIMElem.isPrimitiveType() ||           typeOfIMElem.asClass().isFinal())) {        // Writing something of a final type to an array of that        // final type is safe        Move.mutate(s, GUARD_MOVE, StoreCheck.getClearGuardResult(s), StoreCheck.getClearGuard(s));        return MOVE_REDUCED;      }    }    if (ref.isConstant() && (arrayTypeRef == VM_TypeReference.JavaLangObjectArray)) {      // We know this to be an array of objects so any store must      // be safe      Move.mutate(s, GUARD_MOVE, StoreCheck.getClearGuardResult(s),                  StoreCheck.getClearGuard(s));      return MOVE_REDUCED;              }    if (val.isConstant() && ref.isConstant()) {      // writing a constant value into a constant array      byte ans = OPT_ClassLoaderProxy.includesType(arrayTypeRef.getArrayElementType(), val.getType());      if (ans == OPT_Constants.YES) {        // all stores should succeed        Move.mutate(s, GUARD_MOVE, StoreCheck.getClearGuardResult(s), StoreCheck.getClearGuard(s));        return MOVE_REDUCED;      }      else if (ans == OPT_Constants.NO) {        // all stores will fail        Trap.mutate(s, TRAP, StoreCheck.getClearGuardResult(s), OPT_TrapCodeOperand.StoreCheck());        return TRAP_REDUCED;      }    }    return UNCHANGED;  }