I surprisingly found a VisualApplets 3.0 's bug for CastBitWidth Operator.
For CastBItWidth operator, if I cast a negative numer to 64bit(just for 64 bit), then it would become -1 anyhow!
Subsequently, I tried the same operation in VisualApplets 2.2 version, and there's no problem.va3.0bug.JPG