The Watcom C/C++ compiler used to have a neat shift optimization bug. If you shifted one way a few bits then shifted back a few bits (As you would in calculati

The Watcom C/C++ compiler used to have a neat shift optimization bug. If you shifted one way a few bits then shifted back a few bits (As you would in calculating addresses for graphics operations), the optimizer would think you were undoing the operation and do nothing. or interestingly shift n-m bits. You had to do some dummy operation in between for the code to actually execute. This was true at least up to Watcom 11.