If he's still teaching it, I recommend his advanced embedded systems class to anyone at utah.edu who wants to gain practical experience with such compiler errors.

Thanks :). I'll be teaching it in the Fall.

It was actually this class that motivated the whole compiler bug-finding project. The quality of the average embedded compiler is appalling, students trip on codegen bugs all the time.

Of course as many people are pointing out in this thread, most of the time the compiler is not to blame when changing optimization options changes program behavior.