Eh, often there is not a clear distinction between the two. Whether an optimization is correct or not depends heavily on the interpretation of very subtle aspec

Eh, often there is not a clear distinction between the two. Whether an optimization is correct or not depends heavily on the interpretation of very subtle aspects of the specification. For correctness, it is most important that the programmer and the compiler agree on the interpretation of the specification. The good thing here is that there is an unambiguous interpretation which the compiler uses, and that anyone can read. The downside is that most C programmers probably can't understand this machine-readable language, and so will simply refer to the original human-readable specification. What would be quite neat is if they translated the machine-readale specification back into a set of clarifying notes against the original spec.