There is no such thing as "undefined behaviour". The machine code does exactly what it is told to do in exactly the manner in which it has been told to do it and obtains exactly the correct answer every time.
That the computation is "advanced beyond the realm of understanding of the observer" does not make the behaviour undefined. It is perfectly defined, however, it is occasionally necessary to describe things as "undefined", oftentimes because it is too complicated to explain. Just because someone says something as "undefined" does not mean that is so. It is simply a euphemism for "I don't understand how it did that/what it is supposed to be doing (or, more often an appeal to self-proclaimed authority which said that such behaviour was undefined" without having to admit fault, much in the same way that "supported" is a euphemism for "make money from". Things will only be non-deterministic and perhaps undefined when run on Quantum Computers using Heisenberg registers for intermediate results. > <http://blog.regehr.org/archives/1292> > "SQLite is a carefully engineered and thoroughly tested piece of software. > Even so, it contains undefined behaviors because, until recently, no good > checker for these behaviors existed. If anything is going to save us from > UB hell, it?s tools combined with developers who care to listen to them. " > Simon.
