[xorblurb]

Nope. The age of the sufficiently "advanced" (actually: retarded?) compiler was only theoretical during most of the lifetime of C, and UB were actually defined mostly because of differences between processors, NOT compilers. Compilers were faster thanks to their backend.

The standard even says: "undefined behavior: behavior, upon use of a nonportable or erroneous program construct or of erroneous data, for which this International Standard imposes no requirements"

However, today, you should act as if the nonportable part of this statement don't exist anymore, and act as if ALL UB are absolutely forbidden and result in the worst non-deterministic consequences, in all cases and regardless of your actual target. Meaning that today on e.g. x86, if you use a mainstream compiler, you ARE limited by some of the limitations of e.g. some obscure outdated DSPs.

And this is likely impossible to check in a non-trivial program.

So just use another language. C for serious purposes is dead. (some projects that started in that language continue to be developed in it, but given the security issues it creates, this will become unacceptable in a not too far future; so don't wait it is too late to switch: lead that movement.)