Full employment theorem
en.wikipedia.org
en.wikipedia.org
So why is this called a "theorem"? There is yet no proof that there are classes of problems inherently better solvable by the human mind. Or otherwise, that the human is something extra, computationally-wise, than a Turing machine.
It's not A theorem, it's an informal name for a class of theorems. Specifically theorems that imply creativity will never be useless.
Of course, a "strong AI" in this usage would probably have to not only be computationally equivalent to the human mind, but also be provided with the same insanely complex and chaotic input that the human mind operates on.
To truly mimic human "creativity," this strong AI would probably need all the qualitative experience and memories that human beings have. It would probably need to undergo development in a dynamic social environment, or at least have the memory of doing so.
Until that happens, it will always be possible to write a better space-optimizing compiler. Afterwards, it will still be possible, but the strong AI will beat you to the punch.
That's also the key difference between science and engineering. In engineering, you need a good-enough solution, but you are not so concerned with proving that there is possible better implementation.
In this case, there are indeed machine learning algorithms that can do this task.
http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=5533...