As pointed out in the comments the code is quite contrived to begin with, no surprise such mistakes go unnoticed. As long as a warning is emitted when the comp

As pointed out in the comments the code is quite contrived to begin with, no surprise such mistakes go unnoticed. As long as a warning is emitted when the compiler relies only such undefined behavior it is a good thing to optimize this heavily, there are not many other ways to get more performance from C/C++.