I am deeply confused by your argument, for the simple reason that you can just turn off optimizations. In fact, it's literally the default in most compilers to

I am deeply confused by your argument, for the simple reason that you can just turn off optimizations. In fact, it's literally the default in most compilers to have no optimization, you have to explicitly request them. Are you actually complaining that a compiler told to optimize is... optimizing? > How likely do you think is it that a program that contains memset and has this optimisation applied how diverts from the indented behaviour and now has a serious flaw in it? What if this optimization happens after three levels of inlining and some other dead code elimination? Is that "diverting from intended behavior"?