I think that compiler optimizations should be classified into "leaky" and "non-leaky" (much like Joel's leaky abstractions). Basically, a "leaky" optimization w

I think that compiler optimizations should be classified into "leaky" and "non-leaky" (much like Joel's leaky abstractions). Basically, a "leaky" optimization would be where the compiler looks for basic patterns that can be optimized away, but where sufficiently complicated and convoluted code can cause the compiler not to recognize the optimization. A "non-leaky" optimization would be one where the compiler can always optimize away a specific coding pattern. Though, to some, tail-call elimination is dark magic, in reality the optimization can always be performed. As alluded to in the article, all that's necessary is to replace the existing stack frame when returning a value.