I'm pretty sure there was a detailed explanation of what makes goto slower (in most cases?) than a plain ⊂ call. But while searching for it I did end up finding this post and this answer. I would be tempted to guess that the function call with goto was more expensive (because of the extra magic to clear the local scope and play with the call stack), but the return was more efficient because it didn't require going back through all the calling stack (ie, tail recursion done right). I wouldn't rely on the result of benchmarks from 2005 for current versions of perl though :P