This sounds like premature optimization to me (I know, that phrase gets used a lot lately). As with all optimizations it probably makes sense to not do it and k

This sounds like premature optimization to me (I know, that phrase gets used a lot lately). As with all optimizations it probably makes sense to not do it and keep your code highly readable until the point where you've profiled issues at this level. And definitely my focus in writing a post like this is to be as explicit as reasonable to serve as the best educational reference. I also haven't seen real world compilers do what you say (thinking V8, CPython, other mainstream ones) but I'll keep an eye out for it now.