Recompiling code at runtime

[snailbite]

Is there a performance increase if you recompile "away" unused code at runtime or do the jvm take care of that for you? Switch cases and such I mean or cant this be answered in the general case? Do shorter bytecode representing the same code yield better performance?

[kul_th_las]

If the code is unused, meaning that it is never run, then how can it be a performance problem?

This is the most out-of-this-world optimization technique I've ever heard of. Just stick to writing efficient algorithms, and you'll do 90% of the work needed to get good performance out of your applications.