If you need to super-optimize execution you can build C or ASM code and call it via a library or inline it into your high-level language. Java can call functions in shared libraries (or use JNI) and Perl can inline straight C or ASM.

I'm not sure why you'd want to get "all the juice" out of higher level languages, though. I thought the whole point was to abstract away from machine optimization? For example, to learn to write more efficient Perl I picked up "Mastering Algorithms with Perl" and it had loads of helpful tips.