do you wonder what -optimise really does

This is a diff of the javap output of the scala-library jar, compiled
without and with -optimise.

https://github.com/downloads/scala/scala/scala-library-r25686-unopt-opt-...

If you were looking for a little light reading. The javap output has
a lot of detail stomped out of it so that the diff will mostly stick
to relevant differences.