Optimization for OOP

Hello,

I'm in the beginning of writing an optimizer for an object oriented
programming language. At the moment I'm working on developing a list
of possible optimizations that can be performed on the code. The
language runs on a virtual machine.

While I have a fairly good list of optimizations possible I seem to be
drawing a blank on what to do to optimize objects and classes in the
language. I was wondering if anyone could point me in the right
direction for OOP optimization resources (for example... detailed info
on what Java does to optimize classes and objects at compile time).

In addition I am looking for some good books or articles pertaining to
common subexpression elimination. I've read a few things on it and
understand the general concept and implementation, but would like
additional information if possible.

Thanks :)