I think that the method you use is "Token Threaded Code" [1]. It's one good way of implementing a VM.

I only added the blog link in case you were interested in extending the VM to use Just In Time compiling. Using a JIT would mean generating assembly.

I like your VM - there is no need to change it. Thanks for sharing.

[1] http://realityforge.org/code/virtual-machines/2011/05/19/int...