In my study of the native java compilation ecosystem, I discovered an interesting compiler project, GCJX. One of the goals of GCJX is to replace the current Java front-end in GCJ. Sounds nice.
Then I discovered that its main developer, Tom Tromey, is seriously reconsidering his project. But in that same message, I learnt the existence of the seemingly little-known Eclipse Java Compiler (ecj). Which looks nice from a performances point of view, but doesn't even answer to its name...
Anyway. I kind of goofed around with MinGW/MSYS-based gcc compilation, without much luck for now. But I spent some time on cross-native (or whatever it's called) compilation of a Windows gcc compiler under linux, and this looks very promising.
Hum, the previous link doesn't seem up at all time; here is the goggle cache entry.