A few days ago I finally moved gcjx development from sourceforge
to gcc.gnu.org. The branch is named gcjx-branch. It
isn’t fully hooked up to the build system yet, but you can build the
gcjx directory standalone and have a bytecode compiler.

I also recently ran jacks tests of both gcj and gcjx. The
results are overwhelmingly in gcjx’s favor:

gcjx:	Total	4928	Passed	4711	Skipped	45	Failed	172
gcj:	Total	4928	Passed	4166	Skipped	44	Failed	718

What’s funny is that their failures don’t overlap very much, and yet
they both manage to compile all of Classpath. Partly this can be
explained by the fact that compilers tend to do better on correct
code than incorrect code, but partly I just observe that even a
fairly buggy java compiler is still useful.

Andrew points out that, of course, gcjx will come with its own new
undiscovered bugs as well — and he said that without even looking at
the incomplete tree-generating back end. Still, at this point we seem
to have a lot of interesting code out there to use as test cases; I’m
sure at merge time (I think optimistically it will be sometime this
year) we’ll have confidence in the result.