Apparently it is, and has been done:
And there are bindings for CUDA to Java, I guess:
So the answer should be "yes", but the real question is "is it built in to ECJ," and I believe the answer is "no." If you want to do this, you might try contacting the authors of that paper and see if they're willing to share their code or if it's on their respective homepages.
On Wed, Jan 4, 2012 at 8:55 AM, Carlo Rossi <[log in to unmask]>
a further question if possibile: is there any chance to run ECJ on "cuda" ? (if not, anything in the foreseeable future?)