Indeed. The last time I tried (about 5~6 years ago, I think) some patches were needed but nothing that required a huge investment of time. Unfortunately its not Sisal90 that had other goodies, (starting with true multi-dimensional arrays and not just array of arrays).

If you are digging into this take a look at the parts that call backends. Many optimization passes are disabled by default by hard coding. At least that's the way it was when I had picked it up. There was not much interest in merging the changes and I thought a fork would be rather rude and presumptuous (I am hardly the compiler writer type).