Question about register allocators

What is the status of RegAllocLocal, RegAllocBigBlock and RegAllocSimple allocators? I am considering using one of them as a basis for a course project on register allocation in my class. In particular, are those allocators in regular use and/or have they been tested recently? I am particularly interested in the code as of version 4.0 but if anything has improved since then, the current code would be useful too.

Also, any suggestions for simple but useful projects are welcome.



RegAllocLocal is tested regularly. I can't say about the other two.