So, I finished my rewrite of the core evaluation code for GNU Backgammon last week~ I've got a decent bit of cleanup left to do before I'll submit a patch—chiefly, I want to add header & inline comments to all of my functions, and I want to reorder the function parameters to follow a consistent scheme (input parameters first, output parameters last, etc.).
That being said, I'm already quite pleased with the results: Individual position evaluations run about 23% faster now, and even extended rollouts run about 10% faster, heheheh~