xcore (mentioned in that thread) is pretty obscure and still in trunk last I looked. Extra backends don't carry that much of a maintenance cost, mostly patching

xcore (mentioned in that thread) is pretty obscure and still in trunk last I looked. Extra backends don't carry that much of a maintenance cost, mostly patching them up on api changes. Weirder targets hit bugs that the common ones don't so there's a benefit from having them in tree too. I'm not sure that generalises beyond modular compilers though.