As an author of that paper, I can tell you that the code generator was rather simple and mainly used to perform loop unrolling, avoid explicit indexing, and replicate bits of code that couldn't quite be encapsulated in inline functions. It's possible to go further, but this sort of metaprogramming doesn't really eliminate the need to write in CUDA C.
For what it's worth, we long ago abandoned scala in favor of python for the code generator, just to make it more accessible to others interested in working on the project (generally particle physicists by training): http://lattice.github.com/quda/
For what it's worth, we long ago abandoned scala in favor of python for the code generator, just to make it more accessible to others interested in working on the project (generally particle physicists by training): http://lattice.github.com/quda/