We are currently relying on a hacked branch of LLVM 3.1svn from around the SIGGRAPH deadline, which we had to patch to fix a variety of codegen bugs for ARM and add features to the PTX backend. This should be updated to 3.2svn. The limiting factor is that the PTX codegen needs to be updated to work with the new conventions of NVPTX instead of the older independent PTX target.