The process is a little brittle right now, but when it works, it works. Remill (the binary lifter) sometimes has issues with certain constructs such as switch statements, and we've hit a number of LLVM and ptxas (PTX assembler) bugs as well, since LLVM's PTX backend isn't fully mature and most CUDA kernels are light on function calls and don't look like typical application code. However, when the process works, the PTX doesn't look too terribly different from the original code.