You are missing the point. PTX is not designed as a vendor neutral abstraction like JVM/CLR bytecode. Furthermore CUDA is a lot more than PTX. There's a whole API there, plus applications ship machine code and rely on Nvidia libraries which can be prohibited from running on AMD by license and with DRM, so those large libraries would also become part of the API boundary that AMD would have to reimplement and support.
Chasing CUDA compatibility is a fool's errand when the most important users of CUDA are open source. Just add explicit AMD support upstream and skip the never ending compatibility treadmill, and get better performance too. And once support is established and well used the community will pitch in to maintain it.
Chasing CUDA compatibility is a fool's errand when the most important users of CUDA are open source. Just add explicit AMD support upstream and skip the never ending compatibility treadmill, and get better performance too. And once support is established and well used the community will pitch in to maintain it.