It's not an implementation of CUDA, it's an implementation of the CUDA runtime API. The API is used to configure the card, allocate and copy memory, and run kernels. Importantly you cannot use this to write the actual kernels which run on the GPU!
> It all just works. No code changes were needed.
To make it even more insulting, even simply installing ROCm itself is a massive burden, even on an ostensibly-supported (as geohot discovered) and even just “it works out of the box if you distribute and compile it locally” is ignoring that whole massive “draw the rest of the owl” stage of getting ROCm installed and building properly in your environment.
Even a source-compatible layer that let you just recompile CUDA code for an AMD GPU would be a huge improvement. That alone would eliminate the CUDA lock-in.
I have enough issues using graphics already so I'll stick with Mesa.
But it currently only runs on CDNA boards and enterprise-y Linux distros (Ubuntu LTS, Centos, etc.)
TLDR; If you provide even more functions through the overloaded headers, incl. "hidden ones", e.g., `__cudaPushCallConfiguration`, you can use LLVM/Clang as a CUDA compiler and target AMD GPUs, the host, and soon GPUs of two other manufacturers.
FWIW, we have some alternative ideas on how to get out of the vendor trap, as well as some existing prototypes to deal with things like CUBLAS and Thrust. Feel free to reach out, or just keep an eye out.