Not for mixed CPU/GPU, but there is the concept of a superoptimizer, that basically brute forces for the most optimal correct code. But it is not practical, bes

Not for mixed CPU/GPU, but there is the concept of a superoptimizer, that basically brute forces for the most optimal correct code. But it is not practical, besides using for very very short program snippets (and they are usually CPU-only, though there is nothing fundamental why it couldn’t utilize the GPU as well). There is also https://futhark-lang.org/ https://futhark-lang.org/ , though I haven’t tried it, just heard about it.