The above project somewhat supports GPUs if you pass the correct GGML compile flags to it. `GGML_CUBLAS` for example is supported when compiling. You get a decent speedup relative to pure C/C++.
But don't get me wrong, I look forward to playing with ggml SD and its development.
The fastest implementation on my 2060 laptop is AITemplate, being about 2x faster than pure optimized HF diffusers.