Optimizing the Goertzel Algorithm (opens in new tab)

Hi everyone, for some years now I have a small tool that uses the Goertzel algorithm for spectral analysis. Since I moved the project to 0.16.0 the performance dropped a lot. The reason being Loop-Vectorization-Disabled. So I started to vectorize it manually, which helped a bit, but performance is still about one order of magnitude away from what it was. So maybe someone can give me some hints how to further improve it (given, I do not just want to wait for the llvm fix to arrive). I compared...