I tried. That actually made the rust slower for me (i7-6700k, gcc-12.2, rustc-1.64). 1180 frames/s. And without the -march=native the Nim was at 1620. And it also did not help the C++ branch (but helped Nim about 1.2x).

But really the original author/poster should do some set on his box. I cannot even compile/run all his things. The point of my comment was just to give a reference for how far off impressions can be from build flags. PGO (available to Nim, c++, but maybe not to Rust yet?) is a whole other set of maybe nothing burgers or maybe big improvements.

(But, btw, I could not agree more that all experiments in this entire general space should have various big, bold disclaimers. Over-concluding from these things is rampant.)