I was in the demoscene long ago and that kind of optimisation is definitely in the ballpark of what we did: optimize algorithm down to machine code level (and additionally, cheat like hell to make you believe we ran the algorithm for real :-)).

But to be honest, I wonder what algorithm they implement. I have read the code for 2 minutes, and it sound like random forest prediction. Anyone knows what the code does ?

It’s some useless problem like a random tree walk or something like that, the actual algorithm is not particularly important to the problem

Yeah, I assume it was partly chosen since the problem structure provides some convenient hooks for selectively introducing subtle and less subtle inefficiencies in the baseline algorithm that match common optimization patterns.

perfetto is pretty widely used for such traces, because building a viewer for your traces is a completely avoidable pain.

it's designed to select for people who can be trusted to manually write ptx :-)