As others have commented, it would be more like deciding which optimisation passes to run and in which order. Things like loop unrolling and inlining are not al

As others have commented, it would be more like deciding which optimisation passes to run and in which order. Things like loop unrolling and inlining are not always helpful. Things like polyhedral optimization can be very slow. Running every optimization pass every time it might help is certainly far too slow.