if you look at
https://perf.haskell.org/ghc/#graph/nofib/time/cryptarithm1 you see that it’s performance varies a lot, sometimes by 10%, between
commits should have nothing to do with performance. But most (not all!)
of the commits where the performance changes affect the runtime in some
way. I conclude that there is something about the code layout that
makes this program run faster or slower.
If anyone here enjoys tracing and understanding such low-level issues:
Here is a nice target to aim at.
(I don’t… but I’d appreciate less noise from gipeda :-))