19 Mar
2007
19 Mar
'07
3:25 p.m.
| I've written a Haskell program which goes slower with -O1 (19 seconds) | than -O0 (12 seconds). Is this considered to be a bug? How interested | are you in tracking this down? Yes, very interested. Should not happen. One thing to check is heap usage and GC time. Does GC time, or residency (both reported by -Sstderr) go up a lot? It's possible that an optimisation is changing space behaviour for the worse. Does it still happen if you use profiling? If so, the profile should narrow down the culprit a lot. That might avoid the need to reproduce it elsewhere. Simon