Replying to [comment:24 awson]:
Most interesting is that while many notice `-kc1M` cure the problem
#7850: Strangely high memory usage on optimized Ackermann function ---------------------------------+------------------------------------------ Reporter: dolio | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.2 Keywords: | Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: Runtime performance bug Difficulty: Unknown | Testcase: Blockedby: | Blocking: Related: | ---------------------------------+------------------------------------------ Comment(by awson): Replying to [comment:25 refold]: they still insist it runs much slower than Ocaml version. But it is *NOT*!
Interesting to hear about this difference between platforms. On Linux
(and apparently OS X) it just eats all memory and does not finish. AFAIU on Linux and OS X `-kc1M` on 7.6.x makes memory consumption very good, but performance is still several times worse than that of Ocaml both for 7.6.x with `-kc1M` and HEAD (where this bug is declared to be fixed). Still, the performance is *several times* better under Windows for 7.6.x (sadly, there are no HEAD builds for Windows to try). -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7850#comment:26 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler