#14208: Performance with O0 is much better than the default or with -O2, runghc performs the best -------------------------------------+------------------------------------- Reporter: harendra | Owner: osa1 Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by mpickering): Another possible answer is that your library has a lot of recursive functions in it and the base types are written in CPS which means things don't optimise too well. Again, this is not an answer as to why the optimiser makes the program slower. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14208#comment:36 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler