#8763: forM_ [1..N] does not get fused (10 times slower than go function) -------------------------------------+------------------------------------- Reporter: nh2 | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.2.1 Component: Compiler | Version: 7.6.3 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 simonpj): Good to know that's it. The program in rep.hs is rather unusual because it has a ''constant'' list, not dependent on input data. Real programs usually depend on input data. So this probem may be less of a probem in practice than in benchmarks. It would be great if someone felt able to dig into #7206 and figure out why it's not a straight win Simon -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8763#comment:30 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler