#7258: Compiling DynFlags is jolly slow -------------------------------------+------------------------------------- Reporter: simonpj | Owner: simonpj Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.1 Resolution: | Keywords: deriving-perf Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): Indeed. Actually any use of `elem` on a long list is suspicious. c.f. `ListSetOpts.unionLists` which warns if it sees long lists. Maybe we could have `ListSetOps.checkedElem` which checks for over-long lists and warns. And change all uses of `elem` into `checkedElem`. There may be more of these land-mines! -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/7258#comment:61 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler