#1600: Optimisation: CPR the results of IO -------------------------------------+------------------------------------- Reporter: simonmar | Owner: Type: task | Status: new Priority: lowest | Milestone: 7.6.2 Component: Compiler | Version: 6.6.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: Runtime | Difficulty: Moderate (less performance bug | than a day) Test Case: | Blocked By: Blocking: | Related Tickets: -------------------------------------+------------------------------------- Comment (by nomeata): One solution, which seems to make sense, is to make the analysis a little bit less precise and more careful with recursive definition. If I make sure that an `Id` that is a LoopBreaker never has a `DmdResult` that `Converges` (by lub’ing it with `Diverges`), both the example above and the typecheck program of nofib compiles. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/1600#comment:21 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler