#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): Replying to [comment:22 simonpj]:

A neat approach might be to say that, when doing the fixpoint on a recursive group, trim off any nested CPR info from the demand signatures we use when processing the RHSs.

Woudn’t that be far too imprecise? That would completely prevent nested CPR in loops, like `factIO` above... -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/1600#comment:23 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler