#5075: CPR optimisation for sum types if only one constructor is used ---------------------------------+------------------------------------------ Reporter: batterseapower | Owner: simonpj Type: feature request | Status: patch Priority: normal | Milestone: 7.6.2 Component: Compiler | Version: 7.0.3 Keywords: | Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: None/Unknown Difficulty: Unknown | Testcase: Blockedby: | Blocking: Related: | ---------------------------------+------------------------------------------ Changes (by simonpj): * cc: nfrisby@… (added) Comment: Indeed. But the opportunity only arises after `SpecConstr`, and we don't currently run the demand/CPR analyser after `SpecConstr`, we run it before. Several other tickets (#6087, #5302, #6070) identify other opportunities that could be exploited by running the demand analyser again, late in the optimisation pipeline. Nick Frisby is planning to experiment with this. Thanks for a new example. Simon -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/5075#comment:12 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler