#12368: Demand Analyzer: Cunnig plan not adhered to with aborting fixpoint interation -------------------------------------+------------------------------------- Reporter: nomeata | Owner: Type: bug | Status: new Priority: low | Milestone: Component: Compiler | Version: 8.0.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by nomeata): The warning is disabled at the moment. It would be much less rare if we had nested demands on sum types; right now the easiest way to trigger it is a recursive function over a recursive product type (e.g. `data Stream a = S a (Stream a)` or `data BinTree a = Node (BinTree a) a (BinTree a)`. Maybe there is a way to fix this by doing a final single iteration with sound, but conservative assumptions about the strictness signature, and then using `pairs'` instead of `orig_pairs`. This would also make me less worry that the `lazy_fv` returned in the `n>=10` case could be wrong (as they are produced from the unsound assumption). -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12368#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler