#15696: Derived Ord instance for enumerations with more than 8 elements seems to be incorrect -------------------------------------+------------------------------------- Reporter: mrkkrp | Owner: osa1 Type: bug | Status: patch Priority: highest | Milestone: 8.6.2 Component: Compiler | Version: 8.6.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Incorrect result | Unknown/Multiple at runtime | Test Case: Blocked By: | Blocking: Related Tickets: #14677, #15155 | Differential Rev(s): Phab:D5196, Wiki Page: | Phab:D5201, Phab:D5226 -------------------------------------+------------------------------------- Comment (by simonpj):
Revert change in app_ok general case, don't give case binders evaldUnfolding in simplAlts (first suggestion in comment:77)
This is my preferred option; I don't like disabling binder swapping - it's there for a good reason! It would be illuminating to know (perhaps via `-ticky`) what code is improved by reverting the `app_ok` general case. If we knew, we could add an example to the code so that we had a concrete reason for that `isEvaldUnfolding` case. But it's only curiosity. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15696#comment:83 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler