#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 osa1): Just an update before I forget where I had left: the performance regression in `wip/T15696` is fixed by any of these: - Revert change in `app_ok` general case, don't give case binders `evaldUnfolding` in `simplAlts` (first suggestion in comment:77) - Revert change in `app_ok` general case, disable binder swapping of case bidners and scrutinee. Both validate, but I don't have nofib results yet. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15696#comment:82 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler