#15696: Derived Ord instance for enumerations with more than 8 elements seems to be incorrect -------------------------------------+------------------------------------- Reporter: mrkkrp | Owner: (none) 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: | Differential Rev(s): Phab:D5196 Wiki Page: | -------------------------------------+------------------------------------- Comment (by dfeuer): I guess what I'm suggesting would be implemented most easily by replacing the `dataToTag#` primop a little bit. {{{#!hs unKnownType, smallType, largeType :: Int# unKnownType = 0# smallType = 1# largeType = 2# dataToTag# x = dataToTagUsing# unknownType x -- Takes the "strategy" to use dataToTagUsing# :: Int# -> a -> Int# }}} This arrangement is designed so we shouldn't have to do any painful restructuring of the `caseRules` or `dataToTagRule`. The only potential problem I see is if any user-written `RULES` match on `dataToTag#`, because that won't work anymore. Should we worry about that? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15696#comment:29 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler