#15493: Elide empty dictionaries -------------------------------------+------------------------------------- Reporter: mnoonan | Owner: (none) Type: feature request | Status: new Priority: normal | Milestone: 8.6.1 Component: Compiler | Version: 8.4.3 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 simonpj): In Core, an empty dictionary turns into a dead variable, which is optimised away (with `-O` anyway). But it'll still take up a field in `FPack1`. Reason: it might be bottom. I'd be surprised if you found any appreciable performance impact. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15493#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler