#12234: 'deriving Eq' on recursive datatype makes ghc eat a lot of CPU and RAM -------------------------------------+------------------------------------- Reporter: slyfox | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Resolution: | Keywords: deriving-perf Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by niteria): I was able to reproduce it, and indeed my commit has some effect. I narrowed it down with https://phabricator.haskell.org/P127 to ordering inside `occAnalRecBind`. It appears that the simplifier is sensitive to this order in this case. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12234#comment:10 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler