#8095: TypeFamilies painfully slow -------------------------------------+------------------------------------- Reporter: MikeIzbicki | Owner: bgamari Type: bug | Status: new Priority: high | Milestone: 8.0.1 Component: Compiler (Type | Version: 7.6.3 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: 5321 | Differential Rev(s): -------------------------------------+------------------------------------- Comment (by goldfire): The blowup in coercions is fixed in the simplifier, yes? That means that coercion optimization is working. When you vary `N`, what changes in the output? The long sequence of coercions in the middle of that dump looks correct to me. I'm less sure about the two casts at the end. The unoptimized Core term for this program may truly grow quadratically. Maybe the solution is to be more eager with the coercion optimizer? I don't see any harm in doing so, if we can observe a speedup. Let me know if I can be of further assistance. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8095#comment:11 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler