#9233: Compiler performance regression ---------------------------------+------------------------------------ Reporter: augustss | Owner: Type: bug | Status: new Priority: low | Milestone: Component: Compiler | Version: 7.8.2 Resolution: | Keywords: Operating System: Windows | Architecture: Unknown/Multiple Type of failure: None/Unknown | Difficulty: Unknown Test Case: | Blocked By: Blocking: | Related Tickets: ---------------------------------+------------------------------------ Comment (by goldfire): Hrm -- I'm responsible for the offending code. If `coercionRole` calling `coercionKind` is the hotspot that's taking the trouble, that only seems to happen from the `NthCo` case in `coercionRole`. It would be straightforward to add a `Role` field to `NthCo` to make `coercionRole` on an `NthCo` run in constant time. Would that solve this problem? I'm 95% sure that this change would be very straightforward. However, it seems that the change you made already mitigates the problem significantly. Let me know if I can help further! -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9233#comment:11 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler