I would love to have some hard evidence that we actually do have a
#11735: Optimize coercionKind -------------------------------------+------------------------------------- Reporter: goldfire | Owner: (none) Type: task | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.3 Resolution: | Keywords: 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 tdammers): Replying to [comment:24 simonpj]: problem.
Well, without caching we know that getting the role of `NthCo i1 (NthCo
i2 (NthCo i3 ...))` will take time at least quadratic in the nesting depth. Caching cheaply avoids nasty corner case. And not much code is involved. Fair enough, I'll get to it. Just wanted a test case for practical verification. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11735#comment:25 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler