#12191: 7% allocation regression in Haddock performance tests -------------------------------------+------------------------------------- Reporter: bgamari | Owner: niteria Type: task | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: #10482 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): When typechecking a particular module M, `checkFamInstConsistency` does indeed need to check that the imported family instances are consistent; and that requires checking any instance for `F` imported from `I1` with all instances of `F` imported from some other module `I2`. (Multiple instances all imported from `I1` have already been checked, when compiling `I1`.) I don't understand Haddock's use-case to know why the algorithm is behaving so badly, but I bet there is some low-hanging fruit. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12191#comment:11 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler