#14737: Improve performance of Simplify.simplCast -------------------------------------+------------------------------------- Reporter: tdammers | Owner: goldfire Type: bug | Status: patch Priority: highest | Milestone: 8.6.1 Component: Compiler | Version: 8.2.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: #11735 #14683 | Differential Rev(s): Phab:D4385 Wiki Page: | Phab:D4568 -------------------------------------+------------------------------------- Comment (by simonpj): OK, well commit the patch, and let's investigate the regressions. The places I'd start would be (distinct alternatives) * Try a `cheapEqType`, so we get something in between `isReflCo` (dirt cheap) and `isReflexiveCo` (which uses `eqType`, can be expensive). * Take a regression and see what the (presumably) bigger coercion look like. Then we can see if there's an easy way to kill them off. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14737#comment:29 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler