#14201: Implement ideas from "Compiling Pattern Matching to Good Decision Trees" -------------------------------------+------------------------------------- Reporter: AndreasK | Owner: AndreasK Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): I wonder if anyone else can work with Andreas on this? I lack bandwidth. Very brief thoughts: * Giving two or three actual concrete examples where we get better code would be useful. * Comparing ''after'' simplification is quite important. If the simplifier automatically gets most of the benefit, it wouldn't be worth having a more complicated pattern-match compiler. * Do a `nofib` run with and without your patch. Is there any measurable difference? * How big is your patch? The existing pattern match compiler is already quite subtle; how hard was it to implement your new scheme? Bottom line: to justify the extra complexity and maintenance burden, we'd have to be convinced that some programs run a lot faster; or that many programs run a bit faster. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14201#comment:12 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler