#2159: Use a more efficient representation than [DynFlag] -------------------------------------+------------------------------------- Reporter: igloo | Owner: Type: bug | Status: closed Priority: lowest | Milestone: Component: Compiler | Version: 6.8.2 Resolution: fixed | 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 rwbarton): According to a statistical profiling run that I did some time ago GHC spends about 0.3% of its total time in the module `libraries/containers/Data/IntSet/Base.hs`. I don't know how much of that 0.3% is from `DynFlag`-checking versus other users of `IntSet` (another one is `UnVarSet`, whatever that is). Unfortunately, reliably measuring a speedup that is expected to be at most ~0.25% is itself a somewhat nontrivial project. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/2159#comment:24 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler