#10069: CPR related performance issue -------------------------------------+------------------------------------- Reporter: pacak | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.1-rc2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by Fuuzetsu): Data-point from 8.6.2 using original code (first comment): {{{ [nix-shell:/tmp]$ ghc -O2 Blah.hs && ./Blah benchmarking single call/A time 21.83 ns (21.55 ns .. 22.09 ns) 0.999 R² (0.999 R² .. 1.000 R²) mean 21.77 ns (21.62 ns .. 22.07 ns) std dev 705.5 ps (434.8 ps .. 1.223 ns) variance introduced by outliers: 53% (severely inflated) benchmarking single call/B time 9.741 ns (9.581 ns .. 9.937 ns) 0.998 R² (0.996 R² .. 0.999 R²) mean 9.762 ns (9.641 ns .. 9.942 ns) std dev 490.4 ps (347.4 ps .. 649.6 ps) variance introduced by outliers: 74% (severely inflated) }}} I'm attaching -ddump-simpl output (Blah.dump-simpl). It seems the ticket is still a problem and not 3-5% but 100% -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10069#comment:26 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler