#9320: Inlining regression/strangeness in 7.8 -------------------------------------+------------------------------------- Reporter: dolio | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.2 Resolution: | Keywords: Inlining 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 nfrisby): FYI, with GHC 7.10.2, both `-O1` and `-O2` give code where `test0` takes 80x as much time as does `test1`. {{{ $ uname -a Linux sci-host-a-i-bd1bec66 3.13.0-100-generic #147-Ubuntu SMP Tue Oct 18 16:48:51 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux $ ghc --version The Glorious Glasgow Haskell Compilation System, version 7.10.2 $ ghc -fforce-recomp -O2 --make Main.hs $ time ./Main 500000 True; time ./Main 500000 False 1 real 0m4.703s user 0m4.682s sys 0m0.020s 1 real 0m0.055s user 0m0.051s sys 0m0.004s $ echo '4.7 / 0.055' | bc -l 85.45454545454545454545 }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9320#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler