#13253: Exponential compilation time with RWST & ReaderT stack with `-02` -------------------------------------+------------------------------------- Reporter: phadej | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 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 phadej): Simon, see the `bad.hs` attached. I can see the expontential behaviour with current `HEAD` too. Remember to use `-O2`. {{{ time .../bin/ghc-stage2 -O2 -fforce-recomp bad.hs # 38sec time .../bin/ghc-stage2 -O2 -fforce-recomp -DBIG bad.hs # 3min 16sec time .../bin/ghc-stage2 -O1 -fforce-recomp bad.hs # 9.8sec time .../bin/ghc-stage2 -O1 -fforce-recomp -DBIG bad.hs # 9.9sec }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13253#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler