#14208: Performance with O0 is much better than the default or with -O2, runghc performs the best -------------------------------------+------------------------------------- Reporter: harendra | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 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 harendra): A similar issue has been reported in this stack overflow question as well: https://stackoverflow.com/questions/46296919/haskell-webframeworks-speed- ghci-vs-compiled . There is an appalling difference in the ghc compiled code vs ghci code, in case of snap it is a 50x difference! That sounds unacceptable whatever the reason maybe. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14208#comment:21 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler