#11677: Dramatic de-optimization with "-O", "-O1", "-O2" options -------------------------------------+------------------------------------- Reporter: malphunction | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.3 Resolution: | Keywords: optimization | deoptimization Operating System: Linux | Architecture: x86_64 Type of failure: Runtime | (amd64) performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by malphunction): Update: if disable `-fenable-rewrite-rule` (i.e. `-O2 -fno-enable-rewrite- rule`), then compiled program runs fast! -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11677#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler