#11172: Turning on optimisations produces SEGFAULT or Impossible case alternative -------------------------------------+------------------------------------- Reporter: nh2 | Owner: bgamari Type: bug | Status: new Priority: highest | Milestone: 8.0.1 Component: Compiler | Version: 7.10.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Runtime crash | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by jscholl): I tried the fix with ghc-7.10.3 and the segfault vanished. If I compare the core it is almost identical, the only difference is that the fixed version generates a {{{Left}}} and a {{{Right}}} branch in Main.main3 while without the fix the {{{Left}}} branch is missing. So I think the segfault is really just another instance of the bug in the simplifier. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11172#comment:30 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler