#14908: Compiling using O1 works but panic using O2 or O3 -------------------------------------+------------------------------------- Reporter: josejuan | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 Resolution: | Keywords: Operating System: Linux | Architecture: x86_64 Type of failure: Compile-time | (amd64) crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by RyanGlScott): To be clear, this is the panic that results: {{{ $ $(pwd)/../../../Software/ghc-8.0.2/bin/ghc Bug.hs -O2 -fforce-recomp [1 of 1] Compiling Main ( Bug.hs, Bug.o ) ghc.exe: panic! (the 'impossible' happened) (GHC version 8.0.2 for x86_64-unknown-mingw32): Simplifier ticks exhausted When trying UnfoldingDone $srec_s9Kw To increase the limit, use -fsimpl-tick-factor=N (default 100) If you need to do this, let GHC HQ know, and what factor you needed To see detailed counts use -ddump-simpl-stats Total ticks: 59242 }}} I can't reproduce this panic with GHC 8.2.2. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14908#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler