#13209: ghc panic with optimization. -------------------------------------+------------------------------------- Reporter: 1chb | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.3 Resolution: | Keywords: Operating System: Linux | Architecture: x86 Type of failure: GHC rejects | Test Case: valid program | Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by mpickering): You can tell the compiler to not inline `==` by saying `{-# NOINLINE (==) #-}`. This causes the program to compile quickly. Reid reopened this ticket as he says (on IRC) that he doesn't expect the simplifier to behave like this without an `INLINE` pragma. He said he would reply here shortly. You example is quite interesting as the type class allows the compiler to repeatably inline `==` but at different types each time. Normal recursive definitions, even with a fixed input, are not unrolled but with the "recursion" happening in this way it is easier to trick the compiler. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13209#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler