#7369: Simplifier bug(?) ------------------------------+--------------------------------------------- Reporter: sweirich | Owner: Type: bug | Status: new Priority: normal | Component: Compiler Version: 7.6.1 | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: Other | Testcase: Blockedby: | Blocking: Related: | ------------------------------+--------------------------------------------- Not sure if it is really a bug. I was playing around with the following infinite loop in GHC 7.6:
{{{ {-# LANGUAGE GADTs, KindSignatures #-} data False data I (c :: * -> *) data R (c :: *) where R :: (a (I a) -> False) -> R (I a) delta :: R (I R) -> False delta = \ (R f) -> f (R f) omega :: False omega = delta (R delta) main :: IO () main = seq omega (return ()) }}} And I got the following result. It's supposed to be an infinite loop, though, so maybe it is ok. GHC 7.4 just hangs on this example. {{{ spaceman:haskell sweirich$ ghc inj4.hs [1 of 1] Compiling Main ( inj4.hs, inj4.o ) ghc: panic! (the 'impossible' happened) (GHC version 7.6.1 for i386-apple-darwin): Simplifier ticks exhausted When trying UnfoldingDone main:Main.$WR{v reV} [gid[DataConWrapper]] 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: 5160 Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7369> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler _______________________________________________ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs