[GHC] #14521: Infinite loop at runtime

[GHC]

#14521: Infinite loop at runtime
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        Reporter:  OlivierSohn       |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  high              |            Milestone:  8.2.3
       Component:  Compiler          |              Version:  8.2.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Incorrect result  |  Unknown/Multiple
  at runtime                         |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by bgamari):

 For the record, I am seeing the program loop in
 `Animation_zdwanimatedNumber_info`.

 Indeed looking at the simplified Core, the "bad" configuration compiles to
 {{{#!hs
 -- RHS size: {terms: 3, types: 1, coercions: 0, joins: 0/0}
 Animation.$wanimatedNumber [InlPrag=[0], Occ=LoopBreaker]
   :: GHC.Prim.Int# -> Tree -> Animation -> IO (Maybe Animation)
 [GblId, Arity=1, Caf=NoCafRefs, Str=<B,1*U>b]
 Animation.$wanimatedNumber
   = \ (ww_s3v3 :: GHC.Prim.Int#) ->
       Animation.$wanimatedNumber ww_s3v3
 end Rec }
 }}}

 Bad news bears.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14521#comment:19>
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