[GHC] #1916: compiling truncate :: Float -> Int with -O2 panics ghc

[GHC]

#1916: compiling truncate :: Float -> Int with -O2 panics ghc
----------------------+-----------------------------------------------------
 Reporter:  conal     |          Owner:         
     Type:  bug       |         Status:  new    
 Priority:  normal    |      Milestone:         
Component:  Compiler  |        Version:  6.8.1  
 Severity:  normal    |       Keywords:         
 Testcase:            |   Architecture:  Unknown
       Os:  Unknown   |  
----------------------+-----------------------------------------------------
 {{{
 bash-3.2$ cat Bug.hs
 {-# OPTIONS -fglasgow-exts -O2 #-}
 module Bug (tst) where
 tst :: Float -> Bool
 tst x = truncate x > (0::Int)

 bash-3.2$ ghc Bug.hs
 ghc.exe: panic! (the 'impossible' happened)
   (GHC version 6.8.1.20071102 for i386-unknown-mingw32):
         narrowTo
 Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug
 }}}

 Same results reported on linux.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/1916>
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The Glasgow Haskell Compiler