[GHC] #7446: GHC -O0 goes into a loop

[GHC]

#7446: GHC -O0 goes into a loop
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Reporter:  EyalLotem     |          Owner:          
    Type:  bug           |         Status:  new     
Priority:  normal        |      Component:  Compiler
 Version:  7.6.1         |       Keywords:          
      Os:  Linux         |   Architecture:  x86     
 Failure:  None/Unknown  |      Blockedby:          
Blocking:                |        Related:          
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Comment(by int-e):

 Note that the second example,

 {{{
 data V = V {-# UNPACK #-} !L
 data L = L V
 }}}

 produces an "unusable UNPACK pragma" warning (but not always, see #7447)
 if compiled with -O1 or -O2. This also seems wrong -- I would expect the
 compiler to unpack it into something isomorphic to {{{data V = V V}}}.

 P.S. reproduced on x86_64.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7446#comment:2>
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