[GHC] #9155: allocateRegsAndSpill: Cannot read from uninitialized register %vI_s154O (GHC version 7.8.2 for x86_64-unknown-linux)

[GHC]

#9155: allocateRegsAndSpill: Cannot read from uninitialized register %vI_s154O
(GHC version 7.8.2 for x86_64-unknown-linux)
------------------------------------+-------------------------------------
       Reporter:  slyfox            |             Owner:
           Type:  bug               |            Status:  new
       Priority:  normal            |         Milestone:
      Component:  Compiler          |           Version:  7.8.2
       Keywords:                    |  Operating System:  Unknown/Multiple
   Architecture:  Unknown/Multiple  |   Type of failure:  None/Unknown
     Difficulty:  Unknown           |         Test Case:
     Blocked By:                    |          Blocking:
Related Tickets:                    |
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 When building all world with '''-O2''' I've stuck on wxhaskell (all
 versions):
 {{{
 [11 of 16] Compiling Graphics.UI.WX.Controls (
 src/Graphics/UI/WX/Controls.hs, dist/build/Graphics/UI/WX/Controls.o )

 <no location info>:
     ghc: panic! (the 'impossible' happened)
   (GHC version 7.8.2 for x86_64-unknown-linux):
         allocateRegsAndSpill: Cannot read from uninitialized register
     %vI_s154O
 }}}

 I've stripped it down to minimal complete example (but it significantly
 changed error message)
 {{{
 ghc: panic! (the 'impossible' happened)
   (GHC version 7.8.2 for x86_64-unknown-linux):
         RegAlloc.Liveness.computeLivenss
     SCCs aren't in reverse dependent order
     bad blockId c1tU
     [NONREC
         c1uc:
                 movq $-8,%rbx
                 andq $main:M.AlignLeft{v rb}_closure+1,%rbx
                 addq $8,%rbp
                 jmp *(%rbx),
      NONREC
 ...
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9155>
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