[GHC] #9831: the 'impossible' happened : iselExpr64(powerpc)

[GHC]

#9831: the 'impossible' happened : iselExpr64(powerpc)
----------------------------+----------------------------------------------
       Reporter:  erikd     |                   Owner:
           Type:  bug       |                  Status:  new
       Priority:  normal    |               Milestone:
      Component:  Compiler  |                 Version:  7.9
       Keywords:            |        Operating System:  Linux
   Architecture:  powerpc   |         Type of failure:  Building GHC failed
     Difficulty:  Unknown   |               Test Case:
     Blocked By:            |                Blocking:
Related Tickets:            |  Differential Revisions:
----------------------------+----------------------------------------------
 After working around the problem in #9828 I now run into this:

 {{{
 "inplace/bin/ghc-stage1" -static  -H64m -O -fasm -keep-tmp-files
 -Iincludes \
     -Iincludes/dist -Iincludes/dist-derivedconstants/header \
     -Iincludes/dist-ghcconstants/header -Irts -Irts/dist/build \
     -DCOMPILING_RTS -this-package-key rts -dcmm-lint      -i -irts \
     -irts/dist/build -irts/dist/build/autogen -Irts/dist/build \
     -Irts/dist/build/autogen -O2    -c rts/StgStartup.cmm \
     -o rts/dist/build/StgStartup.o

 ghc-stage1: panic! (the 'impossible' happened)
   (GHC version 7.9.20141122 for powerpc-unknown-linux):
         iselExpr64(powerpc)
   I64[_c1::P32 + 64] - %MO_UU_Conv_W32_W64((Hp + 4) - I32[_c2::I32])

 Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9831>
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