[GHC] #16094: panic! (the 'impossible' happened): for powerpc-unknown-linux getRegister(ppc): I64[I32[BaseReg + 812] + 64]

[GHC]

#16094: panic! (the 'impossible' happened): for powerpc-unknown-linux
getRegister(ppc): I64[I32[BaseReg + 812] + 64]
----------------------------------------+--------------------------------
        Reporter:  slyfox               |                Owner:  trommler
            Type:  bug                  |               Status:  new
        Priority:  normal               |            Milestone:
       Component:  Compiler             |              Version:  8.6.3
      Resolution:                       |             Keywords:
Operating System:  Linux                |         Architecture:  powerpc
 Type of failure:  Building GHC failed  |            Test Case:
      Blocked By:                       |             Blocking:
 Related Tickets:                       |  Differential Rev(s):
       Wiki Page:                       |
----------------------------------------+--------------------------------
Changes (by trommler):

 * owner:  (none) => trommler
 * failure:  None/Unknown => Building GHC failed
 * os:  Unknown/Multiple => Linux
 * architecture:  Unknown/Multiple => powerpc


Comment:

 I think the panic is caused by a lack of 64-bit comparison operations on
 32-bit PowerPC.

 The change in `stg_gc_noregs` is in
 changeset:d70b19bfb5ed79b22c2ac31e22f46782fc47a117. This commit has an
 implementation for X86 but not for PowerPC.

 I can provide a patch but I will need help with testing. There is no
 support for PowerPC 32-bit in openSUSE anymore :-(

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16094#comment:2>
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