[GHC] #8971: Native Code Generator 7.8.1 RC2 is not as optimized as 7.6.3...

[GHC]

#8971: Native Code Generator 7.8.1 RC2 is not as optimized as 7.6.3...
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        Reporter:  GordonBGood              |            Owner:
            Type:  bug                      |           Status:  new
        Priority:  normal                   |        Milestone:
       Component:  Compiler (NCG)           |          Version:  7.8.1-rc2
      Resolution:                           |         Keywords:
Operating System:  Unknown/Multiple         |     Architecture:
 Type of failure:  Runtime performance bug  |  Unknown/Multiple
       Test Case:                           |       Difficulty:  Unknown
        Blocking:                           |       Blocked By:
                                            |  Related Tickets:
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Comment (by tibbe):

 Replying to [comment:8 GordonBGood]:
 > I only referred to LLVM as proof that the problem seems to be limited to
 NCG as both NCG and LLVM will share the same C-- output (or at least I
 think so???) yet NCG shows this step backwards whereas LLVM does not.

 That's a good indication that the NGC is to blame, but it's also possible
 that the Cmm codegen has regressed but some LLVM optimizations make up for
 the regression.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8971#comment:9>
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