[GHC] #11688: Bytestring break failing rewrite to breakByte and failing to eliminate boxing/unboxing

[GHC]

#11688: Bytestring break failing rewrite to breakByte and failing to eliminate
boxing/unboxing
-------------------------------------+-------------------------------------
        Reporter:  alexbiehl         |                Owner:
            Type:  bug               |               Status:  patch
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  7.10.3
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Runtime           |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D1980
       Wiki Page:                    |
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Comment (by bgamari):

 Oh dear, Phab:D1980 actually won't work at all; the problem isn't the
 inlining of the class methods themselves, it is the class op rule
 generated by GHC. Namely,
 {{{
 Rule fired
     Rule: Class op ==
     Before: GHC.Classes.==
               TyArg GHC.Word.Word8
               ValArg GHC.Word.$fEqWord8
               ValArg ds_d2p3
               ValArg ds_d2p4
     After:  GHC.Word.$fEqWord8_$c==
     Cont:   Stop[BoringCtxt] GHC.Types.Bool
 }}}

 This will require further pondering.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11688#comment:5>
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