[GHC] #15249: Add support for cmpeq and cmpgt MMX intrinsics

[GHC]

#15249: Add support for cmpeq and cmpgt MMX intrinsics
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        Reporter:  newhoggy          |                Owner:  (none)
            Type:  task              |               Status:  new
        Priority:  normal            |            Milestone:  8.6.1
       Component:  Compiler          |              Version:  8.4.3
      Resolution:                    |             Keywords:  primops
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by newhoggy):

 I need this instruction to optimise my succinct data structure based CSV
 parser.  If this instruction was available to me, I would be able to
 replace code that generates six instructions with code that generates one.

 https://github.com/haskell-works/hw-dsv/pull/12/files

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15249#comment:2>
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