[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:  newhoggy
            Type:  task              |               Status:  new
        Priority:  normal            |            Milestone:  8.8.1
       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):

 For motivation, SIMD instructions are really good for writing very high
 performance parsers.  For example, the following C example shows a short C
 program using AVX2 intrinsics to produce a Rank-Select-Bit-String from a
 CSV file that can be used to index into the CSV file:

 https://github.com/haskell-works/hw-dsv/tree/simd

 The program is able to index a 7G CSV file in under 4s:

 {{{
 $ time ./simd
 ./simd  1.10s user 2.34s system 89% cpu 3.840 total
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15249#comment:5>
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