[GHC] #1600: Optimisation: CPR the results of IO

[GHC]

#1600: Optimisation: CPR the results of IO
-------------------------------------+-------------------------------------
        Reporter:  simonmar          |                Owner:
            Type:  task              |               Status:  new
        Priority:  lowest            |            Milestone:
       Component:  Compiler          |              Version:  6.6.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Runtime           |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #8598             |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by akio):

 I've rebased nomeata's branch: https://github.com/takano-
 akio/ghc/compare/afdde48...f8eb150

 Some nofib results:

 {{{
 --------------------------------------------------------------------------------
         Program           Size    Allocs   Runtime   Elapsed  TotalMem
 --------------------------------------------------------------------------------
          mandel          +1.9%    -25.0%     0.047     0.047      0.0%
             gcd          +2.0%    -21.6%     0.030     0.031      0.0%
    k-nucleotide          +1.7%    -18.0%     +3.4%     +2.7%      0.0%
       wave4main          +2.0%    +12.3%     0.179     0.179      0.0%
           kahan          +2.0%     +7.8%     +1.4%     +1.3%      0.0%
           solid          +2.0%     -6.4%     0.081     0.081      0.0%
          sphere          +2.0%     +5.8%     0.040     0.040      0.0%
             hpg          +2.0%     +4.1%     0.102     0.102      0.0%
          symalg          +1.9%     +3.6%     0.007     0.007      0.0%
          gamteb          +2.4%     -4.8%     0.026     0.026      0.0%
 --------------------------------------------------------------------------------
             Min          +1.5%    -25.0%     -0.6%     -0.4%    -20.0%
             Max          +2.8%    +12.3%    +12.7%    +12.8%    +12.0%
  Geometric Mean          +2.0%     -0.5%     +5.0%     +4.7%     +0.2%
 }}}

 I'll look into the allocation regressions next.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/1600#comment:52>
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