[GHC] #14727: Unboxed sum performance surprisingly poor

[GHC]

#14727: Unboxed sum performance surprisingly poor
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        Reporter:  dfeuer            |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.6.1
       Component:  Compiler          |              Version:  8.2.2
      Resolution:                    |             Keywords:  UnboxedSums
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Runtime           |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by osa1):

 > I'm not sure how much you're likely to get from a Criterion benchmark.
 Is there a specific thing you'd like me to try dumping?

 I think looking at `lookup` in `benchmarks/IntMap.hs` (and any functions
 referenced by that function) would be helpful.

 I also think that it may be a good idea to add `{-# NOINLINE lookup #-}`
 in `benchmarks/IntMap.hs` just to avoid accidentally optimising the code
 at the use site (i.e. the benchmarking code).

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14727#comment:3>
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