[GHC] #11701: ghc generates significant slower code

GHC ghc-devs at haskell.org
Sat Mar 12 00:06:15 UTC 2016


#11701: ghc generates significant slower code
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        Reporter:  HuStmpHrrr        |                Owner:
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  7.10.3
      Resolution:                    |             Keywords:  efficiency
Operating System:  Linux             |         Architecture:  x86_64
 Type of failure:  Runtime           |  (amd64)
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by bgamari):

 Ahh, the problem appears to be that `GHC.Real.even` and `odd` are not
 marked as `INLINE` but rather are merely specialized to `Integer` and
 `Int`, whereas you use it at `Word32`. We should specialize these to these
 other types but it seems to me like they are cheap enough operations to be
 worth inlining.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11701#comment:3>
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