[GHC] #13001: EnumFromThenTo is is not a good producer

[GHC]

#13001: EnumFromThenTo is is not a good producer
-------------------------------------+-------------------------------------
        Reporter:  George            |                Owner:  akio
            Type:  bug               |               Status:  new
        Priority:  low               |            Milestone:
       Component:  libraries/base    |              Version:  8.0.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:  x86_64
 Type of failure:  Runtime           |  (amd64)
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D2951
       Wiki Page:                    |
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Comment (by Ben Gamari <ben@…>):

 In [changeset:"09bce7accd330e99b1667f8b4eda7def722d6f0c/ghc"
 09bce7ac/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="09bce7accd330e99b1667f8b4eda7def722d6f0c"
 Mark *FB functions INLINE[0] (Fixes #13001)

 When fusion rules successfully fire, we are left with calls to
 *FB functions. They are higher-order functions, and therefore they
 often benefit from inlining. This is particularly important when
 then final consumer is a strict fold (foldl', length, etc.), because
 not inlining these functions means allocating a function closure
 for each element in the list, which often is more costly than what
 fusion eliminates.

 Nofib shows a slight increase in the binary size:

 ------------------------------------------------------------------------
        Program           Size    Allocs   Runtime   Elapsed  TotalMem
 ------------------------------------------------------------------------
    gen_regexps          -0.3%      0.0%     0.000     0.000      0.0%
         puzzle          +0.8%      0.0%     0.089     0.090      0.0%
        reptile          +0.8%     -0.0%     0.008     0.008      0.0%
 ------------------------------------------------------------------------
            Min          -0.3%     -0.0%     -7.3%     -7.1%      0.0%
            Max          +0.8%     +0.0%     +7.8%     +7.7%     +1.8%
 Geometric Mean          +0.0%     -0.0%     +0.2%     +0.2%     +0.0%
 ------------------------------------------------------------------------

 Reviewers: simonpj, austin, hvr, bgamari

 Reviewed By: simonpj

 Subscribers: simonpj, thomie

 Differential Revision: https://phabricator.haskell.org/D2951

 GHC Trac Issues: #13001
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13001#comment:10>
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