[GHC] #11795: Performance issues with replicateM_

[GHC]

#11795: Performance issues with replicateM_
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        Reporter:  snoyberg          |                Owner:  snoyberg
            Type:  bug               |               Status:  merge
        Priority:  normal            |            Milestone:  8.0.1
       Component:  libraries/base    |              Version:  7.10.3
      Resolution:                    |             Keywords:
Operating System:  MacOS X           |         Architecture:  x86_64
 Type of failure:  Runtime           |  (amd64)
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D2086
       Wiki Page:                    |
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Comment (by Ben Gamari <ben@…>):

 In [changeset:"c4a7520ef3a0b5e0e33d66ae1d628af93e0d7590/ghc"
 c4a7520e/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="c4a7520ef3a0b5e0e33d66ae1d628af93e0d7590"
 Provide an optimized replicateM_ implementation #11795

 In my testing, the worker/wrapper transformation applied here
 significantly decreases the number of allocations performed when using
 replicateM_. Additionally, this version of the function behaves
 correctly for negative numbers (namely, it will behave the same as
 replicateM_ 0, which is what previous versions of base have done).

 Reviewers: bgamari, simonpj, hvr, austin

 Reviewed By: bgamari, simonpj, austin

 Subscribers: nomeata, simonpj, mpickering, thomie

 Differential Revision: https://phabricator.haskell.org/D2086

 GHC Trac Issues: #11795
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11795#comment:11>
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