[GHC] #13739: Very slow linking of profiled executables

[GHC]

#13739: Very slow linking of profiled executables
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        Reporter:  duog              |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.2.1-rc2
      Resolution:                    |             Keywords:
Operating System:  Linux             |         Architecture:  x86_64
 Type of failure:  Compile-time      |  (amd64)
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by duog):

 I have attached a script and my output that exhibits a large slowdown in
 linking a trivial profiled executable.

 It times linking a file Main.hs with {{{main = return ()}}} with ghc-8.0.2
 and ghc-8.2.0.2017.0522.

 It shows that the linking times irrespective of -fwhole-archive-hs-libs
 has slowed considerably, and that -fwhole-archive-hs-libs slows down
 linking by 4-5x on both ghc versions.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13739#comment:8>
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