[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 RyanGlScott):

 Really, you don't even need profiled code to notice a difference. On my
 machine with `gcc-4.8.4`/`ld-2.24`, I experience longer linking times with
 an ordinary, non-profiled `main=return ()` executable:

 {{{
 $ time /opt/ghc/8.0.2/bin/ghc -fforce-recomp -O0 Bug.hs
 [1 of 1] Compiling Main             ( Bug.hs, Bug.o )
 Linking Bug ...

 real    0m0.441s
 user    0m0.360s
 sys     0m0.060s
 $ time /opt/ghc/8.2.1/bin/ghc -fforce-recomp -O0 Bug.hs
 [1 of 1] Compiling Main             ( Bug.hs, Bug.o )
 Linking Bug ...

 real    0m1.616s
 user    0m1.476s
 sys     0m0.116s
 }}}

 On larger programs, the delay is more noticeable.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13739#comment:19>
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