[GHC] #8763: forM_ [1..N] does not get fused (10 times slower than go function)

[GHC]

#8763: forM_ [1..N] does not get fused (10 times slower than go function)
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        Reporter:  nh2               |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.6.1
       Component:  Compiler          |              Version:  7.6.3
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Runtime           |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #7206             |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by nomeata):

 > In general we should avoid to call c in builds more than once because of
 scenarios like this.

 I vaguely having seen a Note about this somewhere, but I cannot find it
 right now. But yes, a single occurrence of `c` is beneficial.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8763#comment:51>
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