[GHC] #14738: Investigate performance of CoreTidy

[GHC]

#14738: Investigate performance of CoreTidy
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        Reporter:  tdammers          |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.2.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #11735 #14683     |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by tdammers):

 The problem seems to mysteriously go away on newer commits. Adding more
 cost centres to GHC HEAD, I've found that `CoreTidy` hardly shows up in
 the profile at all, and practically all the remaining slowdown comes from
 code in `Simplify.hs`, which I believe #14737 is about.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14738#comment:2>
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