[GHC] #14944: Compile speed regression

[GHC]

#14944: Compile speed regression
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        Reporter:  br1               |                Owner:  dfeuer
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.4.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by dfeuer):

 Running with a development build of either 8.2.2 or 8.4ish (I haven't
 checked others yet) turns up an interesting warning when compiling
 `Paper.hs`: the simplifier bails out after 4 iterations. So it seems at
 least ''possible'' that whatever goes wrong in `Main.hs` may start in
 `Paper.hs`, if we end up with incompletely simplified unfoldings. One
 problem I'm facing is that this source code is ... not very simple. It's
 full of rather involved constraint-based programming that's presumably
 documented in a paper somewhere.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14944#comment:11>
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