[GHC] #9872: Runing type functions is too slow

[GHC]

#9872: Runing type functions is too slow
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              Reporter:  simonpj     |            Owner:
                  Type:  bug         |           Status:  new
              Priority:  normal      |        Milestone:
             Component:  Compiler    |          Version:  7.8.3
            Resolution:              |         Keywords:
      Operating System:              |     Architecture:  Unknown/Multiple
  Unknown/Multiple                   |       Difficulty:  Unknown
       Type of failure:              |       Blocked By:
  None/Unknown                       |  Related Tickets:
             Test Case:              |
              Blocking:              |
Differential Revisions:              |
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Comment (by cactus):

 With the latest changes I am seeing some further performance regression,
 to put it mildly. I've only tested `slow1.hs`, but as of
 2515686ff695169238b673423f01768f5aaa9750, I am getting this on a perf
 build on Windows:

 {{{
 real    54m45.347s
 user    0m0.000s
 sys     0m0.062s
 }}}

 Now, granted, it's not the same machine as the one I originally reported
 this from, but... 55 '''minutes'''!

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9872#comment:8>
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