[GHC] #12908: Tuple constraints refactoring seems to regress performance considerably

[GHC]

#12908: Tuple constraints refactoring seems to regress performance considerably
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           Reporter:  bgamari        |             Owner:  bgamari
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:
          Component:  Compiler       |           Version:  8.0.1
           Keywords:  performance    |  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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 ffc21506894c7887d3620423aaf86bc6113a1071 seems to cause compiler runtime
 regression as large as 15%. This deserves some attention.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12908>
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