[GHC] #10397: Compiler performance regression 7.6 -> 7.8 in elimCommonBlocks

[GHC]

#10397: Compiler performance regression 7.6 -> 7.8 in elimCommonBlocks
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        Reporter:  TobyGoodwin       |                   Owner:
            Type:  bug               |                  Status:  new
        Priority:  normal            |               Milestone:
       Component:  Compiler          |                 Version:  7.8.4
      Resolution:                    |                Keywords:
Operating System:  Unknown/Multiple  |  performance
 Type of failure:  None/Unknown      |            Architecture:
      Blocked By:                    |  Unknown/Multiple
 Related Tickets:                    |               Test Case:  see ticket
                                     |                Blocking:
                                     |  Differential Revisions:
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Comment (by rwbarton):

 The source is very small, but the simplifier blows things up quite a lot,
 even though I have not used any INLINE directives. That is probably worth
 a separate issue. However, even after that blow-up the Core program size
 is not so unreasonably large that it should take several minutes to
 compile. (That is it is unreasonably large for the specific source program
 which produced it, but not unreasonably large for a different, reasonably
 large source program.)

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10397#comment:4>
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