[GHC] #14240: CSE’ing w/w’ed code regresses program runtime

[GHC]

#14240: CSE’ing w/w’ed code regresses program runtime
-------------------------------------+-------------------------------------
           Reporter:  nomeata        |             Owner:  (none)
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:
          Component:  Compiler       |           Version:  8.2.1
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  Runtime
  Unknown/Multiple                   |  performance bug
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
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 Commit changeset:fe04f378/ghc, which fixed #14186, causes two runtime
 regressions:
 {{{
 nofib/time/integer 1.529        + 4.19% 1.593   seconds
 nofib/time/lambda  1.041        + 7.3%  1.117   seconds
 }}}

 Sigh. I guess it up to me to track that one down.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14240>
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