[GHC] #9441: CSE should deal with letrec

[GHC]

#9441: CSE should deal with letrec
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        Reporter:  dfeuer            |                Owner:  (none)
            Type:  feature request   |               Status:  closed
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  7.8.2
      Resolution:  fixed             |             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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Changes (by dfeuer):

 * status:  new => closed
 * resolution:   => fixed


Comment:

 commit 55efc9718b520ef354e32c15c4b49cdfecce412f
 {{{
 Author: Simon Peyton Jones <simonpj at microsoft.com>
 Date:   Tue Feb 28 16:00:49 2017 -0500

     Combine identical case alternatives in CSE

     See Note [Combine case alternatives] in CSE.  This opportunity
     surfaced when I was was studying early inlining.  It's easy (and
     cheap) to exploit, and sometimes makes a worthwhile saving.

     Reviewers: austin, bgamari

     Subscribers: thomie

     Differential Revision: https://phabricator.haskell.org/D3194
 }}}

 This change seems to handle enough recursive cases to solve the problem in
 this case!

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9441#comment:3>
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