[GHC] #9476: Implement late lambda-lifting

[GHC]

#9476: Implement late lambda-lifting
-------------------------------------+-------------------------------------
        Reporter:  simonpj           |                Owner:  sgraf
            Type:  feature request   |               Status:  patch
        Priority:  normal            |            Milestone:  8.8.1
       Component:  Compiler          |              Version:  7.8.2
      Resolution:                    |             Keywords:  LateLamLift
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Runtime           |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #8763 #13286      |  Differential Rev(s):  Phab:D5224
       Wiki Page:  LateLamLift       |
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Comment (by Sebastian Graf <sebastian.graf@…>):

 In [changeset:"b2950e03b551d82d62ec25eb232284aaf121b4e2/ghc"
 b2950e03/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="b2950e03b551d82d62ec25eb232284aaf121b4e2"
 Implement late lambda lift

 Summary:
 This implements a selective lambda-lifting pass late in the STG
 pipeline.

 Lambda lifting has the effect of avoiding closure allocation at the cost
 of having to make former free vars available at call sites, possibly
 enlarging closures surrounding call sites in turn.

 We identify beneficial cases by means of an analysis that estimates
 closure growth.

 There's a Wiki page at
 https://ghc.haskell.org/trac/ghc/wiki/LateLamLift.

 Reviewers: simonpj, bgamari, simonmar

 Reviewed By: simonpj

 Subscribers: rwbarton, carter

 GHC Trac Issues: #9476

 Differential Revision: https://phabricator.haskell.org/D5224
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9476#comment:53>
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