[GHC] #14461: Reuse free variable lists through nested closures

[GHC]

#14461: Reuse free variable lists through nested closures
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        Reporter:  tdammers          |                Owner:  alexbiehl
            Type:  task              |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.2.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  7258              |  Differential Rev(s):
       Wiki Page:  NestedClosures    |
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Comment (by alexbiehl):

 Transforming the free variables in the codegen (as done in the mentioned
 patch) remains hairy.

 I have another plan: I will introduce a new `data GenStgFreeVar occ =
 StgFreeVar occ [occ]` type and calculate the sharing in CoreToStg as we
 have all the relevant data available and in good shape anyway.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14461#comment:3>
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