[GHC] #10918: Float once-used let binding into a recursive function

[GHC]

#10918: Float once-used let binding into a recursive function
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        Reporter:  nomeata           |                Owner:
            Type:  task              |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  7.10.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
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Comment (by simonpj):

 I think float-in is the right place.  The simplifier does only strictly-
 local floating; and only float out.  Really the only floating
 transformation the simplifier does is
 {{{
   let
      x = let y = e in (e1:e2)
   in ...
 ===>
   let y = e in
   let x = e1:e2 in ...
 }}}
 So yes: float-in!

 Simon

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10918#comment:2>
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