[GHC] #8457: -ffull-laziness does more harm than good

[GHC]

#8457: -ffull-laziness does more harm than good
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        Reporter:  errge             |            Owner:
            Type:  bug               |           Status:  new
        Priority:  high              |        Milestone:  7.8.1
       Component:  Compiler          |          Version:  7.7
      Resolution:                    |         Keywords:
Operating System:  Unknown/Multiple  |     Architecture:  Unknown/Multiple
 Type of failure:  None/Unknown      |       Difficulty:  Unknown
       Test Case:                    |       Blocked By:
        Blocking:                    |  Related Tickets:
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Comment (by rwbarton):

 Very nice work!

 I just want to point out a
 [http://ghc.haskell.org/trac/ghc/ticket/7367#comment:7 suggestion] I made
 a little while ago, but haven't followed up on: it may be easy to identify
 certain occurrences of let-floating that are truly "safe" performance-
 wise, and control them with a separate flag, which would be on by default
 under `-O`. Then remove `-ffull-laziness` from `-O`. I would be interested
 to see the results of your experiment with such a patch.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8457#comment:1>
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