[GHC] #9434: GHC.List.reverse does not fuse

[GHC]

#9434: GHC.List.reverse does not fuse
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              Reporter:  dfeuer      |            Owner:
                  Type:  bug         |           Status:  new
              Priority:  normal      |        Milestone:
             Component:              |          Version:  7.9
  libraries/base                     |         Keywords:
            Resolution:              |     Architecture:  Unknown/Multiple
      Operating System:              |       Difficulty:  Easy (less than 1
  Unknown/Multiple                   |  hour)
       Type of failure:  Runtime     |       Blocked By:
  performance bug                    |  Related Tickets:
             Test Case:              |
              Blocking:              |
Differential Revisions:              |
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Comment (by dfeuer):

 Oh yes, of course. We want to wrap it in `build` to make it fuse with
 `map`. `reverse` inherently has lousy fusion behavior, but I think we
 should still do what we can. I think even improving the simple cases of
 `map f . reverse` and `reverse . map f` is sufficient to justify this
 change.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9434#comment:1>
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