[GHC] #9740: D380 caused fft2 regressions

[GHC]

#9740: D380 caused fft2 regressions
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              Reporter:  dfeuer      |            Owner:
                  Type:  bug         |           Status:  patch
              Priority:  normal      |        Milestone:  7.10.1
             Component:  Core        |          Version:  7.8.3
  Libraries                          |         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:  Phab:D394   |
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Comment (by Joachim Breitner <mail@…>):

 In [changeset:"64d0a198be05c7baff36e43ab96928a402f00a19/ghc"]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="64d0a198be05c7baff36e43ab96928a402f00a19"
 Really fix fft2 regression. #9740

 Rewrite `take` more aggressively for fusion. Add some more explicit
 strictness to `unsafeTake` and `unsafeDrop` that seems to help code size
 and
 allocation just a drop in some nofib tests. They were not previously
 strict in their numerical arguments, but always called in contexts where
 those had been forced; it didn't make a difference in simple test cases,
 but made a small difference for nofib. See #9740.

 Differential Revision: https://phabricator.haskell.org/D394
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9740#comment:9>
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