[GHC] #16004: Vector performance regression in GHC 8.6

[GHC]

#16004: Vector performance regression in GHC 8.6
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        Reporter:  guibou            |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.6.3
       Component:  Compiler          |              Version:  8.6.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Runtime           |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by simonpj):

 Yes, that's great.  I think we know why this is happening too.

 Can someone try the patch in #7206, specifically `wip/cheap-build-osa1`,
 and see if it nails this case?  And perhaps do a new nofib run.

 The conclusion on #7206 was that we should probably accept the patch --
 and if it cures this vector problem that'd be a strong positive reason to
 do so.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16004#comment:8>
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