[GHC] #14980: Runtime performance regression with binary operations on vectors

[GHC]

#14980: Runtime performance regression with binary operations on vectors
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        Reporter:  ttylec            |                Owner:  bgamari
            Type:  bug               |               Status:  new
        Priority:  high              |            Milestone:  8.8.1
       Component:  Compiler          |              Version:  8.2.2
      Resolution:                    |             Keywords:  vector
                                     |  bitwise operations
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 ttylec):

 Hm... not exactly the bug disappear, you observed no speedup with "binary
 packed" version in the first place. Notice that in my benchmark, the
 "binary packed" version is an order of magnitude faster that the "unbox
 vectors" and the bug is about loosing that speed-up when we compile with
 8.2.2 (and later)

 In your case, there was no speed-up in the first place. May I ask you to
 check also `stack exec performance-bug-pair-2` and `stack exec
 performance-bug-2`? I am curious on what machine/system you did tested it?
 Oh, and obviously optimization must be enabled (in case you didn't `stack
 build` it).

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14980#comment:7>
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