[GHC] #11533: Stack check not optimized out even if it could be

[GHC]

#11533: Stack check not optimized out even if it could be
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        Reporter:  jscholl           |                Owner:
            Type:  bug               |               Status:  closed
        Priority:  normal            |            Milestone:  8.0.1
       Component:  Compiler          |              Version:  7.10.3
  (CodeGen)                          |
      Resolution:  fixed             |             Keywords:  cmm
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Runtime           |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D1881
       Wiki Page:                    |
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Comment (by thomie):

 For the record,
 [https://perf.haskell.org/ghc/#revision/4ec61411930495fc109be27993c176fd7aaf486d
 perf.haskell.org] reports:
 {{{
 nofib/time/fannkuch-redux       2.727   + 4.66% 2.854   seconds
 }}}

 On Phab, Jonas said:

    "I think nofib contained maybe between 20 and 40 cases where the the
 stack check was incorrectly not dropped. I could not measure a performance
 difference, but binary size decreased by a few bytes (as one would
 expect)"

 `fannkuch-redux` has been investigated for performance regressions before:
 #7367, #10457, #10677, #10844,
 https://phabricator.haskell.org/rGHCb949c96b4960.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11533#comment:5>
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