Re: #10069: CPR related performance issue

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#10069: CPR related performance issue
-------------------------------------+-------------------------------------
        Reporter:  pacak             |                Owner:  (none)
            Type:  bug               |               Status:  patch
        Priority:  normal            |            Milestone:  8.8.1
       Component:  Compiler          |              Version:  8.6.2
      Resolution:                    |             Keywords:
                                     |  DemandAnalysis
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Runtime           |  Unknown/Multiple
  performance bug                    |            Test Case:  T10069
      Blocked By:                    |             Blocking:
 Related Tickets:  #13143            |  Differential Rev(s):  !401
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by Marge Bot <ben+marge-bot@…>):

 In [changeset:"1675d40afe07b9c414eaa37d85819f37f8420118/ghc"
 1675d40a/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="1675d40afe07b9c414eaa37d85819f37f8420118"
 Always do the worker/wrapper split for NOINLINEs

 Trac #10069 revealed that small NOINLINE functions didn't get split
 into worker and wrapper. This was due to `certainlyWillInline`
 saying that any unfoldings with a guidance of `UnfWhen` inline
 unconditionally. That isn't the case for NOINLINE functions, so we
 catch this case earlier now.

 Nofib results:

 --------------------------------------------------------------------------------
         Program         Allocs    Instrs
 --------------------------------------------------------------------------------
  fannkuch-redux          -0.3%      0.0%
              gg          +0.0%     +0.1%
        maillist          -0.2%     -0.2%
         minimax           0.0%     -0.8%
 --------------------------------------------------------------------------------
             Min          -0.3%     -0.8%
             Max          +0.0%     +0.1%
  Geometric Mean          -0.0%     -0.0%

 Fixes #10069.

 -------------------------
 Metric Increase:
     T9233
 -------------------------
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10069#comment:37>