[GHC] #9342: Branchless arithmetic operations

[GHC]

#9342: Branchless arithmetic operations
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        Reporter:  hvr               |                Owner:
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:  8.0.1
       Component:  Compiler          |              Version:  7.8.3
  (CodeGen)                          |
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
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Comment (by svenpanne):

 I'd like to point out my previous email on a similar topic:
 https://mail.haskell.org/pipermail/ghc-devs/2015-April/008858.html

 In a nutshell: It's far from clear that code with branches is "sub-
 optimal", toy benchmarks are totally meaningless (they don't stress e.g.
 the very limited number of shifting units in CPUs), and benchmarks on a
 single (micro-)architecture are even less meaningful (what's good for one
 HW makes things worse on another HW). Applying rules of thumb from
 previous decades doesn't really work anymore today, this has already been
 learned the hard way in several other compilers/JITs, I just wanted to
 warn about this again...

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9342#comment:6>
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