[GHC] #15364: Replace the atomicModifyMutVar# primop

[GHC]

#15364: Replace the atomicModifyMutVar# primop
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        Reporter:  dfeuer            |                Owner:  (none)
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:  8.8.1
       Component:  Runtime System    |              Version:  8.5
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D4884
       Wiki Page:                    |
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Changes (by dfeuer):

 * cc: fryguybob (added)


Comment:

 I've put up a differential that implements everything except
 `atomicSwapMutVar#`, and that sets the stage for adding that as well. I
 could use some help with `atomicSwapMutVar#`, which is the only primop I
 ''can't'' implement by just removing code from other ones. I think we'll
 probably need to add C bits to get access to the necessary exchange
 intrinsic.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15364#comment:1>
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