[GHC] #8275: Loopification breaks profiling

[GHC]

#8275: Loopification breaks profiling
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        Reporter:  jstolarek            |            Owner:
            Type:  bug                  |           Status:  new
        Priority:  highest              |        Milestone:
       Component:  Profiling            |          Version:  7.7
      Resolution:                       |         Keywords:
Operating System:  Unknown/Multiple     |     Architecture:
 Type of failure:  Building GHC failed  |  Unknown/Multiple
       Test Case:                       |       Difficulty:  Unknown
        Blocking:  8298                 |       Blocked By:
                                        |  Related Tickets:
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Comment (by jstolarek):

 I actually already implemented 1), but the implementation is only a proof-
 of-concept. It's available
 [https://github.com/jstolarek/ghc/commit/66d5598bc1163c32267c55670c579d93cce9c237
 here], but it need testing, cleanup (we can just drop sp_high and use
 final_hwn instead and perhaps entry_args are not used anymore?) and
 improving `constantFoldMachOpM` in `CmmOpt`, so that `if ((Sp + 56) - 96 <
 SpLim) goto u4yi; else goto u4yh;` gets constant folded properly.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8275#comment:15>
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