[GHC] #8275: Loopification breaks profiling

[GHC]

#8275: Loopification breaks profiling
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        Reporter:  jstolarek            |            Owner:  jstolarek
            Type:  bug                  |           Status:  new
        Priority:  high                 |        Milestone:  7.8.1
       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:  8456
                                        |  Related Tickets:
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Comment (by simonpj):

 It's absolutely right to refer to `(old+0)`.

 But I don't understand the patch (in comment 19), to `CmmLayoutStack`.
 The change made there is simply to ''pass a different (larger) value to
 `manifestSp`''.  And that's the only change to that module.  So we'll
 generate different, wrong code.  I don't see how this can possibly work.
 And yet apparently it does.  What am I missing?

 (The change to `StgCmmHeap` is different, and is fine.)

 Simon

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8275#comment:24>
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