[GHC] #10717: fannkuch-redux allocations increase 10000% between 7.4.2 and 7.6.3

[GHC]

#10717: fannkuch-redux allocations increase 10000% between 7.4.2 and 7.6.3
-------------------------------------+-------------------------------------
              Reporter:  bgamari     |             Owner:
                  Type:  bug         |            Status:  new
              Priority:  normal      |         Milestone:  7.12.1
             Component:  Compiler    |           Version:  7.6.3
              Keywords:              |  Operating System:  Unknown/Multiple
          Architecture:              |   Type of failure:  Runtime
  Unknown/Multiple                   |  performance bug
             Test Case:              |        Blocked By:
              Blocking:              |   Related Tickets:
Differential Revisions:              |
-------------------------------------+-------------------------------------
 In a recent look at [http://home.smart-cactus.org/~ben/nofib.html
 historical] nofib trends I noticed that fannkuck-redux appears to regress
 an almost unbelievable amount in its allocations,
 == 7.6.3 ==
 {{{
 <<ghc: 870987952 bytes, 1668 GCs (1666 + 2),
   0/0 avg/max bytes residency (0 samples),
   84640 bytes GC work, 1M in use,
   0.00 INIT (0.00 elapsed), 2.43 MUT (2.43 elapsed), 0.00 GC (0.00
 elapsed),
   0.00 GC(0) (0.00 elapsed), 0.00 GC(1) (0.00 elapsed), 1 balance :ghc>>
 }}}

 == 7.4.2
 {{{
 <<ghc: 74944 bytes, 1 GCs (0 + 1),
   0/0 avg/max bytes residency (0 samples),
   3512 bytes GC work, 1M in use,
   0.00 INIT (0.00 elapsed), 2.25 MUT (2.25 elapsed), 0.00 GC (0.00
 elapsed),
   0.00 GC(0) (0.00 elapsed), 0.00 GC(1) (0.00 elapsed), 1 balance :ghc>>
 }}}

 Given that [FoldrBuildNotes] suggests that this test is quite sensitive to
 fusion, I suspect something broke here.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10717>
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