[GHC] #13930: Cabal configure regresses in space/time

[GHC]

#13930: Cabal configure regresses in space/time
-------------------------------------+-------------------------------------
        Reporter:  bgamari           |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  high              |            Milestone:  8.4.2
       Component:  Compiler          |              Version:  8.3
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Runtime           |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #13982            |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by hvr):

 Ben asked me to provide the STG dumps of the module containing the `accum`
 function;  original code as well the variant w/ the
 `ReadPackageIndexStrict` branch commented out respectively; I hadn't had
 time to look at those myself yet, so here they're unabridged:

 - https://gist.github.com/9fe0cc59b4414351ce0e03c21a068172 (original)

 - https://gist.github.com/759e338c8d841de9b3fb47d892fac398 (commented out
 `ReadPackageIndexStrict`)

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13930#comment:12>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler