[GHC] #13426: compile-time memory-usage regression for DynFlags between GHC 8.0 and GHC 8.2

[GHC]

#13426: compile-time memory-usage regression for DynFlags between GHC 8.0 and GHC
8.2
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        Reporter:  hvr               |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  high              |            Milestone:  8.2.1
       Component:  Compiler          |              Version:  8.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by hvr):

 Ben suggested that reverting 2effe18ab51d66474724d38b20e49cc1b8738f60
 could have an interesting effect... however it appears to have things
 worse :-)

 {{{
 <<ghc: 60080847424 bytes, 4089 GCs, 436124979/1969454128 avg/max bytes
 residency (24 samples), 5367M in use, 0.000 INIT (0.000 elapsed), 33.164
 MUT (34.275 elapsed), 28.562 GC (28.606 elapsed) :ghc>>
 }}}

 I'll attach `--verbose` output as well

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13426#comment:3>
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