[GHC] #13566: Bigger core size in ghc8 compared to ghc7

[GHC]

#13566: Bigger core size in ghc8 compared to ghc7
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        Reporter:  pacak             |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.2.1-rc2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Runtime           |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by pacak):

 GHC 8.2 on original code:

 {{{
 Result size of Demand analysis
   = {terms: 5,548, types: 10,236, coercions: 2,752, joins: 10/79}
 !!! Demand analysis [A]: finished in 198.43 milliseconds, allocated 43.533
 megabytes
 *** CoreTidy [A]:
 Result size of Tidy Core
   = {terms: 1,150, types: 2,274, coercions: 320, joins: 0/14}
 !!! CoreTidy [A]: finished in 6.72 milliseconds, allocated 6.210 megabytes
 writeBinIface: 149 Names
 writeBinIface: 279 dict entries
 writeBinIface: 149 Names
 writeBinIface: 279 dict entries
 *** CorePrep [A]:
 Result size of CorePrep
   = {terms: 1,342, types: 2,838, coercions: 320, joins: 0/66}
 }}}

 Looks like ghc 8.2 also produces similar sized core and manages to clean
 it up later.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13566#comment:7>
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