[GHC] #7258: Compiling DynFlags is jolly slow

[GHC]

#7258: Compiling DynFlags is jolly slow
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        Reporter:  simonpj           |                Owner:  simonpj
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  7.6.1
      Resolution:                    |             Keywords:  deriving-perf
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 tdammers):

 Replying to [comment:69 simonpj]:

 > Is the large Cmm accounted for by the big Core-to-Cmm ratio, or do these
 examples also have Core sizes that scale badly (look at term size only)?
 >
 > I'm guessing that the Core size does not scale badly.  If that was so
 our questions would be
 >
 > * Why do we generate so much Cmm per unit of Core
 > * Can we make `sink` scale better
 >
 > Both are worth working on.

 https://ghc.haskell.org/trac/ghc/attachment/ticket/7258/ghc-large-record-
 types-core-size.png suggests Core size has a slight nonlinearity to it,
 the behavior is roughly the same for all examples, so I believe your guess
 that Core size doesn't scale as badly as C-- size does is justified.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7258#comment:71>
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