[GHC] #13059: High memory usage during compilation

[GHC]

#13059: High memory usage during compilation
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        Reporter:  domenkozar        |                Owner:
            Type:  bug               |               Status:  new
        Priority:  highest           |            Milestone:  8.2.1
       Component:  Compiler          |              Version:  8.0.2-rc2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:  x86_64
 Type of failure:  Compile-time      |  (amd64)
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by simonpj):

 Good data -- but

 * The terms seem to get bigger by 25% and the types/coercions by up to
 50%.  That does not account for a ''quadrupling'' of memory usage, as
 reported in the Description.  I wonder if there is a space leak, which is
 beoming more obvious with this program?  Worth taking a space profile?

 * I doubt that messinng around with default-method generation is going to
 help much.  After all, the user might write the source code as in the
 tweaked version.  What we should focus on is what causes the program size
 to increase so dramatically.  Is it just the usual nested-tuple thing
 (which I still do now know how to fix), or is there more afoot?  Maybe
 take a small example (one small type, one default method) and compare
 before and after.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13059#comment:19>
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