[GHC] #10491: Regression, simplifier explosion with Accelerate, cannot compile, increasing tick factor is not a workaround

[GHC]

#10491: Regression, simplifier explosion with Accelerate, cannot compile,
increasing tick factor is not a workaround
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        Reporter:  robertce          |                   Owner:
            Type:  bug               |                  Status:  new
        Priority:  highest           |               Milestone:  7.10.2
       Component:  Compiler          |                 Version:  7.10.1
      Resolution:                    |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  performance bug                    |               Test Case:
      Blocked By:                    |                Blocking:
 Related Tickets:                    |  Differential Revisions:
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Comment (by simonpj):

 Well I suggest you use `-fno-specialise` in any further investigations.
 It doesn't fix it, but it'll remove distracting clutter from what you see.

 The silent-superclass thing is not really the ''cause''.  (And hence I
 don't think it's worth a heroic effort to port HEAD to 7.10.  It certainly
 generates a lot more dictionaries, so perhaps there might be twice as much
 code as without. But you are seeing MUCH more than that!  So maybe there
 is a bug lurking in HEAD too; it just happens that the code generated by
 silent superclasses in 7.10 tickles it.

 So the hunt goes on.  Monday is a washout for me.

 Simon

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10491#comment:26>
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