[GHC] #10852: ghc 7.8.4 on arm - panic: Simplifier ticks exhausted

[GHC]

#10852: ghc 7.8.4 on arm - panic: Simplifier ticks exhausted
-------------------------------------+-------------------------------------
        Reporter:  andrewufrank      |                Owner:
            Type:  bug               |               Status:  new
        Priority:  high              |            Milestone:
       Component:  Compiler          |              Version:  7.10.2
      Resolution:                    |             Keywords:  Generics
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #5642, #9675      |  Differential Rev(s):
       Wiki Page:                    |
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Changes (by thomie):

 * priority:  normal => high


Comment:

 I made two changes to my test setup, to compile `InstanceSerialize.hs`:

 * use `cereal` commit
 [https://github.com/GaloisInc/cereal/commit/7092614cdea80ab08c225c7a5c74f7ae1608e0bb
 7092614cdea80ab08c225c7a5c74f7ae1608e0bb] instead of cereal-0.4.1
 This includes a [https://github.com/GaloisInc/cereal/pull/54 pull request]
 that @thoughpolice made recently, to split up the `GSerialize` class in
 two. (same trick as ticket:9630#comment:23). I'd hoped this would reduce
 memory consumption and compile time.

 * use ghc-8.0.1 instead of ghc-7.10.3.

 Result:
 {{{
 Simplifier ticks exhausted
   When trying UnfoldingDone unGet
 }}}

 `-fsimpl-tick-factor=400` made it go through (and `300` did not), but it
 still uses 2GB RAM and takes 4-5 minutes to complete.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10852#comment:13>
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