Re: [GHC] #14379: Regression - GHC 2.8.1 Consumes All Memory On Build

27 Oct 2017

      #14379: Regression - GHC 2.8.1 Consumes All Memory On Build
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        Reporter:  jm4games          |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  high              |            Milestone:
       Component:  Compiler          |              Version:  8.2.1
      Resolution:                    |             Keywords:
Operating System:  Linux             |         Architecture:  x86_64
 Type of failure:  Compile-time      |  (amd64)
  crash or panic                     |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  8.0.2
       Wiki Page:                    |
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Comment (by Simon Peyton Jones ):

 In [changeset:"7d7d94fb4876dc7e58263abc9dd65921e09cddac/ghc"
 7d7d94fb/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="7d7d94fb4876dc7e58263abc9dd65921e09cddac"
 Fix an exponential-blowup case in SpecConstr

 Trac #14379 showed a case where use of "forcing" to do
 "damn the torpedos" specialisation without resource limits
 (which 'vector' does a lot) led to exponential blowup.

 The fix is easy.  Finding it wasn't.  See Note [Forcing
 specialisation] and the one-line change in decreaseSpecCount.
 }}}

-- 
Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14379#comment:5
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