[GHC] #8960: SpecConstr usage explodes beyond 4GB with GHC 7.8.1 rc 2

[GHC]

#8960: SpecConstr usage explodes beyond 4GB with GHC 7.8.1 rc 2
-----------------------------------+---------------------------------------
       Reporter:  MichalGajda      |             Owner:
           Type:  bug              |            Status:  new
       Priority:  normal           |         Milestone:  7.8.1
      Component:  Compiler         |           Version:  7.8.1-rc2
       Keywords:                   |  Operating System:  Unknown/Multiple
   Architecture:                   |   Type of failure:  Compile-time crash
  Unknown/Multiple                 |         Test Case:  cabal install hPDB
     Difficulty:  Unknown          |          Blocking:
     Blocked By:                   |
Related Tickets:                   |
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 GHC 7.8 rc2 exhausts all memory on `Bio.PDB.EventParser.PDBEventParser`
 module in -O3 mode, but not in -O2 mode.

 The tail of ''-v3'' input seems to indicate that it dies during SpecConstr
 phase. The module successfully compiled with below 2GB RAM since GHC 6.12,
 so I wonder why the memory use exploded with the most recent version.

 *** SpecConstr:

 ==================== SpecConstr ====================
 Result size of SpecConstr

 STEPS TO REPRODUCE:
 1. `cabal install hPDB`

 RESULT EXPECTED:
 Successful compilation and installation

 CURRENT RESULT:
 Exhausts available memory and crashes when compiling
 `Bio.PDB.EventParser.PDBEventParser`.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8960>
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