[GHC] #7944: GHC goes into an apparently infinite loop at -O2

[GHC]

#7944: GHC goes into an apparently infinite loop at -O2
-------------------------------+--------------------------------------------
    Reporter:  bos             |        Owner:                    
        Type:  bug             |       Status:  closed            
    Priority:  normal          |    Component:  Compiler          
     Version:  7.6.3           |   Resolution:  duplicate         
    Keywords:                  |           Os:  MacOS X           
Architecture:  x86_64 (amd64)  |      Failure:  Compile-time crash
   Blockedby:                  |     Blocking:                    
     Related:  5550            |  
-------------------------------+--------------------------------------------
Changes (by amosrobinson):

  * status:  new => closed
  * resolution:  => duplicate
  * related:  => 5550


Comment:

 Hi,
 This looks like an instance of #5550: ForceSpecConstr was blowing up when
 specialising on recursive types (list, in this case).
 This is fixed in HEAD, but sadly there isn't a good fix until then
 (without modifying the vector library to remove ForceSpecConstr
 annotations).

 Can you change the [Int] to a Vector? Otherwise, you might just need to
 compile with -fno-spec-constr (or the lower threshhold, as you mentioned)
 for now.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7944#comment:2>
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