[GHC] #7192: Bug in -fregs-graph with -fnew-codegen

[GHC]

#7192: Bug in -fregs-graph with -fnew-codegen
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    Reporter:  simonmar          |       Owner:  benl            
        Type:  bug               |      Status:  new             
    Priority:  highest           |   Milestone:  7.8.1           
   Component:  Compiler          |     Version:  7.7             
    Keywords:                    |          Os:  Unknown/Multiple
Architecture:  Unknown/Multiple  |     Failure:  None/Unknown    
  Difficulty:  Unknown           |    Testcase:                  
   Blockedby:                    |    Blocking:  4258            
     Related:                    |  
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Comment(by benl):

 Yeah, if the liveness determinator can't see R1 being read in the block
 that calls stg_gc_fun, then it the allocator isn't obliged to preserve
 it's value across the jump. I think your original cmm code is malformed.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7192#comment:8>
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