[GHC] #14619: Output value of program changes upon compiling with -O optimizations

[GHC]

#14619: Output value of program changes upon compiling with -O optimizations
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        Reporter:  sheaf             |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  highest           |            Milestone:  8.4.1
       Component:  Compiler          |              Version:  8.2.2
      Resolution:                    |             Keywords:
Operating System:  Windows           |         Architecture:  x86_64
 Type of failure:  Incorrect result  |  (amd64)
  at runtime                         |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Changes (by carter):

 * priority:  high => highest
 * milestone:  8.6.1 => 8.4.1


Comment:

 Slyfox on irc was suggesting this is some sort of bug in caller/callee
 save convention on the 64bit windows mingw path.


 That disabling the cmm sink pass or using llvm backend resolve this issue
 is evidence that some register allocation related error only on that
 platform.

 Since this is a tier 1 platform And this seems to be a case of silently
 incorrect programs on a tier 1 platform , I’m marking this as highest
 priority.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14619#comment:14>
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