[GHC] #13518: CMM compiles with 8.0.2, fails with git HEAD

[GHC]

#13518: CMM compiles with 8.0.2, fails with git HEAD
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        Reporter:  erikd             |                Owner:  (none)
            Type:  bug               |               Status:  closed
        Priority:  normal            |            Milestone:  8.4.1
       Component:  Compiler          |              Version:  8.1
      Resolution:  invalid           |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Incorrect         |  Unknown/Multiple
  error/warning at compile-time      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by rwbarton):

 > So how does one express a `Word32` in a portable way in CMM?

 There is no 32-bit integral primitive Haskell type anyways, so the problem
 never arises.

 The definition of the Haskell type `Word32` is
 {{{#!hs
 data Word32 = W32# Word#
 }}}
 where all but the low 32 bits of the `Word#` are expected to be zero. So
 that's the interface you have to program to, in Cmm.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13518#comment:13>
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