[GHC] #13170: Core Lint error on git HEAD

[GHC]

#13170: Core Lint error on git HEAD
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        Reporter:  dobenour          |                Owner:  rwbarton
            Type:  bug               |               Status:  new
        Priority:  highest           |            Milestone:
       Component:  Compiler          |              Version:  8.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
                                     |  simplCore/should_compile/T13170
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D3008
       Wiki Page:                    |
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Comment (by simonpj):

 > It seems to be caused by ​https://phabricator.haskell.org/D2762 not
 reordering the mapped cases

 That looks absolutely right.  You need to re-sort the alternatives to
 ensure thay are still in ascending order.  See `CoreSyn`
 ```
 --    3. The remaining cases are in order of increasing
 --         tag  (for 'DataAlts') or
 --         lit  (for 'LitAlts').
 --       This makes finding the relevant constructor easy,
 --       and makes comparison easier too.
 ```
 Well spotted.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13170#comment:5>
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