[GHC] #6096: tc126(optasm) is failing with a core lint error

[GHC]

#6096: tc126(optasm) is failing with a core lint error
---------------------------------+------------------------------------------
    Reporter:  igloo             |       Owner:                           
        Type:  bug               |      Status:  new                      
    Priority:  high              |   Milestone:  7.6.1                    
   Component:  Compiler          |     Version:  7.5                      
    Keywords:                    |          Os:  Unknown/Multiple         
Architecture:  Unknown/Multiple  |     Failure:  GHC rejects valid program
  Difficulty:  Unknown           |    Testcase:  tc126                    
   Blockedby:                    |    Blocking:                           
     Related:                    |  
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Comment(by simonpj@…):

 commit ebcad7641a1e37e2e4abd7f513feb10c4ee458bc
 {{{
 Author: Simon Peyton Jones <simonpj at microsoft.com>
 Date:   Wed May 16 10:50:36 2012 +0100

     When comparing Case expressions, take account of empty alternatives

     After the recent change that allows empty case alternatives, we
     were accidentally saying that these two were equal:
        Case x _ Int  []
        Case x _ Bool []
     Usually if the alternatives are equal so is the result type -- but
     not if the alternatives are empty!

     There are two places to fix:
       CoreUtils.eqExpr
       TrieMap with CoreExpr key

     Fixes #6096, #6097

  compiler/coreSyn/CoreUtils.lhs |    9 +++--
  compiler/coreSyn/TrieMap.lhs   |   60
 ++++++++++++++++++++++++++-------------
  2 files changed, 45 insertions(+), 24 deletions(-)
 }}}

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/6096#comment:1>
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