[GHC] #13763: Performance regression (~34%) in 8.2.1, poor register allocation(?) in an inner loop over an array

[GHC]

#13763: Performance regression (~34%) in 8.2.1, poor register allocation(?) in an
inner loop over an array
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        Reporter:  jberryman         |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler (NCG)    |              Version:  8.2.1-rc2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Runtime           |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Changes (by jberryman):

 * Attachment "8.0.1.regressing_and_non_regressing_asm_diff.png" added.

 Adding the second line (which causes regression in 8.2) on 8.0.1

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13763>
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