[GHC] #14880: GHC panic: updateRole

[GHC]

#14880: GHC panic: updateRole
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        Reporter:  RyanGlScott       |                Owner:  goldfire
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.8.1
       Component:  Compiler (Type    |              Version:  8.2.2
  checker)                           |
      Resolution:                    |             Keywords:  TypeInType
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  crash or panic                     |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #15076            |  Differential Rev(s):  Phab:D4769
       Wiki Page:                    |
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Comment (by tdammers):

 Looks like step 0 already introduces a performance regression:

 {{{
 Unexpected results from:
 TEST="T9630"

 SUMMARY for test run started at Mon Sep 10 12:56:45 2018 CEST
  0:06:01 spent to go through
      110 total tests, which gave rise to
      526 test cases, of which
      416 were skipped

        4 had missing libraries
      105 expected passes
        0 expected failures

        0 caused framework failures
        0 caused framework warnings
        0 unexpected passes
        0 unexpected failures
        1 unexpected stat failures

 Unexpected stat failures:
    compiler/T9630.run  T9630 [stat not good enough] (normal)
 }}}

 That one test deviates by +15% allocations.

 (The relevant patch:
 http://git.haskell.org/ghc.git/commitdiff/c8a1f9c42a37eb0c3514aef1a716fdbcb912da31?hp=510c5f4f22aca29a9c36fd993ac79e9077b28173)

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14880#comment:115>
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