[ET Trac] [Einstein Toolkit] #1995: McLachlan constraint tests fail

[Einstein Toolkit]

#1995: McLachlan constraint tests fail
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  Reporter:  hinder                 |       Owner:                                                   
      Type:  defect                 |      Status:  new                                              
  Priority:  critical               |   Milestone:  ET_2017_05                                       
 Component:  EinsteinToolkit thorn  |     Version:  development version                              
Resolution:                         |    Keywords:  McLachlan constraints tests compiler optimization
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Comment (by hinder):

 Summary of problem from the above reports:
 * Test failures in thorns Dissipation and RotatingSymmetry90/180 (which
 tests?)
   * Constraints computed using ML_ADMConstraints, not ML_BSSN (is this
 true for all the failing tests?)
   * Failures occur on several machines (which machines?)
   * Tests do not fail in Jenkins (gcc)
   * See failures with Intel 15 and 16, but not all Intel 16 machines fail
 (do all Intel 15 machine fail?)
   * Failures with -O2 but not with -O1.
   * Adding a print statement to the code makes the problem go away
   * Problem is reproducible using 1 process and 1 thread
   * valgrind does not find any problem
   * defining "restrict" to empty does not solve the problem
 * NaNs in initial constraints in unigrid multi-block Minkowski
   * May be related to boundary initialisation, but maybe not
 * Large constraints in BNS simulation
   * Intel 17.0.1
   * ML_ADMConstraints::ML_Ham / ML_Mom
 * Large constraints in TOV star
   * Constraints 3 orders of magnitude larger with Intel 17.0.1 than with
 GCC
   * ML_ADMConstraints::ML_Ham / ML_Mom
   * Problem seen with Intel 17.0.2 and -O3
   * Problem goes away with Intel 17.0.2 and -O0
   * With Intel 17.0.2 and -O3, the values of the constraints depend on the
 number of MPI processes
   * Problem seen with Intel 15.0.4 and -O3

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Ticket URL: <https://trac.einsteintoolkit.org/ticket/1995#comment:19>
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