#1995: McLachlan constraint tests fail ------------------------------------+--------------------------------------- Reporter: hinder | Owner: Type: defect | Status: confirmed Priority: critical | Milestone: ET_2017_05 Component: EinsteinToolkit thorn | Version: development version Resolution: | Keywords: McLachlan constraints tests compiler optimization ------------------------------------+---------------------------------------
Comment (by hinder):
I have written a new test in ML_BSSN_Test which uses the shifted gauge wave from EinsteinExact and outputs the constraints as calculated by ML_ADMConstraints. This test suffers from the same problem. The test fails when run with Intel 17.0.4, while the test data was generated using gcc 4.9.2. I have pushed the test to master, since it's always good to have more tests. This eliminates the possibility that the problem is caused by "irregular" or strange initial data.
I have also tried adding {{{ printf("Hello World!\n");" }}} as the last line of the loop in ML_ADMConstraints_evaluate_Body. This causes the test to pass, whereas previously it failed. If the problem is so sensitive to changes in the code, I'm worried that it will be difficult to produce a cut-down example to send to Intel. On the other hand, if doing something as drastic as disabling vectorisation doesn't cause the bug to go away, then maybe there is hope.