Fix some reduction race conditions and thread-safety issues #745
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zingale
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Jan 25, 2020
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zingale
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Feb 4, 2020
Extension of #745. I missed that the Fortran cycle statements result in some threads failing to execute the reduction, so the reduction was sometimes generate NaNs.
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PR summary
Thread-safe reductions in the CUDA build have two requirements: (1) we must use the corresponding function in reduction.F90, such as reduce_add, otherwise there will be a race condition among CUDA threads; (2) we cannot call functions like reduce_add in a conditional branch that is true for some threads but not others (otherwise there could be a code hang).
Fixes #728
PR checklist
CHANGESfile has been updated