I’ve upgraded PGI compiler from 18.3 to 19.1. Fortran+OpenACC code I’m working with generated different/invalid numerical results.
I have tried to narrow down the problem and it turned out that different results are generated when -acc is switched on for a single file which contains only data copying directives (no acc kernels or acc loops).
Moreover, I’ve commented out all data copying directives (as well as all other acc directives in the code) and the results are still different with and without -acc option for this single file.
I’m not sure how to proceed with it… should I try to play with switching on/off different compiler options encapsulated within -acc ?