Error with Debug (plus OpenMP) mode, but not with Release

[hadesmajesty]

My Fortran code can run well in

(1) Debug mode without OpenMP.

(2) Release mode with OpenMP.

Both results are closed up to 1.0e-4.

Some Nan errors occur in

(3) Debug mode with OpenMP.

So I wonder if there is any bug in my code?

Thank you.

[anishtain4]

Probably,
As you know houndred of thousands of right answers does not prove your code but a single wrong answer makes sure there is a problem.
Probably when you are in debug mode slower speed of the running makes the racing condition more evident

[jimdempseyatthecove]

The usual suspects are:

a) Uninitialized variables (in multi-threaded programming this can mean not yet initialized variables)
b) Race conditions where a critical section or atomic is missing

Enable all debug checks and enable gen-interfaces/check-interfaces to catch most of a) problems. You can remove these options after you find/fix the error.

Jim Dempsey