OpenMP library

[lan0907]

Dear all,

I have a code with multi-threading features in it. However, when I tried to excute and debug the code, I got error "LNK2019: unresolved external sybol OMP_GET_THREAD_NUM referenced in function abc..." and error 'LNK2001:unresolved external sybol OMP_GET_THREAD_NUM', also other error LNK2001 for related variables, methods with OpenMP.

I guess, I did NOT specified library or other commends correctly for the compiler???

The core code is the following:

!$omp parallel private(id)

id = omp_get_thread_num() ! id starts with 0

call xyz_Subroutine

!$omp end parallel

I am using Intel Visual Fortan Compiler (Professional Edition) for Windows - Version 10 and Microsoft Visual Studion on a x64 bit Machine.

See if anybody has some ideas on this. Thank you very much in advance!

--

Lan

[Steven_L_Intel1]

Add this:

use omp_lib

after your PROGRAM, SUBROUTINE or FUNCTION statement to properly declare the routine. You should also be sure to have set the "Process OpenMP Directives" option under Fortran > Language in Visual Studio, or use the /Qopenmp option on the command line.

[TimP]

In order to make a program which works regardless of whether /Qopenmp is set, according to OpenMP standard, you guard those by #ifdef _OPENMP:
#ifdef _OPENMP
use omp_lib
#endif
....
#ifdef _OPENMP
... =omp_get_thread_num()
..
#endif

but then you must set /fpp for Windows compilation.
I've never seen anyone attempt to use the version date aspect of _OPENMP.
I do frequently see legacy programs which declare e.g.
integer omp_get_thread_num
which should be flagged as at least a warning with strict checking enabled.

[Steven_L_Intel1]

It really isn't necessary to conditionalize the USE.