topic parallelizing array assignments in Intel® Fortran Compiler

parallelizing array assignments

john-l-ditter — Tue, 28 May 2013 20:40:21 GMT

Hi,

If I have a DO loop where the values of array B are assigned to array A in the form:

DO N=N1,N2

A(:,N)=B(:,N)

ENDDO

Will parallelizing it in OpenMP like below work, or do i need to explicitly loop through the first index:

!$OMP PARALLEL DO

!$OMP& PRIVATE(N)

DO N=N1,N2

A(:,N)=B(:,N)

ENDDO

What if, instead of an array B on the right-hand side, it is a scalar?

Your code will work in

jimdempseyatthecove — Tue, 28 May 2013 21:27:42 GMT

Your code will work in parallel, even with scalar.

For small arrays you might want to avoid the parallel code. For large arrays, you might want to limit the number of threads to 2-4 as you will soon hit a memory bandwidth situation.

Jim Dempsey

Thank you, Jim.

john-l-ditter — Fri, 07 Jun 2013 15:38:17 GMT

Thank you, Jim.