SWM is a simplified kernel representing the nonlinear PDE's governing geophysical fluid flow.
Please contact the Point of Contact below before distributing it further, or if any questions or issues arise.

Resolution:

Resolution may be changed by the following procedure.
In shallow_swap.c change these 

#define M 64
#define N 64

to the desired numbers. M and N can be changed independently.

COPY vs SWAP:

There is an optimization that avoids copies in loop 300 by swapping pointers. COPY can be turned on and off by defining _COPY_ or not, as desired.

Building:

bash-3.2$ gcc -O2 shallow_swap.c wtime.c
bash-3.2$ ./a.out > results.txt

Validation: 

Compare results.txt with the provided file results_ref.txt, particularly the last values printed, namely those below-
 diagonal elements of p
 diagonal elements of u
 diagonal elements of v

Performance: 

Performance reported in results_ref.txt is that obtained on a single core of a 2.6 GHz Intel Core i7 Macbook Pro with 2400 MHz DDR4 memory.

Point of Contact:

Dr. Richard Loft
National Center for Atmospheric Research
loft@ucar.edu