Technical data

Writing Parallel Fortran
75
Example 1
The code fragment
DO 10 I = 1, 100
A(I) = B(I)
10 CONTINUE
could be multiprocessed with the directive
C$DOACROSS LOCAL(I), SHARE(A, B)
DO 10 I = 1, 100
A(I) = B(I)
10 CONTINUE
Here, the defaults are sufficient, provided A and B are mentioned in a
nonparallel region or in another SHARE list. The following then works:
C$DOACROSS
DO 10 I = 1, 100
A(I) = B(I)
10 CONTINUE
Example 2
DO 10 I = 1, N
X = SQRT(A(I))
B(I) = X*C(I) + X*D(I)
10 CONTINUE
You can be fully explicit:
C$DOACROSS LOCAL(I, X), share(A, B, C, D, N)
DO 10 I = 1, N
X = SQRT(A(I))
B(I) = X*C(I) + X*D(I)
10 CONTINUE
or you can use the defaults
C$DOACROSS LOCAL(X)
DO 10 I = 1, N
X = SQRT(A(I))
B(I) = X*C(I) + X*D(I)
10 CONTINUE