12. array construct

The array construct is for work mapping of array assignment statements.

• XMP/C program

#pragma xmp align a[i] with t[i]
  :
#pragma xmp array on t[0:N]
a[0:N] = 1.0;

• XMP/Fortran program

!$xmp align a(i) with t(i)
  :
!$xmp array on t(1:N)
a(1:N) = 1.0

The above is equivalent to the below.

• XMP/C program

#pragma xmp align a[i] with t[i]
  :
#pragma xmp loop on t[i]
for(int i=0;i<N;i++)
  a[i] = 1.0;

• XMP/Fortran program

!$xmp align a(i) with t(i)
  :
!$xmp loop on t(i)
do i=1, N
  a(i) = 1.0
enddo

This construct can also be applied to multi-dimensional arrays. The triplet notation enables specifying operations for all elements of the array.

• XMP/C program

#pragma xmp align a[i][j] with t[i][j]
  :
#pragma xmp array on t[:][:]
a[:][:] = 1.0;

• XMP/Fortran program

!$xmp align a(j,i) with t(j,i)
  :
!$xmp array on t(:,:)
a(:,:) = 1.0

Note

The template appearing in the on clause must have the same shape of arrays in the following statement. The right-hand side value must be identical among all nodes because the array construct is a collective operation.