Listing 3. Fortran Matrix Multiplication Loop, Tagged to Be Compiled for
the Accelerator

!$acc begin

do i = 1,n1
  do k = 1,n3
    c(i,k) = 0.0
    do j = 1,n2
      c(i,k) = c(i,k) + a(i,j) + b(j,k)
    enddo
  enddo
enddo

!$acc end