1         program main 2         use omp_lib 3         use openacc 4         implicit none 5          6         real,allocatable:: v1(:) 7         integer length, idx 8          9         call acc_set_device_num(2,acc_device_nvidia)10         length = 1024!*1024!*102411         allocate(v1(length))12         v1(1:length) = 0.013         !使用data语句，将数据copy到device上14         !$acc data copy(v1(1:length))15         call add1(v1, length) !子程序在device上执行16         17         !print只能cpu实行，所以讲数据update到cpu上18         !$acc update host(v1(1:5))19         print*, "v1(1) = ", v1(1:5)20         !下面是在cpu上执行21         do idx = 1,length22         v1(idx) = v1(idx) + 1023         enddo24         print*, "v1(1) = ", v1(1:5) !直接打印出cpu上的结果25         26         !将cpu上的执行结果update到device上27         !$acc update device(v1(1:5))28         call add1(v1, length)29         30         !上面子程序在device上执行完，update到本地输出31         !$acc update host(v1(1:5))32         print*, "v1(1) = ", v1(1:5)33         !结束34         !$acc end data35         36         deallocate(v1)37 38         end program 39         40         subroutine add1(vec, length)41         use openacc42         implicit none43         integer, intent(in)::length44         real, intent(inout) :: vec(1:length)45         integer idx46         !$acc parallel loop present(vec(1:length))47         do idx = 1, length48             vec(idx) = vec(idx) + idx49         enddo50         end subroutine