1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59
|
program openmp_29
use omp_lib
implicit none
integer :: i
integer :: seed
integer, parameter :: n = 10000
double precision :: x(n)
double precision :: max1
double precision :: max2
double precision :: max3
seed = 1325
do i = 1, n
seed = mod ( ( 3125 * seed ), 65536 )
x(i) = ( seed - 32768.0 ) / 16384.0
end do
max1 = - huge(max1)
do i = 1, n
if ( max1 < x(i) ) then
max1 = x(i)
end if
end do
!$omp parallel shared(x) private(i) reduction(max:max2)
!$omp do
do i = 1, n
max2 = max ( max2, x(i) )
end do
!$omp end do
!$omp end parallel
print *, "Done with parallel loop 1"
max3 = - huge(max3)
!$omp parallel shared(x) private(i) reduction(max:max3)
!$omp do
do i = 1, n
if ( max3 < x(i) ) then
max3 = x(i)
end if
end do
!$omp end do
!$omp end parallel
print *, 'Done'
print *, ' X_MAX should be ', max1
print *, ' Computed X_MAX2 = ', max2
print *, ' Computed X_MAX3 = ', max3
if (abs(max1 - max2) > 1e-8) error stop
if (abs(max1 - max3) > 1e-8) error stop
if (abs(max2 - max3) > 1e-8) error stop
end
|