http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60928
Bug ID: 60928
Summary: gfortran issue with allocatable components and OpenMP
Product: gcc
Version: 4.8.3
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: quantheory at gmail dot com
Just as a disclaimer up front, this is probably an OpenMP 4.0 issue. OpenMP 3.1
sort of glossed over this use case, but OpenMP 4.0 quietly added language about
it. Still, it would be nice to get right, and it doesn't involve any of the new
constructs.
The following test case works with nagfor, xlf, and newer versions of
pgfortran, but not gfortran or ifort:
use omp_lib, only: omp_get_thread_num
implicit none
type :: foo
integer, allocatable :: a(:)
end type foo
type(foo) :: bar
integer :: i, sum_arr(5)
!$omp parallel private (i, bar)
allocate(bar%a(3))
!$omp do
do i = 1, 5
bar%a = [1, 2, 3] + omp_get_thread_num()
sum_arr(i) = sum(bar%a)
end do
!$omp barrier
print *, sum(bar%a)
!$omp barrier
!$omp single
print *, sum(sum_arr)
!$omp end single
deallocate(bar%a)
!$omp end parallel
end
This is the runtime's error message:
Fortran runtime error: Attempting to allocate already allocated variable 'bar'
I think this signifies that the private version of "bar" is not being set up
correctly, so the threads end up sharing the allocatable component.
