https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109831
Bug ID: 109831
Summary: [OpenMP] Handle absent optional arguments in depend,
has_device_addr, to/from and allocatable/pointer vars
in map
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Keywords: openmp, wrong-code
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: burnus at gcc dot gnu.org
Target Milestone: ---
ISSUE 1: allocatated/associated vs. present cannot be distinguished for scalar
allocatables/pointers, i.e.
subroutine foo(x)
integer, allocatable, optional :: x
!$omp target
if (.not.present(x))
print *, "not present"
else if (.not. allocated(x)) then
print *, "not allocated"
else
print *, "value: ", x
end if
!$omp end target
end
Does not work correctly as we pass 'x == NULL ? NULL : *x' as argument
to the map. We should map *x (if present) and a pointer variable to which we
attach the *x pointer.
ISSUE 2: Extend the set of permitted clauses.
Absent optionals are permitted for some other clauses besides 'map'. Per
post-TR11 discussions (→ OpenMP Spec issue #3490), there are *not* permitted
...
* ... for variables that are evaluated in a clause such as 'if(...)'
* ... for variables that are privatized ('firstprivate', 'private',
'is_device_ptr')
* ... at places where the clause poses restrictions that can only be fulfilled
when the variable is present – like 'copyprivate' (argument must be privatized,
hence, it has to exist)
Besides 'map', that's the case for
* the 'to'/from' motion clauses
* has_device_addr
* depend
* < something else ? >
