https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104949
--- Comment #1 from Tobias Burnus <burnus at gcc dot gnu.org> --- The following addition to testcase is needed. ! ------------------------------- !$omp parallel default(A) !$omp master if (any (A /= [1,2,3,4,5])) error stop A(:) = [99,88,77,66,55] !$omp end master !$omp end parallel if (any (A /= [1,2,3,4,5])) error stop !$omp target defaultmap(firstprivate) if (any (A /= [1,2,3,4,5])) error stop A(:) = [99,88,77,66,55] !$omp end target if (any (A /= [1,2,3,4,5])) error stop ! ------------------------------- Reason: A different code path for (a) defaultmap(firstprivate) and default(firstprivate) For them gfc_omp_finish_clause is invoked (b) explicit firstprivate(a) Handled via gfc_trans_omp_clauses -> gfc_trans_omp_variable_list. but gfc_omp_finish_clause is not called (should it?) The 'parallel' variant works – and for both variants the gfc_omp_clause_copy_ctor is invoked for both via lower_rec_input_clauses()'s the block which follows the 'do_firstprivate:' label. Both 'target' variants only create 'firstprivate(a)' - but additionally 'firstprivate(a.data)' is needed, including doing a pointer attach. * * * Currently, we support either code using attach like: map(force_to:var) map(force_to:*var.data [len...]) map(attach_detach:var.data [bias: 0]) or pointer-set/pointer assign like for map(to:var.data [len:...]) map(to:var [pointer set, len: 64]) map(alloc: var.data [pointer assign, bias: 0]) In my understanding, either code requires that 'var.data' can be found as host->device lookup, which does not work for firstprivate. And just internally adding 'a' to the host->device mapping for firstprivate purpose internally does not handle the following. a = 5 !$omp target enter data map(to: a) a = 7 ! adding internally 'a' (host)->'a'(firstprivate) mapping to find the 'a.var' ! for the usage in attach/pointer assign does not work as 'a' already exists. !$omp target firstprivate(a) ! a should be now 7 !$omp end firstprivate !$omp target ! a is 5 !$omp end target For the usage in type t integer, allocatable :: a, b end type t type(t) :: var !$omp target firstprivate(var) ... multiple attachments are needed, i.e. just using firstprivate(a) firstprivate(b) pointer_attach (a.data) and working with index i, i+1, i+2 does not work.