https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127646
Bug ID: 127646
Summary: [OpenMP][6.0] Implement 'groupprivate' on the host
Product: gcc
Version: 17.0
Status: UNCONFIRMED
Keywords: openmp
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: burnus at gcc dot gnu.org
Target Milestone: ---
'groupprivate' implies that each team (contention group) has its own copy of
that variable. (For such variables, an initializer is not permitted.)
Currently, groupprivate lacks:
- Support in C/C++ (only Fortran)
- Support in GCN (only nvptx)
- Support on the host (only device_type(nohost) - not 'host' not 'any')
For the last item (and also a bit the second item), see:
https://gcc.gnu.org/pipermail/gcc-patches/2026-September/732780.html
This email sketches out how a host implementation can look like
(and how the GCN version can be implemented).
The main purpose of this issue is only the last, namely:
* Add support for 'groupprivate' on the host [device_type({any|host})]
... to handle code like:
int global;
#pragma omp groupprivate(global)
int f(bool first) {
int local;
#pragma omp groupprivate(local)
if (first) local = 5;
return ++local;
}
where 'global' is accessing / 'f' called - either in "normal" code
or from within an 'omp teams' or 'omp target teams' region (running
on the host [or on a non-host device]).
Note that 'target' can also run concurrently ('nowait'), i.e. that
also needs to work.
