https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90743
--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> --- (In reply to Thomas Schwinge from comment #2) > Thanks for your comment; I wasn't aware of the (default) '-frealloc-lhs' > behavior (PR90741), and indeed that's supported inside offloading regions, > too. > > (In reply to Jakub Jelinek from comment #1) > > The code in the region could deallocate (c) or > > do similar stuff, and while that might be undefined with some offloading > > specs under some conditions, there are many cases where it must be valid. > > Indeed that's not permitted per my reading of OpenMP 5.0 -- but it does seem > to work in the GCC implementation, inside an offloading region to > 'deallocate' and then re-'allocate', which seems to make the device object > "detached" from the host object. Is that something we should thus be > testing (with a comment: "implementation-defined behavior"), or should we > not test such things? It is undefined behavior, so we shouldn't be testing it.