On Nov 4 2014, Jeff Law wrote:
On 11/04/14 09:11, Jakub Jelinek wrote:
The point is, if the target can implement just a subset of the Fortran
(or C or C++) standards, then ideally if you use anything that is not
supported would just cause always host fallback, the code will still
work, but will not be offloaded. So even supporting a subset of the
standard is worthwhile, usually one will just offload the most
performance critical parts of his code.
As I see it, this isn't a free-standing compilation environment, but a
component of one for heterogeneous architectures. There are similar
issues for some embedded systems, in several languages. That doesn't
fit well with the current build model, unfortunately :-(
Also note there's a reasonable chance that the GPUs will continue to
evolve and will be able to support more of the standard language
features. Not sure if they'll ever do the IO side of Fortran, but they
could always surprise us.
I am almost certain that the current situation is going to change
significantly, probably by 2020, but there is as yet no indication of
how. And it wouldn't be entirely reasonable to say nothing should be
done for this sort of use until the situation becomes clear.
Regards,
Nick Maclaren.
