Un-parallelized OpenACC kernels constructs with nvptx offloading: "avoid offloading"

[Bernd Schmidt]

On 02/10/2016 03:39 PM, Thomas Schwinge wrote:

> Yes, we need a hammer that big: we have to ensure consistency between
> data regions on the device and code offloading to the device, as
> otherwise we'll very easily run into inconsistencies, because of the
> non-shared memory.  In the general case, it's "all or nothing": you
> either have to offload all kernels or none of them.

That's unfortunately not the impression I got from the earlier 
discussion, and this seems to imply that one unprofitable kernel would 
disable all the others - IMO this is not acceptable. There need to be 
more compiler smarts to figure out whether a kernel is a valid candidate 
for skipping the offloading.


Bernd