Un-parallelized OpenACC kernels constructs with nvptx offloading: "avoid offloading"
Wed Feb 10 14:40:00 GMT 2016
On Wed, 10 Feb 2016 14:25:50 +0100, Bernd Schmidt <email@example.com> wrote:
> On 02/10/2016 12:49 PM, Thomas Schwinge wrote:
> > [...]
> I think this has to be considered after gcc-6.
Hmm, I see.
> In general, what's the
> state of OpenACC these days?
Much improved compared to GCC 5. :-) Anything specific you'd like me to
elaborate on? <https://gcc.gnu.org/wiki/OpenACC> should be fairly
> I'm slightly confused by the interface between offloaded code and
> libgomp. It looks like you're collecting avoid-offloading flags
> per-function, but then when things get registered, it seems like a
> per-image flag.
(Per-image flag that affects all offloading for a given offloading type,
> Is that right? It seems like too large a hammer.
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.
> >> [...]
> Avoid unnecessary braces.
> >> [...]
Thanks for the review; fixed.
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