On Thu, Nov 13, 2014 at 04:15:48PM +0100, Tobias Burnus wrote:
> Question: Is the latter up to date - and the item above correct?
Will leave that to Kirill.
> BTW: you could update gcc.gnu.org ->news and gcc.gnu.org/gcc-5/changes.html
Indeed, that should be updated.
> Otherwise:
> * OpenACC support is about to be merged (as alternative to OpenMP 4)
I hope so.
> * Support for offloading to NVidia GPUs via PTX is also about to be merged.
Ditto.
Then the question is how hard will it be to get OpenACC offloading to
XeonPhi (real hw or emulation) - I guess it is a matter of whether the
plugin needs to implement some extra hooks for OpenACC, and also
whether we can get OpenMP offloading to PTX (dunno if Thomas or his
collegues have actually tried it on simple testcases, I bet the hardest part
will be porting libgomp away from pthread_* to optionally be supported
by the limited nvptx target and use its threading model; whether __thread
is already supported by nvptx etc.). I'm willing to help with this once I
have some hw, but some help from people familiar with PTX would be certainly
appreciated. Because without libgomp ported to nvptx-*-* target (or some
way to inline all the GOMP_*/omp_* calls in offloading regions for nvptx,
but the latter might be too hard), I guess one could offload very simple
target regions, but not anything using #pragma omp inside of them.
Jakub
