Re: trying out openacc 2.0

[Mark Farnell <mark dot farnell at gmail dot com>]

That's good news.  Does it mean that if I want to try out openACC with
KNL and PTX support, then all I need to do is to compile the
gomp-4_0-branch *without* any extra parameters into ./configure ?

Also, are other GPUs such as the AMD ATI and the built-in GPUs such as
the Intel GPU and AMD fusion supported?  If so, are they already
supported in the trunk, or only specific branch?

Finally, when will support of Knights Corner (knc) be added to the
trunk and/or one of the branches?

Thanks!

Mark


On Tue, Dec 16, 2014 at 9:22 PM, Tobias Burnus
<tobias.burnus@physik.fu-berlin.de> wrote:
> Mark Farnell wrote:
>> Has OpenACC 2.0 support been merged into the trunk yet?  If not, then
>> is it contained in gomp-4_0-branch?
>>
>> If so, what parameters should I pass to ./configure to enable OpenACC
>> 2.0, and relevant backends such as CUDA, MIC and other GPGPU/manycore
>> architecture?
>>
>> Also, I have a feeling that OpenACC 2.0 did NOT make it to gcc 5.0, am
>> I correct?  If I am correct, then will it be included in gcc 5.1?  If
>> I am wrong and it is already included into gcc 5.0, then I would
>> really really like to use it.
>>
>> In the latter case, will I be able to write OpenACC 2.0 / OpenMP 4.0
>> code that runs on my nvidia GPU and/or Intel Xeon Phi?
>
> Let's start from the end: OpenMP 4 support for Intel's Xeon Phi is in the
> trunk and - in principle - working. The only problem is that only
> Knights Landing (knl) is supported and not the old Knights Corner (knc);
> given that Knights Landing is not yet available, you currently can only use
> it with a simulator.
>
> Regarding the question how to build GCC with accelerator support, see
> https://gcc.gnu.org/wiki/Offloading - That page applies both to OpenACC
> and OpenMP and to KNL and Nvidia's PTX. However, it is currently still a bit
> KNL centric.
>
> Regarding OpenACC: The support has not yet been merged, however, I think the
> goal is still to get it included in GCC 5. The first bits - like PTX support -
> have already been merged. I think the gomp-4_0-branch provides all what's
> needed and it has been recently updated to match the trunk (last Sunday).
> For building the branch and using OpenACC+PTX, again start with
> https://gcc.gnu.org/wiki/Offloading
>
> Tobias,
> who has yet to try offloading himself