[llvm-dev] [cfe-dev] [Openmp-dev] RFC: Proposing an LLVM subproject for parallelism runtime and support libraries

Fri Apr 22 22:20:58 PDT 2016

Please ensure that you have more than just Carlo's feedback from the OMP
side on this. If Intel isn't in agreement then you're leaving out the most
important stakeholder. (I'd also ask that Hal weigh in since he has quite a
bit of insight into the politics for this)

Pushing forward quickly (steamroller) with something just because the
thread "stalled" doesn't make any sense. Please work with those who have
experience and expertise.

I'll leave technical feedback for later after rereading the meat of
proposal.

On Sat, Apr 23, 2016 at 9:50 AM, Carlo Bertolli via cfe-dev <
cfe-dev at lists.llvm.org> wrote:

> Hi Chandler
>
> About your points:
>
> > 3) Initially, leave the OpenMP offloading stuff targeted at OpenMP.
> Then, as it evolves, consider moving it to be another runtime in the broad
> project if and when it makes sense.
> > 4) As both OpenMP and SE evolve and are used some in the project,
> evaluate whether there is a common core that makes sense to extract. If so,
> do it and rebase them appropriately.
>
> I agree with you.
>
> I had some discussion within my group and there seems to be some agreement
> that OpenMP offloading, if properly extended, could be used as a plugin for
> SE. As time progresses and we learn more about SE we will be able to
> re-evaluate this.
>
> Thanks
>
> -- Carlo
>
> [image: Inactive hide details for Chandler Carruth via cfe-dev
> ---04/22/2016 06:02:24 PM---I feel like this thread got a bit stalled. I]Chandler
> Carruth via cfe-dev ---04/22/2016 06:02:24 PM---I feel like this thread got
> a bit stalled. I'd like to pick it up and try to suggest a path forward.
>
> From: Chandler Carruth via cfe-dev <cfe-dev at lists.llvm.org>
> To: Mehdi Amini <mehdi.amini at apple.com>, Jason Henline <jhen at google.com>,
> Hal Finkel <hfinkel at anl.gov>
> Cc: llvm-dev <llvm-dev at lists.llvm.org>, cfe-dev <cfe-dev at lists.llvm.org>,
> "openmp-dev at lists.llvm.org" <openmp-dev at lists.llvm.org>
> Date: 04/22/2016 06:02 PM
> Subject: Re: [cfe-dev] [Openmp-dev] [llvm-dev] RFC: Proposing an LLVM
> subproject for parallelism runtime and support libraries
> Sent by: "cfe-dev" <cfe-dev-bounces at lists.llvm.org>
> ------------------------------
>
>
>
> I feel like this thread got a bit stalled. I'd like to pick it up and try
> to suggest a path forward.
>
> I don't hear any real objections to the overall idea of having an LLVM
> subproject for parallelism runtimes and support libraries. I think we
> should get that created.
>
> I don't actually see any real objections to StreamExecutor being one of
> the runtimes. There are some interesting questions however:
> - Is there common code in the OpenMP runtime that could be unified with
> this?
> - Could OpenMP end up using SE or some common shared library between them
> as a basis for offloading?
> - Would instead it make more sense to have the OpenMP offload library be a
> plugin for StreamExecutor?
>
> I don't know the answer to any of these really, but I also don't think
> that they should prevent us from making progress here. And I think if
> anything, they'll become easier to answer if we do.
>
> So my suggestion would be:
> 1) Create the broader scoped LLVM subproject, including writing up its
> charter, scope, plans, etc.
>
> 2) Add stream executor to it
>
> 3) Initially, leave the OpenMP offloading stuff targeted at OpenMP. Then,
> as it evolves, consider moving it to be another runtime in the broad
> project if and when it makes sense.
>
> 4) As both OpenMP and SE evolve and are used some in the project, evaluate
> whether there is a common core that makes sense to extract. If so, do it
> and rebase them appropriately.
>
>
> Does this make sense? Are there objections to moving forward here?
> _______________________________________________
> cfe-dev mailing list
> cfe-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev
>
>
>
>
> _______________________________________________
> cfe-dev mailing list
> cfe-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20160423/66c1514f/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: graycol.gif
Type: image/gif
Size: 105 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20160423/66c1514f/attachment.gif>