[llvm-dev] Scalable Vector Types in IR - Next Steps?

[David Greene via llvm-dev]

Francesco Petrogalli via llvm-dev <llvm-dev at lists.llvm.org> writes:

>> On Mar 14, 2019, at 5:45 AM, Graham Hunter via llvm-dev <llvm-dev at lists.llvm.org> wrote:
>> 
>> We would like to be able to reach consensus on an approach around the end
>> of EuroLLVM this year so that we can begin a full implementation.
>
> EuroLLVM will be a very good occasion to hear all the opinions and reach consensus on the approach.
>
> @Graham, maybe you should set up a round table open to anyone, and
> make sure that key people (third parties asking for a different
> approach, people involved in this discussion) will receive the invite?

We tried two round tables at the Nov. LLVMDev and no serious objections
were raised, but we knew we didn't have all the right people there.  I
am somewhat skeptical another roundtable without commitment to attend
from all able parties ahead of time will accomplish much.

Speaking for myself (and not Cray), it is frustrating to have had a
bunch of discussion on the mailing list and in reviews where concerns
were raised and to see a lot of radio silence to responses to those
concerns, only to see a message about a potential change in direction
driven by off-list discussions where concerns and responses to concerns
are unknown and therefore not addressable.

I completely understand that ARM needs to make progress and I very much
want to see that progress.  I just don't want to see a Plan B leading to
a situation where VLA support doesn't ever make it into LLVM.  It is
somewhat embarrassing that gcc already has a release with VLA support
for SVE and LLVM is stuck in the starting blocks.

                            -David