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

[Graham Hunter via llvm-dev]

Hi,

> From what Graham said, and from his current work, I guess the "new"
> (not public) consensus seems to be to go with intrinsics first, then
> move to native support, which is a valid path.

There wasn't a consensus, just a proposal for a different option to
present to the community for feedback and discussion to get things
moving (whether for the full scalable IR proposal, the opaque types one,
or something in between). Sorry if I didn't make that clear enough.

Arm felt it was worth investing some time in investigating an alternative
if there was the possibility of progressing upstreaming, then presenting
the findings for discussion.

> If the public agreement becomes that this is the path we want to take,
> then that specific patch-set is dead, because even if we do native, it
> will be a different set.
> 
> If the end result is that we'll stop at intrinsics (I really hope
> not), the patch-set is also dead.
> 
> However, if people want to continue pushing for native support now,
> the patch-set is not dead. But then we need to re-do the meeting that
> happened in the US dev meeting with everyone in it, which won't
> happen.

While there was a roundtable at the devmeeting last year, there weren't
that many people in attendance to talk purely about SVE or scalable
types -- most of the discussion revolved around predication support,
from what I remember.

The main feedback I had which led to changes in the RFC were in side chats
when people had a few minutes of spare time (since they had other sessions
to attend which clashed with the roundtable slots).

-Graham