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

[Renato Golin via llvm-dev]

On Wed, 13 Mar 2019 at 13:57, Graham Hunter <Graham.Hunter at arm.com> wrote:
> I did ask them to post their arguments on the list, but I guess they've been busy for the last month (or forgot about it).

Who is "them" and who will write up a proposal / RFC on the use of
intrinsics for both lowering and vectorisation?

It goes without saying that those discussions should have been had in
the mailing list, not behind closed doors. Agreeing to implementations
in private is asking to get bad reviews in public, as the SVE process
has shown *over and over again*.

I don't understand why, after so many problems for so many years, this
is still the modus operandi...

> The basic argument was that they didn't believe the value gained from enabling VLA autovectorization was worth the added complexity in maintaining the codebase. They were open to changing their minds if we could demonstrate sufficient demand for the feature.

In that case, the current patches to change the IR should be
abandoned, as well as reverting the previous change to the types, so
that we don't carry any unnecessary code forward.

The review you sent seems to be a mechanical change to include the
intrinsics, but the target lowering change seems to be too small to
actually be able to lower anything.

Without context, it's hard to know what's going on.

cheers,
--renato