[llvm-dev] [RFC] Polly Status and Integration

Renato Golin via llvm-dev
Fri, 20 Oct 2017 20:50:24 -0000

On 17 October 2017 at 00:51, Saito, Hideki <hideki.saito at intel.com>
wrote:
> Renato, I kicked off this secondary discussion, borrowing the opportunity
from Michael's RFC,
> but to the point of reviewing https://reviews.llvm.org/D38676, I'd like
the review to proceed
> separately from this bigger (and most likely longer) discussion. We
intentionally made the interfaces
> similar such that whatever the outcome of this discussion would be, the
changes we have to make later,
> if any, is small and mechanical. We just need to agree that
>         VPValue/VPUser/VPInstruction
> is not a precedence, i.e., still subject to ongoing discussion and is
expected to abide by the eventual
> outcome of this discussion.

Agreed.


> To the best of my understanding, if we do not want to modify the IR (i.e.,
CFG, Instructions, and Uses/Defs hooked up
> in the Function) before we decide to let vectorizer transform (i.e., cost
modeling phase of LV), we really don't have anything
> that we can use today in the LLVM infrastructure. If the collective wisdom
concludes investment into that, we are more than
> happy to contribute our share of effort, but that longer term work (one
year is probably too optimistic) should not block shorter
> term development of vectorizer.

We don't want to change the IR, no.

My point was to take whatever already exists from Value and do the
rest in VPValue (same for Inst), but I don't know if that's desirable,
I was just raising the issue.

cheers,
--renato