[PATCH] D68577: [LV] Apply sink-after & interleave-groups as VPlan transformations (NFC)

[Gil Rapaport via Phabricator via llvm-commits]

gilr added a comment.

In D68577#1701381 <https://reviews.llvm.org/D68577#1701381>, @rengolin wrote:

> So, IIUC, this is changing tryCreateRecipe to move the interleave recipe creation to the caller, buildVPlanWithVPRecipes. The dependencies with the sink values is recorded initially, then the plans are created, then the sinks are applied and, if any, the interleave groups.


Correct. Motivation is to express these dependecies as VPlan transformation phase ordering. Ayal discussed this is more details in his 2017 VPlan talk <https://www.youtube.com/watch?v=BjBSJFzYDVk&t=25m58s>.

> ... but this doesn't look like an NFC change. Not that this is a bad thing, but I can't quite reach the conclusion that all the loops that would have been interleaved will continue to do so, because the order of the plans may change (for better or worse) the conditions in which the plan starts with.
>  Regardless, I think this is a positive change and goes in the direction we want the VPlan infrastructure to be. It also looks semantically equivalent (with the caveat above), so the change looks good to me.
>  It would be good to wait for further reviews on the next few days, just in case I missed something.

Excellent. The intention is indeed to only change the way Planner executes these already-taken decisions (SA by Legal, IG by CostModel).
Thanks!


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  https://reviews.llvm.org/D68577/new/

https://reviews.llvm.org/D68577