[PATCH] D76992: [VPlan] Add & use VPValue operands for VPWidenRecipe (NFC).

[Ayal Zaks via Phabricator via llvm-commits]

Ayal added a comment.

In D76992#1952322 <https://reviews.llvm.org/D76992#1952322>, @fhahn wrote:

> In D76992#1951192 <https://reviews.llvm.org/D76992#1951192>, @Ayal wrote:
>
> > Thanks for following-up quickly. The part that extends VPWidenRecipe to have a User for holding its VPValue operands looks ok, but could the patch make sure that these operands are indeed used correctly by ILV::widenInstruction(), instead of moving the latter over to its execute()? The former may involve refactoring the case that deals with Calls, to record cost-based UseVectorInstrinsic/NeedToScalarize decisions when constructing the VPlan/recipe rather than during codegen; to record InvariantCond of Selects instead of accessing getSCEV(I.getOperand(0)) during codegen, possibly cleaning up to generate ScalarCond OR Cond but not both. In any case, accesses to I’s operands should all change to access User's operands instead, possibly with their underlying ingredient if needed.
>
>
> The main reason for moving it into the recipe is so we can use getUnderlyingValue when lowering calls. A cleaner solution to deal with call would be to move them to their own recipe/instruction and record the required info as suggested. Is that along the line you suggest? I.e. something like the following: Move calls to their own recipe (NFC) and then move VPWidenRecipe and VPCallRecipe to VPUser in parallel?
>
> Without changes to the call handling, I am not sure how we would be able to use the existing logic (unless we expose getUnderlyingValue to ILV.


Yes, let's go for this cleaner solution. The first phase of VPlan integration using recipes is focused on refactoring ILV logic so that decisions are made and recorded in VPlan rather than during codegen. The latter, taken care of by recipe::execute(), should be as straightforward as possible.


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