[llvm] [VPlan] Add VPValue for VF, use it for VPWidenIntOrFpInductionRecipe. (PR #95305)

[via llvm-commits]

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@@ -8189,10 +8189,12 @@ createWidenInductionRecipes(PHINode *Phi, Instruction *PhiOrTrunc,
   VPValue *Step =
       vputils::getOrCreateVPValueForSCEVExpr(Plan, IndDesc.getStep(), SE);
   if (auto *TruncI = dyn_cast<TruncInst>(PhiOrTrunc)) {
-    return new VPWidenIntOrFpInductionRecipe(Phi, Start, Step, IndDesc, TruncI);
+    return new VPWidenIntOrFpInductionRecipe(Phi, Start, Step, Plan.getVF(),
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ayalz wrote:

VPWidenIntOrFpInductionRecipe could retrieve VF by looking up Plan.getVF() on demand rather than recording it as on operand, but the latter helps in checking if VF has users, i.e., if any VPWidenIntOrFpInductionRecipe exists?

Surely VF is needed to vectorize any loop, including ones free of VPWidenIntOrFpInductionRecipes. Does it need to be cached somehow, to prevent regeneration?

https://github.com/llvm/llvm-project/pull/95305