[llvm] [VPlan] Generalize usesScalars using WideInfo (NFCI) (PR #208910)

[Florian Hahn via llvm-commits]

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@@ -56,6 +56,12 @@ static cl::opt<bool> VPlanPrintMetadata(
     cl::desc("Controls the printing of recipe metadata when debugging."));
 #endif
 
+bool VPUser::usesScalars(const VPValue *Op) const {
+  assert(is_contained(operands(), Op) && "Op must be an operand of the recipe");
+  VPWideningInfo WideInfo = vputils::getWideningInfo(*cast<VPRecipeBase>(this));
+  return WideInfo.hasSingleScalarOperands() || usesFirstLaneOnly(Op);
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fhahn wrote:

This reads a bit confusing and does not seem NFC, even if operands are not single scalar, he recipe can still use scalars (e.g. replicating VPReplicateRecipe)?

https://github.com/llvm/llvm-project/pull/208910