[llvm] [VPlan] Handle live-in extend operands in partial reduction ::computeCost (PR #163175)

[Florian Hahn via llvm-commits]

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@@ -330,6 +330,8 @@ VPPartialReductionRecipe::computeCost(ElementCount VF,
   auto HandleWiden = [&](VPWidenRecipe *Widen) {
     if (match(Widen, m_Sub(m_ZeroInt(), m_VPValue(Op)))) {
       Widen = dyn_cast<VPWidenRecipe>(Op->getDefiningRecipe());
+      if (!Widen)
+        return;
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fhahn wrote:

Currently it must always be a live-in I think. I added an assert for now, thanks

https://github.com/llvm/llvm-project/pull/163175