[llvm] [SLP]Fix graph traversal in getSpillCost (PR #124984)

[Alexey Bataev via llvm-commits]

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@@ -12255,17 +12257,18 @@ InstructionCost BoUpSLP::getSpillCost() const {
     }
 
     if (NumCalls) {
-      SmallVector<Type *, 4> V;
-      for (auto *II : LiveValues) {
-        auto *ScalarTy = II->getType();
-        if (auto *VectorTy = dyn_cast<FixedVectorType>(ScalarTy))
-          ScalarTy = VectorTy->getElementType();
-        V.push_back(getWidenedType(ScalarTy, BundleWidth));
+      SmallVector<Type *, 4> EntriesTypes;
+      for (const TreeEntry *TE : LiveEntries) {
+        auto *ScalarTy = TE->getMainOp()->getType();
+        auto It = MinBWs.find(TE);
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alexey-bataev wrote:

It was a bug, we need estimate whole vector here. For revec, if the ScalarTy is 4x and there are 2 elements, it estimates the spill cost for vector 2x, but instead it should estimate for vector 8x.

https://github.com/llvm/llvm-project/pull/124984