[llvm] [SLP][REVEC] Make ShuffleCostEstimator and ShuffleInstructionBuilder support vector instructions. (PR #99499)

[Han-Kuan Chen via llvm-commits]

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@@ -9172,12 +9172,30 @@ class BoUpSLP::ShuffleCostEstimator : public BaseShuffleAnalysis {
         }
         Vals.push_back(Constant::getNullValue(V->getType()));
       }
+      if (auto *VecTy = dyn_cast<FixedVectorType>(Vals.front()->getType())) {
+        // When REVEC is enabled, we need to expand vector types into scalar
+        // types.
+        unsigned VecTyNumElements = VecTy->getNumElements();
+        SmallVector<Constant *> NewVals;
+        NewVals.reserve(VL.size() * VecTyNumElements);
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HanKuanChen wrote:

1. It should be VF because `for (Value *V : VL.take_front(VF))`
2. I use nullptr here.

https://github.com/llvm/llvm-project/pull/99499