[llvm] [SLP][REVEC] Use VL.front()->getType() as ScalarTy. (PR #102437)

[Han-Kuan Chen via llvm-commits]

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@@ -12391,8 +12391,8 @@ Value *BoUpSLP::vectorizeOperand(TreeEntry *E, unsigned NodeIdx,
     }
     if (IsSameVE) {
       auto FinalShuffle = [&](Value *V, ArrayRef<int> Mask) {
-        ShuffleInstructionBuilder ShuffleBuilder(
-            cast<VectorType>(V->getType())->getElementType(), Builder, *this);
+        ShuffleInstructionBuilder ShuffleBuilder(VL.front()->getType(), Builder,
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HanKuanChen wrote:

`ShuffleInstructionBuilder::add` will call `castToScalarTyElem`.
If `V` is affected by `MinBWs`, then `castToScalarTyElem` will use `CreateIntCast` and make `V` have a same type as `VL.front()->getType()`.

https://github.com/llvm/llvm-project/pull/102437