[llvm] [SLP] NFC. Use InstructionsState::valid if users just want to know whether VL has same opcode. (PR #120217)

[Han-Kuan Chen via llvm-commits]

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@@ -8144,9 +8147,8 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
   }
 
   // Don't handle scalable vectors
-  if (S.getOpcode() == Instruction::ExtractElement &&
-      isa<ScalableVectorType>(
-          cast<ExtractElementInst>(S.getMainOp())->getVectorOperandType())) {
+  if (auto *EE = dyn_cast_if_present<ExtractElementInst>(S.getMainOp());
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HanKuanChen wrote:

It can work. See https://github.com/llvm/llvm-project/pull/120210/commits/c9ccb5577ac8c9994199bd761231ab1b1fd41321.
`isa_and_present<>` = `S.valid() && isa<>`

https://github.com/llvm/llvm-project/pull/120217