[llvm] [LV] Avoid querying the cost of invalid operations (PR #89161)

[Shih-Po Hung via llvm-commits]

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@@ -7067,6 +7067,10 @@ LoopVectorizationCostModel::getInstructionCost(Instruction *I, ElementCount VF,
         SrcVecTy = smallestIntegerVectorType(SrcVecTy, MinVecTy);
         VectorTy =
             largestIntegerVectorType(ToVectorTy(I->getType(), VF), MinVecTy);
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arcbbb wrote:

Looks like it is intended in the original patch 55d633bd60235.
Think about this for a while but I haven't fully grasped the author's intentions yet.

https://github.com/llvm/llvm-project/pull/89161