[llvm] [VectorCombine] Fix invalid shuffle cost argument of foldShuffleOfSelects (PR #130281)

[Simon Pilgrim via llvm-commits]

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@@ -2051,24 +2050,26 @@ bool VectorCombine::foldShuffleOfSelects(Instruction &I) {
        (SI0FOp->getFastMathFlags() != SI1FOp->getFastMathFlags())))
     return false;
 
+  auto *SrcVecTy = dyn_cast<FixedVectorType>(T1->getType());
+  auto *DstVecTy = dyn_cast<FixedVectorType>(I.getType());
   auto SK = TargetTransformInfo::SK_PermuteTwoSrc;
   auto SelOp = Instruction::Select;
   InstructionCost OldCost = TTI.getCmpSelInstrCost(
-      SelOp, T1->getType(), C1VecTy, CmpInst::BAD_ICMP_PREDICATE, CostKind);
-  OldCost += TTI.getCmpSelInstrCost(SelOp, T2->getType(), C2VecTy,
+      SelOp, DstVecTy, C1VecTy, CmpInst::BAD_ICMP_PREDICATE, CostKind);
+  OldCost += TTI.getCmpSelInstrCost(SelOp, DstVecTy, C2VecTy,
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RKSimon wrote:

DstVecTy in this case is the result of the shuffle, SrcVecTy is the result of the select

https://github.com/llvm/llvm-project/pull/130281