[llvm] [RISCV][TTI] Adjust VLS shuffle costing to account for sub-mask reuse (PR #129793)

[Alexey Bataev via llvm-commits]

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@@ -430,11 +430,14 @@ costShuffleViaVRegSplitting(RISCVTTIImpl &TTI, MVT LegalVT,
   copy(Mask, NormalizedMask.begin());
   InstructionCost Cost = 0;
   int NumShuffles = 0;
+  DenseSet<std::pair<ArrayRef<int>, unsigned>> ReusedSingleSrcShuffles;
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alexey-bataev wrote:

SmallDenseSet

https://github.com/llvm/llvm-project/pull/129793