[llvm] [RISCV][TTI] Add shuffle costing for masked slide lowering (PR #128537)

[Craig Topper via llvm-commits]

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@@ -413,6 +413,36 @@ bool llvm::getShuffleDemandedElts(int SrcWidth, ArrayRef<int> Mask,
   return true;
 }
 
+bool llvm::isMaskedSlidePair(ArrayRef<int> Mask, int NumElts,
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topperc wrote:

Why did this need to move up to VectorUtils? Couldn't it stay in the RISCV backend?

https://github.com/llvm/llvm-project/pull/128537