[llvm] [SLP][NFC] Extract VectorizableTree into own ForestTree class (PR #222805)

[Alexey Bataev via llvm-commits]

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@@ -21245,6 +21767,7 @@ class BoUpSLP::ShuffleInstructionBuilder final : public BaseShuffleAnalysis {
   SmallVector<Value *, 2> InVectors;
   IRBuilderBase &Builder;
   BoUpSLP &R;
+  ForestTree &FT;
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alexey-bataev wrote:

Unused, you're passing it as a param to the member functions

https://github.com/llvm/llvm-project/pull/222805