[llvm] [SLP] SLP's copyable elements based upon Main/Alt operations. (PR #124242)

[Alexey Bataev via llvm-commits]

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@@ -1473,6 +1611,7 @@ class BoUpSLP {
     ScalarToTreeEntries.clear();
     MustGather.clear();
     NonScheduledFirst.clear();
+    CopyableAltOp.clear();
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alexey-bataev wrote:

Why do you need this storage? As I mentioned before, we should encode InstructionsState and build correct set of operands, this should be enough

https://github.com/llvm/llvm-project/pull/124242