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

[Alexey Bataev via llvm-commits]

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@@ -3416,7 +3566,7 @@ class BoUpSLP {
     }
 
     /// Some of the instructions in the list have alternate opcodes.
-    bool isAltShuffle() const { return S.isAltShuffle(); }
+    bool isAltShuffle() const { return S.isAltShuffle() && !IsAltOpCopy; }
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alexey-bataev wrote:

I don't think it should be here, S should explicitly state, that it does not represent alternate op

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