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

[Alexey Bataev via llvm-commits]

================
@@ -1125,6 +1244,24 @@ static bool doesInTreeUserNeedToExtract(Value *Scalar, Instruction *UserInst,
   }
 }
 
+// Determine that the vector could be vectorized with copyable elements.
+static bool isCopyableOp(ArrayRef<Value *> VL, Value *Main, Value *Alt) {
+  if (Main == Alt || !isa<BinaryOperator>(Main) || !isa<Instruction>(Alt) ||
+      any_of(VL, IsaPred<PoisonValue, PHINode>))
+    return false;
+
+  Instruction *MainOp = cast<Instruction>(Main);
+  Instruction *AltOp = cast<Instruction>(Alt);
----------------
alexey-bataev wrote:

```suggestion
  auto *MainOp = cast<Instruction>(Main);
  auto *AltOp = cast<Instruction>(Alt);
```

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