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

[Alexey Bataev via llvm-commits]

================
@@ -1125,6 +1244,25 @@ 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 (any_of(VL, IsaPred<PoisonValue>) || Main == Alt ||
+      !isa<BinaryOperator>(Main) || !isa<Instruction>(Alt) ||
----------------
alexey-bataev wrote:

Also, why `Alt` should be an instruction? I thought we should support non-instructions here too.

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