[llvm] [SLP] NFC. Replace MainOp and AltOp in TreeEntry with InstructionsState. (PR #122443)

[Alexey Bataev via llvm-commits]

================
@@ -2414,15 +2414,16 @@ class BoUpSLP {
     }
 
     /// Go through the instructions in VL and append their operands.
-    void appendOperandsOfVL(ArrayRef<Value *> VL, Instruction *VL0) {
+    void appendOperandsOfVL(ArrayRef<Value *> VL, const InstructionsState &S) {
       assert(!VL.empty() && "Bad VL");
       assert((empty() || VL.size() == getNumLanes()) &&
              "Expected same number of lanes");
       // IntrinsicInst::isCommutative returns true if swapping the first "two"
       // arguments to the intrinsic produces the same result.
       constexpr unsigned IntrinsicNumOperands = 2;
-      unsigned NumOperands = VL0->getNumOperands();
-      ArgSize = isa<IntrinsicInst>(VL0) ? IntrinsicNumOperands : NumOperands;
+      unsigned NumOperands = S.getMainOp()->getNumOperands();
----------------
alexey-bataev wrote:

```suggestion
      Instruction *VL0 = S.getMainOp();
      unsigned NumOperands = VL0->getNumOperands();
```
to prevent multiple references

https://github.com/llvm/llvm-project/pull/122443