[llvm] [VPlan] Introduce VPlanConstantFolder (PR #125365)

[Florian Hahn via llvm-commits]

================
@@ -937,10 +938,84 @@ static void recursivelyDeleteDeadRecipes(VPValue *V) {
   }
 }
 
+class VPConstantFolder {
+  TargetFolder Folder;
+  VPTypeAnalysis TypeInfo;
+
+public:
+  VPConstantFolder(const DataLayout &DL, const VPTypeAnalysis &TypeInfo)
+      : Folder(DL), TypeInfo(TypeInfo) {}
+
+  Value *tryToConstantFold(VPRecipeBase &R, unsigned Opcode,
+                           ArrayRef<VPValue *> Operands) {
+    SmallVector<Value *, 4> Ops;
+    for (VPValue *Op : Operands) {
+      if (!Op->isLiveIn() || !Op->getLiveInIRValue())
+        return nullptr;
+      Ops.emplace_back(Op->getLiveInIRValue());
----------------
fhahn wrote:

```suggestion
      Ops.push_back(Op->getLiveInIRValue());
```

as we are just adding pointers?

https://github.com/llvm/llvm-project/pull/125365