[llvm-branch-commits] [llvm][IR] Extend BranchWeightMetadata to track provenance of weights (PR #86609)

[Matthias Braun via llvm-branch-commits]

================
@@ -1210,12 +1210,22 @@ Instruction *Instruction::cloneImpl() const {
 
 void Instruction::swapProfMetadata() {
   MDNode *ProfileData = getBranchWeightMDNode(*this);
-  if (!ProfileData || ProfileData->getNumOperands() != 3)
+  if (!isBranchWeightMD(ProfileData))
     return;
 
-  // The first operand is the name. Fetch them backwards and build a new one.
-  Metadata *Ops[] = {ProfileData->getOperand(0), ProfileData->getOperand(2),
-                     ProfileData->getOperand(1)};
+  SmallVector<Metadata *, 4> Ops;
+  unsigned int FirstIdx = getBranchWeightOffset(ProfileData);
----------------
MatzeB wrote:

Not a strong opinion, but I think most people just write `unsigned` in LLVM codebase...
```suggestion
  unsigned FirstIdx = getBranchWeightOffset(ProfileData);
```

https://github.com/llvm/llvm-project/pull/86609