-unsigned PostDominatorTree::DFSPass(BasicBlock *V, unsigned N) {
- std::vector<BasicBlock *> workStack;
- SmallPtrSet<BasicBlock *, 32> Visited;
- workStack.push_back(V);
-
- do {
- BasicBlock *currentBB = workStack.back();
- InfoRec &CurVInfo = Info[currentBB];
-
- // Visit each block only once.
- if (Visited.insert(currentBB)) {
- CurVInfo.Semi = ++N;
- CurVInfo.Label = currentBB;
-
- Vertex.push_back(currentBB); // Vertex[n] = current;
- // Info[currentBB].Ancestor = 0;
- // Ancestor[n] = 0
- // Child[currentBB] = 0;
- CurVInfo.Size = 1; // Size[currentBB] = 1
- }
-
- // Visit children
- bool visitChild = false;
- for (pred_iterator PI = pred_begin(currentBB), PE = pred_end(currentBB);
- PI != PE && !visitChild; ++PI) {
- InfoRec &SuccVInfo = Info[*PI];
- if (SuccVInfo.Semi == 0) {
- SuccVInfo.Parent = currentBB;
- if (!Visited.count(*PI)) {
- workStack.push_back(*PI);
- visitChild = true;
- }
- }
- }
-
- // If all children are visited or if this block has no child then pop this
- // block out of workStack.
- if (!visitChild)
- workStack.pop_back();
-
- } while (!workStack.empty());
-
- return N;
-}
-