diff options
| -rw-r--r-- | llvm/include/llvm/Analysis/Dominators.h | 52 |
1 files changed, 29 insertions, 23 deletions
diff --git a/llvm/include/llvm/Analysis/Dominators.h b/llvm/include/llvm/Analysis/Dominators.h index 2e149d59e98..7ac474aff34 100644 --- a/llvm/include/llvm/Analysis/Dominators.h +++ b/llvm/include/llvm/Analysis/Dominators.h @@ -585,29 +585,35 @@ protected: SmallVector<std::pair<DomTreeNodeBase<NodeT>*, typename DomTreeNodeBase<NodeT>::iterator>, 32> WorkStack; - for (unsigned i = 0, e = (unsigned)this->Roots.size(); i != e; ++i) { - DomTreeNodeBase<NodeT> *ThisRoot = getNode(this->Roots[i]); - WorkStack.push_back(std::make_pair(ThisRoot, ThisRoot->begin())); - ThisRoot->DFSNumIn = DFSNum++; - - while (!WorkStack.empty()) { - DomTreeNodeBase<NodeT> *Node = WorkStack.back().first; - typename DomTreeNodeBase<NodeT>::iterator ChildIt = - WorkStack.back().second; - - // If we visited all of the children of this node, "recurse" back up the - // stack setting the DFOutNum. - if (ChildIt == Node->end()) { - Node->DFSNumOut = DFSNum++; - WorkStack.pop_back(); - } else { - // Otherwise, recursively visit this child. - DomTreeNodeBase<NodeT> *Child = *ChildIt; - ++WorkStack.back().second; - - WorkStack.push_back(std::make_pair(Child, Child->begin())); - Child->DFSNumIn = DFSNum++; - } + DomTreeNodeBase<NodeT> *ThisRoot = getRootNode(); + + if (!ThisRoot) + return; + + // Even in the case of multiple exits that form the post dominator root + // nodes, do not iterate over all exits, but start from the virtual root + // node. Otherwise bbs, that are not post dominated by any exit but by the + // virtual root node, will never be assigned a DFS number. + WorkStack.push_back(std::make_pair(ThisRoot, ThisRoot->begin())); + ThisRoot->DFSNumIn = DFSNum++; + + while (!WorkStack.empty()) { + DomTreeNodeBase<NodeT> *Node = WorkStack.back().first; + typename DomTreeNodeBase<NodeT>::iterator ChildIt = + WorkStack.back().second; + + // If we visited all of the children of this node, "recurse" back up the + // stack setting the DFOutNum. + if (ChildIt == Node->end()) { + Node->DFSNumOut = DFSNum++; + WorkStack.pop_back(); + } else { + // Otherwise, recursively visit this child. + DomTreeNodeBase<NodeT> *Child = *ChildIt; + ++WorkStack.back().second; + + WorkStack.push_back(std::make_pair(Child, Child->begin())); + Child->DFSNumIn = DFSNum++; } } |
