forked from OSchip/llvm-project
[Dominators] Move helper functions into SemiNCAInfo
Summary: Helper functions (DFSPass, ReverseDFSPass, Eval) need SemiNCAInfo anyway, so it's simpler to have them there as member functions. This also makes them simpler by removing template boilerplate. Reviewers: dberlin, sanjoy, chandlerc Reviewed By: dberlin Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D34427 llvm-svn: 306579
This commit is contained in:
Jakub Kuderski
parent
64d182d36f
commit
f01cd723a8
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@ -76,47 +76,42 @@ struct SemiNCAInfo {
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llvm::make_unique<DomTreeNodeBase<NodeT>>(BB, IDomNode)))
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.get();
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}
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};
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} // namespace DomTreeBuilder
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// External storage for depth first iterator that reuses the info lookup map
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// domtree already has. We don't have a set, but a map instead, so we are
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// SemiNCAInfo already has. We don't have a set, but a map instead, so we are
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// converting the one argument insert calls.
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template <class NodeRef, class InfoType> struct df_iterator_dom_storage {
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struct df_iterator_dom_storage {
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public:
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using BaseSet = DenseMap<NodeRef, InfoType>;
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using BaseSet = decltype(NodeToInfo);
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df_iterator_dom_storage(BaseSet &Storage) : Storage(Storage) {}
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using iterator = typename BaseSet::iterator;
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std::pair<iterator, bool> insert(NodeRef N) {
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return Storage.insert({N, InfoType()});
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std::pair<iterator, bool> insert(NodePtr N) {
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return Storage.insert({N, InfoRec()});
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}
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void completed(NodeRef) {}
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void completed(NodePtr) {}
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private:
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BaseSet &Storage;
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};
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template <class NodePtr,
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class NodeT = typename std::remove_pointer<NodePtr>::type>
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unsigned ReverseDFSPass(NodePtr V, DomTreeBuilder::SemiNCAInfo<NodeT> &SNCA,
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unsigned N) {
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using SNCAInfoTy = DomTreeBuilder::SemiNCAInfo<NodeT>;
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df_iterator_dom_storage<NodePtr, typename SNCAInfoTy::InfoRec> DFStorage(
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SNCA.NodeToInfo);
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df_iterator_dom_storage getStorage() { return {NodeToInfo}; }
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unsigned runReverseDFS(NodePtr V, unsigned N) {
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auto DFStorage = getStorage();
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bool IsChildOfArtificialExit = (N != 0);
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for (auto I = idf_ext_begin(V, DFStorage), E = idf_ext_end(V, DFStorage);
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I != E; ++I) {
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NodePtr BB = *I;
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auto &BBInfo = SNCA.NodeToInfo[BB];
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auto &BBInfo = NodeToInfo[BB];
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BBInfo.DFSNum = BBInfo.Semi = ++N;
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BBInfo.Label = BB;
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// Set the parent to the top of the visited stack. The stack includes us,
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// and is 1 based, so we subtract to account for both of these.
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if (I.getPathLength() > 1)
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BBInfo.Parent = SNCA.NodeToInfo[I.getPath(I.getPathLength() - 2)].DFSNum;
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SNCA.NumToNode.push_back(BB); // NumToNode[n] = V;
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BBInfo.Parent = NodeToInfo[I.getPath(I.getPathLength() - 2)].DFSNum;
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NumToNode.push_back(BB); // NumToNode[n] = V;
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if (IsChildOfArtificialExit)
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BBInfo.Parent = 1;
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@ -126,33 +121,26 @@ unsigned ReverseDFSPass(NodePtr V, DomTreeBuilder::SemiNCAInfo<NodeT> &SNCA,
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return N;
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}
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template <class NodePtr,
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class NodeT = typename std::remove_pointer<NodePtr>::type>
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unsigned DFSPass(NodePtr V, DomTreeBuilder::SemiNCAInfo<NodeT> &SNCA, unsigned N) {
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using SNCAInfoTy = DomTreeBuilder::SemiNCAInfo<NodeT>;
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df_iterator_dom_storage<NodePtr, typename SNCAInfoTy::InfoRec> DFStorage(
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SNCA.NodeToInfo);
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unsigned runDFS(NodePtr V, unsigned N) {
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auto DFStorage = getStorage();
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for (auto I = df_ext_begin(V, DFStorage), E = df_ext_end(V, DFStorage);
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I != E; ++I) {
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NodePtr BB = *I;
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auto &BBInfo = SNCA.NodeToInfo[BB];
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auto &BBInfo = NodeToInfo[BB];
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BBInfo.DFSNum = BBInfo.Semi = ++N;
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BBInfo.Label = BB;
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// Set the parent to the top of the visited stack. The stack includes us,
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// and is 1 based, so we subtract to account for both of these.
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if (I.getPathLength() > 1)
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BBInfo.Parent = SNCA.NodeToInfo[I.getPath(I.getPathLength() - 2)].DFSNum;
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SNCA.NumToNode.push_back(BB); // NumToNode[n] = V;
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BBInfo.Parent = NodeToInfo[I.getPath(I.getPathLength() - 2)].DFSNum;
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NumToNode.push_back(BB); // NumToNode[n] = V;
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}
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return N;
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}
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template <class NodePtr,
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class NodeT = typename std::remove_pointer<NodePtr>::type>
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NodePtr Eval(NodePtr VIn, DomTreeBuilder::SemiNCAInfo<NodeT> &SNCA,
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unsigned LastLinked) {
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auto &VInInfo = SNCA.NodeToInfo[VIn];
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NodePtr eval(NodePtr VIn, unsigned LastLinked) {
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auto &VInInfo = NodeToInfo[VIn];
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if (VInInfo.DFSNum < LastLinked)
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return VIn;
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@ -164,8 +152,8 @@ NodePtr Eval(NodePtr VIn, DomTreeBuilder::SemiNCAInfo<NodeT> &SNCA,
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while (!Work.empty()) {
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NodePtr V = Work.back();
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auto &VInfo = SNCA.NodeToInfo[V];
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NodePtr VAncestor = SNCA.NumToNode[VInfo.Parent];
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auto &VInfo = NodeToInfo[V];
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NodePtr VAncestor = NumToNode[VInfo.Parent];
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// Process Ancestor first
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if (Visited.insert(VAncestor).second && VInfo.Parent >= LastLinked) {
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@ -178,10 +166,10 @@ NodePtr Eval(NodePtr VIn, DomTreeBuilder::SemiNCAInfo<NodeT> &SNCA,
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if (VInfo.Parent < LastLinked)
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continue;
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auto &VAInfo = SNCA.NodeToInfo[VAncestor];
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auto &VAInfo = NodeToInfo[VAncestor];
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NodePtr VAncestorLabel = VAInfo.Label;
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NodePtr VLabel = VInfo.Label;
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if (SNCA.NodeToInfo[VAncestorLabel].Semi < SNCA.NodeToInfo[VLabel].Semi)
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if (NodeToInfo[VAncestorLabel].Semi < NodeToInfo[VLabel].Semi)
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VInfo.Label = VAncestorLabel;
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VInfo.Parent = VAInfo.Parent;
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}
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@ -189,26 +177,18 @@ NodePtr Eval(NodePtr VIn, DomTreeBuilder::SemiNCAInfo<NodeT> &SNCA,
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return VInInfo.Label;
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}
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template <class FuncT, class NodeT>
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void Calculate(DominatorTreeBaseByGraphTraits<GraphTraits<NodeT>> &DT,
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FuncT &F) {
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using GraphT = GraphTraits<NodeT>;
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using NodePtr = typename GraphT::NodeRef;
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static_assert(std::is_pointer<NodePtr>::value,
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"NodePtr should be a pointer type");
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using NodeType = typename std::remove_pointer<NodePtr>::type;
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template <typename NodeType>
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void runSemiNCA(unsigned NumBlocks) {
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unsigned N = 0;
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DomTreeBuilder::SemiNCAInfo<NodeType> SNCA(DT);
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SNCA.NumToNode.push_back(nullptr);
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NumToNode.push_back(nullptr);
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bool MultipleRoots = (DT.Roots.size() > 1);
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if (MultipleRoots) {
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auto &BBInfo = SNCA.NodeToInfo[nullptr];
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auto &BBInfo = NodeToInfo[nullptr];
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BBInfo.DFSNum = BBInfo.Semi = ++N;
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BBInfo.Label = nullptr;
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SNCA.NumToNode.push_back(nullptr); // NumToNode[n] = V;
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NumToNode.push_back(nullptr); // NumToNode[n] = V;
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}
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// Step #1: Number blocks in depth-first order and initialize variables used
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@ -216,49 +196,48 @@ void Calculate(DominatorTreeBaseByGraphTraits<GraphTraits<NodeT>> &DT,
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if (DT.isPostDominator()){
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for (unsigned i = 0, e = static_cast<unsigned>(DT.Roots.size());
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i != e; ++i)
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N = ReverseDFSPass<NodePtr>(DT.Roots[i], SNCA, N);
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N = runReverseDFS(DT.Roots[i], N);
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} else {
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N = DFSPass<NodePtr>(DT.Roots[0], SNCA, N);
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N = runDFS(DT.Roots[0], N);
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}
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// It might be that some blocks did not get a DFS number (e.g., blocks of
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// infinite loops). In these cases an artificial exit node is required.
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MultipleRoots |= (DT.isPostDominator() && N != GraphTraits<FuncT*>::size(&F));
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MultipleRoots |= (DT.isPostDominator() && N != NumBlocks);
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// Initialize IDoms to spanning tree parents.
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for (unsigned i = 1; i <= N; ++i) {
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const NodePtr V = SNCA.NumToNode[i];
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auto &VInfo = SNCA.NodeToInfo[V];
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VInfo.IDom = SNCA.NumToNode[VInfo.Parent];
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const NodePtr V = NumToNode[i];
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auto &VInfo = NodeToInfo[V];
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VInfo.IDom = NumToNode[VInfo.Parent];
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}
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// Step #2: Calculate the semidominators of all vertices.
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for (unsigned i = N; i >= 2; --i) {
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NodePtr W = SNCA.NumToNode[i];
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auto &WInfo = SNCA.NodeToInfo[W];
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NodePtr W = NumToNode[i];
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auto &WInfo = NodeToInfo[W];
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// Initialize the semi dominator to point to the parent node.
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WInfo.Semi = WInfo.Parent;
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for (const auto &N : inverse_children<NodeT>(W))
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if (SNCA.NodeToInfo.count(N)) { // Only if this predecessor is reachable!
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unsigned SemiU = SNCA.NodeToInfo[Eval<NodePtr>(N, SNCA, i + 1)].Semi;
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for (const auto &N : inverse_children<NodeType>(W))
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if (NodeToInfo.count(N)) { // Only if this predecessor is reachable!
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unsigned SemiU = NodeToInfo[eval(N, i + 1)].Semi;
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if (SemiU < WInfo.Semi)
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WInfo.Semi = SemiU;
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}
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}
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// Step #3: Explicitly define the immediate dominator of each vertex.
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// IDom[i] = NCA(SDom[i], SpanningTreeParent(i)).
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// Note that the parents were stored in IDoms and later got invalidated during
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// path compression in Eval.
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// Note that the parents were stored in IDoms and later got invalidated
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// during path compression in Eval.
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for (unsigned i = 2; i <= N; ++i) {
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const NodePtr W = SNCA.NumToNode[i];
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auto &WInfo = SNCA.NodeToInfo[W];
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const unsigned SDomNum = SNCA.NodeToInfo[SNCA.NumToNode[WInfo.Semi]].DFSNum;
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const NodePtr W = NumToNode[i];
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auto &WInfo = NodeToInfo[W];
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const unsigned SDomNum = NodeToInfo[NumToNode[WInfo.Semi]].DFSNum;
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NodePtr WIDomCandidate = WInfo.IDom;
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while (SNCA.NodeToInfo[WIDomCandidate].DFSNum > SDomNum)
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WIDomCandidate = SNCA.NodeToInfo[WIDomCandidate].IDom;
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while (NodeToInfo[WIDomCandidate].DFSNum > SDomNum)
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WIDomCandidate = NodeToInfo[WIDomCandidate].IDom;
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WInfo.IDom = WIDomCandidate;
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}
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@ -266,39 +245,53 @@ void Calculate(DominatorTreeBaseByGraphTraits<GraphTraits<NodeT>> &DT,
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if (DT.Roots.empty()) return;
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// Add a node for the root. This node might be the actual root, if there is
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// one exit block, or it may be the virtual exit (denoted by (BasicBlock *)0)
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// which postdominates all real exits if there are multiple exit blocks, or
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// an infinite loop.
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// one exit block, or it may be the virtual exit (denoted by
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// (BasicBlock *)0) which postdominates all real exits if there are multiple
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// exit blocks, or an infinite loop.
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NodePtr Root = !MultipleRoots ? DT.Roots[0] : nullptr;
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DT.RootNode =
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(DT.DomTreeNodes[Root] =
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llvm::make_unique<DomTreeNodeBase<NodeType>>(Root, nullptr))
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llvm::make_unique<DomTreeNodeBase<NodeT>>(Root, nullptr))
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.get();
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// Loop over all of the reachable blocks in the function...
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for (unsigned i = 2; i <= N; ++i) {
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NodePtr W = SNCA.NumToNode[i];
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NodePtr W = NumToNode[i];
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// Don't replace this with 'count', the insertion side effect is important
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if (DT.DomTreeNodes[W])
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continue; // Haven't calculated this node yet?
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NodePtr ImmDom = SNCA.getIDom(W);
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NodePtr ImmDom = getIDom(W);
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assert(ImmDom || DT.DomTreeNodes[nullptr]);
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// Get or calculate the node for the immediate dominator
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DomTreeNodeBase<NodeType> *IDomNode = SNCA.getNodeForBlock(ImmDom);
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TreeNodePtr IDomNode = getNodeForBlock(ImmDom);
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// Add a new tree node for this BasicBlock, and link it as a child of
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// IDomNode
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DT.DomTreeNodes[W] = IDomNode->addChild(
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llvm::make_unique<DomTreeNodeBase<NodeType>>(W, IDomNode));
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llvm::make_unique<DomTreeNodeBase<NodeT>>(W, IDomNode));
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}
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DT.updateDFSNumbers();
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}
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};
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} // namespace DomTreeBuilder
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template <class FuncT, class NodeT>
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void Calculate(DominatorTreeBaseByGraphTraits<GraphTraits<NodeT>> &DT,
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FuncT &F) {
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using NodePtr = typename GraphTraits<NodeT>::NodeRef;
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static_assert(std::is_pointer<NodePtr>::value,
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"NodePtr should be a pointer type");
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DomTreeBuilder::SemiNCAInfo<typename std::remove_pointer<NodePtr>::type>
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SNCA(DT);
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SNCA.template runSemiNCA<NodeT>(GraphTraits<FuncT *>::size(&F));
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}
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} // namespace llvm
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#endif
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