-//===-- Support/SCCIterator.h - Strongly Connected Comp. Iter. --*- C++ -*-===//
+//===---- ADT/SCCIterator.h - Strongly Connected Comp. Iter. ----*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// First element is basic block pointer, second is the 'next child' to visit
std::vector<std::pair<NodeType *, ChildItTy> > VisitStack;
- // MinVistNumStack - Stack holding the "min" values for each node in the DFS.
+ // MinVisitNumStack - Stack holding the "min" values for each node in the DFS.
// This is used to track the minimum uplink values for all children of
// the corresponding node on the VisitStack.
std::vector<unsigned> MinVisitNumStack;
// A single "visit" within the non-recursive DFS traversal.
- void DFSVisitOne(NodeType* N) {
+ void DFSVisitOne(NodeType *N) {
++visitNum; // Global counter for the visit order
nodeVisitNumbers[N] = visitNum;
SCCNodeStack.push_back(N);
// TOS has at least one more child so continue DFS
NodeType *childN = *VisitStack.back().second++;
if (!nodeVisitNumbers.count(childN)) {
- // this node has never been seen
+ // this node has never been seen.
DFSVisitOne(childN);
continue;
}
-
+
unsigned childNum = nodeVisitNumbers[childN];
if (MinVisitNumStack.back() > childNum)
MinVisitNumStack.back() = childNum;
if (minVisitNum != nodeVisitNumbers[visitingN])
continue;
-
+
// A full SCC is on the SCCNodeStack! It includes all nodes below
// visitingN on the stack. Copy those nodes to CurrentSCC,
// reset their minVisit values, and return (this suspends
typedef scc_iterator<GraphT, GT> _Self;
// Provide static "constructors"...
- static inline _Self begin(const GraphT& G) { return _Self(GT::getEntryNode(G)); }
- static inline _Self end (const GraphT& G) { return _Self(); }
+ static inline _Self begin(const GraphT &G){return _Self(GT::getEntryNode(G));}
+ static inline _Self end (const GraphT &) { return _Self(); }
- // Direct loop termination test (I.fini() is more efficient than I == end())
- inline bool fini() const {
+ // Direct loop termination test: I.isAtEnd() is more efficient than I == end()
+ inline bool isAtEnd() const {
assert(!CurrentSCC.empty() || VisitStack.empty());
return CurrentSCC.empty();
}
return true;
return false;
}
+
+ /// ReplaceNode - This informs the scc_iterator that the specified Old node
+ /// has been deleted, and New is to be used in its place.
+ void ReplaceNode(NodeType *Old, NodeType *New) {
+ assert(nodeVisitNumbers.count(Old) && "Old not in scc_iterator?");
+ nodeVisitNumbers[New] = nodeVisitNumbers[Old];
+ nodeVisitNumbers.erase(Old);
+ }
};