MaximumSpanningTree.h [plain text]
#ifndef LLVM_ANALYSIS_MAXIMUMSPANNINGTREE_H
#define LLVM_ANALYSIS_MAXIMUMSPANNINGTREE_H
#include "llvm/BasicBlock.h"
#include "llvm/ADT/EquivalenceClasses.h"
#include <vector>
#include <algorithm>
namespace llvm {
template <typename T>
class MaximumSpanningTree {
template <typename CT>
struct EdgeWeightCompare {
bool operator()(typename MaximumSpanningTree<CT>::EdgeWeight X,
typename MaximumSpanningTree<CT>::EdgeWeight Y) const {
if (X.second > Y.second) return true;
if (X.second < Y.second) return false;
if (const BasicBlock *BBX = dyn_cast<BasicBlock>(X.first.first)) {
if (const BasicBlock *BBY = dyn_cast<BasicBlock>(Y.first.first)) {
if (BBX->size() > BBY->size()) return true;
if (BBX->size() < BBY->size()) return false;
}
}
if (const BasicBlock *BBX = dyn_cast<BasicBlock>(X.first.second)) {
if (const BasicBlock *BBY = dyn_cast<BasicBlock>(Y.first.second)) {
if (BBX->size() > BBY->size()) return true;
if (BBX->size() < BBY->size()) return false;
}
}
return false;
}
};
public:
typedef std::pair<const T*, const T*> Edge;
typedef std::pair<Edge, double> EdgeWeight;
typedef std::vector<EdgeWeight> EdgeWeights;
protected:
typedef std::vector<Edge> MaxSpanTree;
MaxSpanTree MST;
public:
static char ID;
MaximumSpanningTree(EdgeWeights &EdgeVector) {
std::stable_sort(EdgeVector.begin(), EdgeVector.end(), EdgeWeightCompare<T>());
EquivalenceClasses<const T*> Forest;
for (typename EdgeWeights::iterator EWi = EdgeVector.begin(),
EWe = EdgeVector.end(); EWi != EWe; ++EWi) {
Edge e = (*EWi).first;
Forest.insert(e.first);
Forest.insert(e.second);
}
for (typename EdgeWeights::iterator EWi = EdgeVector.begin(),
EWe = EdgeVector.end(); EWi != EWe; ++EWi) {
Edge e = (*EWi).first;
if (Forest.findLeader(e.first) != Forest.findLeader(e.second)) {
Forest.unionSets(e.first, e.second);
MST.push_back(e);
}
}
}
typename MaxSpanTree::iterator begin() {
return MST.begin();
}
typename MaxSpanTree::iterator end() {
return MST.end();
}
};
}
#endif