+++ /dev/null
-//===- MaximumSpanningTree.cpp - LLVM Pass to estimate profile info -------===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This module privides means for calculating a maximum spanning tree for the
-// CFG of a function according to a given profile. The tree does not contain
-// leaf edges, since they are needed for optimal edge profiling.
-//
-//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "maximum-spanning-tree"
-#include "MaximumSpanningTree.h"
-#include "llvm/ADT/EquivalenceClasses.h"
-#include "llvm/Support/Compiler.h"
-#include "llvm/Support/CFG.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/Format.h"
-using namespace llvm;
-
-namespace {
- // compare two weighted edges
- struct VISIBILITY_HIDDEN EdgeWeightCompare {
- bool operator()(const ProfileInfo::EdgeWeight X,
- const ProfileInfo::EdgeWeight Y) const {
- if (X.second > Y.second) return true;
- if (X.second < Y.second) return false;
-
- // It would be enough to just compare the weights of the edges and be
- // done. With edges of the same weight this may lead to a different MST
- // each time the MST is created. To have more stable sorting (and thus
- // more stable MSTs) furhter sort the edges.
- if (X.first.first != 0 && Y.first.first == 0) return true;
- if (X.first.first == 0 && Y.first.first != 0) return false;
- if (X.first.first == 0 && Y.first.first == 0) return false;
-
- if (X.first.first->size() > Y.first.first->size()) return true;
- if (X.first.first->size() < Y.first.first->size()) return false;
-
- if (X.first.second != 0 && Y.first.second == 0) return true;
- if (X.first.second == 0 && Y.first.second != 0) return false;
- if (X.first.second == 0 && Y.first.second == 0) return false;
-
- if (X.first.second->size() > Y.first.second->size()) return true;
- if (X.first.second->size() < Y.first.second->size()) return false;
-
- return false;
- }
- };
-}
-
-static void inline printMSTEdge(ProfileInfo::EdgeWeight E,
- const char *M) {
- DEBUG(errs() << "--Edge " << E.first
- <<" (Weight "<< format("%g",E.second) << ") "
- << (M) << "\n");
-}
-
-// MaximumSpanningTree() - Takes a function and returns a spanning tree
-// according to the currently active profiling information, the leaf edges are
-// NOT in the MST. MaximumSpanningTree uses the algorithm of Kruskal.
-MaximumSpanningTree::MaximumSpanningTree(std::vector<ProfileInfo::EdgeWeight>
- &EdgeVector) {
-
- std::sort(EdgeVector.begin(), EdgeVector.end(), EdgeWeightCompare());
-
- // Create spanning tree, Forest contains a special data structure
- // that makes checking if two nodes are already in a common (sub-)tree
- // fast and cheap.
- EquivalenceClasses<const BasicBlock*> Forest;
- for (std::vector<ProfileInfo::EdgeWeight>::iterator bbi = EdgeVector.begin(),
- bbe = EdgeVector.end(); bbi != bbe; ++bbi) {
- Forest.insert(bbi->first.first);
- Forest.insert(bbi->first.second);
- }
- Forest.insert(0);
-
- // Iterate over the sorted edges, biggest first.
- for (std::vector<ProfileInfo::EdgeWeight>::iterator bbi = EdgeVector.begin(),
- bbe = EdgeVector.end(); bbi != bbe; ++bbi) {
- ProfileInfo::Edge e = (*bbi).first;
-
- if (Forest.findLeader(e.first) != Forest.findLeader(e.second)) {
- Forest.unionSets(e.first, e.second);
- // So we know now that the edge is not already in a subtree (and not
- // (0,entry)), so we push the edge to the MST if it has some successors.
- MST.push_back(e);
- printMSTEdge(*bbi,"in MST");
- } else {
- // This edge is either (0,entry) or (BB,0) or would create a circle in a
- // subtree.
- printMSTEdge(*bbi,"*not* in MST");
- }
- }
-
- // Sort the MST edges.
- std::stable_sort(MST.begin(),MST.end());
-}
-
-MaximumSpanningTree::MaxSpanTree::iterator MaximumSpanningTree::begin() {
- return MST.begin();
-}
-
-MaximumSpanningTree::MaxSpanTree::iterator MaximumSpanningTree::end() {
- return MST.end();
-}
-
-void MaximumSpanningTree::dump() {
- errs()<<"{";
- for ( MaxSpanTree::iterator ei = MST.begin(), ee = MST.end();
- ei!=ee; ++ei ) {
- errs()<<"("<<((*ei).first?(*ei).first->getNameStr():"0")<<",";
- errs()<<(*ei).second->getNameStr()<<")";
- }
- errs()<<"}\n";
-}
//
//===----------------------------------------------------------------------===//
//
-// This module privides means for calculating a maximum spanning tree for the
-// CFG of a function according to a given profile.
+// This module privides means for calculating a maximum spanning tree for a
+// given set of weighted edges. The type parameter T is the type of a node.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ANALYSIS_MAXIMUMSPANNINGTREE_H
#define LLVM_ANALYSIS_MAXIMUMSPANNINGTREE_H
-#include "llvm/Analysis/ProfileInfo.h"
-#include "llvm/Support/raw_ostream.h"
+#include "llvm/ADT/EquivalenceClasses.h"
#include <vector>
+#include <algorithm>
namespace llvm {
- class Function;
+ /// MaximumSpanningTree - A MST implementation.
+ /// The type parameter T determines the type of the nodes of the graph.
+ template <typename T>
class MaximumSpanningTree {
- public:
- typedef std::vector<ProfileInfo::Edge> MaxSpanTree;
+ // A comparing class for comparing weighted edges.
+ 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;
+ 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; // Class identification, replacement for typeinfo
- // MaxSpanTree() - Calculates a MST for a function according to a profile.
- // If inverted is true, all the edges *not* in the MST are returned. As a
- // special also all leaf edges of the MST are not included, this makes it
- // easier for the OptimalEdgeProfileInstrumentation to use this MST to do
- // an optimal profiling.
- MaximumSpanningTree(std::vector<ProfileInfo::EdgeWeight>&);
- virtual ~MaximumSpanningTree() {}
+ /// MaximumSpanningTree() - Takes a vector of weighted edges and returns a
+ /// spanning tree.
+ MaximumSpanningTree(EdgeWeights &EdgeVector) {
+
+ std::stable_sort(EdgeVector.begin(), EdgeVector.end(), EdgeWeightCompare<T>());
+
+ // Create spanning tree, Forest contains a special data structure
+ // that makes checking if two nodes are already in a common (sub-)tree
+ // fast and cheap.
+ 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);
+ }
+
+ // Iterate over the sorted edges, biggest first.
+ 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);
+ // So we know now that the edge is not already in a subtree, so we push
+ // the edge to the MST.
+ MST.push_back(e);
+ }
+ }
+ }
- virtual MaxSpanTree::iterator begin();
- virtual MaxSpanTree::iterator end();
+ typename MaxSpanTree::iterator begin() {
+ return MST.begin();
+ }
- virtual void dump();
+ typename MaxSpanTree::iterator end() {
+ return MST.end();
+ }
};
} // End llvm namespace
projects / oota-llvm.git / commitdiff