Converted MaximumSpanningTree algorithm to a generic template, this could go

into llvm/ADT.

llvm-svn: 81001

1 files changed, 0 insertions, 119 deletions

diff --git a/llvm/lib/Transforms/Instrumentation/MaximumSpanningTree.cpp b/llvm/lib/Transforms/Instrumentation/MaximumSpanningTree.cpp
deleted file mode 100644
index 19c4a83..0000000
--- a/llvm/lib/Transforms/Instrumentation/MaximumSpanningTree.cpp
+++ /dev/null
@@ -1,119 +0,0 @@
-//===- 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";
-}