// Adds the edge F -> T with weight Weight.
APInt IneqGraph::findShortestPath(Value *F, Value *T) {
DEBUG(dbgs() << "IneqGraph: findShortestPath: " << *F << " ==> " << *T << "\n");
if (isa<ConstantInt>(F) || isa<ConstantInt>(T)) {
APInt RangeF = getUpper(F);
APInt RangeT = getLower(T);
DEBUG(dbgs() << "Ranges: " << RangeF << " and " << RangeT << "\n");
if (RangeF.isMaxSignedValue() || RangeF.isMinSignedValue() ||
RangeT.isMaxSignedValue() || RangeT.isMinSignedValue())
return APInt::getSignedMaxValue(64);
return RangeF.sextOrSelf(64) - RangeT.sextOrSelf(64);
}
GraphNode *FN = getOrCreateNode(F);
GraphNode *TN = getOrCreateNode(T);
return FN->findShortestPath(TN);
}
APInt GraphNode::findShortestPath(GraphNode *Dest, SetVector<GraphNode*> Visited) {
if (Dest == this) {
DEBUG(dbgs() << "IneqGraph: Reached: " << *Dest->getValue() << "\n");
return APInt(64, 0, true);
}
DEBUG(dbgs() << "IneqGraph: Node: " << *V << "\n");
if (Visited.count(this)) {
DEBUG(dbgs() << "IneqGraph: Visited\n");
return APInt::getSignedMaxValue(64); //(64, , true);
}
Visited.insert(this);
APInt MayMin = APInt::getSignedMaxValue(64);
for (may_iterator It = may_begin(), E = may_end();
It != E; ++It) {
APInt Total = It->getToEdge()->findShortestPath(Dest, Visited);
if (Total.slt(MayMin))
MayMin = Total + It->getWeight();
}
//DEBUG(dbgs() << "IneqGraph: Node: " << *V << ", MayMin: " << MayMin << "\n");
APInt MustMax = APInt::getSignedMinValue(64);
for (must_iterator It = must_begin(), E = must_end();
It != E; ++It) {
APInt Total = It->getToEdge()->findShortestPath(Dest, Visited);
if (MustMax.slt(Total))
MustMax = Total;
}
// DEBUG(dbgs() << "IneqGraph: Node: " << *V << ", MustMax: " << MustMax << "\n");
if (MustMax.isMinSignedValue()) {
//DEBUG(dbgs() << "IneqGraph: Node: " << *V << ", Distance: " << MayMin << "\n");
DEBUG(dbgs() << "IneqGraph: Ret: " << MayMin << "\n");
return MayMin;
} else {
APInt Min = MustMax.slt(MayMin) ? MustMax : MayMin;
//DEBUG(dbgs() << "IneqGraph: Node: " << *V << ", Distance: " << Min << "\n");
DEBUG(dbgs() << "IneqGraph: Ret: " << Min << "\n");
return Min;
}
}
