-const DominanceFrontier::DomSetType &
-DominanceFrontier::calculate(const DominatorTree &DT,
- const DomTreeNode *Node) {
- BasicBlock *BB = Node->getBlock();
- DomSetType *Result = NULL;
-
- std::vector<DFCalculateWorkObject> workList;
- SmallPtrSet<BasicBlock *, 32> visited;
-
- workList.push_back(DFCalculateWorkObject(BB, NULL, Node, NULL));
- do {
- DFCalculateWorkObject *currentW = &workList.back();
- assert (currentW && "Missing work object.");
-
- BasicBlock *currentBB = currentW->currentBB;
- BasicBlock *parentBB = currentW->parentBB;
- const DomTreeNode *currentNode = currentW->Node;
- const DomTreeNode *parentNode = currentW->parentNode;
- assert (currentBB && "Invalid work object. Missing current Basic Block");
- assert (currentNode && "Invalid work object. Missing current Node");
- DomSetType &S = Frontiers[currentBB];
-
- // Visit each block only once.
- if (visited.count(currentBB) == 0) {
- visited.insert(currentBB);
-
- // Loop over CFG successors to calculate DFlocal[currentNode]
- for (succ_iterator SI = succ_begin(currentBB), SE = succ_end(currentBB);
- SI != SE; ++SI) {
- // Does Node immediately dominate this successor?
- if (DT[*SI]->getIDom() != currentNode)
- S.insert(*SI);
- }
- }
-
- // At this point, S is DFlocal. Now we union in DFup's of our children...
- // Loop through and visit the nodes that Node immediately dominates (Node's
- // children in the IDomTree)
- bool visitChild = false;
- for (DomTreeNode::const_iterator NI = currentNode->begin(),
- NE = currentNode->end(); NI != NE; ++NI) {
- DomTreeNode *IDominee = *NI;
- BasicBlock *childBB = IDominee->getBlock();
- if (visited.count(childBB) == 0) {
- workList.push_back(DFCalculateWorkObject(childBB, currentBB,
- IDominee, currentNode));
- visitChild = true;
- }
- }
-
- // If all children are visited or there is any child then pop this block
- // from the workList.
- if (!visitChild) {
-
- if (!parentBB) {
- Result = &S;
- break;
- }
-
- DomSetType::const_iterator CDFI = S.begin(), CDFE = S.end();
- DomSetType &parentSet = Frontiers[parentBB];
- for (; CDFI != CDFE; ++CDFI) {
- if (!DT.properlyDominates(parentNode, DT[*CDFI]))
- parentSet.insert(*CDFI);
- }
- workList.pop_back();
- }
-
- } while (!workList.empty());
-
- return *Result;
-}
-
-void DominanceFrontierBase::print(std::ostream &o, const Module* ) const {
- for (const_iterator I = begin(), E = end(); I != E; ++I) {
- o << " DomFrontier for BB";
- if (I->first)
- WriteAsOperand(o, I->first, false);
- else
- o << " <<exit node>>";
- o << " is:\t" << I->second << "\n";
- }
-}
-
-void DominanceFrontierBase::dump() {
- print (llvm::cerr);
+// dominates - Return true if A dominates a use in B. This performs the
+// special checks necessary if A and B are in the same basic block.
+bool DominatorTree::dominates(const Instruction *A, const Instruction *B) const{
+ const BasicBlock *BBA = A->getParent(), *BBB = B->getParent();
+
+ // If A is an invoke instruction, its value is only available in this normal
+ // successor block.
+ if (const InvokeInst *II = dyn_cast<InvokeInst>(A))
+ BBA = II->getNormalDest();
+
+ if (BBA != BBB) return dominates(BBA, BBB);
+
+ // It is not possible to determine dominance between two PHI nodes
+ // based on their ordering.
+ if (isa<PHINode>(A) && isa<PHINode>(B))
+ return false;
+
+ // Loop through the basic block until we find A or B.
+ BasicBlock::const_iterator I = BBA->begin();
+ for (; &*I != A && &*I != B; ++I)
+ /*empty*/;
+
+ return &*I == A;