- SmallPtrSet<DomTreeNode*, 32> Visited;
- SmallVector<DomTreeNode*, 32> Worklist;
- while (!PQ.empty()) {
- DomTreeNodePair RootPair = PQ.top();
- PQ.pop();
- DomTreeNode *Root = RootPair.first;
- unsigned RootLevel = RootPair.second;
-
- // Walk all dominator tree children of Root, inspecting their CFG edges with
- // targets elsewhere on the dominator tree. Only targets whose level is at
- // most Root's level are added to the iterated dominance frontier of the
- // definition set.
-
- Worklist.clear();
- Worklist.push_back(Root);
-
- while (!Worklist.empty()) {
- DomTreeNode *Node = Worklist.pop_back_val();
- BasicBlock *BB = Node->getBlock();
-
- for (succ_iterator SI = succ_begin(BB), SE = succ_end(BB); SI != SE;
- ++SI) {
- DomTreeNode *SuccNode = DT.getNode(*SI);
-
- // Quickly skip all CFG edges that are also dominator tree edges instead
- // of catching them below.
- if (SuccNode->getIDom() == Node)
- continue;
-
- unsigned SuccLevel = DomLevels[SuccNode];
- if (SuccLevel > RootLevel)
- continue;
-
- if (!Visited.insert(SuccNode))
- continue;
-
- BasicBlock *SuccBB = SuccNode->getBlock();
- if (!LiveInBlocks.count(SuccBB))
- continue;
-
- DFBlocks.push_back(std::make_pair(BBNumbers[SuccBB], SuccBB));
- if (!DefBlocks.count(SuccBB))
- PQ.push(std::make_pair(SuccNode, SuccLevel));
- }
-
- for (DomTreeNode::iterator CI = Node->begin(), CE = Node->end(); CI != CE;
- ++CI) {
- if (!Visited.count(*CI))
- Worklist.push_back(*CI);
- }
+ while (!Info.DefiningBlocks.empty()) {
+ BasicBlock *BB = Info.DefiningBlocks.back();
+ Info.DefiningBlocks.pop_back();
+
+ // Look up the DF for this write, add it to defining blocks.
+ DominanceFrontier::const_iterator it = DF.find(BB);
+ if (it == DF.end()) continue;
+
+ const DominanceFrontier::DomSetType &S = it->second;
+
+ // In theory we don't need the indirection through the DFBlocks vector.
+ // In practice, the order of calling QueuePhiNode would depend on the
+ // (unspecified) ordering of basic blocks in the dominance frontier,
+ // which would give PHI nodes non-determinstic subscripts. Fix this by
+ // processing blocks in order of the occurance in the function.
+ for (DominanceFrontier::DomSetType::const_iterator P = S.begin(),
+ PE = S.end(); P != PE; ++P) {
+ // If the frontier block is not in the live-in set for the alloca, don't
+ // bother processing it.
+ if (!LiveInBlocks.count(*P))
+ continue;
+
+ DFBlocks.push_back(std::make_pair(BBNumbers[*P], *P));
+ }
+
+ // Sort by which the block ordering in the function.
+ if (DFBlocks.size() > 1)
+ std::sort(DFBlocks.begin(), DFBlocks.end());
+
+ for (unsigned i = 0, e = DFBlocks.size(); i != e; ++i) {
+ BasicBlock *BB = DFBlocks[i].second;
+ if (QueuePhiNode(BB, AllocaNum, CurrentVersion))
+ Info.DefiningBlocks.push_back(BB);