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+//===- llvm/Analysis/LoopInfoImpl.h - Natural Loop Calculator ---*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This is the generic implementation of LoopInfo used for both Loops and
+// MachineLoops.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ANALYSIS_LOOPINFOIMPL_H
+#define LLVM_ANALYSIS_LOOPINFOIMPL_H
+
+#include "llvm/ADT/PostOrderIterator.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/Analysis/LoopInfo.h"
+
+namespace llvm {
+
+//===----------------------------------------------------------------------===//
+// APIs for simple analysis of the loop. See header notes.
+
+/// getExitingBlocks - Return all blocks inside the loop that have successors
+/// outside of the loop. These are the blocks _inside of the current loop_
+/// which branch out. The returned list is always unique.
+///
+template<class BlockT, class LoopT>
+void LoopBase<BlockT, LoopT>::
+getExitingBlocks(SmallVectorImpl<BlockT *> &ExitingBlocks) const {
+ // Sort the blocks vector so that we can use binary search to do quick
+ // lookups.
+ SmallVector<BlockT*, 128> LoopBBs(block_begin(), block_end());
+ std::sort(LoopBBs.begin(), LoopBBs.end());
+
+ typedef GraphTraits<BlockT*> BlockTraits;
+ for (block_iterator BI = block_begin(), BE = block_end(); BI != BE; ++BI)
+ for (typename BlockTraits::ChildIteratorType I =
+ BlockTraits::child_begin(*BI), E = BlockTraits::child_end(*BI);
+ I != E; ++I)
+ if (!std::binary_search(LoopBBs.begin(), LoopBBs.end(), *I)) {
+ // Not in current loop? It must be an exit block.
+ ExitingBlocks.push_back(*BI);
+ break;
+ }
+}
+
+/// getExitingBlock - If getExitingBlocks would return exactly one block,
+/// return that block. Otherwise return null.
+template<class BlockT, class LoopT>
+BlockT *LoopBase<BlockT, LoopT>::getExitingBlock() const {
+ SmallVector<BlockT*, 8> ExitingBlocks;
+ getExitingBlocks(ExitingBlocks);
+ if (ExitingBlocks.size() == 1)
+ return ExitingBlocks[0];
+ return 0;
+}
+
+/// getExitBlocks - Return all of the successor blocks of this loop. These
+/// are the blocks _outside of the current loop_ which are branched to.
+///
+template<class BlockT, class LoopT>
+void LoopBase<BlockT, LoopT>::
+getExitBlocks(SmallVectorImpl<BlockT*> &ExitBlocks) const {
+ // Sort the blocks vector so that we can use binary search to do quick
+ // lookups.
+ SmallVector<BlockT*, 128> LoopBBs(block_begin(), block_end());
+ std::sort(LoopBBs.begin(), LoopBBs.end());
+
+ typedef GraphTraits<BlockT*> BlockTraits;
+ for (block_iterator BI = block_begin(), BE = block_end(); BI != BE; ++BI)
+ for (typename BlockTraits::ChildIteratorType I =
+ BlockTraits::child_begin(*BI), E = BlockTraits::child_end(*BI);
+ I != E; ++I)
+ if (!std::binary_search(LoopBBs.begin(), LoopBBs.end(), *I))
+ // Not in current loop? It must be an exit block.
+ ExitBlocks.push_back(*I);
+}
+
+/// getExitBlock - If getExitBlocks would return exactly one block,
+/// return that block. Otherwise return null.
+template<class BlockT, class LoopT>
+BlockT *LoopBase<BlockT, LoopT>::getExitBlock() const {
+ SmallVector<BlockT*, 8> ExitBlocks;
+ getExitBlocks(ExitBlocks);
+ if (ExitBlocks.size() == 1)
+ return ExitBlocks[0];
+ return 0;
+}
+
+/// getExitEdges - Return all pairs of (_inside_block_,_outside_block_).
+template<class BlockT, class LoopT>
+void LoopBase<BlockT, LoopT>::
+getExitEdges(SmallVectorImpl<Edge> &ExitEdges) const {
+ // Sort the blocks vector so that we can use binary search to do quick
+ // lookups.
+ SmallVector<BlockT*, 128> LoopBBs(block_begin(), block_end());
+ array_pod_sort(LoopBBs.begin(), LoopBBs.end());
+
+ typedef GraphTraits<BlockT*> BlockTraits;
+ for (block_iterator BI = block_begin(), BE = block_end(); BI != BE; ++BI)
+ for (typename BlockTraits::ChildIteratorType I =
+ BlockTraits::child_begin(*BI), E = BlockTraits::child_end(*BI);
+ I != E; ++I)
+ if (!std::binary_search(LoopBBs.begin(), LoopBBs.end(), *I))
+ // Not in current loop? It must be an exit block.
+ ExitEdges.push_back(Edge(*BI, *I));
+}
+
+/// getLoopPreheader - If there is a preheader for this loop, return it. A
+/// loop has a preheader if there is only one edge to the header of the loop
+/// from outside of the loop. If this is the case, the block branching to the
+/// header of the loop is the preheader node.
+///
+/// This method returns null if there is no preheader for the loop.
+///
+template<class BlockT, class LoopT>
+BlockT *LoopBase<BlockT, LoopT>::getLoopPreheader() const {
+ // Keep track of nodes outside the loop branching to the header...
+ BlockT *Out = getLoopPredecessor();
+ if (!Out) return 0;
+
+ // Make sure there is only one exit out of the preheader.
+ typedef GraphTraits<BlockT*> BlockTraits;
+ typename BlockTraits::ChildIteratorType SI = BlockTraits::child_begin(Out);
+ ++SI;
+ if (SI != BlockTraits::child_end(Out))
+ return 0; // Multiple exits from the block, must not be a preheader.
+
+ // The predecessor has exactly one successor, so it is a preheader.
+ return Out;
+}
+
+/// getLoopPredecessor - If the given loop's header has exactly one unique
+/// predecessor outside the loop, return it. Otherwise return null.
+/// This is less strict that the loop "preheader" concept, which requires
+/// the predecessor to have exactly one successor.
+///
+template<class BlockT, class LoopT>
+BlockT *LoopBase<BlockT, LoopT>::getLoopPredecessor() const {
+ // Keep track of nodes outside the loop branching to the header...
+ BlockT *Out = 0;
+
+ // Loop over the predecessors of the header node...
+ BlockT *Header = getHeader();
+ typedef GraphTraits<Inverse<BlockT*> > InvBlockTraits;
+ for (typename InvBlockTraits::ChildIteratorType PI =
+ InvBlockTraits::child_begin(Header),
+ PE = InvBlockTraits::child_end(Header); PI != PE; ++PI) {
+ typename InvBlockTraits::NodeType *N = *PI;
+ if (!contains(N)) { // If the block is not in the loop...
+ if (Out && Out != N)
+ return 0; // Multiple predecessors outside the loop
+ Out = N;
+ }
+ }
+
+ // Make sure there is only one exit out of the preheader.
+ assert(Out && "Header of loop has no predecessors from outside loop?");
+ return Out;
+}
+
+/// getLoopLatch - If there is a single latch block for this loop, return it.
+/// A latch block is a block that contains a branch back to the header.
+template<class BlockT, class LoopT>
+BlockT *LoopBase<BlockT, LoopT>::getLoopLatch() const {
+ BlockT *Header = getHeader();
+ typedef GraphTraits<Inverse<BlockT*> > InvBlockTraits;
+ typename InvBlockTraits::ChildIteratorType PI =
+ InvBlockTraits::child_begin(Header);
+ typename InvBlockTraits::ChildIteratorType PE =
+ InvBlockTraits::child_end(Header);
+ BlockT *Latch = 0;
+ for (; PI != PE; ++PI) {
+ typename InvBlockTraits::NodeType *N = *PI;
+ if (contains(N)) {
+ if (Latch) return 0;
+ Latch = N;
+ }
+ }
+
+ return Latch;
+}
+
+//===----------------------------------------------------------------------===//
+// APIs for updating loop information after changing the CFG
+//
+
+/// addBasicBlockToLoop - This method is used by other analyses to update loop
+/// information. NewBB is set to be a new member of the current loop.
+/// Because of this, it is added as a member of all parent loops, and is added
+/// to the specified LoopInfo object as being in the current basic block. It
+/// is not valid to replace the loop header with this method.
+///
+template<class BlockT, class LoopT>
+void LoopBase<BlockT, LoopT>::
+addBasicBlockToLoop(BlockT *NewBB, LoopInfoBase<BlockT, LoopT> &LIB) {
+ assert((Blocks.empty() || LIB[getHeader()] == this) &&
+ "Incorrect LI specified for this loop!");
+ assert(NewBB && "Cannot add a null basic block to the loop!");
+ assert(LIB[NewBB] == 0 && "BasicBlock already in the loop!");
+
+ LoopT *L = static_cast<LoopT *>(this);
+
+ // Add the loop mapping to the LoopInfo object...
+ LIB.BBMap[NewBB] = L;
+
+ // Add the basic block to this loop and all parent loops...
+ while (L) {
+ L->Blocks.push_back(NewBB);
+ L = L->getParentLoop();
+ }
+}
+
+/// replaceChildLoopWith - This is used when splitting loops up. It replaces
+/// the OldChild entry in our children list with NewChild, and updates the
+/// parent pointer of OldChild to be null and the NewChild to be this loop.
+/// This updates the loop depth of the new child.
+template<class BlockT, class LoopT>
+void LoopBase<BlockT, LoopT>::
+replaceChildLoopWith(LoopT *OldChild, LoopT *NewChild) {
+ assert(OldChild->ParentLoop == this && "This loop is already broken!");
+ assert(NewChild->ParentLoop == 0 && "NewChild already has a parent!");
+ typename std::vector<LoopT *>::iterator I =
+ std::find(SubLoops.begin(), SubLoops.end(), OldChild);
+ assert(I != SubLoops.end() && "OldChild not in loop!");
+ *I = NewChild;
+ OldChild->ParentLoop = 0;
+ NewChild->ParentLoop = static_cast<LoopT *>(this);
+}
+
+/// verifyLoop - Verify loop structure
+template<class BlockT, class LoopT>
+void LoopBase<BlockT, LoopT>::verifyLoop() const {
+#ifndef NDEBUG
+ assert(!Blocks.empty() && "Loop header is missing");
+
+ // Setup for using a depth-first iterator to visit every block in the loop.
+ SmallVector<BlockT*, 8> ExitBBs;
+ getExitBlocks(ExitBBs);
+ llvm::SmallPtrSet<BlockT*, 8> VisitSet;
+ VisitSet.insert(ExitBBs.begin(), ExitBBs.end());
+ df_ext_iterator<BlockT*, llvm::SmallPtrSet<BlockT*, 8> >
+ BI = df_ext_begin(getHeader(), VisitSet),
+ BE = df_ext_end(getHeader(), VisitSet);
+
+ // Keep track of the number of BBs visited.
+ unsigned NumVisited = 0;
+
+ // Sort the blocks vector so that we can use binary search to do quick
+ // lookups.
+ SmallVector<BlockT*, 128> LoopBBs(block_begin(), block_end());
+ std::sort(LoopBBs.begin(), LoopBBs.end());
+
+ // Check the individual blocks.
+ for ( ; BI != BE; ++BI) {
+ BlockT *BB = *BI;
+ bool HasInsideLoopSuccs = false;
+ bool HasInsideLoopPreds = false;
+ SmallVector<BlockT *, 2> OutsideLoopPreds;
+
+ typedef GraphTraits<BlockT*> BlockTraits;
+ for (typename BlockTraits::ChildIteratorType SI =
+ BlockTraits::child_begin(BB), SE = BlockTraits::child_end(BB);
+ SI != SE; ++SI)
+ if (std::binary_search(LoopBBs.begin(), LoopBBs.end(), *SI)) {
+ HasInsideLoopSuccs = true;
+ break;
+ }
+ typedef GraphTraits<Inverse<BlockT*> > InvBlockTraits;
+ for (typename InvBlockTraits::ChildIteratorType PI =
+ InvBlockTraits::child_begin(BB), PE = InvBlockTraits::child_end(BB);
+ PI != PE; ++PI) {
+ BlockT *N = *PI;
+ if (std::binary_search(LoopBBs.begin(), LoopBBs.end(), N))
+ HasInsideLoopPreds = true;
+ else
+ OutsideLoopPreds.push_back(N);
+ }
+
+ if (BB == getHeader()) {
+ assert(!OutsideLoopPreds.empty() && "Loop is unreachable!");
+ } else if (!OutsideLoopPreds.empty()) {
+ // A non-header loop shouldn't be reachable from outside the loop,
+ // though it is permitted if the predecessor is not itself actually
+ // reachable.
+ BlockT *EntryBB = BB->getParent()->begin();
+ for (df_iterator<BlockT *> NI = df_begin(EntryBB),
+ NE = df_end(EntryBB); NI != NE; ++NI)
+ for (unsigned i = 0, e = OutsideLoopPreds.size(); i != e; ++i)
+ assert(*NI != OutsideLoopPreds[i] &&
+ "Loop has multiple entry points!");
+ }
+ assert(HasInsideLoopPreds && "Loop block has no in-loop predecessors!");
+ assert(HasInsideLoopSuccs && "Loop block has no in-loop successors!");
+ assert(BB != getHeader()->getParent()->begin() &&
+ "Loop contains function entry block!");
+
+ NumVisited++;
+ }
+
+ assert(NumVisited == getNumBlocks() && "Unreachable block in loop");
+
+ // Check the subloops.
+ for (iterator I = begin(), E = end(); I != E; ++I)
+ // Each block in each subloop should be contained within this loop.
+ for (block_iterator BI = (*I)->block_begin(), BE = (*I)->block_end();
+ BI != BE; ++BI) {
+ assert(std::binary_search(LoopBBs.begin(), LoopBBs.end(), *BI) &&
+ "Loop does not contain all the blocks of a subloop!");
+ }
+
+ // Check the parent loop pointer.
+ if (ParentLoop) {
+ assert(std::find(ParentLoop->begin(), ParentLoop->end(), this) !=
+ ParentLoop->end() &&
+ "Loop is not a subloop of its parent!");
+ }
+#endif
+}
+
+/// verifyLoop - Verify loop structure of this loop and all nested loops.
+template<class BlockT, class LoopT>
+void LoopBase<BlockT, LoopT>::verifyLoopNest(
+ DenseSet<const LoopT*> *Loops) const {
+ Loops->insert(static_cast<const LoopT *>(this));
+ // Verify this loop.
+ verifyLoop();
+ // Verify the subloops.
+ for (iterator I = begin(), E = end(); I != E; ++I)
+ (*I)->verifyLoopNest(Loops);
+}
+
+template<class BlockT, class LoopT>
+void LoopBase<BlockT, LoopT>::print(raw_ostream &OS, unsigned Depth) const {
+ OS.indent(Depth*2) << "Loop at depth " << getLoopDepth()
+ << " containing: ";
+
+ for (unsigned i = 0; i < getBlocks().size(); ++i) {
+ if (i) OS << ",";
+ BlockT *BB = getBlocks()[i];
+ WriteAsOperand(OS, BB, false);
+ if (BB == getHeader()) OS << "<header>";
+ if (BB == getLoopLatch()) OS << "<latch>";
+ if (isLoopExiting(BB)) OS << "<exiting>";
+ }
+ OS << "\n";
+
+ for (iterator I = begin(), E = end(); I != E; ++I)
+ (*I)->print(OS, Depth+2);
+}
+
+//===----------------------------------------------------------------------===//
+/// Stable LoopInfo Analysis - Build a loop tree using stable iterators so the
+/// result does / not depend on use list (block predecessor) order.
+///
+
+/// Discover a subloop with the specified backedges such that: All blocks within
+/// this loop are mapped to this loop or a subloop. And all subloops within this
+/// loop have their parent loop set to this loop or a subloop.
+template<class BlockT, class LoopT>
+static void discoverAndMapSubloop(LoopT *L, ArrayRef<BlockT*> Backedges,
+ LoopInfoBase<BlockT, LoopT> *LI,
+ DominatorTreeBase<BlockT> &DomTree) {
+ typedef GraphTraits<Inverse<BlockT*> > InvBlockTraits;
+
+ unsigned NumBlocks = 0;
+ unsigned NumSubloops = 0;
+
+ // Perform a backward CFG traversal using a worklist.
+ std::vector<BlockT *> ReverseCFGWorklist(Backedges.begin(), Backedges.end());
+ while (!ReverseCFGWorklist.empty()) {
+ BlockT *PredBB = ReverseCFGWorklist.back();
+ ReverseCFGWorklist.pop_back();
+
+ LoopT *Subloop = LI->getLoopFor(PredBB);
+ if (!Subloop) {
+ if (!DomTree.isReachableFromEntry(PredBB))
+ continue;
+
+ // This is an undiscovered block. Map it to the current loop.
+ LI->changeLoopFor(PredBB, L);
+ ++NumBlocks;
+ if (PredBB == L->getHeader())
+ continue;
+ // Push all block predecessors on the worklist.
+ ReverseCFGWorklist.insert(ReverseCFGWorklist.end(),
+ InvBlockTraits::child_begin(PredBB),
+ InvBlockTraits::child_end(PredBB));
+ }
+ else {
+ // This is a discovered block. Find its outermost discovered loop.
+ while (LoopT *Parent = Subloop->getParentLoop())
+ Subloop = Parent;
+
+ // If it is already discovered to be a subloop of this loop, continue.
+ if (Subloop == L)
+ continue;
+
+ // Discover a subloop of this loop.
+ Subloop->setParentLoop(L);
+ ++NumSubloops;
+ NumBlocks += Subloop->getBlocks().capacity();
+ PredBB = Subloop->getHeader();
+ // Continue traversal along predecessors that are not loop-back edges from
+ // within this subloop tree itself. Note that a predecessor may directly
+ // reach another subloop that is not yet discovered to be a subloop of
+ // this loop, which we must traverse.
+ for (typename InvBlockTraits::ChildIteratorType PI =
+ InvBlockTraits::child_begin(PredBB),
+ PE = InvBlockTraits::child_end(PredBB); PI != PE; ++PI) {
+ if (LI->getLoopFor(*PI) != Subloop)
+ ReverseCFGWorklist.push_back(*PI);
+ }
+ }
+ }
+ L->getSubLoopsVector().reserve(NumSubloops);
+ L->getBlocksVector().reserve(NumBlocks);
+}
+
+namespace {
+/// Populate all loop data in a stable order during a single forward DFS.
+template<class BlockT, class LoopT>
+class PopulateLoopsDFS {
+ typedef GraphTraits<BlockT*> BlockTraits;
+ typedef typename BlockTraits::ChildIteratorType SuccIterTy;
+
+ LoopInfoBase<BlockT, LoopT> *LI;
+ DenseSet<const BlockT *> VisitedBlocks;
+ std::vector<std::pair<BlockT*, SuccIterTy> > DFSStack;
+
+public:
+ PopulateLoopsDFS(LoopInfoBase<BlockT, LoopT> *li):
+ LI(li) {}
+
+ void traverse(BlockT *EntryBlock);
+
+protected:
+ void insertIntoLoop(BlockT *Block);
+
+ BlockT *dfsSource() { return DFSStack.back().first; }
+ SuccIterTy &dfsSucc() { return DFSStack.back().second; }
+ SuccIterTy dfsSuccEnd() { return BlockTraits::child_end(dfsSource()); }
+
+ void pushBlock(BlockT *Block) {
+ DFSStack.push_back(std::make_pair(Block, BlockTraits::child_begin(Block)));
+ }
+};
+} // anonymous
+
+/// Top-level driver for the forward DFS within the loop.
+template<class BlockT, class LoopT>
+void PopulateLoopsDFS<BlockT, LoopT>::traverse(BlockT *EntryBlock) {
+ pushBlock(EntryBlock);
+ VisitedBlocks.insert(EntryBlock);
+ while (!DFSStack.empty()) {
+ // Traverse the leftmost path as far as possible.
+ while (dfsSucc() != dfsSuccEnd()) {
+ BlockT *BB = *dfsSucc();
+ ++dfsSucc();
+ if (!VisitedBlocks.insert(BB).second)
+ continue;
+
+ // Push the next DFS successor onto the stack.
+ pushBlock(BB);
+ }
+ // Visit the top of the stack in postorder and backtrack.
+ insertIntoLoop(dfsSource());
+ DFSStack.pop_back();
+ }
+}
+
+/// Add a single Block to its ancestor loops in PostOrder. If the block is a
+/// subloop header, add the subloop to its parent in PostOrder, then reverse the
+/// Block and Subloop vectors of the now complete subloop to achieve RPO.
+template<class BlockT, class LoopT>
+void PopulateLoopsDFS<BlockT, LoopT>::insertIntoLoop(BlockT *Block) {
+ LoopT *Subloop = LI->getLoopFor(Block);
+ if (Subloop && Block == Subloop->getHeader()) {
+ // We reach this point once per subloop after processing all the blocks in
+ // the subloop.
+ if (Subloop->getParentLoop())
+ Subloop->getParentLoop()->getSubLoopsVector().push_back(Subloop);
+ else
+ LI->addTopLevelLoop(Subloop);
+
+ // For convenience, Blocks and Subloops are inserted in postorder. Reverse
+ // the lists, except for the loop header, which is always at the beginning.
+ std::reverse(Subloop->getBlocksVector().begin()+1,
+ Subloop->getBlocksVector().end());
+ std::reverse(Subloop->getSubLoopsVector().begin(),
+ Subloop->getSubLoopsVector().end());
+
+ Subloop = Subloop->getParentLoop();
+ }
+ for (; Subloop; Subloop = Subloop->getParentLoop())
+ Subloop->getBlocksVector().push_back(Block);
+}
+
+/// Analyze LoopInfo discovers loops during a postorder DominatorTree traversal
+/// interleaved with backward CFG traversals within each subloop
+/// (discoverAndMapSubloop). The backward traversal skips inner subloops, so
+/// this part of the algorithm is linear in the number of CFG edges. Subloop and
+/// Block vectors are then populated during a single forward CFG traversal
+/// (PopulateLoopDFS).
+///
+/// During the two CFG traversals each block is seen three times:
+/// 1) Discovered and mapped by a reverse CFG traversal.
+/// 2) Visited during a forward DFS CFG traversal.
+/// 3) Reverse-inserted in the loop in postorder following forward DFS.
+///
+/// The Block vectors are inclusive, so step 3 requires loop-depth number of
+/// insertions per block.
+template<class BlockT, class LoopT>
+void LoopInfoBase<BlockT, LoopT>::
+Analyze(DominatorTreeBase<BlockT> &DomTree) {
+
+ // Postorder traversal of the dominator tree.
+ DomTreeNodeBase<BlockT>* DomRoot = DomTree.getRootNode();
+ for (po_iterator<DomTreeNodeBase<BlockT>*> DomIter = po_begin(DomRoot),
+ DomEnd = po_end(DomRoot); DomIter != DomEnd; ++DomIter) {
+
+ BlockT *Header = DomIter->getBlock();
+ SmallVector<BlockT *, 4> Backedges;
+
+ // Check each predecessor of the potential loop header.
+ typedef GraphTraits<Inverse<BlockT*> > InvBlockTraits;
+ for (typename InvBlockTraits::ChildIteratorType PI =
+ InvBlockTraits::child_begin(Header),
+ PE = InvBlockTraits::child_end(Header); PI != PE; ++PI) {
+
+ BlockT *Backedge = *PI;
+
+ // If Header dominates predBB, this is a new loop. Collect the backedges.
+ if (DomTree.dominates(Header, Backedge)
+ && DomTree.isReachableFromEntry(Backedge)) {
+ Backedges.push_back(Backedge);
+ }
+ }
+ // Perform a backward CFG traversal to discover and map blocks in this loop.
+ if (!Backedges.empty()) {
+ LoopT *L = new LoopT(Header);
+ discoverAndMapSubloop(L, ArrayRef<BlockT*>(Backedges), this, DomTree);
+ }
+ }
+ // Perform a single forward CFG traversal to populate block and subloop
+ // vectors for all loops.
+ PopulateLoopsDFS<BlockT, LoopT> DFS(this);
+ DFS.traverse(DomRoot->getBlock());
+}
+
+// Debugging
+template<class BlockT, class LoopT>
+void LoopInfoBase<BlockT, LoopT>::print(raw_ostream &OS) const {
+ for (unsigned i = 0; i < TopLevelLoops.size(); ++i)
+ TopLevelLoops[i]->print(OS);
+#if 0
+ for (DenseMap<BasicBlock*, LoopT*>::const_iterator I = BBMap.begin(),
+ E = BBMap.end(); I != E; ++I)
+ OS << "BB '" << I->first->getName() << "' level = "
+ << I->second->getLoopDepth() << "\n";
+#endif
+}
+
+} // End llvm namespace
+
+#endif
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