typedef std::vector<MergePotentialsElt>::iterator MPIterator;
std::vector<MergePotentialsElt> MergePotentials;
SmallPtrSet<const MachineBasicBlock*, 2> TriedMerging;
+ DenseMap<const MachineBasicBlock *, int> FuncletMembership;
class SameTailElt {
MPIterator MPIter;