56 struct MIRef {  struct
57   MachineInstr *MI = nullptr;
58   MachineBasicBlock *MBB = nullptr;
60   size_t Pos = 0;
62   MIRef(MachineBasicBlock *MBB) : MBB(MBB) {  in MIRef()  argument
67   MIRef(MachineInstr *MI)  in MIRef()  function
70   MIRef(MachineInstr *MI, MachineBasicBlock *MBB)  in MIRef()  argument
73   MIRef(MachineInstr *MI, MachineBasicBlock *MBB, size_t Pos)  in MIRef()  argument
75   operator bool() const { return MBB != nullptr; }  in operator bool()
76   bool operator==(const MIRef &RHS) const {  in operator ==()
79   bool operator!=(const MIRef &RHS) const { return !(*this == RHS); }  in operator !=()
80   bool operator<(const MIRef &RHS) const {  in operator <()
85   bool operator>(const MIRef &RHS) const {  in operator >()