+ explicit MachineRegisterInfo(const MachineFunction *MF);
+
+ const TargetRegisterInfo *getTargetRegisterInfo() const {
+ return MF->getSubtarget().getRegisterInfo();
+ }
+
+ void resetDelegate(Delegate *delegate) {
+ // Ensure another delegate does not take over unless the current
+ // delegate first unattaches itself. If we ever need to multicast
+ // notifications, we will need to change to using a list.
+ assert(TheDelegate == delegate &&
+ "Only the current delegate can perform reset!");
+ TheDelegate = nullptr;
+ }
+
+ void setDelegate(Delegate *delegate) {
+ assert(delegate && !TheDelegate &&
+ "Attempted to set delegate to null, or to change it without "
+ "first resetting it!");
+
+ TheDelegate = delegate;
+ }
+
+ //===--------------------------------------------------------------------===//
+ // Function State
+ //===--------------------------------------------------------------------===//
+
+ // isSSA - Returns true when the machine function is in SSA form. Early
+ // passes require the machine function to be in SSA form where every virtual
+ // register has a single defining instruction.
+ //
+ // The TwoAddressInstructionPass and PHIElimination passes take the machine
+ // function out of SSA form when they introduce multiple defs per virtual
+ // register.
+ bool isSSA() const { return IsSSA; }
+
+ // leaveSSA - Indicates that the machine function is no longer in SSA form.
+ void leaveSSA() { IsSSA = false; }
+
+ /// tracksLiveness - Returns true when tracking register liveness accurately.
+ ///
+ /// While this flag is true, register liveness information in basic block
+ /// live-in lists and machine instruction operands is accurate. This means it
+ /// can be used to change the code in ways that affect the values in
+ /// registers, for example by the register scavenger.
+ ///
+ /// When this flag is false, liveness is no longer reliable.
+ bool tracksLiveness() const { return TracksLiveness; }
+
+ /// invalidateLiveness - Indicates that register liveness is no longer being
+ /// tracked accurately.
+ ///
+ /// This should be called by late passes that invalidate the liveness
+ /// information.
+ void invalidateLiveness() { TracksLiveness = false; }
+
+ /// Returns true if liveness for register class @p RC should be tracked at
+ /// the subregister level.
+ bool shouldTrackSubRegLiveness(const TargetRegisterClass &RC) const {
+ return subRegLivenessEnabled() && RC.HasDisjunctSubRegs;
+ }
+ bool shouldTrackSubRegLiveness(unsigned VReg) const {
+ assert(TargetRegisterInfo::isVirtualRegister(VReg) && "Must pass a VReg");
+ return shouldTrackSubRegLiveness(*getRegClass(VReg));
+ }
+ bool subRegLivenessEnabled() const {
+ return TracksSubRegLiveness;
+ }
+
+ void enableSubRegLiveness(bool Enable = true) {
+ TracksSubRegLiveness = Enable;
+ }
+