- : Node(0), Instr(0), OrigNode(0), SchedClass(0), NodeNum(~0u),
- NodeQueueId(0), NumPreds(0), NumSuccs(0), NumPredsLeft(0),
- NumSuccsLeft(0), WeakPredsLeft(0), WeakSuccsLeft(0), NumRegDefsLeft(0),
- Latency(0), isVRegCycle(false), isCall(false), isCallOp(false),
- isTwoAddress(false), isCommutable(false), hasPhysRegDefs(false),
- hasPhysRegClobbers(false), isPending(false), isAvailable(false),
- isScheduled(false), isScheduleHigh(false), isScheduleLow(false),
- isCloned(false), SchedulingPref(Sched::None),
- isDepthCurrent(false), isHeightCurrent(false), Depth(0), Height(0),
- TopReadyCycle(0), BotReadyCycle(0), CopyDstRC(NULL), CopySrcRC(NULL) {}
+ : Node(nullptr), Instr(nullptr), OrigNode(nullptr), SchedClass(nullptr),
+ NodeNum(BoundaryID), NodeQueueId(0), NumPreds(0), NumSuccs(0),
+ NumPredsLeft(0), NumSuccsLeft(0), WeakPredsLeft(0), WeakSuccsLeft(0),
+ NumRegDefsLeft(0), Latency(0), isVRegCycle(false), isCall(false),
+ isCallOp(false), isTwoAddress(false), isCommutable(false),
+ hasPhysRegUses(false), hasPhysRegDefs(false), hasPhysRegClobbers(false),
+ isPending(false), isAvailable(false), isScheduled(false),
+ isScheduleHigh(false), isScheduleLow(false), isCloned(false),
+ isUnbuffered(false), hasReservedResource(false),
+ SchedulingPref(Sched::None), isDepthCurrent(false),
+ isHeightCurrent(false), Depth(0), Height(0), TopReadyCycle(0),
+ BotReadyCycle(0), CopyDstRC(nullptr), CopySrcRC(nullptr) {}
+
+ /// \brief Boundary nodes are placeholders for the boundary of the
+ /// scheduling region.
+ ///
+ /// BoundaryNodes can have DAG edges, including Data edges, but they do not
+ /// correspond to schedulable entities (e.g. instructions) and do not have a
+ /// valid ID. Consequently, always check for boundary nodes before accessing
+ /// an assoicative data structure keyed on node ID.
+ bool isBoundaryNode() const { return NodeNum == BoundaryID; };