+// Initialize NumNodeDefs for the current Node's opcode.
+void ScheduleDAGSDNodes::RegDefIter::InitNodeNumDefs() {
+ // Check for phys reg copy.
+ if (!Node)
+ return;
+
+ if (!Node->isMachineOpcode()) {
+ if (Node->getOpcode() == ISD::CopyFromReg)
+ NodeNumDefs = 1;
+ else
+ NodeNumDefs = 0;
+ return;
+ }
+ unsigned POpc = Node->getMachineOpcode();
+ if (POpc == TargetOpcode::IMPLICIT_DEF) {
+ // No register need be allocated for this.
+ NodeNumDefs = 0;
+ return;
+ }
+ if (POpc == TargetOpcode::PATCHPOINT &&
+ Node->getValueType(0) == MVT::Other) {
+ // PATCHPOINT is defined to have one result, but it might really have none
+ // if we're not using CallingConv::AnyReg. Don't mistake the chain for a
+ // real definition.
+ NodeNumDefs = 0;
+ return;
+ }
+ unsigned NRegDefs = SchedDAG->TII->get(Node->getMachineOpcode()).getNumDefs();
+ // Some instructions define regs that are not represented in the selection DAG
+ // (e.g. unused flags). See tMOVi8. Make sure we don't access past NumValues.
+ NodeNumDefs = std::min(Node->getNumValues(), NRegDefs);
+ DefIdx = 0;
+}
+
+// Construct a RegDefIter for this SUnit and find the first valid value.
+ScheduleDAGSDNodes::RegDefIter::RegDefIter(const SUnit *SU,
+ const ScheduleDAGSDNodes *SD)
+ : SchedDAG(SD), Node(SU->getNode()), DefIdx(0), NodeNumDefs(0) {
+ InitNodeNumDefs();
+ Advance();
+}
+
+// Advance to the next valid value defined by the SUnit.
+void ScheduleDAGSDNodes::RegDefIter::Advance() {
+ for (;Node;) { // Visit all glued nodes.
+ for (;DefIdx < NodeNumDefs; ++DefIdx) {
+ if (!Node->hasAnyUseOfValue(DefIdx))
+ continue;
+ ValueType = Node->getSimpleValueType(DefIdx);
+ ++DefIdx;
+ return; // Found a normal regdef.
+ }
+ Node = Node->getGluedNode();
+ if (!Node) {
+ return; // No values left to visit.
+ }
+ InitNodeNumDefs();
+ }
+}
+
+void ScheduleDAGSDNodes::InitNumRegDefsLeft(SUnit *SU) {
+ assert(SU->NumRegDefsLeft == 0 && "expect a new node");
+ for (RegDefIter I(SU, this); I.IsValid(); I.Advance()) {
+ assert(SU->NumRegDefsLeft < USHRT_MAX && "overflow is ok but unexpected");
+ ++SU->NumRegDefsLeft;
+ }
+}
+
+void ScheduleDAGSDNodes::computeLatency(SUnit *SU) {
+ SDNode *N = SU->getNode();
+
+ // TokenFactor operands are considered zero latency, and some schedulers
+ // (e.g. Top-Down list) may rely on the fact that operand latency is nonzero
+ // whenever node latency is nonzero.
+ if (N && N->getOpcode() == ISD::TokenFactor) {
+ SU->Latency = 0;
+ return;
+ }
+
+ // Check to see if the scheduler cares about latencies.
+ if (forceUnitLatencies()) {
+ SU->Latency = 1;
+ return;
+ }
+
+ if (!InstrItins || InstrItins->isEmpty()) {
+ if (N && N->isMachineOpcode() &&
+ TII->isHighLatencyDef(N->getMachineOpcode()))
+ SU->Latency = HighLatencyCycles;
+ else
+ SU->Latency = 1;
+ return;
+ }
+