+}
+
+/// Check to see if any of the pending instructions are ready to issue. If
+/// so, add them to the available queue.
+void ScheduleDAGRRList::ReleasePending() {
+ if (!EnableSchedCycles) {
+ assert(PendingQueue.empty() && "pending instrs not allowed in this mode");
+ return;
+ }
+
+ // If the available queue is empty, it is safe to reset MinAvailableCycle.
+ if (AvailableQueue->empty())
+ MinAvailableCycle = UINT_MAX;
+
+ // Check to see if any of the pending instructions are ready to issue. If
+ // so, add them to the available queue.
+ for (unsigned i = 0, e = PendingQueue.size(); i != e; ++i) {
+ unsigned ReadyCycle =
+ isBottomUp ? PendingQueue[i]->getHeight() : PendingQueue[i]->getDepth();
+ if (ReadyCycle < MinAvailableCycle)
+ MinAvailableCycle = ReadyCycle;
+
+ if (PendingQueue[i]->isAvailable) {
+ if (!isReady(PendingQueue[i]))
+ continue;
+ AvailableQueue->push(PendingQueue[i]);
+ }
+ PendingQueue[i]->isPending = false;
+ PendingQueue[i] = PendingQueue.back();
+ PendingQueue.pop_back();
+ --i; --e;
+ }
+}
+
+/// Move the scheduler state forward by the specified number of Cycles.
+void ScheduleDAGRRList::AdvanceToCycle(unsigned NextCycle) {
+ if (NextCycle <= CurCycle)
+ return;
+
+ AvailableQueue->setCurCycle(NextCycle);
+ if (HazardRec->getMaxLookAhead() == 0) {
+ // Bypass lots of virtual calls in case of long latency.
+ CurCycle = NextCycle;
+ }
+ else {
+ for (; CurCycle != NextCycle; ++CurCycle) {
+ if (isBottomUp)
+ HazardRec->RecedeCycle();
+ else
+ HazardRec->AdvanceCycle();
+ }
+ }
+ // FIXME: Instead of visiting the pending Q each time, set a dirty flag on the
+ // available Q to release pending nodes at least once before popping.
+ ReleasePending();
+}
+
+/// Move the scheduler state forward until the specified node's dependents are
+/// ready and can be scheduled with no resource conflicts.
+void ScheduleDAGRRList::AdvancePastStalls(SUnit *SU) {
+ if (!EnableSchedCycles)
+ return;
+
+ unsigned ReadyCycle = isBottomUp ? SU->getHeight() : SU->getDepth();
+
+ // Bump CurCycle to account for latency. We assume the latency of other
+ // available instructions may be hidden by the stall (not a full pipe stall).
+ // This updates the hazard recognizer's cycle before reserving resources for
+ // this instruction.
+ AdvanceToCycle(ReadyCycle);
+
+ // Calls are scheduled in their preceding cycle, so don't conflict with
+ // hazards from instructions after the call. EmitNode will reset the
+ // scoreboard state before emitting the call.
+ if (isBottomUp && SU->isCall)
+ return;
+
+ // FIXME: For resource conflicts in very long non-pipelined stages, we
+ // should probably skip ahead here to avoid useless scoreboard checks.
+ int Stalls = 0;
+ while (true) {
+ ScheduleHazardRecognizer::HazardType HT =
+ HazardRec->getHazardType(SU, isBottomUp ? -Stalls : Stalls);
+
+ if (HT == ScheduleHazardRecognizer::NoHazard)
+ break;
+
+ ++Stalls;
+ }
+ AdvanceToCycle(CurCycle + Stalls);
+}
+
+/// Record this SUnit in the HazardRecognizer.
+/// Does not update CurCycle.
+void ScheduleDAGRRList::EmitNode(SUnit *SU) {
+ if (!EnableSchedCycles || HazardRec->getMaxLookAhead() == 0)
+ return;
+
+ // Check for phys reg copy.
+ if (!SU->getNode())
+ return;
+
+ switch (SU->getNode()->getOpcode()) {
+ default:
+ assert(SU->getNode()->isMachineOpcode() &&
+ "This target-independent node should not be scheduled.");
+ break;
+ case ISD::MERGE_VALUES:
+ case ISD::TokenFactor:
+ case ISD::CopyToReg:
+ case ISD::CopyFromReg:
+ case ISD::EH_LABEL:
+ // Noops don't affect the scoreboard state. Copies are likely to be
+ // removed.
+ return;
+ case ISD::INLINEASM:
+ // For inline asm, clear the pipeline state.
+ HazardRec->Reset();
+ return;
+ }
+ if (isBottomUp && SU->isCall) {
+ // Calls are scheduled with their preceding instructions. For bottom-up
+ // scheduling, clear the pipeline state before emitting.
+ HazardRec->Reset();
+ }
+
+ HazardRec->EmitInstruction(SU);
+
+ if (!isBottomUp && SU->isCall) {
+ HazardRec->Reset();
+ }
+}
+
+/// ScheduleNodeBottomUp - Add the node to the schedule. Decrement the pending
+/// count of its predecessors. If a predecessor pending count is zero, add it to
+/// the Available queue.
+void ScheduleDAGRRList::ScheduleNodeBottomUp(SUnit *SU) {
+ DEBUG(dbgs() << "\n*** Scheduling [" << CurCycle << "]: ");
+ DEBUG(SU->dump(this));
+
+#ifndef NDEBUG
+ if (CurCycle < SU->getHeight())
+ DEBUG(dbgs() << " Height [" << SU->getHeight() << "] pipeline stall!\n");
+#endif
+
+ // FIXME: Do not modify node height. It may interfere with
+ // backtracking. Instead add a "ready cycle" to SUnit. Before scheduling the
+ // node it's ready cycle can aid heuristics, and after scheduling it can
+ // indicate the scheduled cycle.
+ SU->setHeightToAtLeast(CurCycle);
+
+ // Reserve resources for the scheduled intruction.
+ EmitNode(SU);
+
+ Sequence.push_back(SU);
+
+ AvailableQueue->ScheduledNode(SU);
+
+ // Update liveness of predecessors before successors to avoid treating a
+ // two-address node as a live range def.
+ ReleasePredecessors(SU);