static cl::opt<bool> ViewMISchedDAGs("view-misched-dags", cl::Hidden,
cl::desc("Pop up a window to show MISched dags after they are processed"));
+/// In some situations a few uninteresting nodes depend on nearly all other
+/// nodes in the graph, provide a cutoff to hide them.
+static cl::opt<unsigned> ViewMISchedCutoff("view-misched-cutoff", cl::Hidden,
+ cl::desc("Hide nodes with more predecessor/successor than cutoff"));
+
static cl::opt<unsigned> MISchedCutoff("misched-cutoff", cl::Hidden,
cl::desc("Stop scheduling after N instructions"), cl::init(~0U));
void print(raw_ostream &O, const Module* = nullptr) const override;
protected:
- void scheduleRegions(ScheduleDAGInstrs &Scheduler);
+ void scheduleRegions(ScheduleDAGInstrs &Scheduler, bool FixKillFlags);
};
/// MachineScheduler runs after coalescing and before register allocation.
} else if (!mf.getSubtarget().enableMachineScheduler())
return false;
- DEBUG(dbgs() << "Before MISsched:\n"; mf.print(dbgs()));
+ DEBUG(dbgs() << "Before MISched:\n"; mf.print(dbgs()));
// Initialize the context of the pass.
MF = &mf;
// Instantiate the selected scheduler for this target, function, and
// optimization level.
std::unique_ptr<ScheduleDAGInstrs> Scheduler(createMachineScheduler());
- scheduleRegions(*Scheduler);
+ scheduleRegions(*Scheduler, false);
DEBUG(LIS->dump());
if (VerifyScheduling)
// Instantiate the selected scheduler for this target, function, and
// optimization level.
std::unique_ptr<ScheduleDAGInstrs> Scheduler(createPostMachineScheduler());
- scheduleRegions(*Scheduler);
+ scheduleRegions(*Scheduler, true);
if (VerifyScheduling)
MF->verify(this, "After post machine scheduling.");
static bool isSchedBoundary(MachineBasicBlock::iterator MI,
MachineBasicBlock *MBB,
MachineFunction *MF,
- const TargetInstrInfo *TII,
- bool IsPostRA) {
+ const TargetInstrInfo *TII) {
return MI->isCall() || TII->isSchedulingBoundary(MI, MBB, *MF);
}
/// Main driver for both MachineScheduler and PostMachineScheduler.
-void MachineSchedulerBase::scheduleRegions(ScheduleDAGInstrs &Scheduler) {
+void MachineSchedulerBase::scheduleRegions(ScheduleDAGInstrs &Scheduler,
+ bool FixKillFlags) {
const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
- bool IsPostRA = Scheduler.isPostRA();
// Visit all machine basic blocks.
//
for (MachineFunction::iterator MBB = MF->begin(), MBBEnd = MF->end();
MBB != MBBEnd; ++MBB) {
- Scheduler.startBlock(MBB);
+ Scheduler.startBlock(&*MBB);
#ifndef NDEBUG
if (SchedOnlyFunc.getNumOccurrences() && SchedOnlyFunc != MF->getName())
// Avoid decrementing RegionEnd for blocks with no terminator.
if (RegionEnd != MBB->end() ||
- isSchedBoundary(std::prev(RegionEnd), MBB, MF, TII, IsPostRA)) {
+ isSchedBoundary(&*std::prev(RegionEnd), &*MBB, MF, TII)) {
--RegionEnd;
// Count the boundary instruction.
--RemainingInstrs;
unsigned NumRegionInstrs = 0;
MachineBasicBlock::iterator I = RegionEnd;
for(;I != MBB->begin(); --I, --RemainingInstrs) {
- if (isSchedBoundary(std::prev(I), MBB, MF, TII, IsPostRA))
+ if (isSchedBoundary(&*std::prev(I), &*MBB, MF, TII))
break;
if (!I->isDebugValue())
++NumRegionInstrs;
}
// Notify the scheduler of the region, even if we may skip scheduling
// it. Perhaps it still needs to be bundled.
- Scheduler.enterRegion(MBB, I, RegionEnd, NumRegionInstrs);
+ Scheduler.enterRegion(&*MBB, I, RegionEnd, NumRegionInstrs);
// Skip empty scheduling regions (0 or 1 schedulable instructions).
if (I == RegionEnd || I == std::prev(RegionEnd)) {
Scheduler.exitRegion();
continue;
}
- DEBUG(dbgs() << "********** " << ((Scheduler.isPostRA()) ? "PostRA " : "")
- << "MI Scheduling **********\n");
+ DEBUG(dbgs() << "********** MI Scheduling **********\n");
DEBUG(dbgs() << MF->getName()
<< ":BB#" << MBB->getNumber() << " " << MBB->getName()
<< "\n From: " << *I << " To: ";
}
assert(RemainingInstrs == 0 && "Instruction count mismatch!");
Scheduler.finishBlock();
- if (Scheduler.isPostRA()) {
- // FIXME: Ideally, no further passes should rely on kill flags. However,
- // thumb2 size reduction is currently an exception.
- Scheduler.fixupKills(MBB);
- }
+ // FIXME: Ideally, no further passes should rely on kill flags. However,
+ // thumb2 size reduction is currently an exception, so the PostMIScheduler
+ // needs to do this.
+ if (FixKillFlags)
+ Scheduler.fixupKills(&*MBB);
}
Scheduler.finalizeSchedule();
}
LLVM_DUMP_METHOD
void ReadyQueue::dump() {
- dbgs() << Name << ": ";
+ dbgs() << "Queue " << Name << ": ";
for (unsigned i = 0, e = Queue.size(); i < e; ++i)
dbgs() << Queue[i]->NodeNum << " ";
dbgs() << "\n";
/// does not consider liveness or register pressure. It is useful for PostRA
/// scheduling and potentially other custom schedulers.
void ScheduleDAGMI::schedule() {
+ DEBUG(dbgs() << "ScheduleDAGMI::schedule starting\n");
+ DEBUG(SchedImpl->dumpPolicy());
+
// Build the DAG.
buildSchedGraph(AA);
initQueues(TopRoots, BotRoots);
bool IsTopNode = false;
- while (SUnit *SU = SchedImpl->pickNode(IsTopNode)) {
+ while (true) {
+ DEBUG(dbgs() << "** ScheduleDAGMI::schedule picking next node\n");
+ SUnit *SU = SchedImpl->pickNode(IsTopNode);
+ if (!SU) break;
+
assert(!SU->isScheduled && "Node already scheduled");
if (!checkSchedLimit())
break;
}
// RegisterPressureTracker guarantees that readsReg is true for LiveUses.
assert(VNI && "No live value at use.");
- for (VReg2UseMap::iterator
- UI = VRegUses.find(Reg); UI != VRegUses.end(); ++UI) {
- SUnit *SU = UI->SU;
+ for (const VReg2SUnit &V2SU
+ : make_range(VRegUses.find(Reg), VRegUses.end())) {
+ SUnit *SU = V2SU.SU;
DEBUG(dbgs() << " UpdateRegP: SU(" << SU->NodeNum << ") "
<< *SU->getInstr());
// If this use comes before the reaching def, it cannot be a last use, so
/// ScheduleDAGMILive then it will want to override this virtual method in order
/// to update any specialized state.
void ScheduleDAGMILive::schedule() {
+ DEBUG(dbgs() << "ScheduleDAGMILive::schedule starting\n");
+ DEBUG(SchedImpl->dumpPolicy());
buildDAGWithRegPressure();
Topo.InitDAGTopologicalSorting();
}
bool IsTopNode = false;
- while (SUnit *SU = SchedImpl->pickNode(IsTopNode)) {
+ while (true) {
+ DEBUG(dbgs() << "** ScheduleDAGMILive::schedule picking next node\n");
+ SUnit *SU = SchedImpl->pickNode(IsTopNode);
+ if (!SU) break;
+
assert(!SU->isScheduled && "Node already scheduled");
if (!checkSchedLimit())
break;
unsigned LiveOutHeight = DefSU->getHeight();
unsigned LiveOutDepth = DefSU->getDepth() + DefSU->Latency;
// Visit all local users of the vreg def.
- for (VReg2UseMap::iterator
- UI = VRegUses.find(Reg); UI != VRegUses.end(); ++UI) {
- if (UI->SU == &ExitSU)
+ for (const VReg2SUnit &V2SU
+ : make_range(VRegUses.find(Reg), VRegUses.end())) {
+ SUnit *SU = V2SU.SU;
+ if (SU == &ExitSU)
continue;
// Only consider uses of the phi.
LiveQueryResult LRQ =
- LI.Query(LIS->getInstructionIndex(UI->SU->getInstr()));
+ LI.Query(LIS->getInstructionIndex(SU->getInstr()));
if (!LRQ.valueIn()->isPHIDef())
continue;
// overestimate in strange cases. This allows cyclic latency to be
// estimated as the minimum slack of the vreg's depth or height.
unsigned CyclicLatency = 0;
- if (LiveOutDepth > UI->SU->getDepth())
- CyclicLatency = LiveOutDepth - UI->SU->getDepth();
+ if (LiveOutDepth > SU->getDepth())
+ CyclicLatency = LiveOutDepth - SU->getDepth();
- unsigned LiveInHeight = UI->SU->getHeight() + DefSU->Latency;
+ unsigned LiveInHeight = SU->getHeight() + DefSU->Latency;
if (LiveInHeight > LiveOutHeight) {
if (LiveInHeight - LiveOutHeight < CyclicLatency)
CyclicLatency = LiveInHeight - LiveOutHeight;
CyclicLatency = 0;
DEBUG(dbgs() << "Cyclic Path: SU(" << DefSU->NodeNum << ") -> SU("
- << UI->SU->NodeNum << ") = " << CyclicLatency << "c\n");
+ << SU->NodeNum << ") = " << CyclicLatency << "c\n");
if (CyclicLatency > MaxCyclicLatency)
MaxCyclicLatency = CyclicLatency;
}
Latency = Cand.SU->getDepth();
break;
}
- dbgs() << " SU(" << Cand.SU->NodeNum << ") " << getReasonStr(Cand.Reason);
+ dbgs() << " Cand SU(" << Cand.SU->NodeNum << ") " << getReasonStr(Cand.Reason);
if (P.isValid())
dbgs() << " " << TRI->getRegPressureSetName(P.getPSet())
<< ":" << P.getUnitInc() << " ";
}
}
+void GenericScheduler::dumpPolicy() {
+ dbgs() << "GenericScheduler RegionPolicy: "
+ << " ShouldTrackPressure=" << RegionPolicy.ShouldTrackPressure
+ << " OnlyTopDown=" << RegionPolicy.OnlyTopDown
+ << " OnlyBottomUp=" << RegionPolicy.OnlyBottomUp
+ << "\n";
+}
+
/// Set IsAcyclicLatencyLimited if the acyclic path is longer than the cyclic
/// critical path by more cycles than it takes to drain the instruction buffer.
/// We estimate an upper bounds on in-flight instructions as:
}
}
DEBUG(if (TryCand.RPDelta.Excess.isValid())
- dbgs() << " SU(" << TryCand.SU->NodeNum << ") "
+ dbgs() << " Try SU(" << TryCand.SU->NodeNum << ") "
<< TRI->getRegPressureSetName(TryCand.RPDelta.Excess.getPSet())
<< ":" << TryCand.RPDelta.Excess.getUnitInc() << "\n");
// Avoid serializing long latency dependence chains.
// For acyclic path limited loops, latency was already checked above.
- if (Cand.Policy.ReduceLatency && !Rem.IsAcyclicLatencyLimited
- && tryLatency(TryCand, Cand, Zone)) {
+ if (!RegionPolicy.DisableLatencyHeuristic && Cand.Policy.ReduceLatency &&
+ !Rem.IsAcyclicLatencyLimited && tryLatency(TryCand, Cand, Zone)) {
return;
}
}
static bool isNodeHidden(const SUnit *Node) {
- return (Node->Preds.size() > 10 || Node->Succs.size() > 10);
- }
-
- static bool hasNodeAddressLabel(const SUnit *Node,
- const ScheduleDAG *Graph) {
- return false;
+ if (ViewMISchedCutoff == 0)
+ return false;
+ return (Node->Preds.size() > ViewMISchedCutoff
+ || Node->Succs.size() > ViewMISchedCutoff);
}
/// If you want to override the dot attributes printed for a particular