const MachineDominatorTree &mdt,
bool IsPostRAFlag,
LiveIntervals *lis)
- : ScheduleDAG(mf), MLI(mli), MDT(mdt), MFI(mf.getFrameInfo()),
- InstrItins(mf.getTarget().getInstrItineraryData()), LIS(lis),
- IsPostRA(IsPostRAFlag), CanHandleTerminators(false), LoopRegs(MDT),
- FirstDbgValue(0) {
+ : ScheduleDAG(mf), MLI(mli), MDT(mdt), MFI(mf.getFrameInfo()), LIS(lis),
+ IsPostRA(IsPostRAFlag), CanHandleTerminators(false), FirstDbgValue(0) {
assert((IsPostRA || LIS) && "PreRA scheduling requires LiveIntervals");
DbgValues.clear();
assert(!(IsPostRA && MRI.getNumVirtRegs()) &&
void ScheduleDAGInstrs::startBlock(MachineBasicBlock *bb) {
BB = bb;
- LoopRegs.Deps.clear();
- if (MachineLoop *ML = MLI.getLoopFor(BB))
- if (BB == ML->getLoopLatch())
- LoopRegs.VisitLoop(ML);
}
void ScheduleDAGInstrs::finishBlock() {
// Ask the target if address-backscheduling is desirable, and if so how much.
const TargetSubtargetInfo &ST = TM.getSubtarget<TargetSubtargetInfo>();
- unsigned SpecialAddressLatency = ST.getSpecialAddressLatency();
- unsigned DataLatency = SU->Latency;
for (MCRegAliasIterator Alias(MO.getReg(), TRI, true);
Alias.isValid(); ++Alias) {
SUnit *UseSU = UseList[i].SU;
if (UseSU == SU)
continue;
- MachineInstr *UseMI = UseSU->getInstr();
+
+ SDep dep(SU, SDep::Data, 1, *Alias);
+
+ // Adjust the dependence latency using operand def/use information,
+ // then allow the target to perform its own adjustments.
int UseOp = UseList[i].OpIdx;
- unsigned LDataLatency = DataLatency;
- // Optionally add in a special extra latency for nodes that
- // feed addresses.
- // TODO: Perhaps we should get rid of
- // SpecialAddressLatency and just move this into
- // adjustSchedDependency for the targets that care about it.
- if (SpecialAddressLatency != 0 && UseSU != &ExitSU) {
- const MCInstrDesc &UseMCID = UseMI->getDesc();
- int RegUseIndex = UseMI->findRegisterUseOperandIdx(*Alias);
- assert(RegUseIndex >= 0 && "UseMI doesn't use register!");
- if (RegUseIndex >= 0 &&
- (UseMI->mayLoad() || UseMI->mayStore()) &&
- (unsigned)RegUseIndex < UseMCID.getNumOperands() &&
- UseMCID.OpInfo[RegUseIndex].isLookupPtrRegClass())
- LDataLatency += SpecialAddressLatency;
- }
- // Adjust the dependence latency using operand def/use
- // information (if any), and then allow the target to
- // perform its own adjustments.
- SDep dep(SU, SDep::Data, LDataLatency, *Alias);
- MachineInstr *RegUse = UseOp < 0 ? 0 : UseMI;
+ MachineInstr *RegUse = UseOp < 0 ? 0 : UseSU->getInstr();
dep.setLatency(
SchedModel.computeOperandLatency(SU->getInstr(), OperIdx,
RegUse, UseOp, /*FindMin=*/false));
if (Kind == SDep::Anti)
DefSU->addPred(SDep(SU, Kind, 0, /*Reg=*/*Alias));
else {
- unsigned AOLat = TII->getOutputLatency(InstrItins, MI, OperIdx,
- DefSU->getInstr());
+ unsigned AOLat =
+ SchedModel.computeOutputLatency(MI, OperIdx, DefSU->getInstr());
DefSU->addPred(SDep(SU, Kind, AOLat, /*Reg=*/*Alias));
}
}
// retrieve the existing SUnits list for this register's defs.
std::vector<PhysRegSUOper> &DefList = Defs[MO.getReg()];
- // If a def is going to wrap back around to the top of the loop,
- // backschedule it.
- if (DefList.empty()) {
- LoopDependencies::LoopDeps::iterator I = LoopRegs.Deps.find(MO.getReg());
- if (I != LoopRegs.Deps.end()) {
- const MachineOperand *UseMO = I->second.first;
- unsigned Count = I->second.second;
- const MachineInstr *UseMI = UseMO->getParent();
- unsigned UseMOIdx = UseMO - &UseMI->getOperand(0);
- const MCInstrDesc &UseMCID = UseMI->getDesc();
- const TargetSubtargetInfo &ST =
- TM.getSubtarget<TargetSubtargetInfo>();
- unsigned SpecialAddressLatency = ST.getSpecialAddressLatency();
- // TODO: If we knew the total depth of the region here, we could
- // handle the case where the whole loop is inside the region but
- // is large enough that the isScheduleHigh trick isn't needed.
- if (UseMOIdx < UseMCID.getNumOperands()) {
- // Currently, we only support scheduling regions consisting of
- // single basic blocks. Check to see if the instruction is in
- // the same region by checking to see if it has the same parent.
- if (UseMI->getParent() != MI->getParent()) {
- unsigned Latency = SU->Latency;
- if (UseMCID.OpInfo[UseMOIdx].isLookupPtrRegClass())
- Latency += SpecialAddressLatency;
- // This is a wild guess as to the portion of the latency which
- // will be overlapped by work done outside the current
- // scheduling region.
- Latency -= std::min(Latency, Count);
- // Add the artificial edge.
- ExitSU.addPred(SDep(SU, SDep::Order, Latency,
- /*Reg=*/0, /*isNormalMemory=*/false,
- /*isMustAlias=*/false,
- /*isArtificial=*/true));
- } else if (SpecialAddressLatency > 0 &&
- UseMCID.OpInfo[UseMOIdx].isLookupPtrRegClass()) {
- // The entire loop body is within the current scheduling region
- // and the latency of this operation is assumed to be greater
- // than the latency of the loop.
- // TODO: Recursively mark data-edge predecessors as
- // isScheduleHigh too.
- SU->isScheduleHigh = true;
- }
- }
- LoopRegs.Deps.erase(I);
- }
- }
-
// clear this register's use list
if (Uses.contains(MO.getReg()))
Uses[MO.getReg()].clear();
else {
SUnit *DefSU = DefI->SU;
if (DefSU != SU && DefSU != &ExitSU) {
- unsigned OutLatency = TII->getOutputLatency(InstrItins, MI, OperIdx,
- DefSU->getInstr());
+ unsigned OutLatency =
+ SchedModel.computeOutputLatency(MI, OperIdx, DefSU->getInstr());
DefSU->addPred(SDep(SU, SDep::Output, OutLatency, Reg));
}
DefI->SU = SU;
if (DefSU) {
// The reaching Def lives within this scheduling region.
// Create a data dependence.
- //
- // TODO: Handle "special" address latencies cleanly.
- SDep dep(DefSU, SDep::Data, DefSU->Latency, Reg);
+ SDep dep(DefSU, SDep::Data, 1, Reg);
// Adjust the dependence latency using operand def/use information, then
// allow the target to perform its own adjustments.
int DefOp = Def->findRegisterDefOperandIdx(Reg);
SU->isCommutable = MI->isCommutable();
// Assign the Latency field of SU using target-provided information.
- computeLatency(SU);
+ SU->Latency = SchedModel.computeInstrLatency(SU->getInstr());
}
}
PendingLoads.clear();
}
-void ScheduleDAGInstrs::computeLatency(SUnit *SU) {
- // Compute the latency for the node. We only provide a default for missing
- // itineraries. Empty itineraries still have latency properties.
- if (!InstrItins) {
- SU->Latency = 1;
-
- // Simplistic target-independent heuristic: assume that loads take
- // extra time.
- if (SU->getInstr()->mayLoad())
- SU->Latency += 2;
- } else {
- SU->Latency = TII->getInstrLatency(InstrItins, SU->getInstr());
- }
-}
-
void ScheduleDAGInstrs::dumpNode(const SUnit *SU) const {
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
SU->getInstr()->dump();
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