1 //===----- SchedulePostRAList.cpp - list scheduler ------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This implements a top-down list scheduler, using standard algorithms.
11 // The basic approach uses a priority queue of available nodes to schedule.
12 // One at a time, nodes are taken from the priority queue (thus in priority
13 // order), checked for legality to schedule, and emitted if legal.
15 // Nodes may not be legal to schedule either due to structural hazards (e.g.
16 // pipeline or resource constraints) or because an input to the instruction has
17 // not completed execution.
19 //===----------------------------------------------------------------------===//
21 #define DEBUG_TYPE "post-RA-sched"
22 #include "AntiDepBreaker.h"
23 #include "AggressiveAntiDepBreaker.h"
24 #include "CriticalAntiDepBreaker.h"
25 #include "ExactHazardRecognizer.h"
26 #include "SimpleHazardRecognizer.h"
27 #include "ScheduleDAGInstrs.h"
28 #include "llvm/CodeGen/Passes.h"
29 #include "llvm/CodeGen/LatencyPriorityQueue.h"
30 #include "llvm/CodeGen/SchedulerRegistry.h"
31 #include "llvm/CodeGen/MachineDominators.h"
32 #include "llvm/CodeGen/MachineFrameInfo.h"
33 #include "llvm/CodeGen/MachineFunctionPass.h"
34 #include "llvm/CodeGen/MachineLoopInfo.h"
35 #include "llvm/CodeGen/MachineRegisterInfo.h"
36 #include "llvm/CodeGen/ScheduleHazardRecognizer.h"
37 #include "llvm/Analysis/AliasAnalysis.h"
38 #include "llvm/Target/TargetLowering.h"
39 #include "llvm/Target/TargetMachine.h"
40 #include "llvm/Target/TargetInstrInfo.h"
41 #include "llvm/Target/TargetRegisterInfo.h"
42 #include "llvm/Target/TargetSubtarget.h"
43 #include "llvm/Support/CommandLine.h"
44 #include "llvm/Support/Debug.h"
45 #include "llvm/Support/ErrorHandling.h"
46 #include "llvm/Support/raw_ostream.h"
47 #include "llvm/ADT/BitVector.h"
48 #include "llvm/ADT/Statistic.h"
53 STATISTIC(NumNoops, "Number of noops inserted");
54 STATISTIC(NumStalls, "Number of pipeline stalls");
55 STATISTIC(NumFixedAnti, "Number of fixed anti-dependencies");
57 // Post-RA scheduling is enabled with
58 // TargetSubtarget.enablePostRAScheduler(). This flag can be used to
59 // override the target.
61 EnablePostRAScheduler("post-RA-scheduler",
62 cl::desc("Enable scheduling after register allocation"),
63 cl::init(false), cl::Hidden);
64 static cl::opt<std::string>
65 EnableAntiDepBreaking("break-anti-dependencies",
66 cl::desc("Break post-RA scheduling anti-dependencies: "
67 "\"critical\", \"all\", or \"none\""),
68 cl::init("none"), cl::Hidden);
70 EnablePostRAHazardAvoidance("avoid-hazards",
71 cl::desc("Enable exact hazard avoidance"),
72 cl::init(true), cl::Hidden);
74 // If DebugDiv > 0 then only schedule MBB with (ID % DebugDiv) == DebugMod
76 DebugDiv("postra-sched-debugdiv",
77 cl::desc("Debug control MBBs that are scheduled"),
78 cl::init(0), cl::Hidden);
80 DebugMod("postra-sched-debugmod",
81 cl::desc("Debug control MBBs that are scheduled"),
82 cl::init(0), cl::Hidden);
84 AntiDepBreaker::~AntiDepBreaker() { }
87 class PostRAScheduler : public MachineFunctionPass {
89 CodeGenOpt::Level OptLevel;
93 PostRAScheduler(CodeGenOpt::Level ol) :
94 MachineFunctionPass(&ID), OptLevel(ol) {}
96 void getAnalysisUsage(AnalysisUsage &AU) const {
98 AU.addRequired<AliasAnalysis>();
99 AU.addRequired<MachineDominatorTree>();
100 AU.addPreserved<MachineDominatorTree>();
101 AU.addRequired<MachineLoopInfo>();
102 AU.addPreserved<MachineLoopInfo>();
103 MachineFunctionPass::getAnalysisUsage(AU);
106 const char *getPassName() const {
107 return "Post RA top-down list latency scheduler";
110 bool runOnMachineFunction(MachineFunction &Fn);
112 char PostRAScheduler::ID = 0;
114 class SchedulePostRATDList : public ScheduleDAGInstrs {
115 /// AvailableQueue - The priority queue to use for the available SUnits.
117 LatencyPriorityQueue AvailableQueue;
119 /// PendingQueue - This contains all of the instructions whose operands have
120 /// been issued, but their results are not ready yet (due to the latency of
121 /// the operation). Once the operands becomes available, the instruction is
122 /// added to the AvailableQueue.
123 std::vector<SUnit*> PendingQueue;
125 /// Topo - A topological ordering for SUnits.
126 ScheduleDAGTopologicalSort Topo;
128 /// HazardRec - The hazard recognizer to use.
129 ScheduleHazardRecognizer *HazardRec;
131 /// AntiDepBreak - Anti-dependence breaking object, or NULL if none
132 AntiDepBreaker *AntiDepBreak;
134 /// AA - AliasAnalysis for making memory reference queries.
137 /// KillIndices - The index of the most recent kill (proceding bottom-up),
138 /// or ~0u if the register is not live.
139 unsigned KillIndices[TargetRegisterInfo::FirstVirtualRegister];
142 SchedulePostRATDList(MachineFunction &MF,
143 const MachineLoopInfo &MLI,
144 const MachineDominatorTree &MDT,
145 ScheduleHazardRecognizer *HR,
148 : ScheduleDAGInstrs(MF, MLI, MDT), Topo(SUnits),
149 HazardRec(HR), AntiDepBreak(ADB), AA(aa) {}
151 ~SchedulePostRATDList() {
154 /// StartBlock - Initialize register live-range state for scheduling in
157 void StartBlock(MachineBasicBlock *BB);
159 /// Schedule - Schedule the instruction range using list scheduling.
163 /// Observe - Update liveness information to account for the current
164 /// instruction, which will not be scheduled.
166 void Observe(MachineInstr *MI, unsigned Count);
168 /// FinishBlock - Clean up register live-range state.
172 /// FixupKills - Fix register kill flags that have been made
173 /// invalid due to scheduling
175 void FixupKills(MachineBasicBlock *MBB);
178 void ReleaseSucc(SUnit *SU, SDep *SuccEdge);
179 void ReleaseSuccessors(SUnit *SU);
180 void ScheduleNodeTopDown(SUnit *SU, unsigned CurCycle);
181 void ListScheduleTopDown();
182 void StartBlockForKills(MachineBasicBlock *BB);
184 // ToggleKillFlag - Toggle a register operand kill flag. Other
185 // adjustments may be made to the instruction if necessary. Return
186 // true if the operand has been deleted, false if not.
187 bool ToggleKillFlag(MachineInstr *MI, MachineOperand &MO);
191 /// isSchedulingBoundary - Test if the given instruction should be
192 /// considered a scheduling boundary. This primarily includes labels
195 static bool isSchedulingBoundary(const MachineInstr *MI,
196 const MachineFunction &MF) {
197 // Terminators and labels can't be scheduled around.
198 if (MI->getDesc().isTerminator() || MI->isLabel())
201 // Don't attempt to schedule around any instruction that modifies
202 // a stack-oriented pointer, as it's unlikely to be profitable. This
203 // saves compile time, because it doesn't require every single
204 // stack slot reference to depend on the instruction that does the
206 const TargetLowering &TLI = *MF.getTarget().getTargetLowering();
207 if (MI->modifiesRegister(TLI.getStackPointerRegisterToSaveRestore()))
213 bool PostRAScheduler::runOnMachineFunction(MachineFunction &Fn) {
214 AA = &getAnalysis<AliasAnalysis>();
216 // Check for explicit enable/disable of post-ra scheduling.
217 TargetSubtarget::AntiDepBreakMode AntiDepMode = TargetSubtarget::ANTIDEP_NONE;
218 if (EnablePostRAScheduler.getPosition() > 0) {
219 if (!EnablePostRAScheduler)
222 // Check that post-RA scheduling is enabled for this target.
223 const TargetSubtarget &ST = Fn.getTarget().getSubtarget<TargetSubtarget>();
224 if (!ST.enablePostRAScheduler(OptLevel, AntiDepMode))
228 // Check for antidep breaking override...
229 if (EnableAntiDepBreaking.getPosition() > 0) {
230 AntiDepMode = (EnableAntiDepBreaking == "all") ? TargetSubtarget::ANTIDEP_ALL :
231 (EnableAntiDepBreaking == "critical") ? TargetSubtarget::ANTIDEP_CRITICAL :
232 TargetSubtarget::ANTIDEP_NONE;
235 DEBUG(errs() << "PostRAScheduler\n");
237 const MachineLoopInfo &MLI = getAnalysis<MachineLoopInfo>();
238 const MachineDominatorTree &MDT = getAnalysis<MachineDominatorTree>();
239 const InstrItineraryData &InstrItins = Fn.getTarget().getInstrItineraryData();
240 ScheduleHazardRecognizer *HR = EnablePostRAHazardAvoidance ?
241 (ScheduleHazardRecognizer *)new ExactHazardRecognizer(InstrItins) :
242 (ScheduleHazardRecognizer *)new SimpleHazardRecognizer();
243 AntiDepBreaker *ADB =
244 ((AntiDepMode == TargetSubtarget::ANTIDEP_ALL) ?
245 (AntiDepBreaker *)new AggressiveAntiDepBreaker(Fn) :
246 ((AntiDepMode == TargetSubtarget::ANTIDEP_CRITICAL) ?
247 (AntiDepBreaker *)new CriticalAntiDepBreaker(Fn) : NULL));
249 SchedulePostRATDList Scheduler(Fn, MLI, MDT, HR, ADB, AA);
251 // Loop over all of the basic blocks
252 for (MachineFunction::iterator MBB = Fn.begin(), MBBe = Fn.end();
253 MBB != MBBe; ++MBB) {
255 // If DebugDiv > 0 then only schedule MBB with (ID % DebugDiv) == DebugMod
257 static int bbcnt = 0;
258 if (bbcnt++ % DebugDiv != DebugMod)
260 errs() << "*** DEBUG scheduling " << Fn.getFunction()->getNameStr() <<
261 ":BB#" << MBB->getNumber() << " ***\n";
265 // Initialize register live-range state for scheduling in this block.
266 Scheduler.StartBlock(MBB);
268 // Schedule each sequence of instructions not interrupted by a label
269 // or anything else that effectively needs to shut down scheduling.
270 MachineBasicBlock::iterator Current = MBB->end();
271 unsigned Count = MBB->size(), CurrentCount = Count;
272 for (MachineBasicBlock::iterator I = Current; I != MBB->begin(); ) {
273 MachineInstr *MI = prior(I);
274 if (isSchedulingBoundary(MI, Fn)) {
275 Scheduler.Run(MBB, I, Current, CurrentCount);
276 Scheduler.EmitSchedule(0);
278 CurrentCount = Count - 1;
279 Scheduler.Observe(MI, CurrentCount);
284 assert(Count == 0 && "Instruction count mismatch!");
285 assert((MBB->begin() == Current || CurrentCount != 0) &&
286 "Instruction count mismatch!");
287 Scheduler.Run(MBB, MBB->begin(), Current, CurrentCount);
288 Scheduler.EmitSchedule(0);
290 // Clean up register live-range state.
291 Scheduler.FinishBlock();
293 // Update register kills
294 Scheduler.FixupKills(MBB);
303 /// StartBlock - Initialize register live-range state for scheduling in
306 void SchedulePostRATDList::StartBlock(MachineBasicBlock *BB) {
307 // Call the superclass.
308 ScheduleDAGInstrs::StartBlock(BB);
310 // Reset the hazard recognizer and anti-dep breaker.
312 if (AntiDepBreak != NULL)
313 AntiDepBreak->StartBlock(BB);
316 /// Schedule - Schedule the instruction range using list scheduling.
318 void SchedulePostRATDList::Schedule() {
319 // Build the scheduling graph.
322 if (AntiDepBreak != NULL) {
323 for (unsigned i = 0, Trials = AntiDepBreak->GetMaxTrials();
325 DEBUG(errs() << "********** Break Anti-Deps, Trial " <<
326 i << " **********\n");
328 AntiDepBreak->BreakAntiDependencies(SUnits, Begin, InsertPos,
333 // We made changes. Update the dependency graph.
334 // Theoretically we could update the graph in place:
335 // When a live range is changed to use a different register, remove
336 // the def's anti-dependence *and* output-dependence edges due to
337 // that register, and add new anti-dependence and output-dependence
338 // edges based on the next live range of the register.
344 NumFixedAnti += Broken;
348 DEBUG(errs() << "********** List Scheduling **********\n");
350 DEBUG(for (unsigned su = 0, e = SUnits.size(); su != e; ++su)
351 SUnits[su].dumpAll(this));
353 AvailableQueue.initNodes(SUnits);
355 ListScheduleTopDown();
357 AvailableQueue.releaseState();
360 /// Observe - Update liveness information to account for the current
361 /// instruction, which will not be scheduled.
363 void SchedulePostRATDList::Observe(MachineInstr *MI, unsigned Count) {
364 if (AntiDepBreak != NULL)
365 AntiDepBreak->Observe(MI, Count, InsertPosIndex);
368 /// FinishBlock - Clean up register live-range state.
370 void SchedulePostRATDList::FinishBlock() {
371 if (AntiDepBreak != NULL)
372 AntiDepBreak->FinishBlock();
374 // Call the superclass.
375 ScheduleDAGInstrs::FinishBlock();
378 /// StartBlockForKills - Initialize register live-range state for updating kills
380 void SchedulePostRATDList::StartBlockForKills(MachineBasicBlock *BB) {
381 // Initialize the indices to indicate that no registers are live.
382 std::fill(KillIndices, array_endof(KillIndices), ~0u);
384 // Determine the live-out physregs for this block.
385 if (!BB->empty() && BB->back().getDesc().isReturn()) {
386 // In a return block, examine the function live-out regs.
387 for (MachineRegisterInfo::liveout_iterator I = MRI.liveout_begin(),
388 E = MRI.liveout_end(); I != E; ++I) {
390 KillIndices[Reg] = BB->size();
391 // Repeat, for all subregs.
392 for (const unsigned *Subreg = TRI->getSubRegisters(Reg);
394 KillIndices[*Subreg] = BB->size();
399 // In a non-return block, examine the live-in regs of all successors.
400 for (MachineBasicBlock::succ_iterator SI = BB->succ_begin(),
401 SE = BB->succ_end(); SI != SE; ++SI) {
402 for (MachineBasicBlock::livein_iterator I = (*SI)->livein_begin(),
403 E = (*SI)->livein_end(); I != E; ++I) {
405 KillIndices[Reg] = BB->size();
406 // Repeat, for all subregs.
407 for (const unsigned *Subreg = TRI->getSubRegisters(Reg);
409 KillIndices[*Subreg] = BB->size();
416 bool SchedulePostRATDList::ToggleKillFlag(MachineInstr *MI,
417 MachineOperand &MO) {
418 // Setting kill flag...
424 // If MO itself is live, clear the kill flag...
425 if (KillIndices[MO.getReg()] != ~0u) {
430 // If any subreg of MO is live, then create an imp-def for that
431 // subreg and keep MO marked as killed.
434 const unsigned SuperReg = MO.getReg();
435 for (const unsigned *Subreg = TRI->getSubRegisters(SuperReg);
437 if (KillIndices[*Subreg] != ~0u) {
438 MI->addOperand(MachineOperand::CreateReg(*Subreg,
452 /// FixupKills - Fix the register kill flags, they may have been made
453 /// incorrect by instruction reordering.
455 void SchedulePostRATDList::FixupKills(MachineBasicBlock *MBB) {
456 DEBUG(errs() << "Fixup kills for BB#" << MBB->getNumber() << '\n');
458 std::set<unsigned> killedRegs;
459 BitVector ReservedRegs = TRI->getReservedRegs(MF);
461 StartBlockForKills(MBB);
463 // Examine block from end to start...
464 unsigned Count = MBB->size();
465 for (MachineBasicBlock::iterator I = MBB->end(), E = MBB->begin();
467 MachineInstr *MI = --I;
469 // Update liveness. Registers that are defed but not used in this
470 // instruction are now dead. Mark register and all subregs as they
471 // are completely defined.
472 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
473 MachineOperand &MO = MI->getOperand(i);
474 if (!MO.isReg()) continue;
475 unsigned Reg = MO.getReg();
476 if (Reg == 0) continue;
477 if (!MO.isDef()) continue;
478 // Ignore two-addr defs.
479 if (MI->isRegTiedToUseOperand(i)) continue;
481 KillIndices[Reg] = ~0u;
483 // Repeat for all subregs.
484 for (const unsigned *Subreg = TRI->getSubRegisters(Reg);
486 KillIndices[*Subreg] = ~0u;
490 // Examine all used registers and set/clear kill flag. When a
491 // register is used multiple times we only set the kill flag on
494 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
495 MachineOperand &MO = MI->getOperand(i);
496 if (!MO.isReg() || !MO.isUse()) continue;
497 unsigned Reg = MO.getReg();
498 if ((Reg == 0) || ReservedRegs.test(Reg)) continue;
501 if (killedRegs.find(Reg) == killedRegs.end()) {
503 // A register is not killed if any subregs are live...
504 for (const unsigned *Subreg = TRI->getSubRegisters(Reg);
506 if (KillIndices[*Subreg] != ~0u) {
512 // If subreg is not live, then register is killed if it became
513 // live in this instruction
515 kill = (KillIndices[Reg] == ~0u);
518 if (MO.isKill() != kill) {
519 bool removed = ToggleKillFlag(MI, MO);
521 DEBUG(errs() << "Fixed <removed> in ");
523 DEBUG(errs() << "Fixed " << MO << " in ");
528 killedRegs.insert(Reg);
531 // Mark any used register (that is not using undef) and subregs as
533 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
534 MachineOperand &MO = MI->getOperand(i);
535 if (!MO.isReg() || !MO.isUse() || MO.isUndef()) continue;
536 unsigned Reg = MO.getReg();
537 if ((Reg == 0) || ReservedRegs.test(Reg)) continue;
539 KillIndices[Reg] = Count;
541 for (const unsigned *Subreg = TRI->getSubRegisters(Reg);
543 KillIndices[*Subreg] = Count;
549 //===----------------------------------------------------------------------===//
550 // Top-Down Scheduling
551 //===----------------------------------------------------------------------===//
553 /// ReleaseSucc - Decrement the NumPredsLeft count of a successor. Add it to
554 /// the PendingQueue if the count reaches zero. Also update its cycle bound.
555 void SchedulePostRATDList::ReleaseSucc(SUnit *SU, SDep *SuccEdge) {
556 SUnit *SuccSU = SuccEdge->getSUnit();
559 if (SuccSU->NumPredsLeft == 0) {
560 errs() << "*** Scheduling failed! ***\n";
562 errs() << " has been released too many times!\n";
566 --SuccSU->NumPredsLeft;
568 // Compute how many cycles it will be before this actually becomes
569 // available. This is the max of the start time of all predecessors plus
571 SuccSU->setDepthToAtLeast(SU->getDepth() + SuccEdge->getLatency());
573 // If all the node's predecessors are scheduled, this node is ready
574 // to be scheduled. Ignore the special ExitSU node.
575 if (SuccSU->NumPredsLeft == 0 && SuccSU != &ExitSU)
576 PendingQueue.push_back(SuccSU);
579 /// ReleaseSuccessors - Call ReleaseSucc on each of SU's successors.
580 void SchedulePostRATDList::ReleaseSuccessors(SUnit *SU) {
581 for (SUnit::succ_iterator I = SU->Succs.begin(), E = SU->Succs.end();
583 ReleaseSucc(SU, &*I);
586 /// ScheduleNodeTopDown - Add the node to the schedule. Decrement the pending
587 /// count of its successors. If a successor pending count is zero, add it to
588 /// the Available queue.
589 void SchedulePostRATDList::ScheduleNodeTopDown(SUnit *SU, unsigned CurCycle) {
590 DEBUG(errs() << "*** Scheduling [" << CurCycle << "]: ");
591 DEBUG(SU->dump(this));
593 Sequence.push_back(SU);
594 assert(CurCycle >= SU->getDepth() && "Node scheduled above its depth!");
595 SU->setDepthToAtLeast(CurCycle);
597 ReleaseSuccessors(SU);
598 SU->isScheduled = true;
599 AvailableQueue.ScheduledNode(SU);
602 /// ListScheduleTopDown - The main loop of list scheduling for top-down
604 void SchedulePostRATDList::ListScheduleTopDown() {
605 unsigned CurCycle = 0;
607 // Release any successors of the special Entry node.
608 ReleaseSuccessors(&EntrySU);
610 // All leaves to Available queue.
611 for (unsigned i = 0, e = SUnits.size(); i != e; ++i) {
612 // It is available if it has no predecessors.
613 if (SUnits[i].Preds.empty()) {
614 AvailableQueue.push(&SUnits[i]);
615 SUnits[i].isAvailable = true;
619 // In any cycle where we can't schedule any instructions, we must
620 // stall or emit a noop, depending on the target.
621 bool CycleHasInsts = false;
623 // While Available queue is not empty, grab the node with the highest
624 // priority. If it is not ready put it back. Schedule the node.
625 std::vector<SUnit*> NotReady;
626 Sequence.reserve(SUnits.size());
627 while (!AvailableQueue.empty() || !PendingQueue.empty()) {
628 // Check to see if any of the pending instructions are ready to issue. If
629 // so, add them to the available queue.
630 unsigned MinDepth = ~0u;
631 for (unsigned i = 0, e = PendingQueue.size(); i != e; ++i) {
632 if (PendingQueue[i]->getDepth() <= CurCycle) {
633 AvailableQueue.push(PendingQueue[i]);
634 PendingQueue[i]->isAvailable = true;
635 PendingQueue[i] = PendingQueue.back();
636 PendingQueue.pop_back();
638 } else if (PendingQueue[i]->getDepth() < MinDepth)
639 MinDepth = PendingQueue[i]->getDepth();
642 DEBUG(errs() << "\n*** Examining Available\n";
643 LatencyPriorityQueue q = AvailableQueue;
646 errs() << "Height " << su->getHeight() << ": ";
650 SUnit *FoundSUnit = 0;
652 bool HasNoopHazards = false;
653 while (!AvailableQueue.empty()) {
654 SUnit *CurSUnit = AvailableQueue.pop();
656 ScheduleHazardRecognizer::HazardType HT =
657 HazardRec->getHazardType(CurSUnit);
658 if (HT == ScheduleHazardRecognizer::NoHazard) {
659 FoundSUnit = CurSUnit;
663 // Remember if this is a noop hazard.
664 HasNoopHazards |= HT == ScheduleHazardRecognizer::NoopHazard;
666 NotReady.push_back(CurSUnit);
669 // Add the nodes that aren't ready back onto the available list.
670 if (!NotReady.empty()) {
671 AvailableQueue.push_all(NotReady);
675 // If we found a node to schedule, do it now.
677 ScheduleNodeTopDown(FoundSUnit, CurCycle);
678 HazardRec->EmitInstruction(FoundSUnit);
679 CycleHasInsts = true;
681 // If we are using the target-specific hazards, then don't
682 // advance the cycle time just because we schedule a node. If
683 // the target allows it we can schedule multiple nodes in the
685 if (!EnablePostRAHazardAvoidance) {
686 if (FoundSUnit->Latency) // Don't increment CurCycle for pseudo-ops!
691 DEBUG(errs() << "*** Finished cycle " << CurCycle << '\n');
692 HazardRec->AdvanceCycle();
693 } else if (!HasNoopHazards) {
694 // Otherwise, we have a pipeline stall, but no other problem,
695 // just advance the current cycle and try again.
696 DEBUG(errs() << "*** Stall in cycle " << CurCycle << '\n');
697 HazardRec->AdvanceCycle();
700 // Otherwise, we have no instructions to issue and we have instructions
701 // that will fault if we don't do this right. This is the case for
702 // processors without pipeline interlocks and other cases.
703 DEBUG(errs() << "*** Emitting noop in cycle " << CurCycle << '\n');
704 HazardRec->EmitNoop();
705 Sequence.push_back(0); // NULL here means noop
710 CycleHasInsts = false;
715 VerifySchedule(/*isBottomUp=*/false);
719 //===----------------------------------------------------------------------===//
720 // Public Constructor Functions
721 //===----------------------------------------------------------------------===//
723 FunctionPass *llvm::createPostRAScheduler(CodeGenOpt::Level OptLevel) {
724 return new PostRAScheduler(OptLevel);