#include "AntiDepBreaker.h"
#include "AggressiveAntiDepBreaker.h"
#include "CriticalAntiDepBreaker.h"
-#include "ExactHazardRecognizer.h"
-#include "SimpleHazardRecognizer.h"
#include "ScheduleDAGInstrs.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/LatencyPriorityQueue.h"
cl::desc("Break post-RA scheduling anti-dependencies: "
"\"critical\", \"all\", or \"none\""),
cl::init("none"), cl::Hidden);
-static cl::opt<bool>
-EnablePostRAHazardAvoidance("avoid-hazards",
- cl::desc("Enable exact hazard avoidance"),
- cl::init(true), cl::Hidden);
// If DebugDiv > 0 then only schedule MBB with (ID % DebugDiv) == DebugMod
static cl::opt<int>
namespace {
class PostRAScheduler : public MachineFunctionPass {
AliasAnalysis *AA;
+ const TargetInstrInfo *TII;
CodeGenOpt::Level OptLevel;
public:
static char ID;
PostRAScheduler(CodeGenOpt::Level ol) :
- MachineFunctionPass(&ID), OptLevel(ol) {}
+ MachineFunctionPass(ID), OptLevel(ol) {}
void getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesCFG();
/// AvailableQueue - The priority queue to use for the available SUnits.
///
LatencyPriorityQueue AvailableQueue;
-
+
/// PendingQueue - This contains all of the instructions whose operands have
/// been issued, but their results are not ready yet (due to the latency of
/// the operation). Once the operands becomes available, the instruction is
/// KillIndices - The index of the most recent kill (proceding bottom-up),
/// or ~0u if the register is not live.
- unsigned KillIndices[TargetRegisterInfo::FirstVirtualRegister];
+ std::vector<unsigned> KillIndices;
public:
- SchedulePostRATDList(MachineFunction &MF,
- const MachineLoopInfo &MLI,
- const MachineDominatorTree &MDT,
- ScheduleHazardRecognizer *HR,
- AntiDepBreaker *ADB,
- AliasAnalysis *aa)
- : ScheduleDAGInstrs(MF, MLI, MDT), Topo(SUnits),
- HazardRec(HR), AntiDepBreak(ADB), AA(aa) {}
-
- ~SchedulePostRATDList() {
- }
+ SchedulePostRATDList(
+ MachineFunction &MF, MachineLoopInfo &MLI, MachineDominatorTree &MDT,
+ AliasAnalysis *AA, TargetSubtarget::AntiDepBreakMode AntiDepMode,
+ SmallVectorImpl<TargetRegisterClass*> &CriticalPathRCs);
+
+ ~SchedulePostRATDList();
/// StartBlock - Initialize register live-range state for scheduling in
/// this block.
/// Schedule - Schedule the instruction range using list scheduling.
///
void Schedule();
-
+
/// Observe - Update liveness information to account for the current
/// instruction, which will not be scheduled.
///
void ScheduleNodeTopDown(SUnit *SU, unsigned CurCycle);
void ListScheduleTopDown();
void StartBlockForKills(MachineBasicBlock *BB);
-
+
// ToggleKillFlag - Toggle a register operand kill flag. Other
// adjustments may be made to the instruction if necessary. Return
// true if the operand has been deleted, false if not.
};
}
-/// isSchedulingBoundary - Test if the given instruction should be
-/// considered a scheduling boundary. This primarily includes labels
-/// and terminators.
-///
-static bool isSchedulingBoundary(const MachineInstr *MI,
- const MachineFunction &MF) {
- // Terminators and labels can't be scheduled around.
- if (MI->getDesc().isTerminator() || MI->isLabel())
- return true;
-
- // Don't attempt to schedule around any instruction that modifies
- // a stack-oriented pointer, as it's unlikely to be profitable. This
- // saves compile time, because it doesn't require every single
- // stack slot reference to depend on the instruction that does the
- // modification.
- const TargetLowering &TLI = *MF.getTarget().getTargetLowering();
- if (MI->modifiesRegister(TLI.getStackPointerRegisterToSaveRestore()))
- return true;
+SchedulePostRATDList::SchedulePostRATDList(
+ MachineFunction &MF, MachineLoopInfo &MLI, MachineDominatorTree &MDT,
+ AliasAnalysis *AA, TargetSubtarget::AntiDepBreakMode AntiDepMode,
+ SmallVectorImpl<TargetRegisterClass*> &CriticalPathRCs)
+ : ScheduleDAGInstrs(MF, MLI, MDT), Topo(SUnits), AA(AA),
+ KillIndices(TRI->getNumRegs())
+{
+ const TargetMachine &TM = MF.getTarget();
+ const InstrItineraryData *InstrItins = TM.getInstrItineraryData();
+ HazardRec =
+ TM.getInstrInfo()->CreateTargetPostRAHazardRecognizer(InstrItins, this);
+ AntiDepBreak =
+ ((AntiDepMode == TargetSubtarget::ANTIDEP_ALL) ?
+ (AntiDepBreaker *)new AggressiveAntiDepBreaker(MF, CriticalPathRCs) :
+ ((AntiDepMode == TargetSubtarget::ANTIDEP_CRITICAL) ?
+ (AntiDepBreaker *)new CriticalAntiDepBreaker(MF) : NULL));
+}
- return false;
+SchedulePostRATDList::~SchedulePostRATDList() {
+ delete HazardRec;
+ delete AntiDepBreak;
}
bool PostRAScheduler::runOnMachineFunction(MachineFunction &Fn) {
- AA = &getAnalysis<AliasAnalysis>();
+ TII = Fn.getTarget().getInstrInfo();
+ MachineLoopInfo &MLI = getAnalysis<MachineLoopInfo>();
+ MachineDominatorTree &MDT = getAnalysis<MachineDominatorTree>();
+ AliasAnalysis *AA = &getAnalysis<AliasAnalysis>();
// Check for explicit enable/disable of post-ra scheduling.
TargetSubtarget::AntiDepBreakMode AntiDepMode = TargetSubtarget::ANTIDEP_NONE;
return false;
} else {
// Check that post-RA scheduling is enabled for this target.
+ // This may upgrade the AntiDepMode.
const TargetSubtarget &ST = Fn.getTarget().getSubtarget<TargetSubtarget>();
if (!ST.enablePostRAScheduler(OptLevel, AntiDepMode, CriticalPathRCs))
return false;
// Check for antidep breaking override...
if (EnableAntiDepBreaking.getPosition() > 0) {
- AntiDepMode = (EnableAntiDepBreaking == "all") ? TargetSubtarget::ANTIDEP_ALL :
- (EnableAntiDepBreaking == "critical") ? TargetSubtarget::ANTIDEP_CRITICAL :
- TargetSubtarget::ANTIDEP_NONE;
+ AntiDepMode = (EnableAntiDepBreaking == "all") ?
+ TargetSubtarget::ANTIDEP_ALL :
+ (EnableAntiDepBreaking == "critical")
+ ? TargetSubtarget::ANTIDEP_CRITICAL : TargetSubtarget::ANTIDEP_NONE;
}
DEBUG(dbgs() << "PostRAScheduler\n");
- const MachineLoopInfo &MLI = getAnalysis<MachineLoopInfo>();
- const MachineDominatorTree &MDT = getAnalysis<MachineDominatorTree>();
- const InstrItineraryData &InstrItins = Fn.getTarget().getInstrItineraryData();
- ScheduleHazardRecognizer *HR = EnablePostRAHazardAvoidance ?
- (ScheduleHazardRecognizer *)new ExactHazardRecognizer(InstrItins) :
- (ScheduleHazardRecognizer *)new SimpleHazardRecognizer();
- AntiDepBreaker *ADB =
- ((AntiDepMode == TargetSubtarget::ANTIDEP_ALL) ?
- (AntiDepBreaker *)new AggressiveAntiDepBreaker(Fn, CriticalPathRCs) :
- ((AntiDepMode == TargetSubtarget::ANTIDEP_CRITICAL) ?
- (AntiDepBreaker *)new CriticalAntiDepBreaker(Fn) : NULL));
-
- SchedulePostRATDList Scheduler(Fn, MLI, MDT, HR, ADB, AA);
+ SchedulePostRATDList Scheduler(Fn, MLI, MDT, AA, AntiDepMode,
+ CriticalPathRCs);
// Loop over all of the basic blocks
for (MachineFunction::iterator MBB = Fn.begin(), MBBe = Fn.end();
// Initialize register live-range state for scheduling in this block.
Scheduler.StartBlock(MBB);
- // FIXME: Temporary workaround for <rdar://problem/7759363>: The post-RA
- // scheduler has some sort of problem with DebugValue instructions that
- // causes an assertion in LeaksContext.h to fail occasionally. Just
- // remove all those instructions for now.
- for (MachineBasicBlock::iterator I = MBB->begin(), E = MBB->end();
- I != E; ) {
- MachineInstr *MI = &*I++;
- if (MI->isDebugValue())
- MI->eraseFromParent();
- }
-
// Schedule each sequence of instructions not interrupted by a label
// or anything else that effectively needs to shut down scheduling.
MachineBasicBlock::iterator Current = MBB->end();
unsigned Count = MBB->size(), CurrentCount = Count;
for (MachineBasicBlock::iterator I = Current; I != MBB->begin(); ) {
- MachineInstr *MI = prior(I);
- if (isSchedulingBoundary(MI, Fn)) {
+ MachineInstr *MI = llvm::prior(I);
+ if (TII->isSchedulingBoundary(MI, MBB, Fn)) {
Scheduler.Run(MBB, I, Current, CurrentCount);
- Scheduler.EmitSchedule(0);
+ Scheduler.EmitSchedule();
Current = MI;
CurrentCount = Count - 1;
Scheduler.Observe(MI, CurrentCount);
assert((MBB->begin() == Current || CurrentCount != 0) &&
"Instruction count mismatch!");
Scheduler.Run(MBB, MBB->begin(), Current, CurrentCount);
- Scheduler.EmitSchedule(0);
+ Scheduler.EmitSchedule();
// Clean up register live-range state.
Scheduler.FinishBlock();
Scheduler.FixupKills(MBB);
}
- delete HR;
- delete ADB;
-
return true;
}
-
+
/// StartBlock - Initialize register live-range state for scheduling in
/// this block.
///
BuildSchedGraph(AA);
if (AntiDepBreak != NULL) {
- unsigned Broken =
+ unsigned Broken =
AntiDepBreak->BreakAntiDependencies(SUnits, Begin, InsertPos,
InsertPosIndex);
-
+
if (Broken != 0) {
// We made changes. Update the dependency graph.
// Theoretically we could update the graph in place:
EntrySU = SUnit();
ExitSU = SUnit();
BuildSchedGraph(AA);
-
+
NumFixedAnti += Broken;
}
}
MO.setIsKill(true);
return false;
}
-
+
// If MO itself is live, clear the kill flag...
if (KillIndices[MO.getReg()] != ~0u) {
MO.setIsKill(false);
BitVector ReservedRegs = TRI->getReservedRegs(MF);
StartBlockForKills(MBB);
-
+
// Examine block from end to start...
unsigned Count = MBB->size();
for (MachineBasicBlock::iterator I = MBB->end(), E = MBB->begin();
if (!MO.isDef()) continue;
// Ignore two-addr defs.
if (MI->isRegTiedToUseOperand(i)) continue;
-
+
KillIndices[Reg] = ~0u;
-
+
// Repeat for all subregs.
for (const unsigned *Subreg = TRI->getSubRegisters(Reg);
*Subreg; ++Subreg) {
if (kill)
kill = (KillIndices[Reg] == ~0u);
}
-
+
if (MO.isKill() != kill) {
DEBUG(dbgs() << "Fixing " << MO << " in ");
// Warning: ToggleKillFlag may invalidate MO.
ToggleKillFlag(MI, MO);
DEBUG(MI->dump());
}
-
+
killedRegs.insert(Reg);
}
-
+
// Mark any used register (that is not using undef) and subregs as
// now live...
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
if ((Reg == 0) || ReservedRegs.test(Reg)) continue;
KillIndices[Reg] = Count;
-
+
for (const unsigned *Subreg = TRI->getSubRegisters(Reg);
*Subreg; ++Subreg) {
KillIndices[*Subreg] = Count;
// available. This is the max of the start time of all predecessors plus
// their latencies.
SuccSU->setDepthToAtLeast(SU->getDepth() + SuccEdge->getLatency());
-
+
// If all the node's predecessors are scheduled, this node is ready
// to be scheduled. Ignore the special ExitSU node.
if (SuccSU->NumPredsLeft == 0 && SuccSU != &ExitSU)
void SchedulePostRATDList::ScheduleNodeTopDown(SUnit *SU, unsigned CurCycle) {
DEBUG(dbgs() << "*** Scheduling [" << CurCycle << "]: ");
DEBUG(SU->dump(this));
-
+
Sequence.push_back(SU);
- assert(CurCycle >= SU->getDepth() &&
+ assert(CurCycle >= SU->getDepth() &&
"Node scheduled above its depth!");
SU->setDepthToAtLeast(CurCycle);
/// schedulers.
void SchedulePostRATDList::ListScheduleTopDown() {
unsigned CurCycle = 0;
-
+
// We're scheduling top-down but we're visiting the regions in
// bottom-up order, so we don't know the hazards at the start of a
// region. So assume no hazards (this should usually be ok as most
MinDepth = PendingQueue[i]->getDepth();
}
- DEBUG(dbgs() << "\n*** Examining Available\n";
- LatencyPriorityQueue q = AvailableQueue;
- while (!q.empty()) {
- SUnit *su = q.pop();
- dbgs() << "Height " << su->getHeight() << ": ";
- su->dump(this);
- });
+ DEBUG(dbgs() << "\n*** Examining Available\n"; AvailableQueue.dump(this));
SUnit *FoundSUnit = 0;
bool HasNoopHazards = false;
SUnit *CurSUnit = AvailableQueue.pop();
ScheduleHazardRecognizer::HazardType HT =
- HazardRec->getHazardType(CurSUnit);
+ HazardRec->getHazardType(CurSUnit, 0/*no stalls*/);
if (HT == ScheduleHazardRecognizer::NoHazard) {
FoundSUnit = CurSUnit;
break;
ScheduleNodeTopDown(FoundSUnit, CurCycle);
HazardRec->EmitInstruction(FoundSUnit);
CycleHasInsts = true;
-
- // If we are using the target-specific hazards, then don't
- // advance the cycle time just because we schedule a node. If
- // the target allows it we can schedule multiple nodes in the
- // same cycle.
- if (!EnablePostRAHazardAvoidance) {
- if (FoundSUnit->Latency) // Don't increment CurCycle for pseudo-ops!
- ++CurCycle;
- }
} else {
if (CycleHasInsts) {
DEBUG(dbgs() << "*** Finished cycle " << CurCycle << '\n');
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