#include "llvm/CodeGen/RegisterClassInfo.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
-#include "llvm/Target/TargetMachine.h"
using namespace llvm;
}
}
-#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+LLVM_DUMP_METHOD
void llvm::dumpRegSetPressure(ArrayRef<unsigned> SetPressure,
const TargetRegisterInfo *TRI) {
bool Empty = true;
dbgs() << "\n";
}
+LLVM_DUMP_METHOD
void RegisterPressure::dump(const TargetRegisterInfo *TRI) const {
dbgs() << "Max Pressure: ";
dumpRegSetPressure(MaxSetPressure, TRI);
dbgs() << "Live In: ";
- for (unsigned i = 0, e = LiveInRegs.size(); i < e; ++i)
- dbgs() << PrintReg(LiveInRegs[i], TRI) << " ";
+ for (unsigned Reg : LiveInRegs)
+ dbgs() << PrintVRegOrUnit(Reg, TRI) << " ";
dbgs() << '\n';
dbgs() << "Live Out: ";
- for (unsigned i = 0, e = LiveOutRegs.size(); i < e; ++i)
- dbgs() << PrintReg(LiveOutRegs[i], TRI) << " ";
+ for (unsigned Reg : LiveOutRegs)
+ dbgs() << PrintVRegOrUnit(Reg, TRI) << " ";
dbgs() << '\n';
}
+LLVM_DUMP_METHOD
void RegPressureTracker::dump() const {
if (!isTopClosed() || !isBottomClosed()) {
dbgs() << "Curr Pressure: ";
}
P.dump(TRI);
}
-#endif
+
+void PressureDiff::dump(const TargetRegisterInfo &TRI) const {
+ const char *sep = "";
+ for (const PressureChange &Change : *this) {
+ if (!Change.isValid())
+ break;
+ dbgs() << sep << TRI.getRegPressureSetName(Change.getPSet())
+ << " " << Change.getUnitInc();
+ sep = " ";
+ }
+ dbgs() << '\n';
+}
/// Increase the current pressure as impacted by these registers and bump
/// the high water mark if needed.
void RegPressureTracker::increaseRegPressure(ArrayRef<unsigned> RegUnits) {
- for (unsigned i = 0, e = RegUnits.size(); i != e; ++i) {
- PSetIterator PSetI = MRI->getPressureSets(RegUnits[i]);
+ for (unsigned RegUnit : RegUnits) {
+ PSetIterator PSetI = MRI->getPressureSets(RegUnit);
unsigned Weight = PSetI.getWeight();
for (; PSetI.isValid(); ++PSetI) {
CurrSetPressure[*PSetI] += Weight;
- if (CurrSetPressure[*PSetI] > P.MaxSetPressure[*PSetI]) {
- P.MaxSetPressure[*PSetI] = CurrSetPressure[*PSetI];
- }
+ P.MaxSetPressure[*PSetI] =
+ std::max(P.MaxSetPressure[*PSetI], CurrSetPressure[*PSetI]);
}
}
}
/// Simply decrease the current pressure as impacted by these registers.
void RegPressureTracker::decreaseRegPressure(ArrayRef<unsigned> RegUnits) {
- for (unsigned I = 0, E = RegUnits.size(); I != E; ++I)
- decreaseSetPressure(CurrSetPressure, MRI->getPressureSets(RegUnits[I]));
+ for (unsigned RegUnit : RegUnits)
+ decreaseSetPressure(CurrSetPressure, MRI->getPressureSets(RegUnit));
}
/// Clear the result so it can be used for another round of pressure tracking.
LiveInRegs.clear();
}
-const LiveInterval *RegPressureTracker::getInterval(unsigned Reg) const {
+void LiveRegSet::init(const MachineRegisterInfo &MRI) {
+ const TargetRegisterInfo &TRI = *MRI.getTargetRegisterInfo();
+ unsigned NumRegUnits = TRI.getNumRegs();
+ unsigned NumVirtRegs = MRI.getNumVirtRegs();
+ Regs.setUniverse(NumRegUnits + NumVirtRegs);
+ this->NumRegUnits = NumRegUnits;
+}
+
+void LiveRegSet::clear() {
+ Regs.clear();
+}
+
+static const LiveRange *getLiveRange(const LiveIntervals &LIS, unsigned Reg) {
if (TargetRegisterInfo::isVirtualRegister(Reg))
- return &LIS->getInterval(Reg);
- return LIS->getCachedRegUnit(Reg);
+ return &LIS.getInterval(Reg);
+ return LIS.getCachedRegUnit(Reg);
+}
+
+void RegPressureTracker::reset() {
+ MBB = nullptr;
+ LIS = nullptr;
+
+ CurrSetPressure.clear();
+ LiveThruPressure.clear();
+ P.MaxSetPressure.clear();
+
+ if (RequireIntervals)
+ static_cast<IntervalPressure&>(P).reset();
+ else
+ static_cast<RegionPressure&>(P).reset();
+
+ LiveRegs.clear();
+ UntiedDefs.clear();
}
/// Setup the RegPressureTracker.
MachineBasicBlock::const_iterator pos,
bool ShouldTrackUntiedDefs)
{
+ reset();
+
MF = mf;
- TRI = MF->getTarget().getRegisterInfo();
+ TRI = MF->getSubtarget().getRegisterInfo();
RCI = rci;
MRI = &MF->getRegInfo();
MBB = mbb;
CurrPos = pos;
CurrSetPressure.assign(TRI->getNumRegPressureSets(), 0);
- LiveThruPressure.clear();
- if (RequireIntervals)
- static_cast<IntervalPressure&>(P).reset();
- else
- static_cast<RegionPressure&>(P).reset();
P.MaxSetPressure = CurrSetPressure;
- LiveRegs.PhysRegs.clear();
- LiveRegs.PhysRegs.setUniverse(TRI->getNumRegs());
- LiveRegs.VirtRegs.clear();
- LiveRegs.VirtRegs.setUniverse(MRI->getNumVirtRegs());
- UntiedDefs.clear();
+ LiveRegs.init(*MRI);
if (TrackUntiedDefs)
UntiedDefs.setUniverse(MRI->getNumVirtRegs());
}
static_cast<RegionPressure&>(P).TopPos = CurrPos;
assert(P.LiveInRegs.empty() && "inconsistent max pressure result");
- P.LiveInRegs.reserve(LiveRegs.PhysRegs.size() + LiveRegs.VirtRegs.size());
- P.LiveInRegs.append(LiveRegs.PhysRegs.begin(), LiveRegs.PhysRegs.end());
- for (SparseSet<unsigned>::const_iterator I =
- LiveRegs.VirtRegs.begin(), E = LiveRegs.VirtRegs.end(); I != E; ++I)
- P.LiveInRegs.push_back(*I);
- std::sort(P.LiveInRegs.begin(), P.LiveInRegs.end());
- P.LiveInRegs.erase(std::unique(P.LiveInRegs.begin(), P.LiveInRegs.end()),
- P.LiveInRegs.end());
+ P.LiveInRegs.reserve(LiveRegs.size());
+ LiveRegs.appendTo(P.LiveInRegs);
}
/// Set the boundary for the bottom of the region and summarize live outs.
static_cast<RegionPressure&>(P).BottomPos = CurrPos;
assert(P.LiveOutRegs.empty() && "inconsistent max pressure result");
- P.LiveOutRegs.reserve(LiveRegs.PhysRegs.size() + LiveRegs.VirtRegs.size());
- P.LiveOutRegs.append(LiveRegs.PhysRegs.begin(), LiveRegs.PhysRegs.end());
- for (SparseSet<unsigned>::const_iterator I =
- LiveRegs.VirtRegs.begin(), E = LiveRegs.VirtRegs.end(); I != E; ++I)
- P.LiveOutRegs.push_back(*I);
- std::sort(P.LiveOutRegs.begin(), P.LiveOutRegs.end());
- P.LiveOutRegs.erase(std::unique(P.LiveOutRegs.begin(), P.LiveOutRegs.end()),
- P.LiveOutRegs.end());
+ P.LiveOutRegs.reserve(LiveRegs.size());
+ LiveRegs.appendTo(P.LiveOutRegs);
}
/// Finalize the region boundaries and record live ins and live outs.
void RegPressureTracker::closeRegion() {
if (!isTopClosed() && !isBottomClosed()) {
- assert(LiveRegs.PhysRegs.empty() && LiveRegs.VirtRegs.empty() &&
- "no region boundary");
+ assert(LiveRegs.size() == 0 && "no region boundary");
return;
}
if (!isBottomClosed())
void RegPressureTracker::initLiveThru(const RegPressureTracker &RPTracker) {
LiveThruPressure.assign(TRI->getNumRegPressureSets(), 0);
assert(isBottomClosed() && "need bottom-up tracking to intialize.");
- for (unsigned i = 0, e = P.LiveOutRegs.size(); i < e; ++i) {
- unsigned Reg = P.LiveOutRegs[i];
+ for (unsigned Reg : P.LiveOutRegs) {
if (TargetRegisterInfo::isVirtualRegister(Reg)
&& !RPTracker.hasUntiedDef(Reg)) {
increaseSetPressure(LiveThruPressure, MRI->getPressureSets(Reg));
return std::find(RegUnits.begin(), RegUnits.end(), RegUnit) != RegUnits.end();
}
+namespace {
+
/// Collect this instruction's unique uses and defs into SmallVectors for
/// processing defs and uses in order.
///
/// FIXME: always ignore tied opers
-class RegisterOperands {
- const TargetRegisterInfo *TRI;
- const MachineRegisterInfo *MRI;
+class RegisterOperandsCollector {
+ RegisterOperands &RegOpers;
+ const TargetRegisterInfo &TRI;
+ const MachineRegisterInfo &MRI;
bool IgnoreDead;
-public:
- SmallVector<unsigned, 8> Uses;
- SmallVector<unsigned, 8> Defs;
- SmallVector<unsigned, 8> DeadDefs;
-
- RegisterOperands(const TargetRegisterInfo *tri,
- const MachineRegisterInfo *mri, bool ID = false):
- TRI(tri), MRI(mri), IgnoreDead(ID) {}
+ RegisterOperandsCollector(RegisterOperands &RegOpers,
+ const TargetRegisterInfo &TRI,
+ const MachineRegisterInfo &MRI,
+ bool IgnoreDead)
+ : RegOpers(RegOpers), TRI(TRI), MRI(MRI), IgnoreDead(IgnoreDead) {}
+
+ void collectInstr(const MachineInstr &MI) const {
+ for (ConstMIBundleOperands OperI(&MI); OperI.isValid(); ++OperI)
+ collectOperand(*OperI);
+
+ // Remove redundant physreg dead defs.
+ SmallVectorImpl<unsigned>::iterator I =
+ std::remove_if(RegOpers.DeadDefs.begin(), RegOpers.DeadDefs.end(),
+ std::bind1st(std::ptr_fun(containsReg), RegOpers.Defs));
+ RegOpers.DeadDefs.erase(I, RegOpers.DeadDefs.end());
+ }
- /// Push this operand's register onto the correct vector.
- void collect(const MachineOperand &MO) {
+ /// Push this operand's register onto the correct vectors.
+ void collectOperand(const MachineOperand &MO) const {
if (!MO.isReg() || !MO.getReg())
return;
+ unsigned Reg = MO.getReg();
if (MO.readsReg())
- pushRegUnits(MO.getReg(), Uses);
+ pushRegUnits(Reg, RegOpers.Uses);
if (MO.isDef()) {
if (MO.isDead()) {
if (!IgnoreDead)
- pushRegUnits(MO.getReg(), DeadDefs);
- }
- else
- pushRegUnits(MO.getReg(), Defs);
+ pushRegUnits(Reg, RegOpers.DeadDefs);
+ } else
+ pushRegUnits(Reg, RegOpers.Defs);
}
}
-protected:
- void pushRegUnits(unsigned Reg, SmallVectorImpl<unsigned> &RegUnits) {
+ void pushRegUnits(unsigned Reg, SmallVectorImpl<unsigned> &RegUnits) const {
if (TargetRegisterInfo::isVirtualRegister(Reg)) {
if (containsReg(RegUnits, Reg))
return;
RegUnits.push_back(Reg);
- }
- else if (MRI->isAllocatable(Reg)) {
- for (MCRegUnitIterator Units(Reg, TRI); Units.isValid(); ++Units) {
+ } else if (MRI.isAllocatable(Reg)) {
+ for (MCRegUnitIterator Units(Reg, &TRI); Units.isValid(); ++Units) {
if (containsReg(RegUnits, *Units))
continue;
RegUnits.push_back(*Units);
}
}
}
-};
-/// Collect physical and virtual register operands.
-static void collectOperands(const MachineInstr *MI,
- RegisterOperands &RegOpers) {
- for (ConstMIBundleOperands OperI(MI); OperI.isValid(); ++OperI)
- RegOpers.collect(*OperI);
+ friend class llvm::RegisterOperands;
+};
- // Remove redundant physreg dead defs.
- SmallVectorImpl<unsigned>::iterator I =
- std::remove_if(RegOpers.DeadDefs.begin(), RegOpers.DeadDefs.end(),
- std::bind1st(std::ptr_fun(containsReg), RegOpers.Defs));
- RegOpers.DeadDefs.erase(I, RegOpers.DeadDefs.end());
+} // namespace
+
+void RegisterOperands::collect(const MachineInstr &MI,
+ const TargetRegisterInfo &TRI,
+ const MachineRegisterInfo &MRI,
+ bool IgnoreDead) {
+ RegisterOperandsCollector Collector(*this, TRI, MRI, IgnoreDead);
+ Collector.collectInstr(MI);
+}
+
+void RegisterOperands::detectDeadDefs(const MachineInstr &MI,
+ const LiveIntervals &LIS) {
+ SlotIndex SlotIdx = LIS.getInstructionIndex(&MI);
+ for (SmallVectorImpl<unsigned>::iterator RI = Defs.begin();
+ RI != Defs.end(); /*empty*/) {
+ unsigned Reg = *RI;
+ const LiveRange *LR = getLiveRange(LIS, Reg);
+ if (LR != nullptr) {
+ LiveQueryResult LRQ = LR->Query(SlotIdx);
+ if (LRQ.isDeadDef()) {
+ // LiveIntervals knows this is a dead even though it's MachineOperand is
+ // not flagged as such.
+ DeadDefs.push_back(Reg);
+ RI = Defs.erase(RI);
+ continue;
+ }
+ }
+ ++RI;
+ }
}
/// Initialize an array of N PressureDiffs.
PDiffArray = reinterpret_cast<PressureDiff*>(calloc(N, sizeof(PressureDiff)));
}
+void PressureDiffs::addInstruction(unsigned Idx,
+ const RegisterOperands &RegOpers,
+ const MachineRegisterInfo &MRI) {
+ PressureDiff &PDiff = (*this)[Idx];
+ assert(!PDiff.begin()->isValid() && "stale PDiff");
+ for (unsigned Reg : RegOpers.Defs)
+ PDiff.addPressureChange(Reg, true, &MRI);
+
+ for (unsigned Reg : RegOpers.Uses)
+ PDiff.addPressureChange(Reg, false, &MRI);
+}
+
/// Add a change in pressure to the pressure diff of a given instruction.
void PressureDiff::addPressureChange(unsigned RegUnit, bool IsDec,
const MachineRegisterInfo *MRI) {
int Weight = IsDec ? -PSetI.getWeight() : PSetI.getWeight();
for (; PSetI.isValid(); ++PSetI) {
// Find an existing entry in the pressure diff for this PSet.
- PressureDiff::iterator I = begin(), E = end();
+ PressureDiff::iterator I = nonconst_begin(), E = nonconst_end();
for (; I != E && I->isValid(); ++I) {
if (I->getPSet() >= *PSetI)
break;
if (!I->isValid() || I->getPSet() != *PSetI) {
PressureChange PTmp = PressureChange(*PSetI);
for (PressureDiff::iterator J = I; J != E && PTmp.isValid(); ++J)
- std::swap(*J,PTmp);
+ std::swap(*J, PTmp);
}
// Update the units for this pressure set.
- I->setUnitInc(I->getUnitInc() + Weight);
- }
-}
-
-/// Record the pressure difference induced by the given operand list.
-static void collectPDiff(PressureDiff &PDiff, RegisterOperands &RegOpers,
- const MachineRegisterInfo *MRI) {
- assert(!PDiff.begin()->isValid() && "stale PDiff");
-
- for (unsigned i = 0, e = RegOpers.Defs.size(); i != e; ++i) {
- if (!containsReg(RegOpers.Uses, RegOpers.Defs[i]))
- PDiff.addPressureChange(RegOpers.Defs[i], true, MRI);
+ unsigned NewUnitInc = I->getUnitInc() + Weight;
+ if (NewUnitInc != 0) {
+ I->setUnitInc(NewUnitInc);
+ } else {
+ // Remove entry
+ PressureDiff::iterator J;
+ for (J = std::next(I); J != E && J->isValid(); ++J, ++I)
+ *I = *J;
+ if (J != E)
+ *I = *J;
+ }
}
- for (unsigned i = 0, e = RegOpers.Uses.size(); i != e; ++i)
- PDiff.addPressureChange(RegOpers.Uses[i], false, MRI);
}
/// Force liveness of registers.
void RegPressureTracker::addLiveRegs(ArrayRef<unsigned> Regs) {
- for (unsigned i = 0, e = Regs.size(); i != e; ++i) {
- if (LiveRegs.insert(Regs[i]))
- increaseRegPressure(Regs[i]);
+ for (unsigned Reg : Regs) {
+ if (LiveRegs.insert(Reg))
+ increaseRegPressure(Reg);
}
}
increaseSetPressure(P.MaxSetPressure, MRI->getPressureSets(Reg));
}
-/// Recede across the previous instruction.
-/// Record the pressure difference if it is provided.
-bool RegPressureTracker::recede(PressureDiff *PDiff) {
- // Check for the top of the analyzable region.
- if (CurrPos == MBB->begin()) {
- closeRegion();
- return false;
- }
- if (!isBottomClosed())
- closeBottom();
-
- // Open the top of the region using block iterators.
- if (!RequireIntervals && isTopClosed())
- static_cast<RegionPressure&>(P).openTop(CurrPos);
-
- // Find the previous instruction.
- do
- --CurrPos;
- while (CurrPos != MBB->begin() && CurrPos->isDebugValue());
-
- if (CurrPos->isDebugValue()) {
- closeRegion();
- return false;
- }
- SlotIndex SlotIdx;
- if (RequireIntervals)
- SlotIdx = LIS->getInstructionIndex(CurrPos).getRegSlot();
-
- // Open the top of the region using slot indexes.
- if (RequireIntervals && isTopClosed())
- static_cast<IntervalPressure&>(P).openTop(SlotIdx);
-
- RegisterOperands RegOpers(TRI, MRI);
- collectOperands(CurrPos, RegOpers);
-
- if (PDiff)
- collectPDiff(*PDiff, RegOpers, MRI);
+/// Recede across the previous instruction. If LiveUses is provided, record any
+/// RegUnits that are made live by the current instruction's uses. This includes
+/// registers that are both defined and used by the instruction. If a pressure
+/// difference pointer is provided record the changes is pressure caused by this
+/// instruction independent of liveness.
+void RegPressureTracker::recede(const RegisterOperands &RegOpers,
+ SmallVectorImpl<unsigned> *LiveUses) {
+ assert(!CurrPos->isDebugValue());
// Boost pressure for all dead defs together.
increaseRegPressure(RegOpers.DeadDefs);
// Kill liveness at live defs.
// TODO: consider earlyclobbers?
- for (unsigned i = 0, e = RegOpers.Defs.size(); i < e; ++i) {
- unsigned Reg = RegOpers.Defs[i];
+ for (unsigned Reg : RegOpers.Defs) {
if (LiveRegs.erase(Reg))
decreaseRegPressure(Reg);
else
discoverLiveOut(Reg);
}
+ SlotIndex SlotIdx;
+ if (RequireIntervals)
+ SlotIdx = LIS->getInstructionIndex(CurrPos).getRegSlot();
+
// Generate liveness for uses.
- for (unsigned i = 0, e = RegOpers.Uses.size(); i < e; ++i) {
- unsigned Reg = RegOpers.Uses[i];
+ for (unsigned Reg : RegOpers.Uses) {
if (!LiveRegs.contains(Reg)) {
// Adjust liveouts if LiveIntervals are available.
if (RequireIntervals) {
- const LiveInterval *LI = getInterval(Reg);
- if (LI && !LI->killedAt(SlotIdx))
- discoverLiveOut(Reg);
+ const LiveRange *LR = getLiveRange(*LIS, Reg);
+ if (LR) {
+ LiveQueryResult LRQ = LR->Query(SlotIdx);
+ if (!LRQ.isKill() && !LRQ.valueDefined())
+ discoverLiveOut(Reg);
+ }
}
increaseRegPressure(Reg);
LiveRegs.insert(Reg);
+ if (LiveUses && !containsReg(*LiveUses, Reg))
+ LiveUses->push_back(Reg);
}
}
if (TrackUntiedDefs) {
- for (unsigned i = 0, e = RegOpers.Defs.size(); i < e; ++i) {
- unsigned Reg = RegOpers.Defs[i];
+ for (unsigned Reg : RegOpers.Defs) {
if (TargetRegisterInfo::isVirtualRegister(Reg) && !LiveRegs.contains(Reg))
UntiedDefs.insert(Reg);
}
}
- return true;
+}
+
+void RegPressureTracker::recedeSkipDebugValues() {
+ assert(CurrPos != MBB->begin());
+ if (!isBottomClosed())
+ closeBottom();
+
+ // Open the top of the region using block iterators.
+ if (!RequireIntervals && isTopClosed())
+ static_cast<RegionPressure&>(P).openTop(CurrPos);
+
+ // Find the previous instruction.
+ do
+ --CurrPos;
+ while (CurrPos != MBB->begin() && CurrPos->isDebugValue());
+
+ SlotIndex SlotIdx;
+ if (RequireIntervals)
+ SlotIdx = LIS->getInstructionIndex(CurrPos).getRegSlot();
+
+ // Open the top of the region using slot indexes.
+ if (RequireIntervals && isTopClosed())
+ static_cast<IntervalPressure&>(P).openTop(SlotIdx);
+}
+
+void RegPressureTracker::recede(SmallVectorImpl<unsigned> *LiveUses) {
+ recedeSkipDebugValues();
+
+ const MachineInstr &MI = *CurrPos;
+ RegisterOperands RegOpers;
+ RegOpers.collect(MI, *TRI, *MRI);
+ if (RequireIntervals)
+ RegOpers.detectDeadDefs(MI, *LIS);
+
+ recede(RegOpers, LiveUses);
}
/// Advance across the current instruction.
-bool RegPressureTracker::advance() {
+void RegPressureTracker::advance() {
assert(!TrackUntiedDefs && "unsupported mode");
- // Check for the bottom of the analyzable region.
- if (CurrPos == MBB->end()) {
- closeRegion();
- return false;
- }
+ assert(CurrPos != MBB->end());
if (!isTopClosed())
closeTop();
static_cast<RegionPressure&>(P).openBottom(CurrPos);
}
- RegisterOperands RegOpers(TRI, MRI);
- collectOperands(CurrPos, RegOpers);
+ RegisterOperands RegOpers;
+ RegOpers.collect(*CurrPos, *TRI, *MRI);
- for (unsigned i = 0, e = RegOpers.Uses.size(); i < e; ++i) {
- unsigned Reg = RegOpers.Uses[i];
+ for (unsigned Reg : RegOpers.Uses) {
// Discover live-ins.
bool isLive = LiveRegs.contains(Reg);
if (!isLive)
// Kill liveness at last uses.
bool lastUse = false;
if (RequireIntervals) {
- const LiveInterval *LI = getInterval(Reg);
- lastUse = LI && LI->killedAt(SlotIdx);
- }
- else {
+ const LiveRange *LR = getLiveRange(*LIS, Reg);
+ lastUse = LR && LR->Query(SlotIdx).isKill();
+ } else {
// Allocatable physregs are always single-use before register rewriting.
lastUse = !TargetRegisterInfo::isVirtualRegister(Reg);
}
if (lastUse && isLive) {
LiveRegs.erase(Reg);
decreaseRegPressure(Reg);
- }
- else if (!lastUse && !isLive)
+ } else if (!lastUse && !isLive)
increaseRegPressure(Reg);
}
// Generate liveness for defs.
- for (unsigned i = 0, e = RegOpers.Defs.size(); i < e; ++i) {
- unsigned Reg = RegOpers.Defs[i];
+ for (unsigned Reg : RegOpers.Defs) {
if (LiveRegs.insert(Reg))
increaseRegPressure(Reg);
}
do
++CurrPos;
while (CurrPos != MBB->end() && CurrPos->isDebugValue());
- return true;
}
/// Find the max change in excess pressure across all sets.
PDiff = 0; // Under the limit
else
PDiff = PNew - Limit; // Just exceeded limit.
- }
- else if (Limit > PNew)
+ } else if (Limit > PNew)
PDiff = Limit - POld; // Just obeyed limit.
if (PDiff) {
assert(!MI->isDebugValue() && "Expect a nondebug instruction.");
// Account for register pressure similar to RegPressureTracker::recede().
- RegisterOperands RegOpers(TRI, MRI, /*IgnoreDead=*/true);
- collectOperands(MI, RegOpers);
-
- // Boost max pressure for all dead defs together.
- // Since CurrSetPressure and MaxSetPressure
- increaseRegPressure(RegOpers.DeadDefs);
- decreaseRegPressure(RegOpers.DeadDefs);
+ RegisterOperands RegOpers;
+ RegOpers.collect(*MI, *TRI, *MRI, /*IgnoreDead=*/true);
+ assert(RegOpers.DeadDefs.size() == 0);
+ if (RequireIntervals)
+ RegOpers.detectDeadDefs(*MI, *LIS);
// Kill liveness at live defs.
- for (unsigned i = 0, e = RegOpers.Defs.size(); i < e; ++i) {
- unsigned Reg = RegOpers.Defs[i];
+ for (unsigned Reg : RegOpers.Defs) {
if (!containsReg(RegOpers.Uses, Reg))
decreaseRegPressure(Reg);
}
// Generate liveness for uses.
- for (unsigned i = 0, e = RegOpers.Uses.size(); i < e; ++i) {
- unsigned Reg = RegOpers.Uses[i];
+ for (unsigned Reg : RegOpers.Uses) {
if (!LiveRegs.contains(Reg))
increaseRegPressure(Reg);
}
///
/// This assumes that the current LiveOut set is sufficient.
///
-/// FIXME: This is expensive for an on-the-fly query. We need to cache the
-/// result per-SUnit with enough information to adjust for the current
-/// scheduling position. But this works as a proof of concept.
+/// This is expensive for an on-the-fly query because it calls
+/// bumpUpwardPressure to recompute the pressure sets based on current
+/// liveness. This mainly exists to verify correctness, e.g. with
+/// -verify-misched. getUpwardPressureDelta is the fast version of this query
+/// that uses the per-SUnit cache of the PressureDiff.
void RegPressureTracker::
getMaxUpwardPressureDelta(const MachineInstr *MI, PressureDiff *PDiff,
RegPressureDelta &Delta,
RegPressureDelta Delta2;
getUpwardPressureDelta(MI, *PDiff, Delta2, CriticalPSets, MaxPressureLimit);
if (Delta != Delta2) {
+ dbgs() << "PDiff: ";
+ PDiff->dump(*TRI);
dbgs() << "DELTA: " << *MI;
if (Delta.Excess.isValid())
dbgs() << "Excess1 " << TRI->getRegPressureSetName(Delta.Excess.getPSet())
#endif
}
-/// This is a prototype of the fast version of querying register pressure that
-/// does not directly depend on current liveness. It's still slow because we
-/// recompute pressure change on-the-fly. This implementation only exists to
-/// prove correctness.
+/// This is the fast version of querying register pressure that does not
+/// directly depend on current liveness.
///
/// @param Delta captures information needed for heuristics.
///
/// @param MaxPressureLimit Is the max pressure within the region, not
/// necessarily at the current position.
void RegPressureTracker::
-getUpwardPressureDelta(const MachineInstr *MI, /*const*/ PressureDiff &PDiff1,
+getUpwardPressureDelta(const MachineInstr *MI, /*const*/ PressureDiff &PDiff,
RegPressureDelta &Delta,
ArrayRef<PressureChange> CriticalPSets,
ArrayRef<unsigned> MaxPressureLimit) const {
- RegisterOperands RegOpers(TRI, MRI, /*IgnoreDead=*/true);
- collectOperands(MI, RegOpers);
-
- // Decrease the pressure change for live uses.
- PressureDiff PDiff = PDiff1;
- for (unsigned i = 0, e = RegOpers.Uses.size(); i != e; ++i) {
- if (LiveRegs.contains(RegOpers.Uses[i]))
- PDiff.addPressureChange(RegOpers.Uses[i], true, MRI);
- }
-
- // Now directly query pressure from PDiff. Everything above this can be
- // cached and updated independent of the query.
unsigned CritIdx = 0, CritEnd = CriticalPSets.size();
for (PressureDiff::const_iterator
PDiffI = PDiff.begin(), PDiffE = PDiff.end();
unsigned MNew = MOld;
// Ignore DeadDefs here because they aren't captured by PressureChange.
unsigned PNew = POld + PDiffI->getUnitInc();
- assert((PDiffI->getUnitInc() >= 0) == (PNew >= POld) && "PSet overflow");
+ assert((PDiffI->getUnitInc() >= 0) == (PNew >= POld)
+ && "PSet overflow/underflow");
if (PNew > MOld)
MNew = PNew;
// Check if current pressure has exceeded the limit.
}
/// Helper to find a vreg use between two indices [PriorUseIdx, NextUseIdx).
-static bool findUseBetween(unsigned Reg,
- SlotIndex PriorUseIdx, SlotIndex NextUseIdx,
- const MachineRegisterInfo *MRI,
+static bool findUseBetween(unsigned Reg, SlotIndex PriorUseIdx,
+ SlotIndex NextUseIdx, const MachineRegisterInfo &MRI,
const LiveIntervals *LIS) {
- for (MachineRegisterInfo::use_nodbg_iterator
- UI = MRI->use_nodbg_begin(Reg), UE = MRI->use_nodbg_end();
- UI != UE; UI.skipInstruction()) {
- const MachineInstr* MI = &*UI;
- if (MI->isDebugValue())
- continue;
- SlotIndex InstSlot = LIS->getInstructionIndex(MI).getRegSlot();
- if (InstSlot >= PriorUseIdx && InstSlot < NextUseIdx)
- return true;
+ for (const MachineInstr &MI : MRI.use_nodbg_instructions(Reg)) {
+ SlotIndex InstSlot = LIS->getInstructionIndex(&MI).getRegSlot();
+ if (InstSlot >= PriorUseIdx && InstSlot < NextUseIdx)
+ return true;
}
return false;
}
assert(!MI->isDebugValue() && "Expect a nondebug instruction.");
// Account for register pressure similar to RegPressureTracker::recede().
- RegisterOperands RegOpers(TRI, MRI);
- collectOperands(MI, RegOpers);
+ RegisterOperands RegOpers;
+ RegOpers.collect(*MI, *TRI, *MRI);
// Kill liveness at last uses. Assume allocatable physregs are single-use
// rather than checking LiveIntervals.
if (RequireIntervals)
SlotIdx = LIS->getInstructionIndex(MI).getRegSlot();
- for (unsigned i = 0, e = RegOpers.Uses.size(); i < e; ++i) {
- unsigned Reg = RegOpers.Uses[i];
+ for (unsigned Reg : RegOpers.Uses) {
if (RequireIntervals) {
// FIXME: allow the caller to pass in the list of vreg uses that remain
// to be bottom-scheduled to avoid searching uses at each query.
SlotIndex CurrIdx = getCurrSlot();
- const LiveInterval *LI = getInterval(Reg);
- if (LI && LI->killedAt(SlotIdx)
- && !findUseBetween(Reg, CurrIdx, SlotIdx, MRI, LIS)) {
- decreaseRegPressure(Reg);
+ const LiveRange *LR = getLiveRange(*LIS, Reg);
+ if (LR) {
+ LiveQueryResult LRQ = LR->Query(SlotIdx);
+ if (LRQ.isKill() && !findUseBetween(Reg, CurrIdx, SlotIdx, *MRI, LIS))
+ decreaseRegPressure(Reg);
}
- }
- else if (!TargetRegisterInfo::isVirtualRegister(Reg)) {
+ } else if (!TargetRegisterInfo::isVirtualRegister(Reg)) {
// Allocatable physregs are always single-use before register rewriting.
decreaseRegPressure(Reg);
}
/// register units of that pressure set introduced by this instruction.
///
/// This assumes that the current LiveIn set is sufficient.
+///
+/// This is expensive for an on-the-fly query because it calls
+/// bumpDownwardPressure to recompute the pressure sets based on current
+/// liveness. We don't yet have a fast version of downward pressure tracking
+/// analogous to getUpwardPressureDelta.
void RegPressureTracker::
getMaxDownwardPressureDelta(const MachineInstr *MI, RegPressureDelta &Delta,
ArrayRef<PressureChange> CriticalPSets,
projects / oota-llvm.git / blobdiff