diff options
Diffstat (limited to 'lib/CodeGen/RegisterPressure.cpp')
| -rw-r--r-- | lib/CodeGen/RegisterPressure.cpp | 431 |
1 files changed, 291 insertions, 140 deletions
diff --git a/lib/CodeGen/RegisterPressure.cpp b/lib/CodeGen/RegisterPressure.cpp index b7ab138..092ecdd 100644 --- a/lib/CodeGen/RegisterPressure.cpp +++ b/lib/CodeGen/RegisterPressure.cpp @@ -25,53 +25,19 @@ using namespace llvm; /// Increase pressure for each pressure set provided by TargetRegisterInfo. static void increaseSetPressure(std::vector<unsigned> &CurrSetPressure, - std::vector<unsigned> &MaxSetPressure, - const int *PSet, unsigned Weight) { - for (; *PSet != -1; ++PSet) { - CurrSetPressure[*PSet] += Weight; - if (&CurrSetPressure != &MaxSetPressure - && CurrSetPressure[*PSet] > MaxSetPressure[*PSet]) { - MaxSetPressure[*PSet] = CurrSetPressure[*PSet]; - } - } + PSetIterator PSetI) { + unsigned Weight = PSetI.getWeight(); + for (; PSetI.isValid(); ++PSetI) + CurrSetPressure[*PSetI] += Weight; } /// Decrease pressure for each pressure set provided by TargetRegisterInfo. static void decreaseSetPressure(std::vector<unsigned> &CurrSetPressure, - const int *PSet, unsigned Weight) { - for (; *PSet != -1; ++PSet) { - assert(CurrSetPressure[*PSet] >= Weight && "register pressure underflow"); - CurrSetPressure[*PSet] -= Weight; - } -} - -/// Directly increase pressure only within this RegisterPressure result. -void RegisterPressure::increase(unsigned Reg, const TargetRegisterInfo *TRI, - const MachineRegisterInfo *MRI) { - if (TargetRegisterInfo::isVirtualRegister(Reg)) { - const TargetRegisterClass *RC = MRI->getRegClass(Reg); - increaseSetPressure(MaxSetPressure, MaxSetPressure, - TRI->getRegClassPressureSets(RC), - TRI->getRegClassWeight(RC).RegWeight); - } - else { - increaseSetPressure(MaxSetPressure, MaxSetPressure, - TRI->getRegUnitPressureSets(Reg), - TRI->getRegUnitWeight(Reg)); - } -} - -/// Directly decrease pressure only within this RegisterPressure result. -void RegisterPressure::decrease(unsigned Reg, const TargetRegisterInfo *TRI, - const MachineRegisterInfo *MRI) { - if (TargetRegisterInfo::isVirtualRegister(Reg)) { - const TargetRegisterClass *RC = MRI->getRegClass(Reg); - decreaseSetPressure(MaxSetPressure, TRI->getRegClassPressureSets(RC), - TRI->getRegClassWeight(RC).RegWeight); - } - else { - decreaseSetPressure(MaxSetPressure, TRI->getRegUnitPressureSets(Reg), - TRI->getRegUnitWeight(Reg)); + PSetIterator PSetI) { + unsigned Weight = PSetI.getWeight(); + for (; PSetI.isValid(); ++PSetI) { + assert(CurrSetPressure[*PSetI] >= Weight && "register pressure underflow"); + CurrSetPressure[*PSetI] -= Weight; } } @@ -113,36 +79,23 @@ void RegPressureTracker::dump() const { /// Increase the current pressure as impacted by these registers and bump /// the high water mark if needed. -void RegPressureTracker::increaseRegPressure(ArrayRef<unsigned> Regs) { - for (unsigned I = 0, E = Regs.size(); I != E; ++I) { - if (TargetRegisterInfo::isVirtualRegister(Regs[I])) { - const TargetRegisterClass *RC = MRI->getRegClass(Regs[I]); - increaseSetPressure(CurrSetPressure, P.MaxSetPressure, - TRI->getRegClassPressureSets(RC), - TRI->getRegClassWeight(RC).RegWeight); - } - else { - increaseSetPressure(CurrSetPressure, P.MaxSetPressure, - TRI->getRegUnitPressureSets(Regs[I]), - TRI->getRegUnitWeight(Regs[I])); +void RegPressureTracker::increaseRegPressure(ArrayRef<unsigned> RegUnits) { + for (unsigned i = 0, e = RegUnits.size(); i != e; ++i) { + PSetIterator PSetI = MRI->getPressureSets(RegUnits[i]); + unsigned Weight = PSetI.getWeight(); + for (; PSetI.isValid(); ++PSetI) { + CurrSetPressure[*PSetI] += Weight; + if (CurrSetPressure[*PSetI] > P.MaxSetPressure[*PSetI]) { + P.MaxSetPressure[*PSetI] = CurrSetPressure[*PSetI]; + } } } } /// Simply decrease the current pressure as impacted by these registers. -void RegPressureTracker::decreaseRegPressure(ArrayRef<unsigned> Regs) { - for (unsigned I = 0, E = Regs.size(); I != E; ++I) { - if (TargetRegisterInfo::isVirtualRegister(Regs[I])) { - const TargetRegisterClass *RC = MRI->getRegClass(Regs[I]); - decreaseSetPressure(CurrSetPressure, - TRI->getRegClassPressureSets(RC), - TRI->getRegClassWeight(RC).RegWeight); - } - else { - decreaseSetPressure(CurrSetPressure, TRI->getRegUnitPressureSets(Regs[I]), - TRI->getRegUnitWeight(Regs[I])); - } - } +void RegPressureTracker::decreaseRegPressure(ArrayRef<unsigned> RegUnits) { + for (unsigned I = 0, E = RegUnits.size(); I != E; ++I) + decreaseSetPressure(CurrSetPressure, MRI->getPressureSets(RegUnits[I])); } /// Clear the result so it can be used for another round of pressure tracking. @@ -194,12 +147,30 @@ void RegionPressure::openBottom(MachineBasicBlock::const_iterator PrevBottom) { LiveInRegs.clear(); } -const LiveInterval *RegPressureTracker::getInterval(unsigned Reg) const { +const LiveRange *RegPressureTracker::getLiveRange(unsigned Reg) const { if (TargetRegisterInfo::isVirtualRegister(Reg)) return &LIS->getInterval(Reg); return LIS->getCachedRegUnit(Reg); } +void RegPressureTracker::reset() { + MBB = 0; + LIS = 0; + + CurrSetPressure.clear(); + LiveThruPressure.clear(); + P.MaxSetPressure.clear(); + + if (RequireIntervals) + static_cast<IntervalPressure&>(P).reset(); + else + static_cast<RegionPressure&>(P).reset(); + + LiveRegs.PhysRegs.clear(); + LiveRegs.VirtRegs.clear(); + UntiedDefs.clear(); +} + /// Setup the RegPressureTracker. /// /// TODO: Add support for pressure without LiveIntervals. @@ -210,6 +181,8 @@ void RegPressureTracker::init(const MachineFunction *mf, MachineBasicBlock::const_iterator pos, bool ShouldTrackUntiedDefs) { + reset(); + MF = mf; TRI = MF->getTarget().getRegisterInfo(); RCI = rci; @@ -224,19 +197,11 @@ void RegPressureTracker::init(const MachineFunction *mf, 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(); if (TrackUntiedDefs) UntiedDefs.setUniverse(MRI->getNumVirtRegs()); } @@ -328,24 +293,25 @@ void RegPressureTracker::initLiveThru(const RegPressureTracker &RPTracker) { unsigned Reg = P.LiveOutRegs[i]; if (TargetRegisterInfo::isVirtualRegister(Reg) && !RPTracker.hasUntiedDef(Reg)) { - const TargetRegisterClass *RC = MRI->getRegClass(Reg); - increaseSetPressure(LiveThruPressure, LiveThruPressure, - TRI->getRegClassPressureSets(RC), - TRI->getRegClassWeight(RC).RegWeight); + increaseSetPressure(LiveThruPressure, MRI->getPressureSets(Reg)); } } } /// \brief Convenient wrapper for checking membership in RegisterOperands. -static bool containsReg(ArrayRef<unsigned> Regs, unsigned Reg) { - return std::find(Regs.begin(), Regs.end(), Reg) != Regs.end(); +/// (std::count() doesn't have an early exit). +static bool containsReg(ArrayRef<unsigned> RegUnits, unsigned RegUnit) { + return std::find(RegUnits.begin(), RegUnits.end(), RegUnit) != RegUnits.end(); } /// 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; + bool IgnoreDead; public: SmallVector<unsigned, 8> Uses; @@ -353,7 +319,8 @@ public: SmallVector<unsigned, 8> DeadDefs; RegisterOperands(const TargetRegisterInfo *tri, - const MachineRegisterInfo *mri): TRI(tri), MRI(mri) {} + const MachineRegisterInfo *mri, bool ID = false): + TRI(tri), MRI(mri), IgnoreDead(ID) {} /// Push this operand's register onto the correct vector. void collect(const MachineOperand &MO) { @@ -362,25 +329,27 @@ public: if (MO.readsReg()) pushRegUnits(MO.getReg(), Uses); if (MO.isDef()) { - if (MO.isDead()) - pushRegUnits(MO.getReg(), DeadDefs); + if (MO.isDead()) { + if (!IgnoreDead) + pushRegUnits(MO.getReg(), DeadDefs); + } else pushRegUnits(MO.getReg(), Defs); } } protected: - void pushRegUnits(unsigned Reg, SmallVectorImpl<unsigned> &Regs) { + void pushRegUnits(unsigned Reg, SmallVectorImpl<unsigned> &RegUnits) { if (TargetRegisterInfo::isVirtualRegister(Reg)) { - if (containsReg(Regs, Reg)) + if (containsReg(RegUnits, Reg)) return; - Regs.push_back(Reg); + RegUnits.push_back(Reg); } else if (MRI->isAllocatable(Reg)) { for (MCRegUnitIterator Units(Reg, TRI); Units.isValid(); ++Units) { - if (containsReg(Regs, *Units)) + if (containsReg(RegUnits, *Units)) continue; - Regs.push_back(*Units); + RegUnits.push_back(*Units); } } } @@ -399,6 +368,56 @@ static void collectOperands(const MachineInstr *MI, RegOpers.DeadDefs.erase(I, RegOpers.DeadDefs.end()); } +/// Initialize an array of N PressureDiffs. +void PressureDiffs::init(unsigned N) { + Size = N; + if (N <= Max) { + memset(PDiffArray, 0, N * sizeof(PressureDiff)); + return; + } + Max = Size; + free(PDiffArray); + PDiffArray = reinterpret_cast<PressureDiff*>(calloc(N, sizeof(PressureDiff))); +} + +/// Add a change in pressure to the pressure diff of a given instruction. +void PressureDiff::addPressureChange(unsigned RegUnit, bool IsDec, + const MachineRegisterInfo *MRI) { + PSetIterator PSetI = MRI->getPressureSets(RegUnit); + 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(); + for (; I != E && I->isValid(); ++I) { + if (I->getPSet() >= *PSetI) + break; + } + // If all pressure sets are more constrained, skip the remaining PSets. + if (I == E) + break; + // Insert this PressureChange. + if (!I->isValid() || I->getPSet() != *PSetI) { + PressureChange PTmp = PressureChange(*PSetI); + for (PressureDiff::iterator J = I; J != E && PTmp.isValid(); ++J) + 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) + PDiff.addPressureChange(RegOpers.Defs[i], true, MRI); + + 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) { @@ -415,7 +434,7 @@ void RegPressureTracker::discoverLiveIn(unsigned Reg) { // At live in discovery, unconditionally increase the high water mark. P.LiveInRegs.push_back(Reg); - P.increase(Reg, TRI, MRI); + increaseSetPressure(P.MaxSetPressure, MRI->getPressureSets(Reg)); } /// Add Reg to the live out set and increase max pressure. @@ -426,11 +445,16 @@ void RegPressureTracker::discoverLiveOut(unsigned Reg) { // At live out discovery, unconditionally increase the high water mark. P.LiveOutRegs.push_back(Reg); - P.increase(Reg, TRI, MRI); + increaseSetPressure(P.MaxSetPressure, MRI->getPressureSets(Reg)); } -/// Recede across the previous instruction. -bool RegPressureTracker::recede() { +/// 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. +bool RegPressureTracker::recede(SmallVectorImpl<unsigned> *LiveUses, + PressureDiff *PDiff) { // Check for the top of the analyzable region. if (CurrPos == MBB->begin()) { closeRegion(); @@ -463,6 +487,9 @@ bool RegPressureTracker::recede() { RegisterOperands RegOpers(TRI, MRI); collectOperands(CurrPos, RegOpers); + if (PDiff) + collectPDiff(*PDiff, RegOpers, MRI); + // Boost pressure for all dead defs together. increaseRegPressure(RegOpers.DeadDefs); decreaseRegPressure(RegOpers.DeadDefs); @@ -471,10 +498,20 @@ bool RegPressureTracker::recede() { // TODO: consider earlyclobbers? for (unsigned i = 0, e = RegOpers.Defs.size(); i < e; ++i) { unsigned Reg = RegOpers.Defs[i]; - if (LiveRegs.erase(Reg)) - decreaseRegPressure(Reg); - else - discoverLiveOut(Reg); + bool DeadDef = false; + if (RequireIntervals) { + const LiveRange *LR = getLiveRange(Reg); + if (LR) { + LiveQueryResult LRQ = LR->Query(SlotIdx); + DeadDef = LRQ.isDeadDef(); + } + } + if (!DeadDef) { + if (LiveRegs.erase(Reg)) + decreaseRegPressure(Reg); + else + discoverLiveOut(Reg); + } } // Generate liveness for uses. @@ -483,12 +520,17 @@ bool RegPressureTracker::recede() { 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(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) { @@ -537,8 +579,8 @@ bool RegPressureTracker::advance() { // Kill liveness at last uses. bool lastUse = false; if (RequireIntervals) { - const LiveInterval *LI = getInterval(Reg); - lastUse = LI && LI->killedAt(SlotIdx); + const LiveRange *LR = getLiveRange(Reg); + lastUse = LR && LR->Query(SlotIdx).isKill(); } else { // Allocatable physregs are always single-use before register rewriting. @@ -576,8 +618,7 @@ static void computeExcessPressureDelta(ArrayRef<unsigned> OldPressureVec, RegPressureDelta &Delta, const RegisterClassInfo *RCI, ArrayRef<unsigned> LiveThruPressureVec) { - int ExcessUnits = 0; - unsigned PSetID = ~0U; + Delta.Excess = PressureChange(); for (unsigned i = 0, e = OldPressureVec.size(); i < e; ++i) { unsigned POld = OldPressureVec[i]; unsigned PNew = NewPressureVec[i]; @@ -599,13 +640,11 @@ static void computeExcessPressureDelta(ArrayRef<unsigned> OldPressureVec, PDiff = Limit - POld; // Just obeyed limit. if (PDiff) { - ExcessUnits = PDiff; - PSetID = i; + Delta.Excess = PressureChange(i); + Delta.Excess.setUnitInc(PDiff); break; } } - Delta.Excess.PSetID = PSetID; - Delta.Excess.UnitIncrease = ExcessUnits; } /// Find the max change in max pressure that either surpasses a critical PSet @@ -616,11 +655,11 @@ static void computeExcessPressureDelta(ArrayRef<unsigned> OldPressureVec, /// RegPressureTracker API change to work with pressure differences. static void computeMaxPressureDelta(ArrayRef<unsigned> OldMaxPressureVec, ArrayRef<unsigned> NewMaxPressureVec, - ArrayRef<PressureElement> CriticalPSets, + ArrayRef<PressureChange> CriticalPSets, ArrayRef<unsigned> MaxPressureLimit, RegPressureDelta &Delta) { - Delta.CriticalMax = PressureElement(); - Delta.CurrentMax = PressureElement(); + Delta.CriticalMax = PressureChange(); + Delta.CurrentMax = PressureChange(); unsigned CritIdx = 0, CritEnd = CriticalPSets.size(); for (unsigned i = 0, e = OldMaxPressureVec.size(); i < e; ++i) { @@ -630,27 +669,24 @@ static void computeMaxPressureDelta(ArrayRef<unsigned> OldMaxPressureVec, continue; if (!Delta.CriticalMax.isValid()) { - while (CritIdx != CritEnd && CriticalPSets[CritIdx].PSetID < i) + while (CritIdx != CritEnd && CriticalPSets[CritIdx].getPSet() < i) ++CritIdx; - if (CritIdx != CritEnd && CriticalPSets[CritIdx].PSetID == i) { - int PDiff = (int)PNew - (int)CriticalPSets[CritIdx].UnitIncrease; + if (CritIdx != CritEnd && CriticalPSets[CritIdx].getPSet() == i) { + int PDiff = (int)PNew - (int)CriticalPSets[CritIdx].getUnitInc(); if (PDiff > 0) { - Delta.CriticalMax.PSetID = i; - Delta.CriticalMax.UnitIncrease = PDiff; + Delta.CriticalMax = PressureChange(i); + Delta.CriticalMax.setUnitInc(PDiff); } } } // Find the first increase above MaxPressureLimit. // (Ignores negative MDiff). - if (!Delta.CurrentMax.isValid()) { - int MDiff = (int)PNew - (int)MaxPressureLimit[i]; - if (MDiff > 0) { - Delta.CurrentMax.PSetID = i; - Delta.CurrentMax.UnitIncrease = MDiff; - if (CritIdx == CritEnd || Delta.CriticalMax.isValid()) - break; - } + if (!Delta.CurrentMax.isValid() && PNew > MaxPressureLimit[i]) { + Delta.CurrentMax = PressureChange(i); + Delta.CurrentMax.setUnitInc(PNew - POld); + if (CritIdx == CritEnd || Delta.CriticalMax.isValid()) + break; } } } @@ -665,7 +701,7 @@ void RegPressureTracker::bumpUpwardPressure(const MachineInstr *MI) { assert(!MI->isDebugValue() && "Expect a nondebug instruction."); // Account for register pressure similar to RegPressureTracker::recede(). - RegisterOperands RegOpers(TRI, MRI); + RegisterOperands RegOpers(TRI, MRI, /*IgnoreDead=*/true); collectOperands(MI, RegOpers); // Boost max pressure for all dead defs together. @@ -676,8 +712,19 @@ void RegPressureTracker::bumpUpwardPressure(const MachineInstr *MI) { // Kill liveness at live defs. for (unsigned i = 0, e = RegOpers.Defs.size(); i < e; ++i) { unsigned Reg = RegOpers.Defs[i]; - if (!containsReg(RegOpers.Uses, Reg)) - decreaseRegPressure(Reg); + bool DeadDef = false; + if (RequireIntervals) { + const LiveRange *LR = getLiveRange(Reg); + if (LR) { + SlotIndex SlotIdx = LIS->getInstructionIndex(MI); + LiveQueryResult LRQ = LR->Query(SlotIdx); + DeadDef = LRQ.isDeadDef(); + } + } + if (!DeadDef) { + if (!containsReg(RegOpers.Uses, Reg)) + decreaseRegPressure(Reg); + } } // Generate liveness for uses. for (unsigned i = 0, e = RegOpers.Uses.size(); i < e; ++i) { @@ -699,8 +746,9 @@ void RegPressureTracker::bumpUpwardPressure(const MachineInstr *MI) { /// result per-SUnit with enough information to adjust for the current /// scheduling position. But this works as a proof of concept. void RegPressureTracker:: -getMaxUpwardPressureDelta(const MachineInstr *MI, RegPressureDelta &Delta, - ArrayRef<PressureElement> CriticalPSets, +getMaxUpwardPressureDelta(const MachineInstr *MI, PressureDiff *PDiff, + RegPressureDelta &Delta, + ArrayRef<PressureChange> CriticalPSets, ArrayRef<unsigned> MaxPressureLimit) { // Snapshot Pressure. // FIXME: The snapshot heap space should persist. But I'm planning to @@ -714,12 +762,113 @@ getMaxUpwardPressureDelta(const MachineInstr *MI, RegPressureDelta &Delta, LiveThruPressure); computeMaxPressureDelta(SavedMaxPressure, P.MaxSetPressure, CriticalPSets, MaxPressureLimit, Delta); - assert(Delta.CriticalMax.UnitIncrease >= 0 && - Delta.CurrentMax.UnitIncrease >= 0 && "cannot decrease max pressure"); + assert(Delta.CriticalMax.getUnitInc() >= 0 && + Delta.CurrentMax.getUnitInc() >= 0 && "cannot decrease max pressure"); // Restore the tracker's state. P.MaxSetPressure.swap(SavedMaxPressure); CurrSetPressure.swap(SavedPressure); + +#ifndef NDEBUG + if (!PDiff) + return; + + // Check if the alternate algorithm yields the same result. + RegPressureDelta Delta2; + getUpwardPressureDelta(MI, *PDiff, Delta2, CriticalPSets, MaxPressureLimit); + if (Delta != Delta2) { + dbgs() << "DELTA: " << *MI; + if (Delta.Excess.isValid()) + dbgs() << "Excess1 " << TRI->getRegPressureSetName(Delta.Excess.getPSet()) + << " " << Delta.Excess.getUnitInc() << "\n"; + if (Delta.CriticalMax.isValid()) + dbgs() << "Critic1 " << TRI->getRegPressureSetName(Delta.CriticalMax.getPSet()) + << " " << Delta.CriticalMax.getUnitInc() << "\n"; + if (Delta.CurrentMax.isValid()) + dbgs() << "CurrMx1 " << TRI->getRegPressureSetName(Delta.CurrentMax.getPSet()) + << " " << Delta.CurrentMax.getUnitInc() << "\n"; + if (Delta2.Excess.isValid()) + dbgs() << "Excess2 " << TRI->getRegPressureSetName(Delta2.Excess.getPSet()) + << " " << Delta2.Excess.getUnitInc() << "\n"; + if (Delta2.CriticalMax.isValid()) + dbgs() << "Critic2 " << TRI->getRegPressureSetName(Delta2.CriticalMax.getPSet()) + << " " << Delta2.CriticalMax.getUnitInc() << "\n"; + if (Delta2.CurrentMax.isValid()) + dbgs() << "CurrMx2 " << TRI->getRegPressureSetName(Delta2.CurrentMax.getPSet()) + << " " << Delta2.CurrentMax.getUnitInc() << "\n"; + llvm_unreachable("RegP Delta Mismatch"); + } +#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. +/// +/// @param Delta captures information needed for heuristics. +/// +/// @param CriticalPSets Are the pressure sets that are known to exceed some +/// limit within the region, not necessarily at the current position. +/// +/// @param MaxPressureLimit Is the max pressure within the region, not +/// necessarily at the current position. +void RegPressureTracker:: +getUpwardPressureDelta(const MachineInstr *MI, /*const*/ PressureDiff &PDiff, + RegPressureDelta &Delta, + ArrayRef<PressureChange> CriticalPSets, + ArrayRef<unsigned> MaxPressureLimit) const { + unsigned CritIdx = 0, CritEnd = CriticalPSets.size(); + for (PressureDiff::const_iterator + PDiffI = PDiff.begin(), PDiffE = PDiff.end(); + PDiffI != PDiffE && PDiffI->isValid(); ++PDiffI) { + + unsigned PSetID = PDiffI->getPSet(); + unsigned Limit = RCI->getRegPressureSetLimit(PSetID); + if (!LiveThruPressure.empty()) + Limit += LiveThruPressure[PSetID]; + + unsigned POld = CurrSetPressure[PSetID]; + unsigned MOld = P.MaxSetPressure[PSetID]; + 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"); + if (PNew > MOld) + MNew = PNew; + // Check if current pressure has exceeded the limit. + if (!Delta.Excess.isValid()) { + unsigned ExcessInc = 0; + if (PNew > Limit) + ExcessInc = POld > Limit ? PNew - POld : PNew - Limit; + else if (POld > Limit) + ExcessInc = Limit - POld; + if (ExcessInc) { + Delta.Excess = PressureChange(PSetID); + Delta.Excess.setUnitInc(ExcessInc); + } + } + // Check if max pressure has exceeded a critical pressure set max. + if (MNew == MOld) + continue; + if (!Delta.CriticalMax.isValid()) { + while (CritIdx != CritEnd && CriticalPSets[CritIdx].getPSet() < PSetID) + ++CritIdx; + + if (CritIdx != CritEnd && CriticalPSets[CritIdx].getPSet() == PSetID) { + int CritInc = (int)MNew - (int)CriticalPSets[CritIdx].getUnitInc(); + if (CritInc > 0 && CritInc <= INT16_MAX) { + Delta.CriticalMax = PressureChange(PSetID); + Delta.CriticalMax.setUnitInc(CritInc); + } + } + } + // Check if max pressure has exceeded the current max. + if (!Delta.CurrentMax.isValid() && MNew > MaxPressureLimit[PSetID]) { + Delta.CurrentMax = PressureChange(PSetID); + Delta.CurrentMax.setUnitInc(MNew - MOld); + } + } } /// Helper to find a vreg use between two indices [PriorUseIdx, NextUseIdx). @@ -765,10 +914,12 @@ void RegPressureTracker::bumpDownwardPressure(const MachineInstr *MI) { // 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(Reg); + if (LR) { + LiveQueryResult LRQ = LR->Query(SlotIdx); + if (LRQ.isKill() && !findUseBetween(Reg, CurrIdx, SlotIdx, MRI, LIS)) { + decreaseRegPressure(Reg); + } } } else if (!TargetRegisterInfo::isVirtualRegister(Reg)) { @@ -793,7 +944,7 @@ void RegPressureTracker::bumpDownwardPressure(const MachineInstr *MI) { /// This assumes that the current LiveIn set is sufficient. void RegPressureTracker:: getMaxDownwardPressureDelta(const MachineInstr *MI, RegPressureDelta &Delta, - ArrayRef<PressureElement> CriticalPSets, + ArrayRef<PressureChange> CriticalPSets, ArrayRef<unsigned> MaxPressureLimit) { // Snapshot Pressure. std::vector<unsigned> SavedPressure = CurrSetPressure; @@ -805,8 +956,8 @@ getMaxDownwardPressureDelta(const MachineInstr *MI, RegPressureDelta &Delta, LiveThruPressure); computeMaxPressureDelta(SavedMaxPressure, P.MaxSetPressure, CriticalPSets, MaxPressureLimit, Delta); - assert(Delta.CriticalMax.UnitIncrease >= 0 && - Delta.CurrentMax.UnitIncrease >= 0 && "cannot decrease max pressure"); + assert(Delta.CriticalMax.getUnitInc() >= 0 && + Delta.CurrentMax.getUnitInc() >= 0 && "cannot decrease max pressure"); // Restore the tracker's state. P.MaxSetPressure.swap(SavedMaxPressure); |