//
//===----------------------------------------------------------------------===//
-#include "RegisterClassInfo.h"
-#include "RegisterPressure.h"
+#include "llvm/CodeGen/RegisterPressure.h"
#include "llvm/CodeGen/LiveInterval.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/RegisterClassInfo.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetMachine.h"
using namespace llvm;
-/// Increase register pressure for each set impacted by this register class.
+/// Increase pressure for each pressure set provided by TargetRegisterInfo.
static void increaseSetPressure(std::vector<unsigned> &CurrSetPressure,
std::vector<unsigned> &MaxSetPressure,
- const TargetRegisterClass *RC,
- const TargetRegisterInfo *TRI) {
- unsigned Weight = TRI->getRegClassWeight(RC).RegWeight;
- for (const int *PSet = TRI->getRegClassPressureSets(RC);
- *PSet != -1; ++PSet) {
+ const int *PSet, unsigned Weight) {
+ for (; *PSet != -1; ++PSet) {
CurrSetPressure[*PSet] += Weight;
- if (CurrSetPressure[*PSet] > MaxSetPressure[*PSet])
+ if (&CurrSetPressure != &MaxSetPressure
+ && CurrSetPressure[*PSet] > MaxSetPressure[*PSet]) {
MaxSetPressure[*PSet] = CurrSetPressure[*PSet];
+ }
}
}
-/// Decrease register pressure for each set impacted by this register class.
+/// Decrease pressure for each pressure set provided by TargetRegisterInfo.
static void decreaseSetPressure(std::vector<unsigned> &CurrSetPressure,
- const TargetRegisterClass *RC,
- const TargetRegisterInfo *TRI) {
- unsigned Weight = TRI->getRegClassWeight(RC).RegWeight;
- for (const int *PSet = TRI->getRegClassPressureSets(RC);
- *PSet != -1; ++PSet) {
+ 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(const TargetRegisterClass *RC,
- const TargetRegisterInfo *TRI) {
- increaseSetPressure(MaxSetPressure, MaxSetPressure, RC, TRI);
+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(const TargetRegisterClass *RC,
- const TargetRegisterInfo *TRI) {
- decreaseSetPressure(MaxSetPressure, RC, TRI);
+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));
+ }
}
-/// Increase the current pressure as impacted by these physical registers and
-/// bump the high water mark if needed.
-void RegPressureTracker::increasePhysRegPressure(ArrayRef<unsigned> Regs) {
- for (unsigned I = 0, E = Regs.size(); I != E; ++I)
- increaseSetPressure(CurrSetPressure, P.MaxSetPressure,
- TRI->getMinimalPhysRegClass(Regs[I]), TRI);
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+static void dumpSetPressure(const std::vector<unsigned> &SetPressure,
+ const TargetRegisterInfo *TRI) {
+ for (unsigned i = 0, e = SetPressure.size(); i < e; ++i) {
+ if (SetPressure[i] != 0)
+ dbgs() << TRI->getRegPressureSetName(i) << "=" << SetPressure[i] << '\n';
+ }
}
-/// Simply decrease the current pressure as impacted by these physcial
-/// registers.
-void RegPressureTracker::decreasePhysRegPressure(ArrayRef<unsigned> Regs) {
- for (unsigned I = 0, E = Regs.size(); I != E; ++I)
- decreaseSetPressure(CurrSetPressure, TRI->getMinimalPhysRegClass(Regs[I]),
- TRI);
+void RegisterPressure::dump(const TargetRegisterInfo *TRI) const {
+ dbgs() << "Max Pressure: ";
+ dumpSetPressure(MaxSetPressure, TRI);
+ dbgs() << "Live In: ";
+ for (unsigned i = 0, e = LiveInRegs.size(); i < e; ++i)
+ dbgs() << PrintReg(LiveInRegs[i], TRI) << " ";
+ dbgs() << '\n';
+ dbgs() << "Live Out: ";
+ for (unsigned i = 0, e = LiveOutRegs.size(); i < e; ++i)
+ dbgs() << PrintReg(LiveOutRegs[i], TRI) << " ";
+ dbgs() << '\n';
}
-/// Increase the current pressure as impacted by these virtual registers and
-/// bump the high water mark if needed.
-void RegPressureTracker::increaseVirtRegPressure(ArrayRef<unsigned> Regs) {
- for (unsigned I = 0, E = Regs.size(); I != E; ++I)
- increaseSetPressure(CurrSetPressure, P.MaxSetPressure,
- MRI->getRegClass(Regs[I]), TRI);
+void RegPressureTracker::dump(const TargetRegisterInfo *TRI) const {
+ dbgs() << "Curr Pressure: ";
+ dumpSetPressure(CurrSetPressure, TRI);
+ P.dump(TRI);
+}
+#endif
+
+/// 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]));
+ }
+ }
}
-/// Simply decrease the current pressure as impacted by these virtual registers.
-void RegPressureTracker::decreaseVirtRegPressure(ArrayRef<unsigned> Regs) {
- for (unsigned I = 0, E = Regs.size(); I != E; ++I)
- decreaseSetPressure(CurrSetPressure, MRI->getRegClass(Regs[I]), TRI);
+/// 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]));
+ }
+ }
}
/// Clear the result so it can be used for another round of pressure tracking.
LiveInRegs.clear();
}
+const LiveInterval *RegPressureTracker::getInterval(unsigned Reg) const {
+ if (TargetRegisterInfo::isVirtualRegister(Reg))
+ return &LIS->getInterval(Reg);
+ return LIS->getCachedRegUnit(Reg);
+}
+
/// Setup the RegPressureTracker.
///
/// TODO: Add support for pressure without LiveIntervals.
}
CurrPos = pos;
- while (CurrPos != MBB->end() && CurrPos->isDebugValue())
- ++CurrPos;
-
CurrSetPressure.assign(TRI->getNumRegPressureSets(), 0);
if (RequireIntervals)
static_cast<RegionPressure&>(P).reset();
P.MaxSetPressure = CurrSetPressure;
- LivePhysRegs.clear();
- LivePhysRegs.setUniverse(TRI->getNumRegs());
- LiveVirtRegs.clear();
- LiveVirtRegs.setUniverse(MRI->getNumVirtRegs());
+ LiveRegs.PhysRegs.clear();
+ LiveRegs.PhysRegs.setUniverse(TRI->getNumRegs());
+ LiveRegs.VirtRegs.clear();
+ LiveRegs.VirtRegs.setUniverse(MRI->getNumVirtRegs());
}
/// Does this pressure result have a valid top position and live ins.
MachineBasicBlock::const_iterator());
}
+
+SlotIndex RegPressureTracker::getCurrSlot() const {
+ MachineBasicBlock::const_iterator IdxPos = CurrPos;
+ while (IdxPos != MBB->end() && IdxPos->isDebugValue())
+ ++IdxPos;
+ if (IdxPos == MBB->end())
+ return LIS->getMBBEndIdx(MBB);
+ return LIS->getInstructionIndex(IdxPos).getRegSlot();
+}
+
/// Set the boundary for the top of the region and summarize live ins.
void RegPressureTracker::closeTop() {
if (RequireIntervals)
- static_cast<IntervalPressure&>(P).TopIdx =
- LIS->getInstructionIndex(CurrPos).getRegSlot();
+ static_cast<IntervalPressure&>(P).TopIdx = getCurrSlot();
else
static_cast<RegionPressure&>(P).TopPos = CurrPos;
assert(P.LiveInRegs.empty() && "inconsistent max pressure result");
- P.LiveInRegs.reserve(LivePhysRegs.size() + LiveVirtRegs.size());
- P.LiveInRegs.append(LivePhysRegs.begin(), LivePhysRegs.end());
+ P.LiveInRegs.reserve(LiveRegs.PhysRegs.size() + LiveRegs.VirtRegs.size());
+ P.LiveInRegs.append(LiveRegs.PhysRegs.begin(), LiveRegs.PhysRegs.end());
for (SparseSet<unsigned>::const_iterator I =
- LiveVirtRegs.begin(), E = LiveVirtRegs.end(); I != E; ++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()),
/// Set the boundary for the bottom of the region and summarize live outs.
void RegPressureTracker::closeBottom() {
if (RequireIntervals)
- if (CurrPos == MBB->end())
- static_cast<IntervalPressure&>(P).BottomIdx = LIS->getMBBEndIdx(MBB);
- else
- static_cast<IntervalPressure&>(P).BottomIdx =
- LIS->getInstructionIndex(CurrPos).getRegSlot();
+ static_cast<IntervalPressure&>(P).BottomIdx = getCurrSlot();
else
static_cast<RegionPressure&>(P).BottomPos = CurrPos;
assert(P.LiveOutRegs.empty() && "inconsistent max pressure result");
- P.LiveOutRegs.reserve(LivePhysRegs.size() + LiveVirtRegs.size());
- P.LiveOutRegs.append(LivePhysRegs.begin(), LivePhysRegs.end());
+ P.LiveOutRegs.reserve(LiveRegs.PhysRegs.size() + LiveRegs.VirtRegs.size());
+ P.LiveOutRegs.append(LiveRegs.PhysRegs.begin(), LiveRegs.PhysRegs.end());
for (SparseSet<unsigned>::const_iterator I =
- LiveVirtRegs.begin(), E = LiveVirtRegs.end(); I != E; ++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()),
/// Finalize the region boundaries and record live ins and live outs.
void RegPressureTracker::closeRegion() {
if (!isTopClosed() && !isBottomClosed()) {
- assert(LivePhysRegs.empty() && LiveVirtRegs.empty() &&
+ assert(LiveRegs.PhysRegs.empty() && LiveRegs.VirtRegs.empty() &&
"no region boundary");
return;
}
// If both top and bottom are closed, do nothing.
}
-/// Return true if Reg aliases a register in Regs SparseSet.
-static bool hasRegAlias(unsigned Reg, SparseSet<unsigned> &Regs,
- const TargetRegisterInfo *TRI) {
- assert(!TargetRegisterInfo::isVirtualRegister(Reg) && "only for physregs");
- for (const uint16_t *Alias = TRI->getOverlaps(Reg); *Alias; ++Alias) {
- if (Regs.count(*Alias))
- return true;
- }
- return false;
-}
-
-/// Return true if Reg aliases a register in unsorted Regs SmallVector.
-/// This is only valid for physical registers.
-static SmallVectorImpl<unsigned>::iterator
-findRegAlias(unsigned Reg, SmallVectorImpl<unsigned> &Regs,
- const TargetRegisterInfo *TRI) {
- for (const uint16_t *Alias = TRI->getOverlaps(Reg); *Alias; ++Alias) {
- SmallVectorImpl<unsigned>::iterator I =
- std::find(Regs.begin(), Regs.end(), *Alias);
- if (I != Regs.end())
- return I;
- }
- return Regs.end();
-}
-
-/// Return true if Reg can be inserted into Regs SmallVector. For virtual
-/// register, do a linear search. For physical registers check for aliases.
-static SmallVectorImpl<unsigned>::iterator
-findReg(unsigned Reg, bool isVReg, SmallVectorImpl<unsigned> &Regs,
- const TargetRegisterInfo *TRI) {
- if(isVReg)
- return std::find(Regs.begin(), Regs.end(), Reg);
- return findRegAlias(Reg, Regs, TRI);
+/// \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();
}
/// Collect this instruction's unique uses and defs into SmallVectors for
/// processing defs and uses in order.
-template<bool isVReg>
-struct RegisterOperands {
+class RegisterOperands {
+ const TargetRegisterInfo *TRI;
+ const MachineRegisterInfo *MRI;
+
+public:
SmallVector<unsigned, 8> Uses;
SmallVector<unsigned, 8> Defs;
SmallVector<unsigned, 8> DeadDefs;
+ RegisterOperands(const TargetRegisterInfo *tri,
+ const MachineRegisterInfo *mri): TRI(tri), MRI(mri) {}
+
/// Push this operand's register onto the correct vector.
- void collect(const MachineOperand &MO, const TargetRegisterInfo *TRI) {
- if (MO.readsReg()) {
- if (findReg(MO.getReg(), isVReg, Uses, TRI) == Uses.end())
- Uses.push_back(MO.getReg());
- }
+ void collect(const MachineOperand &MO) {
+ if (!MO.isReg() || !MO.getReg())
+ return;
+ if (MO.readsReg())
+ pushRegUnits(MO.getReg(), Uses);
if (MO.isDef()) {
- if (MO.isDead()) {
- if (findReg(MO.getReg(), isVReg, DeadDefs, TRI) == DeadDefs.end())
- DeadDefs.push_back(MO.getReg());
- }
- else {
- if (findReg(MO.getReg(), isVReg, Defs, TRI) == Defs.end())
- Defs.push_back(MO.getReg());
+ if (MO.isDead())
+ pushRegUnits(MO.getReg(), DeadDefs);
+ else
+ pushRegUnits(MO.getReg(), Defs);
+ }
+ }
+
+protected:
+ void pushRegUnits(unsigned Reg, SmallVectorImpl<unsigned> &Regs) {
+ if (TargetRegisterInfo::isVirtualRegister(Reg)) {
+ if (containsReg(Regs, Reg))
+ return;
+ Regs.push_back(Reg);
+ }
+ else if (MRI->isAllocatable(Reg)) {
+ for (MCRegUnitIterator Units(Reg, TRI); Units.isValid(); ++Units) {
+ if (containsReg(Regs, *Units))
+ continue;
+ Regs.push_back(*Units);
}
}
}
};
-typedef RegisterOperands<false> PhysRegOperands;
-typedef RegisterOperands<true> VirtRegOperands;
/// Collect physical and virtual register operands.
static void collectOperands(const MachineInstr *MI,
- PhysRegOperands &PhysRegOpers,
- VirtRegOperands &VirtRegOpers,
- const TargetRegisterInfo *TRI,
- const RegisterClassInfo *RCI) {
- for(ConstMIBundleOperands OperI(MI); OperI.isValid(); ++OperI) {
- const MachineOperand &MO = *OperI;
- if (!MO.isReg() || !MO.getReg())
- continue;
+ RegisterOperands &RegOpers) {
+ for(ConstMIBundleOperands OperI(MI); OperI.isValid(); ++OperI)
+ RegOpers.collect(*OperI);
- if (TargetRegisterInfo::isVirtualRegister(MO.getReg()))
- VirtRegOpers.collect(MO, TRI);
- else if (RCI->isAllocatable(MO.getReg()))
- PhysRegOpers.collect(MO, TRI);
- }
// Remove redundant physreg dead defs.
- for (unsigned i = PhysRegOpers.DeadDefs.size(); i > 0; --i) {
- unsigned Reg = PhysRegOpers.DeadDefs[i-1];
- if (findRegAlias(Reg, PhysRegOpers.Defs, TRI) != PhysRegOpers.Defs.end())
- PhysRegOpers.DeadDefs.erase(&PhysRegOpers.DeadDefs[i-1]);
+ for (unsigned i = RegOpers.DeadDefs.size(); i > 0; --i) {
+ unsigned Reg = RegOpers.DeadDefs[i-1];
+ if (containsReg(RegOpers.Defs, Reg))
+ RegOpers.DeadDefs.erase(&RegOpers.DeadDefs[i-1]);
}
}
-/// Add PhysReg to the live in set and increase max pressure.
-void RegPressureTracker::discoverPhysLiveIn(unsigned Reg) {
- assert(!LivePhysRegs.count(Reg) && "avoid bumping max pressure twice");
- if (findRegAlias(Reg, P.LiveInRegs, TRI) == P.LiveInRegs.end())
- return;
-
- // At live in discovery, unconditionally increase the high water mark.
- P.LiveInRegs.push_back(Reg);
- P.increase(TRI->getMinimalPhysRegClass(Reg), TRI);
-}
-
-/// Add PhysReg to the live out set and increase max pressure.
-void RegPressureTracker::discoverPhysLiveOut(unsigned Reg) {
- assert(!LivePhysRegs.count(Reg) && "avoid bumping max pressure twice");
- if (findRegAlias(Reg, P.LiveOutRegs, TRI) == P.LiveOutRegs.end())
- return;
-
- // At live out discovery, unconditionally increase the high water mark.
- P.LiveOutRegs.push_back(Reg);
- P.increase(TRI->getMinimalPhysRegClass(Reg), TRI);
+/// 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]);
+ }
}
-/// Add VirtReg to the live in set and increase max pressure.
-void RegPressureTracker::discoverVirtLiveIn(unsigned Reg) {
- assert(!LiveVirtRegs.count(Reg) && "avoid bumping max pressure twice");
- if (std::find(P.LiveInRegs.begin(), P.LiveInRegs.end(), Reg) !=
- P.LiveInRegs.end())
+/// Add Reg to the live in set and increase max pressure.
+void RegPressureTracker::discoverLiveIn(unsigned Reg) {
+ assert(!LiveRegs.contains(Reg) && "avoid bumping max pressure twice");
+ if (containsReg(P.LiveInRegs, Reg))
return;
// At live in discovery, unconditionally increase the high water mark.
P.LiveInRegs.push_back(Reg);
- P.increase(MRI->getRegClass(Reg), TRI);
+ P.increase(Reg, TRI, MRI);
}
-/// Add VirtReg to the live out set and increase max pressure.
-void RegPressureTracker::discoverVirtLiveOut(unsigned Reg) {
- assert(!LiveVirtRegs.count(Reg) && "avoid bumping max pressure twice");
- if (std::find(P.LiveOutRegs.begin(), P.LiveOutRegs.end(), Reg) !=
- P.LiveOutRegs.end())
+/// Add Reg to the live out set and increase max pressure.
+void RegPressureTracker::discoverLiveOut(unsigned Reg) {
+ assert(!LiveRegs.contains(Reg) && "avoid bumping max pressure twice");
+ if (containsReg(P.LiveOutRegs, Reg))
return;
// At live out discovery, unconditionally increase the high water mark.
P.LiveOutRegs.push_back(Reg);
- P.increase(MRI->getRegClass(Reg), TRI);
+ P.increase(Reg, TRI, MRI);
}
/// Recede across the previous instruction.
if (RequireIntervals && isTopClosed())
static_cast<IntervalPressure&>(P).openTop(SlotIdx);
- PhysRegOperands PhysRegOpers;
- VirtRegOperands VirtRegOpers;
- collectOperands(CurrPos, PhysRegOpers, VirtRegOpers, TRI, RCI);
+ RegisterOperands RegOpers(TRI, MRI);
+ collectOperands(CurrPos, RegOpers);
// Boost pressure for all dead defs together.
- increasePhysRegPressure(PhysRegOpers.DeadDefs);
- increaseVirtRegPressure(VirtRegOpers.DeadDefs);
- decreasePhysRegPressure(PhysRegOpers.DeadDefs);
- decreaseVirtRegPressure(VirtRegOpers.DeadDefs);
+ increaseRegPressure(RegOpers.DeadDefs);
+ decreaseRegPressure(RegOpers.DeadDefs);
// Kill liveness at live defs.
// TODO: consider earlyclobbers?
- for (unsigned i = 0, e = PhysRegOpers.Defs.size(); i < e; ++i) {
- unsigned Reg = PhysRegOpers.Defs[i];
- if (LivePhysRegs.erase(Reg))
- decreasePhysRegPressure(Reg);
- else
- discoverPhysLiveOut(Reg);
- }
- for (unsigned i = 0, e = VirtRegOpers.Defs.size(); i < e; ++i) {
- unsigned Reg = VirtRegOpers.Defs[i];
- if (LiveVirtRegs.erase(Reg))
- decreaseVirtRegPressure(Reg);
+ for (unsigned i = 0, e = RegOpers.Defs.size(); i < e; ++i) {
+ unsigned Reg = RegOpers.Defs[i];
+ if (LiveRegs.erase(Reg))
+ decreaseRegPressure(Reg);
else
- discoverVirtLiveOut(Reg);
+ discoverLiveOut(Reg);
}
// Generate liveness for uses.
- for (unsigned i = 0, e = PhysRegOpers.Uses.size(); i < e; ++i) {
- unsigned Reg = PhysRegOpers.Uses[i];
- if (!hasRegAlias(Reg, LivePhysRegs, TRI)) {
- increasePhysRegPressure(Reg);
- LivePhysRegs.insert(Reg);
- }
- }
- for (unsigned i = 0, e = VirtRegOpers.Uses.size(); i < e; ++i) {
- unsigned Reg = VirtRegOpers.Uses[i];
- if (!LiveVirtRegs.count(Reg)) {
+ for (unsigned i = 0, e = RegOpers.Uses.size(); i < e; ++i) {
+ unsigned Reg = RegOpers.Uses[i];
+ if (!LiveRegs.contains(Reg)) {
// Adjust liveouts if LiveIntervals are available.
if (RequireIntervals) {
- const LiveInterval *LI = &LIS->getInterval(Reg);
- if (!LI->killedAt(SlotIdx))
- discoverVirtLiveOut(Reg);
+ const LiveInterval *LI = getInterval(Reg);
+ if (LI && !LI->killedAt(SlotIdx))
+ discoverLiveOut(Reg);
}
- increaseVirtRegPressure(Reg);
- LiveVirtRegs.insert(Reg);
+ increaseRegPressure(Reg);
+ LiveRegs.insert(Reg);
}
}
return true;
SlotIndex SlotIdx;
if (RequireIntervals)
- SlotIdx = LIS->getInstructionIndex(CurrPos).getRegSlot();
+ SlotIdx = getCurrSlot();
// Open the bottom of the region using slot indexes.
if (isBottomClosed()) {
static_cast<RegionPressure&>(P).openBottom(CurrPos);
}
- PhysRegOperands PhysRegOpers;
- VirtRegOperands VirtRegOpers;
- collectOperands(CurrPos, PhysRegOpers, VirtRegOpers, TRI, RCI);
-
- // Kill liveness at last uses.
- for (unsigned i = 0, e = PhysRegOpers.Uses.size(); i < e; ++i) {
- unsigned Reg = PhysRegOpers.Uses[i];
- if (!hasRegAlias(Reg, LivePhysRegs, TRI))
- discoverPhysLiveIn(Reg);
- else {
- // Allocatable physregs are always single-use before regalloc.
- decreasePhysRegPressure(Reg);
- LivePhysRegs.erase(Reg);
- }
- }
- for (unsigned i = 0, e = VirtRegOpers.Uses.size(); i < e; ++i) {
- unsigned Reg = VirtRegOpers.Uses[i];
+ RegisterOperands RegOpers(TRI, MRI);
+ collectOperands(CurrPos, RegOpers);
+
+ for (unsigned i = 0, e = RegOpers.Uses.size(); i < e; ++i) {
+ unsigned Reg = RegOpers.Uses[i];
+ // Discover live-ins.
+ bool isLive = LiveRegs.contains(Reg);
+ if (!isLive)
+ discoverLiveIn(Reg);
+ // Kill liveness at last uses.
+ bool lastUse = false;
if (RequireIntervals) {
- const LiveInterval *LI = &LIS->getInterval(Reg);
- if (LI->killedAt(SlotIdx)) {
- if (LiveVirtRegs.erase(Reg))
- decreaseVirtRegPressure(Reg);
- else
- discoverVirtLiveIn(Reg);
- }
+ const LiveInterval *LI = getInterval(Reg);
+ lastUse = LI && LI->killedAt(SlotIdx);
+ }
+ else {
+ // Allocatable physregs are always single-use before register rewriting.
+ lastUse = !TargetRegisterInfo::isVirtualRegister(Reg);
}
- else if (!LiveVirtRegs.count(Reg)) {
- discoverVirtLiveIn(Reg);
- increaseVirtRegPressure(Reg);
+ if (lastUse && isLive) {
+ LiveRegs.erase(Reg);
+ decreaseRegPressure(Reg);
}
+ else if (!lastUse && !isLive)
+ increaseRegPressure(Reg);
}
// Generate liveness for defs.
- for (unsigned i = 0, e = PhysRegOpers.Defs.size(); i < e; ++i) {
- unsigned Reg = PhysRegOpers.Defs[i];
- if (!hasRegAlias(Reg, LivePhysRegs, TRI)) {
- increasePhysRegPressure(Reg);
- LivePhysRegs.insert(Reg);
- }
- }
- for (unsigned i = 0, e = VirtRegOpers.Defs.size(); i < e; ++i) {
- unsigned Reg = VirtRegOpers.Defs[i];
- if (LiveVirtRegs.insert(Reg).second)
- increaseVirtRegPressure(Reg);
+ for (unsigned i = 0, e = RegOpers.Defs.size(); i < e; ++i) {
+ unsigned Reg = RegOpers.Defs[i];
+ if (LiveRegs.insert(Reg))
+ increaseRegPressure(Reg);
}
// Boost pressure for all dead defs together.
- increasePhysRegPressure(PhysRegOpers.DeadDefs);
- increaseVirtRegPressure(VirtRegOpers.DeadDefs);
- decreasePhysRegPressure(PhysRegOpers.DeadDefs);
- decreaseVirtRegPressure(VirtRegOpers.DeadDefs);
+ increaseRegPressure(RegOpers.DeadDefs);
+ decreaseRegPressure(RegOpers.DeadDefs);
// Find the next instruction.
do
while (CurrPos != MBB->end() && CurrPos->isDebugValue());
return true;
}
+
+/// Find the max change in excess pressure across all sets.
+static void computeExcessPressureDelta(ArrayRef<unsigned> OldPressureVec,
+ ArrayRef<unsigned> NewPressureVec,
+ RegPressureDelta &Delta,
+ const TargetRegisterInfo *TRI) {
+ int ExcessUnits = 0;
+ unsigned PSetID = ~0U;
+ for (unsigned i = 0, e = OldPressureVec.size(); i < e; ++i) {
+ unsigned POld = OldPressureVec[i];
+ unsigned PNew = NewPressureVec[i];
+ int PDiff = (int)PNew - (int)POld;
+ if (!PDiff) // No change in this set in the common case.
+ continue;
+ // Only consider change beyond the limit.
+ unsigned Limit = TRI->getRegPressureSetLimit(i);
+ if (Limit > POld) {
+ if (Limit > PNew)
+ PDiff = 0; // Under the limit
+ else
+ PDiff = PNew - Limit; // Just exceeded limit.
+ }
+ else if (Limit > PNew)
+ PDiff = Limit - POld; // Just obeyed limit.
+
+ if (std::abs(PDiff) > std::abs(ExcessUnits)) {
+ ExcessUnits = PDiff;
+ PSetID = i;
+ }
+ }
+ Delta.Excess.PSetID = PSetID;
+ Delta.Excess.UnitIncrease = ExcessUnits;
+}
+
+/// Find the max change in max pressure that either surpasses a critical PSet
+/// limit or exceeds the current MaxPressureLimit.
+///
+/// FIXME: comparing each element of the old and new MaxPressure vectors here is
+/// silly. It's done now to demonstrate the concept but will go away with a
+/// RegPressureTracker API change to work with pressure differences.
+static void computeMaxPressureDelta(ArrayRef<unsigned> OldMaxPressureVec,
+ ArrayRef<unsigned> NewMaxPressureVec,
+ ArrayRef<PressureElement> CriticalPSets,
+ ArrayRef<unsigned> MaxPressureLimit,
+ RegPressureDelta &Delta) {
+ Delta.CriticalMax = PressureElement();
+ Delta.CurrentMax = PressureElement();
+
+ unsigned CritIdx = 0, CritEnd = CriticalPSets.size();
+ for (unsigned i = 0, e = OldMaxPressureVec.size(); i < e; ++i) {
+ unsigned POld = OldMaxPressureVec[i];
+ unsigned PNew = NewMaxPressureVec[i];
+ if (PNew == POld) // No change in this set in the common case.
+ continue;
+
+ while (CritIdx != CritEnd && CriticalPSets[CritIdx].PSetID < i)
+ ++CritIdx;
+
+ if (CritIdx != CritEnd && CriticalPSets[CritIdx].PSetID == i) {
+ int PDiff = (int)PNew - (int)CriticalPSets[CritIdx].UnitIncrease;
+ if (PDiff > Delta.CriticalMax.UnitIncrease) {
+ Delta.CriticalMax.PSetID = i;
+ Delta.CriticalMax.UnitIncrease = PDiff;
+ }
+ }
+
+ // Find the greatest increase above MaxPressureLimit.
+ // (Ignores negative MDiff).
+ int MDiff = (int)PNew - (int)MaxPressureLimit[i];
+ if (MDiff > Delta.CurrentMax.UnitIncrease) {
+ Delta.CurrentMax.PSetID = i;
+ Delta.CurrentMax.UnitIncrease = PNew;
+ }
+ }
+}
+
+/// Record the upward impact of a single instruction on current register
+/// pressure. Unlike the advance/recede pressure tracking interface, this does
+/// not discover live in/outs.
+///
+/// This is intended for speculative queries. It leaves pressure inconsistent
+/// with the current position, so must be restored by the caller.
+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);
+ collectOperands(MI, RegOpers);
+
+ // Boost max pressure for all dead defs together.
+ // Since CurrSetPressure and MaxSetPressure
+ increaseRegPressure(RegOpers.DeadDefs);
+ decreaseRegPressure(RegOpers.DeadDefs);
+
+ // 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);
+ }
+ // Generate liveness for uses.
+ for (unsigned i = 0, e = RegOpers.Uses.size(); i < e; ++i) {
+ unsigned Reg = RegOpers.Uses[i];
+ if (!LiveRegs.contains(Reg))
+ increaseRegPressure(Reg);
+ }
+}
+
+/// Consider the pressure increase caused by traversing this instruction
+/// bottom-up. Find the pressure set with the most change beyond its pressure
+/// limit based on the tracker's current pressure, and return the change in
+/// number of register units of that pressure set introduced by this
+/// instruction.
+///
+/// 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.
+void RegPressureTracker::
+getMaxUpwardPressureDelta(const MachineInstr *MI, RegPressureDelta &Delta,
+ ArrayRef<PressureElement> CriticalPSets,
+ ArrayRef<unsigned> MaxPressureLimit) {
+ // Snapshot Pressure.
+ // FIXME: The snapshot heap space should persist. But I'm planning to
+ // summarize the pressure effect so we don't need to snapshot at all.
+ std::vector<unsigned> SavedPressure = CurrSetPressure;
+ std::vector<unsigned> SavedMaxPressure = P.MaxSetPressure;
+
+ bumpUpwardPressure(MI);
+
+ computeExcessPressureDelta(SavedPressure, CurrSetPressure, Delta, TRI);
+ computeMaxPressureDelta(SavedMaxPressure, P.MaxSetPressure, CriticalPSets,
+ MaxPressureLimit, Delta);
+ assert(Delta.CriticalMax.UnitIncrease >= 0 &&
+ Delta.CurrentMax.UnitIncrease >= 0 && "cannot decrease max pressure");
+
+ // Restore the tracker's state.
+ P.MaxSetPressure.swap(SavedMaxPressure);
+ CurrSetPressure.swap(SavedPressure);
+}
+
+/// Helper to find a vreg use between two indices [PriorUseIdx, NextUseIdx).
+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;
+ }
+ return false;
+}
+
+/// Record the downward impact of a single instruction on current register
+/// pressure. Unlike the advance/recede pressure tracking interface, this does
+/// not discover live in/outs.
+///
+/// This is intended for speculative queries. It leaves pressure inconsistent
+/// with the current position, so must be restored by the caller.
+void RegPressureTracker::bumpDownwardPressure(const MachineInstr *MI) {
+ assert(!MI->isDebugValue() && "Expect a nondebug instruction.");
+
+ // Account for register pressure similar to RegPressureTracker::recede().
+ RegisterOperands RegOpers(TRI, MRI);
+ collectOperands(MI, RegOpers);
+
+ // Kill liveness at last uses. Assume allocatable physregs are single-use
+ // rather than checking LiveIntervals.
+ SlotIndex SlotIdx;
+ if (RequireIntervals)
+ SlotIdx = LIS->getInstructionIndex(MI).getRegSlot();
+
+ for (unsigned i = 0, e = RegOpers.Uses.size(); i < e; ++i) {
+ unsigned Reg = RegOpers.Uses[i];
+ 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);
+ }
+ }
+ else if (!TargetRegisterInfo::isVirtualRegister(Reg)) {
+ // Allocatable physregs are always single-use before register rewriting.
+ decreaseRegPressure(Reg);
+ }
+ }
+
+ // Generate liveness for defs.
+ increaseRegPressure(RegOpers.Defs);
+
+ // Boost pressure for all dead defs together.
+ increaseRegPressure(RegOpers.DeadDefs);
+ decreaseRegPressure(RegOpers.DeadDefs);
+}
+
+/// Consider the pressure increase caused by traversing this instruction
+/// top-down. Find the register class with the most change in its pressure limit
+/// based on the tracker's current pressure, and return the number of excess
+/// register units of that pressure set introduced by this instruction.
+///
+/// This assumes that the current LiveIn set is sufficient.
+void RegPressureTracker::
+getMaxDownwardPressureDelta(const MachineInstr *MI, RegPressureDelta &Delta,
+ ArrayRef<PressureElement> CriticalPSets,
+ ArrayRef<unsigned> MaxPressureLimit) {
+ // Snapshot Pressure.
+ std::vector<unsigned> SavedPressure = CurrSetPressure;
+ std::vector<unsigned> SavedMaxPressure = P.MaxSetPressure;
+
+ bumpDownwardPressure(MI);
+
+ computeExcessPressureDelta(SavedPressure, CurrSetPressure, Delta, TRI);
+ computeMaxPressureDelta(SavedMaxPressure, P.MaxSetPressure, CriticalPSets,
+ MaxPressureLimit, Delta);
+ assert(Delta.CriticalMax.UnitIncrease >= 0 &&
+ Delta.CurrentMax.UnitIncrease >= 0 && "cannot decrease max pressure");
+
+ // Restore the tracker's state.
+ P.MaxSetPressure.swap(SavedMaxPressure);
+ CurrSetPressure.swap(SavedPressure);
+}
+
+/// Get the pressure of each PSet after traversing this instruction bottom-up.
+void RegPressureTracker::
+getUpwardPressure(const MachineInstr *MI,
+ std::vector<unsigned> &PressureResult,
+ std::vector<unsigned> &MaxPressureResult) {
+ // Snapshot pressure.
+ PressureResult = CurrSetPressure;
+ MaxPressureResult = P.MaxSetPressure;
+
+ bumpUpwardPressure(MI);
+
+ // Current pressure becomes the result. Restore current pressure.
+ P.MaxSetPressure.swap(MaxPressureResult);
+ CurrSetPressure.swap(PressureResult);
+}
+
+/// Get the pressure of each PSet after traversing this instruction top-down.
+void RegPressureTracker::
+getDownwardPressure(const MachineInstr *MI,
+ std::vector<unsigned> &PressureResult,
+ std::vector<unsigned> &MaxPressureResult) {
+ // Snapshot pressure.
+ PressureResult = CurrSetPressure;
+ MaxPressureResult = P.MaxSetPressure;
+
+ bumpDownwardPressure(MI);
+
+ // Current pressure becomes the result. Restore current pressure.
+ P.MaxSetPressure.swap(MaxPressureResult);
+ CurrSetPressure.swap(PressureResult);
+}
projects / oota-llvm.git / blobdiff