//
// The LLVM Compiler Infrastructure
//
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
#include "llvm/Function.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
-#include "llvm/CodeGen/SSARegMap.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Support/CommandLine.h"
-#include "llvm/Support/Debug.h"
#include "llvm/Support/Compiler.h"
+#include "llvm/Support/Debug.h"
#include "llvm/ADT/BitVector.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/DepthFirstIterator.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallSet.h"
#include <algorithm>
using namespace llvm;
-STATISTIC(NumSpills, "Number of register spills");
-STATISTIC(NumReMats, "Number of re-materialization");
-STATISTIC(NumDRM , "Number of re-materializable defs elided");
-STATISTIC(NumStores, "Number of stores added");
-STATISTIC(NumLoads , "Number of loads added");
-STATISTIC(NumReused, "Number of values reused");
-STATISTIC(NumDSE , "Number of dead stores elided");
-STATISTIC(NumDCE , "Number of copies elided");
+STATISTIC(NumSpills , "Number of register spills");
+STATISTIC(NumPSpills , "Number of physical register spills");
+STATISTIC(NumReMats , "Number of re-materialization");
+STATISTIC(NumDRM , "Number of re-materializable defs elided");
+STATISTIC(NumStores , "Number of stores added");
+STATISTIC(NumLoads , "Number of loads added");
+STATISTIC(NumReused , "Number of values reused");
+STATISTIC(NumDSE , "Number of dead stores elided");
+STATISTIC(NumDCE , "Number of copies elided");
+STATISTIC(NumDSS , "Number of dead spill slots removed");
+STATISTIC(NumCommutes, "Number of instructions commuted");
+STATISTIC(NumOmitted , "Number of reloads omited");
+STATISTIC(NumCopified, "Number of available reloads turned into copies");
namespace {
enum SpillerName { simple, local };
-
- static cl::opt<SpillerName>
- SpillerOpt("spiller",
- cl::desc("Spiller to use: (default: local)"),
- cl::Prefix,
- cl::values(clEnumVal(simple, " simple spiller"),
- clEnumVal(local, " local spiller"),
- clEnumValEnd),
- cl::init(local));
}
+static cl::opt<SpillerName>
+SpillerOpt("spiller",
+ cl::desc("Spiller to use: (default: local)"),
+ cl::Prefix,
+ cl::values(clEnumVal(simple, "simple spiller"),
+ clEnumVal(local, "local spiller"),
+ clEnumValEnd),
+ cl::init(local));
+
//===----------------------------------------------------------------------===//
// VirtRegMap implementation
//===----------------------------------------------------------------------===//
: TII(*mf.getTarget().getInstrInfo()), MF(mf),
Virt2PhysMap(NO_PHYS_REG), Virt2StackSlotMap(NO_STACK_SLOT),
Virt2ReMatIdMap(NO_STACK_SLOT), Virt2SplitMap(0),
- ReMatMap(NULL), ReMatId(MAX_STACK_SLOT+1) {
+ Virt2SplitKillMap(0), ReMatMap(NULL), ReMatId(MAX_STACK_SLOT+1),
+ LowSpillSlot(NO_STACK_SLOT), HighSpillSlot(NO_STACK_SLOT) {
+ SpillSlotToUsesMap.resize(8);
+ ImplicitDefed.resize(MF.getRegInfo().getLastVirtReg()+1-
+ TargetRegisterInfo::FirstVirtualRegister);
grow();
}
void VirtRegMap::grow() {
- unsigned LastVirtReg = MF.getSSARegMap()->getLastVirtReg();
+ unsigned LastVirtReg = MF.getRegInfo().getLastVirtReg();
Virt2PhysMap.grow(LastVirtReg);
Virt2StackSlotMap.grow(LastVirtReg);
Virt2ReMatIdMap.grow(LastVirtReg);
Virt2SplitMap.grow(LastVirtReg);
+ Virt2SplitKillMap.grow(LastVirtReg);
ReMatMap.grow(LastVirtReg);
+ ImplicitDefed.resize(LastVirtReg-TargetRegisterInfo::FirstVirtualRegister+1);
}
int VirtRegMap::assignVirt2StackSlot(unsigned virtReg) {
- assert(MRegisterInfo::isVirtualRegister(virtReg));
+ assert(TargetRegisterInfo::isVirtualRegister(virtReg));
assert(Virt2StackSlotMap[virtReg] == NO_STACK_SLOT &&
"attempt to assign stack slot to already spilled register");
- const TargetRegisterClass* RC = MF.getSSARegMap()->getRegClass(virtReg);
- int frameIndex = MF.getFrameInfo()->CreateStackObject(RC->getSize(),
- RC->getAlignment());
- Virt2StackSlotMap[virtReg] = frameIndex;
+ const TargetRegisterClass* RC = MF.getRegInfo().getRegClass(virtReg);
+ int SS = MF.getFrameInfo()->CreateStackObject(RC->getSize(),
+ RC->getAlignment());
+ if (LowSpillSlot == NO_STACK_SLOT)
+ LowSpillSlot = SS;
+ if (HighSpillSlot == NO_STACK_SLOT || SS > HighSpillSlot)
+ HighSpillSlot = SS;
+ unsigned Idx = SS-LowSpillSlot;
+ while (Idx >= SpillSlotToUsesMap.size())
+ SpillSlotToUsesMap.resize(SpillSlotToUsesMap.size()*2);
+ Virt2StackSlotMap[virtReg] = SS;
++NumSpills;
- return frameIndex;
+ return SS;
}
-void VirtRegMap::assignVirt2StackSlot(unsigned virtReg, int frameIndex) {
- assert(MRegisterInfo::isVirtualRegister(virtReg));
+void VirtRegMap::assignVirt2StackSlot(unsigned virtReg, int SS) {
+ assert(TargetRegisterInfo::isVirtualRegister(virtReg));
assert(Virt2StackSlotMap[virtReg] == NO_STACK_SLOT &&
"attempt to assign stack slot to already spilled register");
- assert((frameIndex >= 0 ||
- (frameIndex >= MF.getFrameInfo()->getObjectIndexBegin())) &&
+ assert((SS >= 0 ||
+ (SS >= MF.getFrameInfo()->getObjectIndexBegin())) &&
"illegal fixed frame index");
- Virt2StackSlotMap[virtReg] = frameIndex;
+ Virt2StackSlotMap[virtReg] = SS;
}
int VirtRegMap::assignVirtReMatId(unsigned virtReg) {
- assert(MRegisterInfo::isVirtualRegister(virtReg));
+ assert(TargetRegisterInfo::isVirtualRegister(virtReg));
assert(Virt2ReMatIdMap[virtReg] == NO_STACK_SLOT &&
"attempt to assign re-mat id to already spilled register");
Virt2ReMatIdMap[virtReg] = ReMatId;
}
void VirtRegMap::assignVirtReMatId(unsigned virtReg, int id) {
- assert(MRegisterInfo::isVirtualRegister(virtReg));
+ assert(TargetRegisterInfo::isVirtualRegister(virtReg));
assert(Virt2ReMatIdMap[virtReg] == NO_STACK_SLOT &&
"attempt to assign re-mat id to already spilled register");
Virt2ReMatIdMap[virtReg] = id;
}
+int VirtRegMap::getEmergencySpillSlot(const TargetRegisterClass *RC) {
+ std::map<const TargetRegisterClass*, int>::iterator I =
+ EmergencySpillSlots.find(RC);
+ if (I != EmergencySpillSlots.end())
+ return I->second;
+ int SS = MF.getFrameInfo()->CreateStackObject(RC->getSize(),
+ RC->getAlignment());
+ if (LowSpillSlot == NO_STACK_SLOT)
+ LowSpillSlot = SS;
+ if (HighSpillSlot == NO_STACK_SLOT || SS > HighSpillSlot)
+ HighSpillSlot = SS;
+ EmergencySpillSlots[RC] = SS;
+ return SS;
+}
+
+void VirtRegMap::addSpillSlotUse(int FI, MachineInstr *MI) {
+ if (!MF.getFrameInfo()->isFixedObjectIndex(FI)) {
+ // If FI < LowSpillSlot, this stack reference was produced by
+ // instruction selection and is not a spill
+ if (FI >= LowSpillSlot) {
+ assert(FI >= 0 && "Spill slot index should not be negative!");
+ assert((unsigned)FI-LowSpillSlot < SpillSlotToUsesMap.size()
+ && "Invalid spill slot");
+ SpillSlotToUsesMap[FI-LowSpillSlot].insert(MI);
+ }
+ }
+}
+
void VirtRegMap::virtFolded(unsigned VirtReg, MachineInstr *OldMI,
- unsigned OpNo, MachineInstr *NewMI) {
+ MachineInstr *NewMI, ModRef MRInfo) {
// Move previous memory references folded to new instruction.
MI2VirtMapTy::iterator IP = MI2VirtMap.lower_bound(NewMI);
for (MI2VirtMapTy::iterator I = MI2VirtMap.lower_bound(OldMI),
MI2VirtMap.erase(I++);
}
- ModRef MRInfo;
- const TargetInstrDescriptor *TID = OldMI->getInstrDescriptor();
- if (TID->getOperandConstraint(OpNo, TOI::TIED_TO) != -1 ||
- TID->findTiedToSrcOperand(OpNo) != -1) {
- // Folded a two-address operand.
- MRInfo = isModRef;
- } else if (OldMI->getOperand(OpNo).isDef()) {
- MRInfo = isMod;
- } else {
- MRInfo = isRef;
- }
-
// add new memory reference
MI2VirtMap.insert(IP, std::make_pair(NewMI, std::make_pair(VirtReg, MRInfo)));
}
MI2VirtMap.insert(IP, std::make_pair(MI, std::make_pair(VirtReg, MRInfo)));
}
+void VirtRegMap::RemoveMachineInstrFromMaps(MachineInstr *MI) {
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ MachineOperand &MO = MI->getOperand(i);
+ if (!MO.isFI())
+ continue;
+ int FI = MO.getIndex();
+ if (MF.getFrameInfo()->isFixedObjectIndex(FI))
+ continue;
+ // This stack reference was produced by instruction selection and
+ // is not a spill
+ if (FI < LowSpillSlot)
+ continue;
+ assert((unsigned)FI-LowSpillSlot < SpillSlotToUsesMap.size()
+ && "Invalid spill slot");
+ SpillSlotToUsesMap[FI-LowSpillSlot].erase(MI);
+ }
+ MI2VirtMap.erase(MI);
+ SpillPt2VirtMap.erase(MI);
+ RestorePt2VirtMap.erase(MI);
+ EmergencySpillMap.erase(MI);
+}
+
void VirtRegMap::print(std::ostream &OS) const {
- const MRegisterInfo* MRI = MF.getTarget().getRegisterInfo();
+ const TargetRegisterInfo* TRI = MF.getTarget().getRegisterInfo();
OS << "********** REGISTER MAP **********\n";
- for (unsigned i = MRegisterInfo::FirstVirtualRegister,
- e = MF.getSSARegMap()->getLastVirtReg(); i <= e; ++i) {
+ for (unsigned i = TargetRegisterInfo::FirstVirtualRegister,
+ e = MF.getRegInfo().getLastVirtReg(); i <= e; ++i) {
if (Virt2PhysMap[i] != (unsigned)VirtRegMap::NO_PHYS_REG)
- OS << "[reg" << i << " -> " << MRI->getName(Virt2PhysMap[i]) << "]\n";
-
+ OS << "[reg" << i << " -> " << TRI->getName(Virt2PhysMap[i])
+ << "]\n";
}
- for (unsigned i = MRegisterInfo::FirstVirtualRegister,
- e = MF.getSSARegMap()->getLastVirtReg(); i <= e; ++i)
+ for (unsigned i = TargetRegisterInfo::FirstVirtualRegister,
+ e = MF.getRegInfo().getLastVirtReg(); i <= e; ++i)
if (Virt2StackSlotMap[i] != VirtRegMap::NO_STACK_SLOT)
OS << "[reg" << i << " -> fi#" << Virt2StackSlotMap[i] << "]\n";
OS << '\n';
}
void VirtRegMap::dump() const {
- print(DOUT);
+ print(cerr);
}
DOUT << "********** REWRITE MACHINE CODE **********\n";
DOUT << "********** Function: " << MF.getFunction()->getName() << '\n';
const TargetMachine &TM = MF.getTarget();
- const MRegisterInfo &MRI = *TM.getRegisterInfo();
+ const TargetInstrInfo &TII = *TM.getInstrInfo();
+ const TargetRegisterInfo &TRI = *TM.getRegisterInfo();
+
// LoadedRegs - Keep track of which vregs are loaded, so that we only load
// each vreg once (in the case where a spilled vreg is used by multiple
MachineInstr &MI = *MII;
for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
MachineOperand &MO = MI.getOperand(i);
- if (MO.isRegister() && MO.getReg())
- if (MRegisterInfo::isVirtualRegister(MO.getReg())) {
+ if (MO.isReg() && MO.getReg()) {
+ if (TargetRegisterInfo::isVirtualRegister(MO.getReg())) {
unsigned VirtReg = MO.getReg();
+ unsigned SubIdx = MO.getSubReg();
unsigned PhysReg = VRM.getPhys(VirtReg);
+ unsigned RReg = SubIdx ? TRI.getSubReg(PhysReg, SubIdx) : PhysReg;
if (!VRM.isAssignedReg(VirtReg)) {
int StackSlot = VRM.getStackSlot(VirtReg);
const TargetRegisterClass* RC =
- MF.getSSARegMap()->getRegClass(VirtReg);
+ MF.getRegInfo().getRegClass(VirtReg);
if (MO.isUse() &&
std::find(LoadedRegs.begin(), LoadedRegs.end(), VirtReg)
== LoadedRegs.end()) {
- MRI.loadRegFromStackSlot(MBB, &MI, PhysReg, StackSlot, RC);
+ TII.loadRegFromStackSlot(MBB, &MI, PhysReg, StackSlot, RC);
+ MachineInstr *LoadMI = prior(MII);
+ VRM.addSpillSlotUse(StackSlot, LoadMI);
LoadedRegs.push_back(VirtReg);
++NumLoads;
- DOUT << '\t' << *prior(MII);
+ DOUT << '\t' << *LoadMI;
}
if (MO.isDef()) {
- MRI.storeRegToStackSlot(MBB, next(MII), PhysReg, StackSlot, RC);
+ TII.storeRegToStackSlot(MBB, next(MII), PhysReg, true,
+ StackSlot, RC);
+ MachineInstr *StoreMI = next(MII);
+ VRM.addSpillSlotUse(StackSlot, StoreMI);
++NumStores;
}
}
- MF.setPhysRegUsed(PhysReg);
- MI.getOperand(i).setReg(PhysReg);
+ MF.getRegInfo().setPhysRegUsed(RReg);
+ MI.getOperand(i).setReg(RReg);
} else {
- MF.setPhysRegUsed(MO.getReg());
+ MF.getRegInfo().setPhysRegUsed(MO.getReg());
}
+ }
}
DOUT << '\t' << MI;
// Local Spiller Implementation
//===----------------------------------------------------------------------===//
-namespace {
- class AvailableSpills;
-
- /// LocalSpiller - This spiller does a simple pass over the machine basic
- /// block to attempt to keep spills in registers as much as possible for
- /// blocks that have low register pressure (the vreg may be spilled due to
- /// register pressure in other blocks).
- class VISIBILITY_HIDDEN LocalSpiller : public Spiller {
- SSARegMap *RegMap;
- const MRegisterInfo *MRI;
- const TargetInstrInfo *TII;
- public:
- bool runOnMachineFunction(MachineFunction &MF, VirtRegMap &VRM) {
- RegMap = MF.getSSARegMap();
- MRI = MF.getTarget().getRegisterInfo();
- TII = MF.getTarget().getInstrInfo();
- DOUT << "\n**** Local spiller rewriting function '"
- << MF.getFunction()->getName() << "':\n";
- DOUT << "**** Machine Instrs (NOTE! Does not include spills and reloads!) ****\n";
- DEBUG(MF.dump());
-
- for (MachineFunction::iterator MBB = MF.begin(), E = MF.end();
- MBB != E; ++MBB)
- RewriteMBB(*MBB, VRM);
-
- DOUT << "**** Post Machine Instrs ****\n";
- DEBUG(MF.dump());
-
- return true;
- }
- private:
- bool PrepForUnfoldOpti(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator &MII,
- std::vector<MachineInstr*> &MaybeDeadStores,
- AvailableSpills &Spills, BitVector &RegKills,
- std::vector<MachineOperand*> &KillOps,
- VirtRegMap &VRM);
- void SpillRegToStackSlot(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator &MII,
- int Idx, unsigned PhysReg, int StackSlot,
- const TargetRegisterClass *RC,
- MachineInstr *&LastStore,
- AvailableSpills &Spills,
- SmallSet<MachineInstr*, 4> &ReMatDefs,
- BitVector &RegKills,
- std::vector<MachineOperand*> &KillOps,
- VirtRegMap &VRM);
- void RewriteMBB(MachineBasicBlock &MBB, VirtRegMap &VRM);
- };
-}
-
/// AvailableSpills - As the local spiller is scanning and rewriting an MBB from
/// top down, keep track of which spills slots or remat are available in each
/// register.
/// this bit and addAvailable sets it if.
namespace {
class VISIBILITY_HIDDEN AvailableSpills {
- const MRegisterInfo *MRI;
+ const TargetRegisterInfo *TRI;
const TargetInstrInfo *TII;
// SpillSlotsOrReMatsAvailable - This map keeps track of all of the spilled
void ClobberPhysRegOnly(unsigned PhysReg);
public:
- AvailableSpills(const MRegisterInfo *mri, const TargetInstrInfo *tii)
- : MRI(mri), TII(tii) {
+ AvailableSpills(const TargetRegisterInfo *tri, const TargetInstrInfo *tii)
+ : TRI(tri), TII(tii) {
+ }
+
+ /// clear - Reset the state.
+ void clear() {
+ SpillSlotsOrReMatsAvailable.clear();
+ PhysRegsAvailable.clear();
}
- const MRegisterInfo *getRegInfo() const { return MRI; }
+ const TargetRegisterInfo *getRegInfo() const { return TRI; }
/// getSpillSlotOrReMatPhysReg - If the specified stack slot or remat is
/// available in a physical register, return that PhysReg, otherwise
/// addAvailable - Mark that the specified stack slot / remat is available in
/// the specified physreg. If CanClobber is true, the physreg can be modified
/// at any time without changing the semantics of the program.
- void addAvailable(int SlotOrReMat, MachineInstr *MI, unsigned Reg,
- bool CanClobber = true) {
+ void addAvailable(int SlotOrReMat, unsigned Reg, bool CanClobber = true) {
// If this stack slot is thought to be available in some other physreg,
// remove its record.
ModifyStackSlotOrReMat(SlotOrReMat);
DOUT << "Remembering RM#" << SlotOrReMat-VirtRegMap::MAX_STACK_SLOT-1;
else
DOUT << "Remembering SS#" << SlotOrReMat;
- DOUT << " in physreg " << MRI->getName(Reg) << "\n";
+ DOUT << " in physreg " << TRI->getName(Reg) << "\n";
}
/// canClobberPhysReg - Return true if the spiller is allowed to change the
"Value not available!");
return SpillSlotsOrReMatsAvailable.find(SlotOrReMat)->second & 1;
}
-
+
/// disallowClobberPhysReg - Unset the CanClobber bit of the specified
/// stackslot register. The register is still available but is no longer
/// allowed to be modifed.
/// slot changes. This removes information about which register the previous
/// value for this slot lives in (as the previous value is dead now).
void ModifyStackSlotOrReMat(int SlotOrReMat);
+
+ void AddAvailableRegsToLiveIn(MachineBasicBlock &MBB);
};
}
assert((SpillSlotsOrReMatsAvailable[SlotOrReMat] >> 1) == PhysReg &&
"Bidirectional map mismatch!");
SpillSlotsOrReMatsAvailable[SlotOrReMat] &= ~1;
- DOUT << "PhysReg " << MRI->getName(PhysReg)
+ DOUT << "PhysReg " << TRI->getName(PhysReg)
<< " copied, it is available for use but can no longer be modified\n";
}
}
/// stackslot register and its aliases. The register and its aliases may
/// still available but is no longer allowed to be modifed.
void AvailableSpills::disallowClobberPhysReg(unsigned PhysReg) {
- for (const unsigned *AS = MRI->getAliasSet(PhysReg); *AS; ++AS)
+ for (const unsigned *AS = TRI->getAliasSet(PhysReg); *AS; ++AS)
disallowClobberPhysRegOnly(*AS);
disallowClobberPhysRegOnly(PhysReg);
}
assert((SpillSlotsOrReMatsAvailable[SlotOrReMat] >> 1) == PhysReg &&
"Bidirectional map mismatch!");
SpillSlotsOrReMatsAvailable.erase(SlotOrReMat);
- DOUT << "PhysReg " << MRI->getName(PhysReg)
+ DOUT << "PhysReg " << TRI->getName(PhysReg)
<< " clobbered, invalidating ";
if (SlotOrReMat > VirtRegMap::MAX_STACK_SLOT)
DOUT << "RM#" << SlotOrReMat-VirtRegMap::MAX_STACK_SLOT-1 << "\n";
/// value. We use this to invalidate any info about stuff we thing lives in
/// it and any of its aliases.
void AvailableSpills::ClobberPhysReg(unsigned PhysReg) {
- for (const unsigned *AS = MRI->getAliasSet(PhysReg); *AS; ++AS)
+ for (const unsigned *AS = TRI->getAliasSet(PhysReg); *AS; ++AS)
ClobberPhysRegOnly(*AS);
ClobberPhysRegOnly(PhysReg);
}
PhysRegsAvailable.erase(I);
}
+/// AddAvailableRegsToLiveIn - Availability information is being kept coming
+/// into the specified MBB. Add available physical registers as live-in's
+/// so register scavenger and post-allocation scheduler are happy.
+void AvailableSpills::AddAvailableRegsToLiveIn(MachineBasicBlock &MBB) {
+ for (std::multimap<unsigned, int>::iterator
+ I = PhysRegsAvailable.begin(), E = PhysRegsAvailable.end();
+ I != E; ++I) {
+ unsigned Reg = (*I).first;
+ const TargetRegisterClass* RC = TRI->getPhysicalRegisterRegClass(Reg);
+ // FIXME: A temporary workaround. We can't reuse available value if it's
+ // not safe to move the def of the virtual register's class. e.g.
+ // X86::RFP* register classes. Do not add it as a live-in.
+ if (!TII->isSafeToMoveRegClassDefs(RC))
+ continue;
+ if (!MBB.isLiveIn(Reg))
+ MBB.addLiveIn(Reg);
+ }
+}
+/// findSinglePredSuccessor - Return via reference a vector of machine basic
+/// blocks each of which is a successor of the specified BB and has no other
+/// predecessor.
+static void findSinglePredSuccessor(MachineBasicBlock *MBB,
+ SmallVectorImpl<MachineBasicBlock *> &Succs) {
+ for (MachineBasicBlock::succ_iterator SI = MBB->succ_begin(),
+ SE = MBB->succ_end(); SI != SE; ++SI) {
+ MachineBasicBlock *SuccMBB = *SI;
+ if (SuccMBB->pred_size() == 1)
+ Succs.push_back(SuccMBB);
+ }
+}
+
+namespace {
+ /// LocalSpiller - This spiller does a simple pass over the machine basic
+ /// block to attempt to keep spills in registers as much as possible for
+ /// blocks that have low register pressure (the vreg may be spilled due to
+ /// register pressure in other blocks).
+ class VISIBILITY_HIDDEN LocalSpiller : public Spiller {
+ MachineRegisterInfo *RegInfo;
+ const TargetRegisterInfo *TRI;
+ const TargetInstrInfo *TII;
+ DenseMap<MachineInstr*, unsigned> DistanceMap;
+ public:
+ bool runOnMachineFunction(MachineFunction &MF, VirtRegMap &VRM) {
+ RegInfo = &MF.getRegInfo();
+ TRI = MF.getTarget().getRegisterInfo();
+ TII = MF.getTarget().getInstrInfo();
+ DOUT << "\n**** Local spiller rewriting function '"
+ << MF.getFunction()->getName() << "':\n";
+ DOUT << "**** Machine Instrs (NOTE! Does not include spills and reloads!)"
+ " ****\n";
+ DEBUG(MF.dump());
+
+ // Spills - Keep track of which spilled values are available in physregs
+ // so that we can choose to reuse the physregs instead of emitting
+ // reloads. This is usually refreshed per basic block.
+ AvailableSpills Spills(TRI, TII);
+
+ // SingleEntrySuccs - Successor blocks which have a single predecessor.
+ SmallVector<MachineBasicBlock*, 4> SinglePredSuccs;
+ SmallPtrSet<MachineBasicBlock*,16> EarlyVisited;
+
+ // Traverse the basic blocks depth first.
+ MachineBasicBlock *Entry = MF.begin();
+ SmallPtrSet<MachineBasicBlock*,16> Visited;
+ for (df_ext_iterator<MachineBasicBlock*,
+ SmallPtrSet<MachineBasicBlock*,16> >
+ DFI = df_ext_begin(Entry, Visited), E = df_ext_end(Entry, Visited);
+ DFI != E; ++DFI) {
+ MachineBasicBlock *MBB = *DFI;
+ if (!EarlyVisited.count(MBB))
+ RewriteMBB(*MBB, VRM, Spills);
+
+ // If this MBB is the only predecessor of a successor. Keep the
+ // availability information and visit it next.
+ do {
+ // Keep visiting single predecessor successor as long as possible.
+ SinglePredSuccs.clear();
+ findSinglePredSuccessor(MBB, SinglePredSuccs);
+ if (SinglePredSuccs.empty())
+ MBB = 0;
+ else {
+ // FIXME: More than one successors, each of which has MBB has
+ // the only predecessor.
+ MBB = SinglePredSuccs[0];
+ if (!Visited.count(MBB) && EarlyVisited.insert(MBB)) {
+ Spills.AddAvailableRegsToLiveIn(*MBB);
+ RewriteMBB(*MBB, VRM, Spills);
+ }
+ }
+ } while (MBB);
+
+ // Clear the availability info.
+ Spills.clear();
+ }
+
+ DOUT << "**** Post Machine Instrs ****\n";
+ DEBUG(MF.dump());
+
+ // Mark unused spill slots.
+ MachineFrameInfo *MFI = MF.getFrameInfo();
+ int SS = VRM.getLowSpillSlot();
+ if (SS != VirtRegMap::NO_STACK_SLOT)
+ for (int e = VRM.getHighSpillSlot(); SS <= e; ++SS)
+ if (!VRM.isSpillSlotUsed(SS)) {
+ MFI->RemoveStackObject(SS);
+ ++NumDSS;
+ }
+
+ return true;
+ }
+ private:
+ void TransferDeadness(MachineBasicBlock *MBB, unsigned CurDist,
+ unsigned Reg, BitVector &RegKills,
+ std::vector<MachineOperand*> &KillOps);
+ bool PrepForUnfoldOpti(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator &MII,
+ std::vector<MachineInstr*> &MaybeDeadStores,
+ AvailableSpills &Spills, BitVector &RegKills,
+ std::vector<MachineOperand*> &KillOps,
+ VirtRegMap &VRM);
+ bool CommuteToFoldReload(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator &MII,
+ unsigned VirtReg, unsigned SrcReg, int SS,
+ BitVector &RegKills,
+ std::vector<MachineOperand*> &KillOps,
+ const TargetRegisterInfo *TRI,
+ VirtRegMap &VRM);
+ void SpillRegToStackSlot(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator &MII,
+ int Idx, unsigned PhysReg, int StackSlot,
+ const TargetRegisterClass *RC,
+ bool isAvailable, MachineInstr *&LastStore,
+ AvailableSpills &Spills,
+ SmallSet<MachineInstr*, 4> &ReMatDefs,
+ BitVector &RegKills,
+ std::vector<MachineOperand*> &KillOps,
+ VirtRegMap &VRM);
+ void RewriteMBB(MachineBasicBlock &MBB, VirtRegMap &VRM,
+ AvailableSpills &Spills);
+ };
+}
/// InvalidateKills - MI is going to be deleted. If any of its operands are
/// marked kill, then invalidate the information.
SmallVector<unsigned, 2> *KillRegs = NULL) {
for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
MachineOperand &MO = MI.getOperand(i);
- if (!MO.isRegister() || !MO.isUse() || !MO.isKill())
+ if (!MO.isReg() || !MO.isUse() || !MO.isKill())
continue;
unsigned Reg = MO.getReg();
+ if (TargetRegisterInfo::isVirtualRegister(Reg))
+ continue;
if (KillRegs)
KillRegs->push_back(Reg);
+ assert(Reg < KillOps.size());
if (KillOps[Reg] == &MO) {
RegKills.reset(Reg);
KillOps[Reg] = NULL;
}
}
+/// InvalidateKill - A MI that defines the specified register is being deleted,
+/// invalidate the register kill information.
+static void InvalidateKill(unsigned Reg, BitVector &RegKills,
+ std::vector<MachineOperand*> &KillOps) {
+ if (RegKills[Reg]) {
+ KillOps[Reg]->setIsKill(false);
+ KillOps[Reg] = NULL;
+ RegKills.reset(Reg);
+ }
+}
+
/// InvalidateRegDef - If the def operand of the specified def MI is now dead
/// (since it's spill instruction is removed), mark it isDead. Also checks if
/// the def MI has other definition operands that are not dead. Returns it by
MachineOperand *DefOp = NULL;
for (unsigned i = 0, e = DefMI->getNumOperands(); i != e; ++i) {
MachineOperand &MO = DefMI->getOperand(i);
- if (MO.isRegister() && MO.isDef()) {
+ if (MO.isReg() && MO.isDef()) {
if (MO.getReg() == Reg)
DefOp = &MO;
else if (!MO.isDead())
return false;
bool FoundUse = false, Done = false;
- MachineBasicBlock::iterator E = NewDef;
+ MachineBasicBlock::iterator E = &NewDef;
++I; ++E;
for (; !Done && I != E; ++I) {
MachineInstr *NMI = I;
for (unsigned j = 0, ee = NMI->getNumOperands(); j != ee; ++j) {
MachineOperand &MO = NMI->getOperand(j);
- if (!MO.isRegister() || MO.getReg() != Reg)
+ if (!MO.isReg() || MO.getReg() != Reg)
continue;
if (MO.isUse())
FoundUse = true;
/// marked kill, then it must be due to register reuse. Transfer the kill info
/// over.
static void UpdateKills(MachineInstr &MI, BitVector &RegKills,
- std::vector<MachineOperand*> &KillOps) {
- const TargetInstrDescriptor *TID = MI.getInstrDescriptor();
+ std::vector<MachineOperand*> &KillOps,
+ const TargetRegisterInfo* TRI) {
+ const TargetInstrDesc &TID = MI.getDesc();
for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
MachineOperand &MO = MI.getOperand(i);
- if (!MO.isRegister() || !MO.isUse())
+ if (!MO.isReg() || !MO.isUse())
continue;
unsigned Reg = MO.getReg();
if (Reg == 0)
continue;
- if (RegKills[Reg]) {
+ if (RegKills[Reg] && KillOps[Reg]->getParent() != &MI) {
// That can't be right. Register is killed but not re-defined and it's
// being reused. Let's fix that.
- KillOps[Reg]->unsetIsKill();
- if (i < TID->numOperands &&
- TID->getOperandConstraint(i, TOI::TIED_TO) == -1)
+ KillOps[Reg]->setIsKill(false);
+ KillOps[Reg] = NULL;
+ RegKills.reset(Reg);
+ if (i < TID.getNumOperands() &&
+ TID.getOperandConstraint(i, TOI::TIED_TO) == -1)
// Unless it's a two-address operand, this is the new kill.
MO.setIsKill();
}
-
if (MO.isKill()) {
RegKills.set(Reg);
KillOps[Reg] = &MO;
for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
const MachineOperand &MO = MI.getOperand(i);
- if (!MO.isRegister() || !MO.isDef())
+ if (!MO.isReg() || !MO.isDef())
continue;
unsigned Reg = MO.getReg();
RegKills.reset(Reg);
KillOps[Reg] = NULL;
+ // It also defines (or partially define) aliases.
+ for (const unsigned *AS = TRI->getAliasSet(Reg); *AS; ++AS) {
+ RegKills.reset(*AS);
+ KillOps[*AS] = NULL;
+ }
+ }
+}
+
+/// ReMaterialize - Re-materialize definition for Reg targetting DestReg.
+///
+static void ReMaterialize(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator &MII,
+ unsigned DestReg, unsigned Reg,
+ const TargetInstrInfo *TII,
+ const TargetRegisterInfo *TRI,
+ VirtRegMap &VRM) {
+ TII->reMaterialize(MBB, MII, DestReg, VRM.getReMaterializedMI(Reg));
+ MachineInstr *NewMI = prior(MII);
+ for (unsigned i = 0, e = NewMI->getNumOperands(); i != e; ++i) {
+ MachineOperand &MO = NewMI->getOperand(i);
+ if (!MO.isReg() || MO.getReg() == 0)
+ continue;
+ unsigned VirtReg = MO.getReg();
+ if (TargetRegisterInfo::isPhysicalRegister(VirtReg))
+ continue;
+ assert(MO.isUse());
+ unsigned SubIdx = MO.getSubReg();
+ unsigned Phys = VRM.getPhys(VirtReg);
+ assert(Phys);
+ unsigned RReg = SubIdx ? TRI->getSubReg(Phys, SubIdx) : Phys;
+ MO.setReg(RReg);
}
+ ++NumReMats;
}
std::vector<ReusedOp> Reuses;
BitVector PhysRegsClobbered;
public:
- ReuseInfo(MachineInstr &mi, const MRegisterInfo *mri) : MI(mi) {
- PhysRegsClobbered.resize(mri->getNumRegs());
+ ReuseInfo(MachineInstr &mi, const TargetRegisterInfo *tri) : MI(mi) {
+ PhysRegsClobbered.resize(tri->getNumRegs());
}
bool hasReuses() const {
BitVector &RegKills,
std::vector<MachineOperand*> &KillOps,
VirtRegMap &VRM) {
+ const TargetInstrInfo* TII = MI->getParent()->getParent()->getTarget()
+ .getInstrInfo();
+
if (Reuses.empty()) return PhysReg; // This is most often empty.
for (unsigned ro = 0, e = Reuses.size(); ro != e; ++ro) {
// value aliases the new register. If so, codegen the previous reload
// and use this one.
unsigned PRRU = Op.PhysRegReused;
- const MRegisterInfo *MRI = Spills.getRegInfo();
- if (MRI->areAliases(PRRU, PhysReg)) {
+ const TargetRegisterInfo *TRI = Spills.getRegInfo();
+ if (TRI->areAliases(PRRU, PhysReg)) {
// Okay, we found out that an alias of a reused register
// was used. This isn't good because it means we have
// to undo a previous reuse.
MachineBasicBlock *MBB = MI->getParent();
const TargetRegisterClass *AliasRC =
- MBB->getParent()->getSSARegMap()->getRegClass(Op.VirtReg);
+ MBB->getParent()->getRegInfo().getRegClass(Op.VirtReg);
// Copy Op out of the vector and remove it, we're going to insert an
// explicit load for it.
MI, Spills, MaybeDeadStores,
Rejected, RegKills, KillOps, VRM);
+ MachineBasicBlock::iterator MII = MI;
if (NewOp.StackSlotOrReMat > VirtRegMap::MAX_STACK_SLOT) {
- MRI->reMaterialize(*MBB, MI, NewPhysReg,
- VRM.getReMaterializedMI(NewOp.VirtReg));
- ++NumReMats;
+ ReMaterialize(*MBB, MII, NewPhysReg, NewOp.VirtReg, TII, TRI,VRM);
} else {
- MRI->loadRegFromStackSlot(*MBB, MI, NewPhysReg,
+ TII->loadRegFromStackSlot(*MBB, MII, NewPhysReg,
NewOp.StackSlotOrReMat, AliasRC);
+ MachineInstr *LoadMI = prior(MII);
+ VRM.addSpillSlotUse(NewOp.StackSlotOrReMat, LoadMI);
// Any stores to this stack slot are not dead anymore.
MaybeDeadStores[NewOp.StackSlotOrReMat] = NULL;
++NumLoads;
}
Spills.ClobberPhysReg(NewPhysReg);
Spills.ClobberPhysReg(NewOp.PhysRegReused);
+
+ unsigned SubIdx = MI->getOperand(NewOp.Operand).getSubReg();
+ unsigned RReg = SubIdx ? TRI->getSubReg(NewPhysReg, SubIdx) : NewPhysReg;
+ MI->getOperand(NewOp.Operand).setReg(RReg);
- MI->getOperand(NewOp.Operand).setReg(NewPhysReg);
-
- Spills.addAvailable(NewOp.StackSlotOrReMat, MI, NewPhysReg);
- MachineBasicBlock::iterator MII = MI;
+ Spills.addAvailable(NewOp.StackSlotOrReMat, NewPhysReg);
--MII;
- UpdateKills(*MII, RegKills, KillOps);
+ UpdateKills(*MII, RegKills, KillOps, TRI);
DOUT << '\t' << *MII;
DOUT << "Reuse undone!\n";
/// xorl %edi, %eax
/// movl %eax, -32(%ebp)
/// movl -36(%ebp), %eax
-/// orl %eax, -32(%ebp)
+/// orl %eax, -32(%ebp)
/// ==>
/// xorl %edi, %eax
/// orl -36(%ebp), %eax
/// This enables unfolding optimization for a subsequent instruction which will
/// also eliminate the newly introduced store instruction.
bool LocalSpiller::PrepForUnfoldOpti(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator &MII,
+ MachineBasicBlock::iterator &MII,
std::vector<MachineInstr*> &MaybeDeadStores,
- AvailableSpills &Spills,
- BitVector &RegKills,
- std::vector<MachineOperand*> &KillOps,
- VirtRegMap &VRM) {
+ AvailableSpills &Spills,
+ BitVector &RegKills,
+ std::vector<MachineOperand*> &KillOps,
+ VirtRegMap &VRM) {
MachineFunction &MF = *MBB.getParent();
MachineInstr &MI = *MII;
unsigned UnfoldedOpc = 0;
unsigned UnfoldVR = 0;
int FoldedSS = VirtRegMap::NO_STACK_SLOT;
VirtRegMap::MI2VirtMapTy::const_iterator I, End;
- for (tie(I, End) = VRM.getFoldedVirts(&MI); I != End; ++I) {
+ for (tie(I, End) = VRM.getFoldedVirts(&MI); I != End; ) {
// Only transform a MI that folds a single register.
if (UnfoldedOpc)
return false;
UnfoldVR = I->second.first;
VirtRegMap::ModRef MR = I->second.second;
+ // MI2VirtMap be can updated which invalidate the iterator.
+ // Increment the iterator first.
+ ++I;
if (VRM.isAssignedReg(UnfoldVR))
continue;
// If this reference is not a use, any previous store is now dead.
MachineInstr* DeadStore = MaybeDeadStores[FoldedSS];
if (DeadStore && (MR & VirtRegMap::isModRef)) {
unsigned PhysReg = Spills.getSpillSlotOrReMatPhysReg(FoldedSS);
- if (!PhysReg ||
- DeadStore->findRegisterUseOperandIdx(PhysReg, true) == -1)
+ if (!PhysReg || !DeadStore->readsRegister(PhysReg))
continue;
UnfoldPR = PhysReg;
- UnfoldedOpc = MRI->getOpcodeAfterMemoryUnfold(MI.getOpcode(),
+ UnfoldedOpc = TII->getOpcodeAfterMemoryUnfold(MI.getOpcode(),
false, true);
}
}
for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
MachineOperand &MO = MI.getOperand(i);
- if (!MO.isRegister() || MO.getReg() == 0 || !MO.isUse())
+ if (!MO.isReg() || MO.getReg() == 0 || !MO.isUse())
continue;
unsigned VirtReg = MO.getReg();
- if (MRegisterInfo::isPhysicalRegister(VirtReg) || MO.getSubReg())
+ if (TargetRegisterInfo::isPhysicalRegister(VirtReg) || MO.getSubReg())
continue;
if (VRM.isAssignedReg(VirtReg)) {
unsigned PhysReg = VRM.getPhys(VirtReg);
- if (PhysReg && MRI->regsOverlap(PhysReg, UnfoldPR))
+ if (PhysReg && TRI->regsOverlap(PhysReg, UnfoldPR))
return false;
} else if (VRM.isReMaterialized(VirtReg))
continue;
int SS = VRM.getStackSlot(VirtReg);
unsigned PhysReg = Spills.getSpillSlotOrReMatPhysReg(SS);
if (PhysReg) {
- if (MRI->regsOverlap(PhysReg, UnfoldPR))
+ if (TRI->regsOverlap(PhysReg, UnfoldPR))
return false;
continue;
}
- PhysReg = VRM.getPhys(VirtReg);
- if (!MRI->regsOverlap(PhysReg, UnfoldPR))
- continue;
+ if (VRM.hasPhys(VirtReg)) {
+ PhysReg = VRM.getPhys(VirtReg);
+ if (!TRI->regsOverlap(PhysReg, UnfoldPR))
+ continue;
+ }
// Ok, we'll need to reload the value into a register which makes
// it impossible to perform the store unfolding optimization later.
// unfolded. This allows us to perform the store unfolding
// optimization.
SmallVector<MachineInstr*, 4> NewMIs;
- if (MRI->unfoldMemoryOperand(MF, &MI, UnfoldVR, false, false, NewMIs)) {
+ if (TII->unfoldMemoryOperand(MF, &MI, UnfoldVR, false, false, NewMIs)) {
assert(NewMIs.size() == 1);
MachineInstr *NewMI = NewMIs.back();
NewMIs.clear();
- int Idx = NewMI->findRegisterUseOperandIdx(VirtReg);
+ int Idx = NewMI->findRegisterUseOperandIdx(VirtReg, false);
assert(Idx != -1);
- MachineInstr *FoldedMI = MRI->foldMemoryOperand(NewMI, Idx, SS);
+ SmallVector<unsigned, 1> Ops;
+ Ops.push_back(Idx);
+ MachineInstr *FoldedMI = TII->foldMemoryOperand(MF, NewMI, Ops, SS);
if (FoldedMI) {
+ VRM.addSpillSlotUse(SS, FoldedMI);
if (!VRM.hasPhys(UnfoldVR))
VRM.assignVirt2Phys(UnfoldVR, UnfoldPR);
VRM.virtFolded(VirtReg, FoldedMI, VirtRegMap::isRef);
MII = MBB.insert(MII, FoldedMI);
+ InvalidateKills(MI, RegKills, KillOps);
VRM.RemoveMachineInstrFromMaps(&MI);
MBB.erase(&MI);
+ MF.DeleteMachineInstr(NewMI);
return true;
}
- delete NewMI;
+ MF.DeleteMachineInstr(NewMI);
}
}
return false;
}
+/// CommuteToFoldReload -
+/// Look for
+/// r1 = load fi#1
+/// r1 = op r1, r2<kill>
+/// store r1, fi#1
+///
+/// If op is commutable and r2 is killed, then we can xform these to
+/// r2 = op r2, fi#1
+/// store r2, fi#1
+bool LocalSpiller::CommuteToFoldReload(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator &MII,
+ unsigned VirtReg, unsigned SrcReg, int SS,
+ BitVector &RegKills,
+ std::vector<MachineOperand*> &KillOps,
+ const TargetRegisterInfo *TRI,
+ VirtRegMap &VRM) {
+ if (MII == MBB.begin() || !MII->killsRegister(SrcReg))
+ return false;
+
+ MachineFunction &MF = *MBB.getParent();
+ MachineInstr &MI = *MII;
+ MachineBasicBlock::iterator DefMII = prior(MII);
+ MachineInstr *DefMI = DefMII;
+ const TargetInstrDesc &TID = DefMI->getDesc();
+ unsigned NewDstIdx;
+ if (DefMII != MBB.begin() &&
+ TID.isCommutable() &&
+ TII->CommuteChangesDestination(DefMI, NewDstIdx)) {
+ MachineOperand &NewDstMO = DefMI->getOperand(NewDstIdx);
+ unsigned NewReg = NewDstMO.getReg();
+ if (!NewDstMO.isKill() || TRI->regsOverlap(NewReg, SrcReg))
+ return false;
+ MachineInstr *ReloadMI = prior(DefMII);
+ int FrameIdx;
+ unsigned DestReg = TII->isLoadFromStackSlot(ReloadMI, FrameIdx);
+ if (DestReg != SrcReg || FrameIdx != SS)
+ return false;
+ int UseIdx = DefMI->findRegisterUseOperandIdx(DestReg, false);
+ if (UseIdx == -1)
+ return false;
+ int DefIdx = TID.getOperandConstraint(UseIdx, TOI::TIED_TO);
+ if (DefIdx == -1)
+ return false;
+ assert(DefMI->getOperand(DefIdx).isReg() &&
+ DefMI->getOperand(DefIdx).getReg() == SrcReg);
+
+ // Now commute def instruction.
+ MachineInstr *CommutedMI = TII->commuteInstruction(DefMI, true);
+ if (!CommutedMI)
+ return false;
+ SmallVector<unsigned, 1> Ops;
+ Ops.push_back(NewDstIdx);
+ MachineInstr *FoldedMI = TII->foldMemoryOperand(MF, CommutedMI, Ops, SS);
+ // Not needed since foldMemoryOperand returns new MI.
+ MF.DeleteMachineInstr(CommutedMI);
+ if (!FoldedMI)
+ return false;
+
+ VRM.addSpillSlotUse(SS, FoldedMI);
+ VRM.virtFolded(VirtReg, FoldedMI, VirtRegMap::isRef);
+ // Insert new def MI and spill MI.
+ const TargetRegisterClass* RC = MF.getRegInfo().getRegClass(VirtReg);
+ TII->storeRegToStackSlot(MBB, &MI, NewReg, true, SS, RC);
+ MII = prior(MII);
+ MachineInstr *StoreMI = MII;
+ VRM.addSpillSlotUse(SS, StoreMI);
+ VRM.virtFolded(VirtReg, StoreMI, VirtRegMap::isMod);
+ MII = MBB.insert(MII, FoldedMI); // Update MII to backtrack.
+
+ // Delete all 3 old instructions.
+ InvalidateKills(*ReloadMI, RegKills, KillOps);
+ VRM.RemoveMachineInstrFromMaps(ReloadMI);
+ MBB.erase(ReloadMI);
+ InvalidateKills(*DefMI, RegKills, KillOps);
+ VRM.RemoveMachineInstrFromMaps(DefMI);
+ MBB.erase(DefMI);
+ InvalidateKills(MI, RegKills, KillOps);
+ VRM.RemoveMachineInstrFromMaps(&MI);
+ MBB.erase(&MI);
+
+ ++NumCommutes;
+ return true;
+ }
+
+ return false;
+}
+
/// findSuperReg - Find the SubReg's super-register of given register class
/// where its SubIdx sub-register is SubReg.
static unsigned findSuperReg(const TargetRegisterClass *RC, unsigned SubReg,
- unsigned SubIdx, const MRegisterInfo *MRI) {
+ unsigned SubIdx, const TargetRegisterInfo *TRI) {
for (TargetRegisterClass::iterator I = RC->begin(), E = RC->end();
I != E; ++I) {
unsigned Reg = *I;
- if (MRI->getSubReg(Reg, SubIdx) == SubReg)
+ if (TRI->getSubReg(Reg, SubIdx) == SubReg)
return Reg;
}
return 0;
MachineBasicBlock::iterator &MII,
int Idx, unsigned PhysReg, int StackSlot,
const TargetRegisterClass *RC,
- MachineInstr *&LastStore,
+ bool isAvailable, MachineInstr *&LastStore,
AvailableSpills &Spills,
SmallSet<MachineInstr*, 4> &ReMatDefs,
BitVector &RegKills,
std::vector<MachineOperand*> &KillOps,
VirtRegMap &VRM) {
- MRI->storeRegToStackSlot(MBB, next(MII), PhysReg, StackSlot, RC);
- DOUT << "Store:\t" << *next(MII);
+ TII->storeRegToStackSlot(MBB, next(MII), PhysReg, true, StackSlot, RC);
+ MachineInstr *StoreMI = next(MII);
+ VRM.addSpillSlotUse(StackSlot, StoreMI);
+ DOUT << "Store:\t" << *StoreMI;
// If there is a dead store to this stack slot, nuke it now.
if (LastStore) {
bool CheckDef = PrevMII != MBB.begin();
if (CheckDef)
--PrevMII;
- MBB.erase(LastStore);
VRM.RemoveMachineInstrFromMaps(LastStore);
+ MBB.erase(LastStore);
if (CheckDef) {
// Look at defs of killed registers on the store. Mark the defs
// as dead since the store has been deleted and they aren't
if (ReMatDefs.count(DeadDef) && !HasOtherDef) {
// FIXME: This assumes a remat def does not have side
// effects.
- MBB.erase(DeadDef);
VRM.RemoveMachineInstrFromMaps(DeadDef);
+ MBB.erase(DeadDef);
++NumDRM;
}
}
// in PhysReg.
Spills.ModifyStackSlotOrReMat(StackSlot);
Spills.ClobberPhysReg(PhysReg);
- Spills.addAvailable(StackSlot, LastStore, PhysReg);
+ Spills.addAvailable(StackSlot, PhysReg, isAvailable);
++NumStores;
}
+/// TransferDeadness - A identity copy definition is dead and it's being
+/// removed. Find the last def or use and mark it as dead / kill.
+void LocalSpiller::TransferDeadness(MachineBasicBlock *MBB, unsigned CurDist,
+ unsigned Reg, BitVector &RegKills,
+ std::vector<MachineOperand*> &KillOps) {
+ int LastUDDist = -1;
+ MachineInstr *LastUDMI = NULL;
+ for (MachineRegisterInfo::reg_iterator RI = RegInfo->reg_begin(Reg),
+ RE = RegInfo->reg_end(); RI != RE; ++RI) {
+ MachineInstr *UDMI = &*RI;
+ if (UDMI->getParent() != MBB)
+ continue;
+ DenseMap<MachineInstr*, unsigned>::iterator DI = DistanceMap.find(UDMI);
+ if (DI == DistanceMap.end() || DI->second > CurDist)
+ continue;
+ if ((int)DI->second < LastUDDist)
+ continue;
+ LastUDDist = DI->second;
+ LastUDMI = UDMI;
+ }
+
+ if (LastUDMI) {
+ const TargetInstrDesc &TID = LastUDMI->getDesc();
+ MachineOperand *LastUD = NULL;
+ for (unsigned i = 0, e = LastUDMI->getNumOperands(); i != e; ++i) {
+ MachineOperand &MO = LastUDMI->getOperand(i);
+ if (!MO.isReg() || MO.getReg() != Reg)
+ continue;
+ if (!LastUD || (LastUD->isUse() && MO.isDef()))
+ LastUD = &MO;
+ if (TID.getOperandConstraint(i, TOI::TIED_TO) != -1)
+ return;
+ }
+ if (LastUD->isDef())
+ LastUD->setIsDead();
+ else {
+ LastUD->setIsKill();
+ RegKills.set(Reg);
+ KillOps[Reg] = LastUD;
+ }
+ }
+}
+
/// rewriteMBB - Keep track of which spills are available even after the
/// register allocator is done with them. If possible, avid reloading vregs.
-void LocalSpiller::RewriteMBB(MachineBasicBlock &MBB, VirtRegMap &VRM) {
- DOUT << MBB.getBasicBlock()->getName() << ":\n";
+void LocalSpiller::RewriteMBB(MachineBasicBlock &MBB, VirtRegMap &VRM,
+ AvailableSpills &Spills) {
+ DOUT << "\n**** Local spiller rewriting MBB '"
+ << MBB.getBasicBlock()->getName() << ":\n";
MachineFunction &MF = *MBB.getParent();
-
- // Spills - Keep track of which spilled values are available in physregs so
- // that we can choose to reuse the physregs instead of emitting reloads.
- AvailableSpills Spills(MRI, TII);
// MaybeDeadStores - When we need to write a value back into a stack slot,
// keep track of the inserted store. If the stack slot value is never read
SmallSet<MachineInstr*, 4> ReMatDefs;
// Keep track of kill information.
- BitVector RegKills(MRI->getNumRegs());
+ BitVector RegKills(TRI->getNumRegs());
std::vector<MachineOperand*> KillOps;
- KillOps.resize(MRI->getNumRegs(), NULL);
+ KillOps.resize(TRI->getNumRegs(), NULL);
+ unsigned Dist = 0;
+ DistanceMap.clear();
for (MachineBasicBlock::iterator MII = MBB.begin(), E = MBB.end();
MII != E; ) {
MachineBasicBlock::iterator NextMII = MII; ++NextMII;
NextMII = next(MII);
MachineInstr &MI = *MII;
- const TargetInstrDescriptor *TID = MI.getInstrDescriptor();
+ const TargetInstrDesc &TID = MI.getDesc();
+
+ if (VRM.hasEmergencySpills(&MI)) {
+ // Spill physical register(s) in the rare case the allocator has run out
+ // of registers to allocate.
+ SmallSet<int, 4> UsedSS;
+ std::vector<unsigned> &EmSpills = VRM.getEmergencySpills(&MI);
+ for (unsigned i = 0, e = EmSpills.size(); i != e; ++i) {
+ unsigned PhysReg = EmSpills[i];
+ const TargetRegisterClass *RC =
+ TRI->getPhysicalRegisterRegClass(PhysReg);
+ assert(RC && "Unable to determine register class!");
+ int SS = VRM.getEmergencySpillSlot(RC);
+ if (UsedSS.count(SS))
+ assert(0 && "Need to spill more than one physical registers!");
+ UsedSS.insert(SS);
+ TII->storeRegToStackSlot(MBB, MII, PhysReg, true, SS, RC);
+ MachineInstr *StoreMI = prior(MII);
+ VRM.addSpillSlotUse(SS, StoreMI);
+ TII->loadRegFromStackSlot(MBB, next(MII), PhysReg, SS, RC);
+ MachineInstr *LoadMI = next(MII);
+ VRM.addSpillSlotUse(SS, LoadMI);
+ ++NumPSpills;
+ }
+ NextMII = next(MII);
+ }
// Insert restores here if asked to.
if (VRM.isRestorePt(&MI)) {
std::vector<unsigned> &RestoreRegs = VRM.getRestorePtRestores(&MI);
for (unsigned i = 0, e = RestoreRegs.size(); i != e; ++i) {
- unsigned VirtReg = RestoreRegs[i];
+ unsigned VirtReg = RestoreRegs[e-i-1]; // Reverse order.
if (!VRM.getPreSplitReg(VirtReg))
continue; // Split interval spilled again.
unsigned Phys = VRM.getPhys(VirtReg);
- MF.setPhysRegUsed(Phys);
+ RegInfo->setPhysRegUsed(Phys);
+
+ // Check if the value being restored if available. If so, it must be
+ // from a predecessor BB that fallthrough into this BB. We do not
+ // expect:
+ // BB1:
+ // r1 = load fi#1
+ // ...
+ // = r1<kill>
+ // ... # r1 not clobbered
+ // ...
+ // = load fi#1
+ bool DoReMat = VRM.isReMaterialized(VirtReg);
+ int SSorRMId = DoReMat
+ ? VRM.getReMatId(VirtReg) : VRM.getStackSlot(VirtReg);
+ const TargetRegisterClass* RC = RegInfo->getRegClass(VirtReg);
+ // FIXME: A temporary workaround. Don't reuse available value if it's
+ // not safe to move the def of the virtual register's class. e.g.
+ // X86::RFP* register classes.
+ unsigned InReg = TII->isSafeToMoveRegClassDefs(RC) ?
+ Spills.getSpillSlotOrReMatPhysReg(SSorRMId) : 0;
+ if (InReg == Phys) {
+ // If the value is already available in the expected register, save
+ // a reload / remat.
+ if (SSorRMId)
+ DOUT << "Reusing RM#" << SSorRMId-VirtRegMap::MAX_STACK_SLOT-1;
+ else
+ DOUT << "Reusing SS#" << SSorRMId;
+ DOUT << " from physreg "
+ << TRI->getName(InReg) << " for vreg"
+ << VirtReg <<" instead of reloading into physreg "
+ << TRI->getName(Phys) << "\n";
+ ++NumOmitted;
+ continue;
+ } else if (InReg && InReg != Phys) {
+ if (SSorRMId)
+ DOUT << "Reusing RM#" << SSorRMId-VirtRegMap::MAX_STACK_SLOT-1;
+ else
+ DOUT << "Reusing SS#" << SSorRMId;
+ DOUT << " from physreg "
+ << TRI->getName(InReg) << " for vreg"
+ << VirtReg <<" by copying it into physreg "
+ << TRI->getName(Phys) << "\n";
+
+ // If the reloaded / remat value is available in another register,
+ // copy it to the desired register.
+ TII->copyRegToReg(MBB, &MI, Phys, InReg, RC, RC);
+
+ // This invalidates Phys.
+ Spills.ClobberPhysReg(Phys);
+ // Remember it's available.
+ Spills.addAvailable(SSorRMId, Phys);
+
+ // Mark is killed.
+ MachineInstr *CopyMI = prior(MII);
+ MachineOperand *KillOpnd = CopyMI->findRegisterUseOperand(InReg);
+ KillOpnd->setIsKill();
+ UpdateKills(*CopyMI, RegKills, KillOps, TRI);
+
+ DOUT << '\t' << *CopyMI;
+ ++NumCopified;
+ continue;
+ }
+
if (VRM.isReMaterialized(VirtReg)) {
- MRI->reMaterialize(MBB, &MI, Phys,
- VRM.getReMaterializedMI(VirtReg));
- ++NumReMats;
+ ReMaterialize(MBB, MII, Phys, VirtReg, TII, TRI, VRM);
} else {
- const TargetRegisterClass* RC = RegMap->getRegClass(VirtReg);
- MRI->loadRegFromStackSlot(MBB, &MI, Phys, VRM.getStackSlot(VirtReg), RC);
+ const TargetRegisterClass* RC = RegInfo->getRegClass(VirtReg);
+ TII->loadRegFromStackSlot(MBB, &MI, Phys, SSorRMId, RC);
+ MachineInstr *LoadMI = prior(MII);
+ VRM.addSpillSlotUse(SSorRMId, LoadMI);
++NumLoads;
}
+
// This invalidates Phys.
Spills.ClobberPhysReg(Phys);
- UpdateKills(*prior(MII), RegKills, KillOps);
+ // Remember it's available.
+ Spills.addAvailable(SSorRMId, Phys);
+
+ UpdateKills(*prior(MII), RegKills, KillOps, TRI);
DOUT << '\t' << *prior(MII);
}
}
// Insert spills here if asked to.
if (VRM.isSpillPt(&MI)) {
- std::vector<unsigned> &SpillRegs = VRM.getSpillPtSpills(&MI);
+ std::vector<std::pair<unsigned,bool> > &SpillRegs =
+ VRM.getSpillPtSpills(&MI);
for (unsigned i = 0, e = SpillRegs.size(); i != e; ++i) {
- unsigned VirtReg = SpillRegs[i];
+ unsigned VirtReg = SpillRegs[i].first;
+ bool isKill = SpillRegs[i].second;
if (!VRM.getPreSplitReg(VirtReg))
continue; // Split interval spilled again.
- const TargetRegisterClass *RC = RegMap->getRegClass(VirtReg);
+ const TargetRegisterClass *RC = RegInfo->getRegClass(VirtReg);
unsigned Phys = VRM.getPhys(VirtReg);
int StackSlot = VRM.getStackSlot(VirtReg);
- MachineInstr *&LastStore = MaybeDeadStores[StackSlot];
- SpillRegToStackSlot(MBB, MII, i, Phys, StackSlot, RC,
- LastStore, Spills, ReMatDefs, RegKills, KillOps, VRM);
+ TII->storeRegToStackSlot(MBB, next(MII), Phys, isKill, StackSlot, RC);
+ MachineInstr *StoreMI = next(MII);
+ VRM.addSpillSlotUse(StackSlot, StoreMI);
+ DOUT << "Store:\t" << *StoreMI;
+ VRM.virtFolded(VirtReg, StoreMI, VirtRegMap::isMod);
}
+ NextMII = next(MII);
}
/// ReusedOperands - Keep track of operand reuse in case we need to undo
/// reuse.
- ReuseInfo ReusedOperands(MI, MRI);
- // Process all of the spilled uses and all non spilled reg references.
+ ReuseInfo ReusedOperands(MI, TRI);
+ SmallVector<unsigned, 4> VirtUseOps;
for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
MachineOperand &MO = MI.getOperand(i);
- if (!MO.isRegister() || MO.getReg() == 0)
+ if (!MO.isReg() || MO.getReg() == 0)
continue; // Ignore non-register operands.
unsigned VirtReg = MO.getReg();
- if (MRegisterInfo::isPhysicalRegister(VirtReg)) {
+ if (TargetRegisterInfo::isPhysicalRegister(VirtReg)) {
// Ignore physregs for spilling, but remember that it is used by this
// function.
- MF.setPhysRegUsed(VirtReg);
+ RegInfo->setPhysRegUsed(VirtReg);
continue;
}
-
- assert(MRegisterInfo::isVirtualRegister(VirtReg) &&
- "Not a virtual or a physical register?");
-
+
+ // We want to process implicit virtual register uses first.
+ if (MO.isImplicit())
+ // If the virtual register is implicitly defined, emit a implicit_def
+ // before so scavenger knows it's "defined".
+ VirtUseOps.insert(VirtUseOps.begin(), i);
+ else
+ VirtUseOps.push_back(i);
+ }
+
+ // Process all of the spilled uses and all non spilled reg references.
+ SmallVector<int, 2> PotentialDeadStoreSlots;
+ for (unsigned j = 0, e = VirtUseOps.size(); j != e; ++j) {
+ unsigned i = VirtUseOps[j];
+ MachineOperand &MO = MI.getOperand(i);
+ unsigned VirtReg = MO.getReg();
+ assert(TargetRegisterInfo::isVirtualRegister(VirtReg) &&
+ "Not a virtual register?");
+
unsigned SubIdx = MO.getSubReg();
if (VRM.isAssignedReg(VirtReg)) {
// This virtual register was assigned a physreg!
unsigned Phys = VRM.getPhys(VirtReg);
- MF.setPhysRegUsed(Phys);
+ RegInfo->setPhysRegUsed(Phys);
if (MO.isDef())
ReusedOperands.markClobbered(Phys);
- unsigned RReg = SubIdx ? MRI->getSubReg(Phys, SubIdx) : Phys;
+ unsigned RReg = SubIdx ? TRI->getSubReg(Phys, SubIdx) : Phys;
MI.getOperand(i).setReg(RReg);
+ if (VRM.isImplicitlyDefined(VirtReg))
+ BuildMI(MBB, &MI, MI.getDebugLoc(),
+ TII->get(TargetInstrInfo::IMPLICIT_DEF), RReg);
continue;
}
// Check to see if this stack slot is available.
unsigned PhysReg = Spills.getSpillSlotOrReMatPhysReg(SSorRMId);
- if (!PhysReg && DoReMat) {
- // This use is rematerializable. But perhaps the value is available in
- // a register if the definition is not deleted. If so, check if we can
- // reuse the value.
- ReuseSlot = VRM.getStackSlot(VirtReg);
- if (ReuseSlot != VirtRegMap::NO_STACK_SLOT)
- PhysReg = Spills.getSpillSlotOrReMatPhysReg(ReuseSlot);
- }
// If this is a sub-register use, make sure the reuse register is in the
// right register class. For example, for x86 not all of the 32-bit
// the right register file.
if (PhysReg &&
(SubIdx || MI.getOpcode() == TargetInstrInfo::EXTRACT_SUBREG)) {
- const TargetRegisterClass* RC = RegMap->getRegClass(VirtReg);
+ const TargetRegisterClass* RC = RegInfo->getRegClass(VirtReg);
if (!RC->contains(PhysReg))
PhysReg = 0;
}
// aren't allowed to modify the reused register. If none of these cases
// apply, reuse it.
bool CanReuse = true;
- int ti = TID->getOperandConstraint(i, TOI::TIED_TO);
+ int ti = TID.getOperandConstraint(i, TOI::TIED_TO);
if (ti != -1 &&
- MI.getOperand(ti).isRegister() &&
+ MI.getOperand(ti).isReg() &&
MI.getOperand(ti).getReg() == VirtReg) {
// Okay, we have a two address operand. We can reuse this physreg as
// long as we are allowed to clobber the value and there isn't an
else
DOUT << "Reusing SS#" << ReuseSlot;
DOUT << " from physreg "
- << MRI->getName(PhysReg) << " for vreg"
+ << TRI->getName(PhysReg) << " for vreg"
<< VirtReg <<" instead of reloading into physreg "
- << MRI->getName(VRM.getPhys(VirtReg)) << "\n";
- unsigned RReg = SubIdx ? MRI->getSubReg(PhysReg, SubIdx) : PhysReg;
+ << TRI->getName(VRM.getPhys(VirtReg)) << "\n";
+ unsigned RReg = SubIdx ? TRI->getSubReg(PhysReg, SubIdx) : PhysReg;
MI.getOperand(i).setReg(RReg);
// The only technical detail we have is that we don't know that
if (MI.getOperand(i).isKill() &&
ReuseSlot <= VirtRegMap::MAX_STACK_SLOT) {
- // This was the last use and the spilled value is still available
- // for reuse. That means the spill was unnecessary!
- MachineInstr* DeadStore = MaybeDeadStores[ReuseSlot];
- if (DeadStore) {
- DOUT << "Removed dead store:\t" << *DeadStore;
- InvalidateKills(*DeadStore, RegKills, KillOps);
- VRM.RemoveMachineInstrFromMaps(DeadStore);
- MBB.erase(DeadStore);
- MaybeDeadStores[ReuseSlot] = NULL;
- ++NumDSE;
- }
+
+ // The store of this spilled value is potentially dead, but we
+ // won't know for certain until we've confirmed that the re-use
+ // above is valid, which means waiting until the other operands
+ // are processed. For now we just track the spill slot, we'll
+ // remove it after the other operands are processed if valid.
+
+ PotentialDeadStoreSlots.push_back(ReuseSlot);
}
+
+ // Assumes this is the last use. IsKill will be unset if reg is reused
+ // unless it's a two-address operand.
+ if (ti == -1)
+ MI.getOperand(i).setIsKill();
+
continue;
} // CanReuse
DOUT << "Reusing RM#" << ReuseSlot-VirtRegMap::MAX_STACK_SLOT-1;
else
DOUT << "Reusing SS#" << ReuseSlot;
- DOUT << " from physreg " << MRI->getName(PhysReg) << " for vreg"
- << VirtReg
+ DOUT << " from physreg " << TRI->getName(PhysReg)
+ << " for vreg" << VirtReg
<< " instead of reloading into same physreg.\n";
- unsigned RReg = SubIdx ? MRI->getSubReg(PhysReg, SubIdx) : PhysReg;
+ unsigned RReg = SubIdx ? TRI->getSubReg(PhysReg, SubIdx) : PhysReg;
MI.getOperand(i).setReg(RReg);
ReusedOperands.markClobbered(RReg);
++NumReused;
continue;
}
- const TargetRegisterClass* RC = RegMap->getRegClass(VirtReg);
- MF.setPhysRegUsed(DesignatedReg);
+ const TargetRegisterClass* RC = RegInfo->getRegClass(VirtReg);
+ RegInfo->setPhysRegUsed(DesignatedReg);
ReusedOperands.markClobbered(DesignatedReg);
- MRI->copyRegToReg(MBB, &MI, DesignatedReg, PhysReg, RC, RC);
+ TII->copyRegToReg(MBB, &MI, DesignatedReg, PhysReg, RC, RC);
MachineInstr *CopyMI = prior(MII);
- UpdateKills(*CopyMI, RegKills, KillOps);
+ UpdateKills(*CopyMI, RegKills, KillOps, TRI);
// This invalidates DesignatedReg.
Spills.ClobberPhysReg(DesignatedReg);
- Spills.addAvailable(ReuseSlot, &MI, DesignatedReg);
+ Spills.addAvailable(ReuseSlot, DesignatedReg);
unsigned RReg =
- SubIdx ? MRI->getSubReg(DesignatedReg, SubIdx) : DesignatedReg;
+ SubIdx ? TRI->getSubReg(DesignatedReg, SubIdx) : DesignatedReg;
MI.getOperand(i).setReg(RReg);
DOUT << '\t' << *prior(MII);
++NumReused;
PhysReg = ReusedOperands.GetRegForReload(PhysReg, &MI,
Spills, MaybeDeadStores, RegKills, KillOps, VRM);
- MF.setPhysRegUsed(PhysReg);
+ RegInfo->setPhysRegUsed(PhysReg);
ReusedOperands.markClobbered(PhysReg);
if (DoReMat) {
- MRI->reMaterialize(MBB, &MI, PhysReg, VRM.getReMaterializedMI(VirtReg));
- ++NumReMats;
+ ReMaterialize(MBB, MII, PhysReg, VirtReg, TII, TRI, VRM);
} else {
- const TargetRegisterClass* RC = RegMap->getRegClass(VirtReg);
- MRI->loadRegFromStackSlot(MBB, &MI, PhysReg, SSorRMId, RC);
+ const TargetRegisterClass* RC = RegInfo->getRegClass(VirtReg);
+ TII->loadRegFromStackSlot(MBB, &MI, PhysReg, SSorRMId, RC);
+ MachineInstr *LoadMI = prior(MII);
+ VRM.addSpillSlotUse(SSorRMId, LoadMI);
++NumLoads;
}
// This invalidates PhysReg.
// Any stores to this stack slot are not dead anymore.
if (!DoReMat)
MaybeDeadStores[SSorRMId] = NULL;
- Spills.addAvailable(SSorRMId, &MI, PhysReg);
+ Spills.addAvailable(SSorRMId, PhysReg);
// Assumes this is the last use. IsKill will be unset if reg is reused
// unless it's a two-address operand.
- if (TID->getOperandConstraint(i, TOI::TIED_TO) == -1)
+ if (TID.getOperandConstraint(i, TOI::TIED_TO) == -1)
MI.getOperand(i).setIsKill();
- unsigned RReg = SubIdx ? MRI->getSubReg(PhysReg, SubIdx) : PhysReg;
+ unsigned RReg = SubIdx ? TRI->getSubReg(PhysReg, SubIdx) : PhysReg;
MI.getOperand(i).setReg(RReg);
- UpdateKills(*prior(MII), RegKills, KillOps);
+ UpdateKills(*prior(MII), RegKills, KillOps, TRI);
DOUT << '\t' << *prior(MII);
}
+ // Ok - now we can remove stores that have been confirmed dead.
+ for (unsigned j = 0, e = PotentialDeadStoreSlots.size(); j != e; ++j) {
+ // This was the last use and the spilled value is still available
+ // for reuse. That means the spill was unnecessary!
+ int PDSSlot = PotentialDeadStoreSlots[j];
+ MachineInstr* DeadStore = MaybeDeadStores[PDSSlot];
+ if (DeadStore) {
+ DOUT << "Removed dead store:\t" << *DeadStore;
+ InvalidateKills(*DeadStore, RegKills, KillOps);
+ VRM.RemoveMachineInstrFromMaps(DeadStore);
+ MBB.erase(DeadStore);
+ MaybeDeadStores[PDSSlot] = NULL;
+ ++NumDSE;
+ }
+ }
+
+
DOUT << '\t' << MI;
// physical registers that may contain the value of the spilled virtual
// register
SmallSet<int, 2> FoldedSS;
- for (tie(I, End) = VRM.getFoldedVirts(&MI); I != End; ++I) {
+ for (tie(I, End) = VRM.getFoldedVirts(&MI); I != End; ) {
unsigned VirtReg = I->second.first;
VirtRegMap::ModRef MR = I->second.second;
DOUT << "Folded vreg: " << VirtReg << " MR: " << MR;
+ // MI2VirtMap be can updated which invalidate the iterator.
+ // Increment the iterator first.
+ ++I;
int SS = VRM.getStackSlot(VirtReg);
if (SS == VirtRegMap::NO_STACK_SLOT)
continue;
if (unsigned InReg = Spills.getSpillSlotOrReMatPhysReg(SS)) {
DOUT << "Promoted Load To Copy: " << MI;
if (DestReg != InReg) {
- const TargetRegisterClass *RC = RegMap->getRegClass(VirtReg);
- MRI->copyRegToReg(MBB, &MI, DestReg, InReg, RC, RC);
+ const TargetRegisterClass *RC = RegInfo->getRegClass(VirtReg);
+ TII->copyRegToReg(MBB, &MI, DestReg, InReg, RC, RC);
+ MachineOperand *DefMO = MI.findRegisterDefOperand(DestReg);
+ unsigned SubIdx = DefMO->getSubReg();
// Revisit the copy so we make sure to notice the effects of the
// operation on the destreg (either needing to RA it if it's
// virtual or needing to clobber any values if it's physical).
NextMII = &MI;
--NextMII; // backtrack to the copy.
+ // Propagate the sub-register index over.
+ if (SubIdx) {
+ DefMO = NextMII->findRegisterDefOperand(DestReg);
+ DefMO->setSubReg(SubIdx);
+ }
+
+ // Mark is killed.
+ MachineOperand *KillOpnd = NextMII->findRegisterUseOperand(InReg);
+ KillOpnd->setIsKill();
+
BackTracked = true;
- } else
+ } else {
DOUT << "Removing now-noop copy: " << MI;
+ // Unset last kill since it's being reused.
+ InvalidateKill(InReg, RegKills, KillOps);
+ }
+ InvalidateKills(MI, RegKills, KillOps);
VRM.RemoveMachineInstrFromMaps(&MI);
MBB.erase(&MI);
Erased = true;
unsigned PhysReg = Spills.getSpillSlotOrReMatPhysReg(SS);
SmallVector<MachineInstr*, 4> NewMIs;
if (PhysReg &&
- MRI->unfoldMemoryOperand(MF, &MI, PhysReg, false, false, NewMIs)) {
+ TII->unfoldMemoryOperand(MF, &MI, PhysReg, false, false, NewMIs)) {
MBB.insert(MII, NewMIs[0]);
+ InvalidateKills(MI, RegKills, KillOps);
VRM.RemoveMachineInstrFromMaps(&MI);
MBB.erase(&MI);
Erased = true;
if (MR & VirtRegMap::isModRef) {
unsigned PhysReg = Spills.getSpillSlotOrReMatPhysReg(SS);
SmallVector<MachineInstr*, 4> NewMIs;
+ // We can reuse this physreg as long as we are allowed to clobber
+ // the value and there isn't an earlier def that has already clobbered
+ // the physreg.
if (PhysReg &&
- DeadStore->findRegisterUseOperandIdx(PhysReg, true) != -1 &&
- MRI->unfoldMemoryOperand(MF, &MI, PhysReg, false, true, NewMIs)) {
- MBB.insert(MII, NewMIs[0]);
- NewStore = NewMIs[1];
- MBB.insert(MII, NewStore);
- VRM.RemoveMachineInstrFromMaps(&MI);
- MBB.erase(&MI);
- Erased = true;
- --NextMII;
- --NextMII; // backtrack to the unfolded instruction.
- BackTracked = true;
- isDead = true;
+ !TII->isStoreToStackSlot(&MI, SS)) { // Not profitable!
+ MachineOperand *KillOpnd =
+ DeadStore->findRegisterUseOperand(PhysReg, true);
+ // Note, if the store is storing a sub-register, it's possible the
+ // super-register is needed below.
+ if (KillOpnd && !KillOpnd->getSubReg() &&
+ TII->unfoldMemoryOperand(MF, &MI, PhysReg, false, true,NewMIs)){
+ MBB.insert(MII, NewMIs[0]);
+ NewStore = NewMIs[1];
+ MBB.insert(MII, NewStore);
+ VRM.addSpillSlotUse(SS, NewStore);
+ InvalidateKills(MI, RegKills, KillOps);
+ VRM.RemoveMachineInstrFromMaps(&MI);
+ MBB.erase(&MI);
+ Erased = true;
+ --NextMII;
+ --NextMII; // backtrack to the unfolded instruction.
+ BackTracked = true;
+ isDead = true;
+ }
}
}
int StackSlot;
if (!(MR & VirtRegMap::isRef)) {
if (unsigned SrcReg = TII->isStoreToStackSlot(&MI, StackSlot)) {
- assert(MRegisterInfo::isPhysicalRegister(SrcReg) &&
+ assert(TargetRegisterInfo::isPhysicalRegister(SrcReg) &&
"Src hasn't been allocated yet?");
+
+ if (CommuteToFoldReload(MBB, MII, VirtReg, SrcReg, StackSlot,
+ RegKills, KillOps, TRI, VRM)) {
+ NextMII = next(MII);
+ BackTracked = true;
+ goto ProcessNextInst;
+ }
+
// Okay, this is certainly a store of SrcReg to [StackSlot]. Mark
// this as a potentially dead store in case there is a subsequent
// store into the stack slot without a read from it.
MaybeDeadStores[StackSlot] = &MI;
// If the stack slot value was previously available in some other
- // register, change it now. Otherwise, make the register available,
- // in PhysReg.
- Spills.addAvailable(StackSlot, &MI, SrcReg, false/*don't clobber*/);
+ // register, change it now. Otherwise, make the register
+ // available in PhysReg.
+ Spills.addAvailable(StackSlot, SrcReg, false/*!clobber*/);
}
}
}
// Process all of the spilled defs.
for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
MachineOperand &MO = MI.getOperand(i);
- if (!(MO.isRegister() && MO.getReg() && MO.isDef()))
+ if (!(MO.isReg() && MO.getReg() && MO.isDef()))
continue;
unsigned VirtReg = MO.getReg();
- if (!MRegisterInfo::isVirtualRegister(VirtReg)) {
+ if (!TargetRegisterInfo::isVirtualRegister(VirtReg)) {
// Check to see if this is a noop copy. If so, eliminate the
// instruction before considering the dest reg to be changed.
- unsigned Src, Dst;
- if (TII->isMoveInstr(MI, Src, Dst) && Src == Dst) {
+ unsigned Src, Dst, SrcSR, DstSR;
+ if (TII->isMoveInstr(MI, Src, Dst, SrcSR, DstSR) && Src == Dst) {
++NumDCE;
DOUT << "Removing now-noop copy: " << MI;
+ SmallVector<unsigned, 2> KillRegs;
+ InvalidateKills(MI, RegKills, KillOps, &KillRegs);
+ if (MO.isDead() && !KillRegs.empty()) {
+ // Source register or an implicit super/sub-register use is killed.
+ assert(KillRegs[0] == Dst ||
+ TRI->isSubRegister(KillRegs[0], Dst) ||
+ TRI->isSuperRegister(KillRegs[0], Dst));
+ // Last def is now dead.
+ TransferDeadness(&MBB, Dist, Src, RegKills, KillOps);
+ }
+ VRM.RemoveMachineInstrFromMaps(&MI);
MBB.erase(&MI);
Erased = true;
- VRM.RemoveMachineInstrFromMaps(&MI);
Spills.disallowClobberPhysReg(VirtReg);
goto ProcessNextInst;
}
// If it is a folded reference, then it's not safe to clobber.
bool Folded = FoldedSS.count(FrameIdx);
// Otherwise, if it wasn't available, remember that it is now!
- Spills.addAvailable(FrameIdx, &MI, DestReg, !Folded);
+ Spills.addAvailable(FrameIdx, DestReg, !Folded);
goto ProcessNextInst;
}
// The only vregs left are stack slot definitions.
int StackSlot = VRM.getStackSlot(VirtReg);
- const TargetRegisterClass *RC = RegMap->getRegClass(VirtReg);
+ const TargetRegisterClass *RC = RegInfo->getRegClass(VirtReg);
// If this def is part of a two-address operand, make sure to execute
// the store from the correct physical register.
unsigned PhysReg;
- int TiedOp = MI.getInstrDescriptor()->findTiedToSrcOperand(i);
+ int TiedOp = MI.getDesc().findTiedToSrcOperand(i);
if (TiedOp != -1) {
PhysReg = MI.getOperand(TiedOp).getReg();
if (SubIdx) {
- unsigned SuperReg = findSuperReg(RC, PhysReg, SubIdx, MRI);
- assert(SuperReg && MRI->getSubReg(SuperReg, SubIdx) == PhysReg &&
+ unsigned SuperReg = findSuperReg(RC, PhysReg, SubIdx, TRI);
+ assert(SuperReg && TRI->getSubReg(SuperReg, SubIdx) == PhysReg &&
"Can't find corresponding super-register!");
PhysReg = SuperReg;
}
}
}
- MF.setPhysRegUsed(PhysReg);
- unsigned RReg = SubIdx ? MRI->getSubReg(PhysReg, SubIdx) : PhysReg;
+ assert(PhysReg && "VR not assigned a physical register?");
+ RegInfo->setPhysRegUsed(PhysReg);
+ unsigned RReg = SubIdx ? TRI->getSubReg(PhysReg, SubIdx) : PhysReg;
ReusedOperands.markClobbered(RReg);
MI.getOperand(i).setReg(RReg);
if (!MO.isDead()) {
MachineInstr *&LastStore = MaybeDeadStores[StackSlot];
- SpillRegToStackSlot(MBB, MII, -1, PhysReg, StackSlot, RC, LastStore,
- Spills, ReMatDefs, RegKills, KillOps, VRM);
+ SpillRegToStackSlot(MBB, MII, -1, PhysReg, StackSlot, RC, true,
+ LastStore, Spills, ReMatDefs, RegKills, KillOps, VRM);
+ NextMII = next(MII);
// Check to see if this is a noop copy. If so, eliminate the
// instruction before considering the dest reg to be changed.
{
- unsigned Src, Dst;
- if (TII->isMoveInstr(MI, Src, Dst) && Src == Dst) {
+ unsigned Src, Dst, SrcSR, DstSR;
+ if (TII->isMoveInstr(MI, Src, Dst, SrcSR, DstSR) && Src == Dst) {
++NumDCE;
DOUT << "Removing now-noop copy: " << MI;
+ InvalidateKills(MI, RegKills, KillOps);
+ VRM.RemoveMachineInstrFromMaps(&MI);
MBB.erase(&MI);
Erased = true;
- VRM.RemoveMachineInstrFromMaps(&MI);
- UpdateKills(*LastStore, RegKills, KillOps);
+ UpdateKills(*LastStore, RegKills, KillOps, TRI);
goto ProcessNextInst;
}
}
}
}
ProcessNextInst:
- if (!Erased && !BackTracked)
- for (MachineBasicBlock::iterator II = MI; II != NextMII; ++II)
- UpdateKills(*II, RegKills, KillOps);
+ DistanceMap.insert(std::make_pair(&MI, Dist++));
+ if (!Erased && !BackTracked) {
+ for (MachineBasicBlock::iterator II = &MI; II != NextMII; ++II)
+ UpdateKills(*II, RegKills, KillOps, TRI);
+ }
MII = NextMII;
}
+
}
llvm::Spiller* llvm::createSpiller() {
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