#include "llvm/Target/TargetOptions.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
+#include "llvm/Support/ErrorHandling.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/STLExtras.h"
cl::desc("Coalesce cross register class copies"),
cl::init(false), cl::Hidden);
+static cl::opt<bool>
+PhysJoinTweak("tweak-phys-join-heuristics",
+ cl::desc("Tweak heuristics for joining phys reg with vr"),
+ cl::init(false), cl::Hidden);
+
static RegisterPass<SimpleRegisterCoalescing>
X("simple-register-coalescing", "Simple Register Coalescing");
// The live interval of ECX is represented as this:
// %reg20,inf = [46,47:1)[174,230:0) 0@174-(230) 1@46-(47)
// The coalescer has no idea there was a def in the middle of [174,230].
- if (AValNo->redefByEC)
+ if (AValNo->hasRedefByEC())
return false;
// If AValNo is defined as a copy from IntB, we can potentially process this.
for (const unsigned *SR = tri_->getSubRegisters(IntB.reg); *SR; ++SR) {
LiveInterval &SRLI = li_->getInterval(*SR);
SRLI.addRange(LiveRange(FillerStart, FillerEnd,
- SRLI.getNextValue(FillerStart, 0, li_->getVNInfoAllocator())));
+ SRLI.getNextValue(FillerStart, 0, true,
+ li_->getVNInfoAllocator())));
}
}
assert(ALR != IntA.end() && "Live range not found!");
VNInfo *AValNo = ALR->valno;
// If other defs can reach uses of this def, then it's not safe to perform
- // the optimization.
- if (AValNo->def == ~0U || AValNo->def == ~1U || AValNo->hasPHIKill)
+ // the optimization. FIXME: Do isPHIDef and isDefAccurate both need to be
+ // tested?
+ if (AValNo->isPHIDef() || !AValNo->isDefAccurate() ||
+ AValNo->isUnused() || AValNo->hasPHIKill())
return false;
MachineInstr *DefMI = li_->getInstructionFromIndex(AValNo->def);
const TargetInstrDesc &TID = DefMI->getDesc();
- unsigned NewDstIdx;
- if (!TID.isCommutable() ||
- !tii_->CommuteChangesDestination(DefMI, NewDstIdx))
+ if (!TID.isCommutable())
+ return false;
+ // If DefMI is a two-address instruction then commuting it will change the
+ // destination register.
+ int DefIdx = DefMI->findRegisterDefOperandIdx(IntA.reg);
+ assert(DefIdx != -1);
+ unsigned UseOpIdx;
+ if (!DefMI->isRegTiedToUseOperand(DefIdx, &UseOpIdx))
+ return false;
+ unsigned Op1, Op2, NewDstIdx;
+ if (!tii_->findCommutedOpIndices(DefMI, Op1, Op2))
+ return false;
+ if (Op1 == UseOpIdx)
+ NewDstIdx = Op2;
+ else if (Op2 == UseOpIdx)
+ NewDstIdx = Op1;
+ else
return false;
MachineOperand &NewDstMO = DefMI->getOperand(NewDstIdx);
unsigned OpIdx = NewMI->findRegisterUseOperandIdx(IntA.reg, false);
NewMI->getOperand(OpIdx).setIsKill();
- bool BHasPHIKill = BValNo->hasPHIKill;
+ bool BHasPHIKill = BValNo->hasPHIKill();
SmallVector<VNInfo*, 4> BDeadValNos;
- SmallVector<unsigned, 4> BKills;
+ VNInfo::KillSet BKills;
std::map<unsigned, unsigned> BExtend;
// If ALR and BLR overlaps and end of BLR extends beyond end of ALR, e.g.
if (Extended)
UseMO.setIsKill(false);
else
- BKills.push_back(li_->getUseIndex(UseIdx)+1);
+ BKills.push_back(VNInfo::KillInfo(false, li_->getUseIndex(UseIdx)+1));
}
unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
if (!tii_->isMoveInstr(*UseMI, SrcReg, DstReg, SrcSubIdx, DstSubIdx))
// extended to the end of the existing live range defined by the copy.
unsigned DefIdx = li_->getDefIndex(UseIdx);
const LiveRange *DLR = IntB.getLiveRangeContaining(DefIdx);
- BHasPHIKill |= DLR->valno->hasPHIKill;
+ BHasPHIKill |= DLR->valno->hasPHIKill();
assert(DLR->valno->def == DefIdx);
BDeadValNos.push_back(DLR->valno);
BExtend[DLR->start] = DLR->end;
ValNo->def = AValNo->def;
ValNo->copy = NULL;
for (unsigned j = 0, ee = ValNo->kills.size(); j != ee; ++j) {
- unsigned Kill = ValNo->kills[j];
+ unsigned Kill = ValNo->kills[j].killIdx;
if (Kill != BLR->end)
- BKills.push_back(Kill);
+ BKills.push_back(VNInfo::KillInfo(ValNo->kills[j].isPHIKill, Kill));
}
ValNo->kills.clear();
for (LiveInterval::iterator AI = IntA.begin(), AE = IntA.end();
}
}
IntB.addKills(ValNo, BKills);
- ValNo->hasPHIKill = BHasPHIKill;
+ ValNo->setHasPHIKill(BHasPHIKill);
DOUT << " result = "; IntB.print(DOUT, tri_);
DOUT << "\n";
// of last use.
LastUse->setIsKill();
removeRange(li, li_->getDefIndex(LastUseIdx), LR->end, li_, tri_);
- li.addKill(LR->valno, LastUseIdx+1);
+ li.addKill(LR->valno, LastUseIdx+1, false);
unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
if (tii_->isMoveInstr(*LastUseMI, SrcReg, DstReg, SrcSubIdx, DstSubIdx) &&
DstReg == li.reg) {
assert(SrcLR != SrcInt.end() && "Live range not found!");
VNInfo *ValNo = SrcLR->valno;
// If other defs can reach uses of this def, then it's not safe to perform
- // the optimization.
- if (ValNo->def == ~0U || ValNo->def == ~1U || ValNo->hasPHIKill)
+ // the optimization. FIXME: Do isPHIDef and isDefAccurate both need to be
+ // tested?
+ if (ValNo->isPHIDef() || !ValNo->isDefAccurate() ||
+ ValNo->isUnused() || ValNo->hasPHIKill())
return false;
MachineInstr *DefMI = li_->getInstructionFromIndex(ValNo->def);
const TargetInstrDesc &TID = DefMI->getDesc();
// If copy kills the source register, find the last use and propagate
// kill.
+ bool checkForDeadDef = false;
MachineBasicBlock *MBB = CopyMI->getParent();
if (CopyMI->killsRegister(SrcInt.reg))
- TrimLiveIntervalToLastUse(CopyIdx, MBB, SrcInt, SrcLR);
+ if (!TrimLiveIntervalToLastUse(CopyIdx, MBB, SrcInt, SrcLR)) {
+ checkForDeadDef = true;
+ }
MachineBasicBlock::iterator MII = next(MachineBasicBlock::iterator(CopyMI));
- CopyMI->removeFromParent();
tii_->reMaterialize(*MBB, MII, DstReg, DefMI);
MachineInstr *NewMI = prior(MII);
+
+ if (checkForDeadDef) {
+ // PR4090 fix: Trim interval failed because there was no use of the
+ // source interval in this MBB. If the def is in this MBB too then we
+ // should mark it dead:
+ if (DefMI->getParent() == MBB) {
+ DefMI->addRegisterDead(SrcInt.reg, tri_);
+ SrcLR->end = SrcLR->start + 1;
+ }
+ }
+
// CopyMI may have implicit operands, transfer them over to the newly
// rematerialized instruction. And update implicit def interval valnos.
for (unsigned i = CopyMI->getDesc().getNumOperands(),
}
li_->ReplaceMachineInstrInMaps(CopyMI, NewMI);
- MBB->getParent()->DeleteMachineInstr(CopyMI);
+ CopyMI->eraseFromParent();
ReMatCopies.insert(CopyMI);
ReMatDefs.insert(DefMI);
++NumReMats;
LI.FindLiveRangeContaining(li_->getDefIndex(DefIdx));
if (DstLR == LI.end())
return false;
- unsigned KillIdx = li_->getMBBEndIdx(MBB) + 1;
- if (DstLR->valno->kills.size() == 1 &&
- DstLR->valno->kills[0] == KillIdx && DstLR->valno->hasPHIKill)
+ if (DstLR->valno->kills.size() == 1 && DstLR->valno->kills[0].isPHIKill)
return true;
return false;
}
// After updating the operand, check if the machine instruction has
// become a copy. If so, update its val# information.
+ if (JoinedCopies.count(UseMI))
+ continue;
+
const TargetInstrDesc &TID = UseMI->getDesc();
unsigned CopySrcReg, CopyDstReg, CopySrcSubIdx, CopyDstSubIdx;
if (TID.getNumDefs() == 1 && TID.getNumOperands() > 2 &&
allocatableRegs_[CopyDstReg])) {
LiveInterval &LI = li_->getInterval(CopyDstReg);
unsigned DefIdx = li_->getDefIndex(li_->getInstructionIndex(UseMI));
- const LiveRange *DLR = LI.getLiveRangeContaining(DefIdx);
- if (DLR->valno->def == DefIdx)
- DLR->valno->copy = UseMI;
+ if (const LiveRange *DLR = LI.getLiveRangeContaining(DefIdx)) {
+ if (DLR->valno->def == DefIdx)
+ DLR->valno->copy = UseMI;
+ }
}
}
}
LiveInterval::iterator LR = li.FindLiveRangeContaining(CopyIdx);
if (LR == li.end())
return false;
- if (LR->valno->hasPHIKill)
+ if (LR->valno->hasPHIKill())
return false;
if (LR->valno->def != CopyIdx)
return false;
}
-/// RemoveCopiesFromValNo - The specified value# is defined by an implicit
-/// def and it is being removed. Turn all copies from this value# into
-/// identity copies so they will be removed.
-void SimpleRegisterCoalescing::RemoveCopiesFromValNo(LiveInterval &li,
- VNInfo *VNI) {
+/// TurnCopiesFromValNoToImpDefs - The specified value# is defined by an
+/// implicit_def and it is being removed. Turn all copies from this value#
+/// into implicit_defs.
+void SimpleRegisterCoalescing::TurnCopiesFromValNoToImpDefs(LiveInterval &li,
+ VNInfo *VNI) {
SmallVector<MachineInstr*, 4> ImpDefs;
MachineOperand *LastUse = NULL;
unsigned LastUseIdx = li_->getUseIndex(VNI->def);
MachineInstr *MI = &*RI;
++RI;
if (MO->isDef()) {
- if (MI->getOpcode() == TargetInstrInfo::IMPLICIT_DEF) {
+ if (MI->getOpcode() == TargetInstrInfo::IMPLICIT_DEF)
ImpDefs.push_back(MI);
- }
continue;
}
if (JoinedCopies.count(MI))
unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
if (tii_->isMoveInstr(*MI, SrcReg, DstReg, SrcSubIdx, DstSubIdx) &&
SrcReg == li.reg) {
- // Each use MI may have multiple uses of this register. Change them all.
- for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
- MachineOperand &MO = MI->getOperand(i);
- if (MO.isReg() && MO.getReg() == li.reg)
- MO.setReg(DstReg);
- }
- JoinedCopies.insert(MI);
+ // Change it to an implicit_def.
+ MI->setDesc(tii_->get(TargetInstrInfo::IMPLICIT_DEF));
+ for (int i = MI->getNumOperands() - 1, e = 0; i > e; --i)
+ MI->RemoveOperand(i);
+ // It's no longer a copy, update the valno it defines.
+ unsigned DefIdx = li_->getDefIndex(UseIdx);
+ LiveInterval &DstInt = li_->getInterval(DstReg);
+ LiveInterval::iterator DLR = DstInt.FindLiveRangeContaining(DefIdx);
+ assert(DLR != DstInt.end() && "Live range not found!");
+ assert(DLR->valno->copy == MI);
+ DLR->valno->copy = NULL;
+ ReMatCopies.insert(MI);
} else if (UseIdx > LastUseIdx) {
LastUseIdx = UseIdx;
LastUse = MO;
}
if (LastUse) {
LastUse->setIsKill();
- li.addKill(VNI, LastUseIdx+1);
+ li.addKill(VNI, LastUseIdx+1, false);
} else {
// Remove dead implicit_def's.
while (!ImpDefs.empty()) {
}
}
-/// getMatchingSuperReg - Return a super-register of the specified register
-/// Reg so its sub-register of index SubIdx is Reg.
-static unsigned getMatchingSuperReg(unsigned Reg, unsigned SubIdx,
- const TargetRegisterClass *RC,
- const TargetRegisterInfo* TRI) {
- for (const unsigned *SRs = TRI->getSuperRegisters(Reg);
- unsigned SR = *SRs; ++SRs)
- if (Reg == TRI->getSubReg(SR, SubIdx) && RC->contains(SR))
- return SR;
- return 0;
+/// isWinToJoinVRWithSrcPhysReg - Return true if it's worth while to join a
+/// a virtual destination register with physical source register.
+bool
+SimpleRegisterCoalescing::isWinToJoinVRWithSrcPhysReg(MachineInstr *CopyMI,
+ MachineBasicBlock *CopyMBB,
+ LiveInterval &DstInt,
+ LiveInterval &SrcInt) {
+ // If the virtual register live interval is long but it has low use desity,
+ // do not join them, instead mark the physical register as its allocation
+ // preference.
+ const TargetRegisterClass *RC = mri_->getRegClass(DstInt.reg);
+ unsigned Threshold = allocatableRCRegs_[RC].count() * 2;
+ unsigned Length = li_->getApproximateInstructionCount(DstInt);
+ if (Length > Threshold &&
+ (((float)std::distance(mri_->use_begin(DstInt.reg),
+ mri_->use_end()) / Length) < (1.0 / Threshold)))
+ return false;
+
+ // If the virtual register live interval extends into a loop, turn down
+ // aggressiveness.
+ unsigned CopyIdx = li_->getDefIndex(li_->getInstructionIndex(CopyMI));
+ const MachineLoop *L = loopInfo->getLoopFor(CopyMBB);
+ if (!L) {
+ // Let's see if the virtual register live interval extends into the loop.
+ LiveInterval::iterator DLR = DstInt.FindLiveRangeContaining(CopyIdx);
+ assert(DLR != DstInt.end() && "Live range not found!");
+ DLR = DstInt.FindLiveRangeContaining(DLR->end+1);
+ if (DLR != DstInt.end()) {
+ CopyMBB = li_->getMBBFromIndex(DLR->start);
+ L = loopInfo->getLoopFor(CopyMBB);
+ }
+ }
+
+ if (!L || Length <= Threshold)
+ return true;
+
+ unsigned UseIdx = li_->getUseIndex(CopyIdx);
+ LiveInterval::iterator SLR = SrcInt.FindLiveRangeContaining(UseIdx);
+ MachineBasicBlock *SMBB = li_->getMBBFromIndex(SLR->start);
+ if (loopInfo->getLoopFor(SMBB) != L) {
+ if (!loopInfo->isLoopHeader(CopyMBB))
+ return false;
+ // If vr's live interval extends pass the loop header, do not join.
+ for (MachineBasicBlock::succ_iterator SI = CopyMBB->succ_begin(),
+ SE = CopyMBB->succ_end(); SI != SE; ++SI) {
+ MachineBasicBlock *SuccMBB = *SI;
+ if (SuccMBB == CopyMBB)
+ continue;
+ if (DstInt.overlaps(li_->getMBBStartIdx(SuccMBB),
+ li_->getMBBEndIdx(SuccMBB)+1))
+ return false;
+ }
+ }
+ return true;
+}
+
+/// isWinToJoinVRWithDstPhysReg - Return true if it's worth while to join a
+/// copy from a virtual source register to a physical destination register.
+bool
+SimpleRegisterCoalescing::isWinToJoinVRWithDstPhysReg(MachineInstr *CopyMI,
+ MachineBasicBlock *CopyMBB,
+ LiveInterval &DstInt,
+ LiveInterval &SrcInt) {
+ // If the virtual register live interval is long but it has low use desity,
+ // do not join them, instead mark the physical register as its allocation
+ // preference.
+ const TargetRegisterClass *RC = mri_->getRegClass(SrcInt.reg);
+ unsigned Threshold = allocatableRCRegs_[RC].count() * 2;
+ unsigned Length = li_->getApproximateInstructionCount(SrcInt);
+ if (Length > Threshold &&
+ (((float)std::distance(mri_->use_begin(SrcInt.reg),
+ mri_->use_end()) / Length) < (1.0 / Threshold)))
+ return false;
+
+ if (SrcInt.empty())
+ // Must be implicit_def.
+ return false;
+
+ // If the virtual register live interval is defined or cross a loop, turn
+ // down aggressiveness.
+ unsigned CopyIdx = li_->getDefIndex(li_->getInstructionIndex(CopyMI));
+ unsigned UseIdx = li_->getUseIndex(CopyIdx);
+ LiveInterval::iterator SLR = SrcInt.FindLiveRangeContaining(UseIdx);
+ assert(SLR != SrcInt.end() && "Live range not found!");
+ SLR = SrcInt.FindLiveRangeContaining(SLR->start-1);
+ if (SLR == SrcInt.end())
+ return true;
+ MachineBasicBlock *SMBB = li_->getMBBFromIndex(SLR->start);
+ const MachineLoop *L = loopInfo->getLoopFor(SMBB);
+
+ if (!L || Length <= Threshold)
+ return true;
+
+ if (loopInfo->getLoopFor(CopyMBB) != L) {
+ if (SMBB != L->getLoopLatch())
+ return false;
+ // If vr's live interval is extended from before the loop latch, do not
+ // join.
+ for (MachineBasicBlock::pred_iterator PI = SMBB->pred_begin(),
+ PE = SMBB->pred_end(); PI != PE; ++PI) {
+ MachineBasicBlock *PredMBB = *PI;
+ if (PredMBB == SMBB)
+ continue;
+ if (SrcInt.overlaps(li_->getMBBStartIdx(PredMBB),
+ li_->getMBBEndIdx(PredMBB)+1))
+ return false;
+ }
+ }
+ return true;
}
/// isWinToJoinCrossClass - Return true if it's profitable to coalesce
TargetRegisterInfo::isPhysicalRegister(SrcReg)
? tri_->getPhysicalRegisterRegClass(SrcReg)
: mri_->getRegClass(SrcReg);
- if (!getMatchingSuperReg(PhysReg, SubIdx, RC, tri_))
+ if (!tri_->getMatchingSuperReg(PhysReg, SubIdx, RC))
return true;
}
}
TargetRegisterInfo::isPhysicalRegister(DstReg)
? tri_->getPhysicalRegisterRegClass(DstReg)
: mri_->getRegClass(DstReg);
- if (!getMatchingSuperReg(PhysReg, SubIdx, RC, tri_))
+ if (!tri_->getMatchingSuperReg(PhysReg, SubIdx, RC))
return true;
}
}
unsigned SrcReg, unsigned SubIdx,
unsigned &RealDstReg) {
const TargetRegisterClass *RC = mri_->getRegClass(SrcReg);
- RealDstReg = getMatchingSuperReg(DstReg, SubIdx, RC, tri_);
+ RealDstReg = tri_->getMatchingSuperReg(DstReg, SubIdx, RC);
assert(RealDstReg && "Invalid extract_subreg instruction!");
// For this type of EXTRACT_SUBREG, conservatively
unsigned SrcReg, unsigned SubIdx,
unsigned &RealSrcReg) {
const TargetRegisterClass *RC = mri_->getRegClass(DstReg);
- RealSrcReg = getMatchingSuperReg(SrcReg, SubIdx, RC, tri_);
+ RealSrcReg = tri_->getMatchingSuperReg(SrcReg, SubIdx, RC);
assert(RealSrcReg && "Invalid extract_subreg instruction!");
LiveInterval &RHS = li_->getInterval(DstReg);
return true;
}
+/// getRegAllocPreference - Return register allocation preference register.
+///
+static unsigned getRegAllocPreference(unsigned Reg, MachineFunction &MF,
+ MachineRegisterInfo *MRI,
+ const TargetRegisterInfo *TRI) {
+ if (TargetRegisterInfo::isPhysicalRegister(Reg))
+ return 0;
+ std::pair<unsigned, unsigned> Hint = MRI->getRegAllocationHint(Reg);
+ return TRI->ResolveRegAllocHint(Hint.first, Hint.second, MF);
+}
+
/// JoinCopy - Attempt to join intervals corresponding to SrcReg/DstReg,
/// which are the src/dst of the copy instruction CopyMI. This returns true
/// if the copy was successfully coalesced away. If it is not currently
DOUT << li_->getInstructionIndex(CopyMI) << '\t' << *CopyMI;
- unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
+ unsigned SrcReg, DstReg, SrcSubIdx = 0, DstSubIdx = 0;
bool isExtSubReg = CopyMI->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG;
bool isInsSubReg = CopyMI->getOpcode() == TargetInstrInfo::INSERT_SUBREG;
bool isSubRegToReg = CopyMI->getOpcode() == TargetInstrInfo::SUBREG_TO_REG;
unsigned SubIdx = 0;
if (isExtSubReg) {
- DstReg = CopyMI->getOperand(0).getReg();
- SrcReg = CopyMI->getOperand(1).getReg();
+ DstReg = CopyMI->getOperand(0).getReg();
+ DstSubIdx = CopyMI->getOperand(0).getSubReg();
+ SrcReg = CopyMI->getOperand(1).getReg();
+ SrcSubIdx = CopyMI->getOperand(2).getImm();
} else if (isInsSubReg || isSubRegToReg) {
if (CopyMI->getOperand(2).getSubReg()) {
DOUT << "\tSource of insert_subreg is already coalesced "
<< "to another register.\n";
return false; // Not coalescable.
}
- DstReg = CopyMI->getOperand(0).getReg();
- SrcReg = CopyMI->getOperand(2).getReg();
+ DstReg = CopyMI->getOperand(0).getReg();
+ DstSubIdx = CopyMI->getOperand(3).getImm();
+ SrcReg = CopyMI->getOperand(2).getReg();
} else if (!tii_->isMoveInstr(*CopyMI, SrcReg, DstReg, SrcSubIdx, DstSubIdx)){
- assert(0 && "Unrecognized copy instruction!");
- return false;
+ LLVM_UNREACHABLE("Unrecognized copy instruction!");
}
// If they are already joined we continue.
return false; // Not coalescable.
}
+ // Check that a physical source register is compatible with dst regclass
+ if (SrcIsPhys) {
+ unsigned SrcSubReg = SrcSubIdx ?
+ tri_->getSubReg(SrcReg, SrcSubIdx) : SrcReg;
+ const TargetRegisterClass *DstRC = mri_->getRegClass(DstReg);
+ const TargetRegisterClass *DstSubRC = DstRC;
+ if (DstSubIdx)
+ DstSubRC = DstRC->getSubRegisterRegClass(DstSubIdx);
+ assert(DstSubRC && "Illegal subregister index");
+ if (!DstSubRC->contains(SrcSubReg)) {
+ DOUT << "\tIncompatible destination regclass: "
+ << tri_->getName(SrcSubReg) << " not in " << DstSubRC->getName()
+ << ".\n";
+ return false; // Not coalescable.
+ }
+ }
+
+ // Check that a physical dst register is compatible with source regclass
+ if (DstIsPhys) {
+ unsigned DstSubReg = DstSubIdx ?
+ tri_->getSubReg(DstReg, DstSubIdx) : DstReg;
+ const TargetRegisterClass *SrcRC = mri_->getRegClass(SrcReg);
+ const TargetRegisterClass *SrcSubRC = SrcRC;
+ if (SrcSubIdx)
+ SrcSubRC = SrcRC->getSubRegisterRegClass(SrcSubIdx);
+ assert(SrcSubRC && "Illegal subregister index");
+ if (!SrcSubRC->contains(DstReg)) {
+ DOUT << "\tIncompatible source regclass: "
+ << tri_->getName(DstSubReg) << " not in " << SrcSubRC->getName()
+ << ".\n";
+ return false; // Not coalescable.
+ }
+ }
+
// Should be non-null only when coalescing to a sub-register class.
bool CrossRC = false;
const TargetRegisterClass *NewRC = NULL;
}
Limit = allocatableRCRegs_[DstRC].count();
} else if (!SrcIsPhys && !DstIsPhys) {
- unsigned SrcSize = SrcRC->getSize();
- unsigned DstSize = DstRC->getSize();
- if (SrcSize < DstSize)
- // For example X86::MOVSD2PDrr copies from FR64 to VR128.
- NewRC = DstRC;
- else if (DstSize > SrcSize) {
- NewRC = SrcRC;
- std::swap(LargeReg, SmallReg);
- } else {
- unsigned SrcNumRegs = SrcRC->getNumRegs();
- unsigned DstNumRegs = DstRC->getNumRegs();
- if (DstNumRegs < SrcNumRegs)
- // Sub-register class?
- NewRC = DstRC;
- else if (SrcNumRegs < DstNumRegs) {
- NewRC = SrcRC;
- std::swap(LargeReg, SmallReg);
- } else
- // No idea what's the right register class to use.
- return false;
+ NewRC = getCommonSubClass(SrcRC, DstRC);
+ if (!NewRC) {
+ DOUT << "\tDisjoint regclasses: "
+ << SrcRC->getName() << ", "
+ << DstRC->getName() << ".\n";
+ return false; // Not coalescable.
}
+ if (DstRC->getSize() > SrcRC->getSize())
+ std::swap(LargeReg, SmallReg);
}
// If we are joining two virtual registers and the resulting register
// these are not spillable! If the destination interval uses are far away,
// think twice about coalescing them!
if (!isDead && (SrcIsPhys || DstIsPhys)) {
- LiveInterval &JoinVInt = SrcIsPhys ? DstInt : SrcInt;
- unsigned JoinVReg = SrcIsPhys ? DstReg : SrcReg;
- unsigned JoinPReg = SrcIsPhys ? SrcReg : DstReg;
- const TargetRegisterClass *RC = mri_->getRegClass(JoinVReg);
- unsigned Threshold = allocatableRCRegs_[RC].count() * 2;
- if (TheCopy.isBackEdge)
- Threshold *= 2; // Favors back edge copies.
-
- // If the virtual register live interval is long but it has low use desity,
- // do not join them, instead mark the physical register as its allocation
- // preference.
- unsigned Length = li_->getApproximateInstructionCount(JoinVInt);
- if (Length > Threshold &&
- (((float)std::distance(mri_->use_begin(JoinVReg), mri_->use_end())
- / Length) < (1.0 / Threshold))) {
- JoinVInt.preference = JoinPReg;
- ++numAborts;
- DOUT << "\tMay tie down a physical register, abort!\n";
- Again = true; // May be possible to coalesce later.
- return false;
+ // If the copy is in a loop, take care not to coalesce aggressively if the
+ // src is coming in from outside the loop (or the dst is out of the loop).
+ // If it's not in a loop, then determine whether to join them base purely
+ // by the length of the interval.
+ if (PhysJoinTweak) {
+ if (SrcIsPhys) {
+ if (!isWinToJoinVRWithSrcPhysReg(CopyMI, CopyMBB, DstInt, SrcInt)) {
+ mri_->setRegAllocationHint(DstInt.reg, 0, SrcReg);
+ ++numAborts;
+ DOUT << "\tMay tie down a physical register, abort!\n";
+ Again = true; // May be possible to coalesce later.
+ return false;
+ }
+ } else {
+ if (!isWinToJoinVRWithDstPhysReg(CopyMI, CopyMBB, DstInt, SrcInt)) {
+ mri_->setRegAllocationHint(SrcInt.reg, 0, DstReg);
+ ++numAborts;
+ DOUT << "\tMay tie down a physical register, abort!\n";
+ Again = true; // May be possible to coalesce later.
+ return false;
+ }
+ }
+ } else {
+ // If the virtual register live interval is long but it has low use desity,
+ // do not join them, instead mark the physical register as its allocation
+ // preference.
+ LiveInterval &JoinVInt = SrcIsPhys ? DstInt : SrcInt;
+ unsigned JoinVReg = SrcIsPhys ? DstReg : SrcReg;
+ unsigned JoinPReg = SrcIsPhys ? SrcReg : DstReg;
+ const TargetRegisterClass *RC = mri_->getRegClass(JoinVReg);
+ unsigned Threshold = allocatableRCRegs_[RC].count() * 2;
+ if (TheCopy.isBackEdge)
+ Threshold *= 2; // Favors back edge copies.
+
+ unsigned Length = li_->getApproximateInstructionCount(JoinVInt);
+ float Ratio = 1.0 / Threshold;
+ if (Length > Threshold &&
+ (((float)std::distance(mri_->use_begin(JoinVReg),
+ mri_->use_end()) / Length) < Ratio)) {
+ mri_->setRegAllocationHint(JoinVInt.reg, 0, JoinPReg);
+ ++numAborts;
+ DOUT << "\tMay tie down a physical register, abort!\n";
+ Again = true; // May be possible to coalesce later.
+ return false;
+ }
}
}
}
E = SavedLI->vni_end(); I != E; ++I) {
const VNInfo *ValNo = *I;
VNInfo *NewValNo = RealInt.getNextValue(ValNo->def, ValNo->copy,
+ false, // updated at *
li_->getVNInfoAllocator());
- NewValNo->hasPHIKill = ValNo->hasPHIKill;
- NewValNo->redefByEC = ValNo->redefByEC;
+ NewValNo->setFlags(ValNo->getFlags()); // * updated here.
RealInt.addKills(NewValNo, ValNo->kills);
RealInt.MergeValueInAsValue(*SavedLI, ValNo, NewValNo);
}
!SrcIsPhys && !DstIsPhys) {
if ((isExtSubReg && !Swapped) ||
((isInsSubReg || isSubRegToReg) && Swapped)) {
- ResSrcInt->Copy(*ResDstInt, li_->getVNInfoAllocator());
+ ResSrcInt->Copy(*ResDstInt, mri_, li_->getVNInfoAllocator());
std::swap(SrcReg, DstReg);
std::swap(ResSrcInt, ResDstInt);
}
for (LiveInterval::const_vni_iterator i = ResSrcInt->vni_begin(),
e = ResSrcInt->vni_end(); i != e; ++i) {
const VNInfo *vni = *i;
- if (!vni->def || vni->def == ~1U || vni->def == ~0U)
+ // FIXME: Do isPHIDef and isDefAccurate both need to be tested?
+ if (!vni->def || vni->isUnused() || vni->isPHIDef() || !vni->isDefAccurate())
continue;
MachineInstr *CopyMI = li_->getInstructionFromIndex(vni->def);
unsigned NewSrcReg, NewDstReg, NewSrcSubIdx, NewDstSubIdx;
// being merged.
li_->removeInterval(SrcReg);
+ // Update regalloc hint.
+ tri_->UpdateRegAllocHint(SrcReg, DstReg, *mf_);
+
// Manually deleted the live interval copy.
if (SavedLI) {
SavedLI->clear();
VNInfo *ImpVal = LR->valno;
assert(ImpVal->def == CopyIdx);
unsigned NextDef = LR->end;
- RemoveCopiesFromValNo(*ResDstInt, ImpVal);
+ TurnCopiesFromValNoToImpDefs(*ResDstInt, ImpVal);
ResDstInt->removeValNo(ImpVal);
LR = ResDstInt->FindLiveRangeContaining(NextDef);
if (LR != ResDstInt->end() && LR->valno->def == NextDef) {
// If resulting interval has a preference that no longer fits because of subreg
// coalescing, just clear the preference.
- if (ResDstInt->preference && (isExtSubReg || isInsSubReg || isSubRegToReg) &&
+ unsigned Preference = getRegAllocPreference(ResDstInt->reg, *mf_, mri_, tri_);
+ if (Preference && (isExtSubReg || isInsSubReg || isSubRegToReg) &&
TargetRegisterInfo::isVirtualRegister(ResDstInt->reg)) {
const TargetRegisterClass *RC = mri_->getRegClass(ResDstInt->reg);
- if (!RC->contains(ResDstInt->preference))
- ResDstInt->preference = 0;
+ if (!RC->contains(Preference))
+ mri_->setRegAllocationHint(ResDstInt->reg, 0, 0);
}
DOUT << "\n\t\tJoined. Result = "; ResDstInt->print(DOUT, tri_);
unsigned SrcReg = li_->getVNInfoSourceReg(LR->valno);
if (SrcReg == Reg)
return true;
- if (LR->valno->def == ~0U &&
+ // FIXME: Do isPHIDef and isDefAccurate both need to be tested?
+ if ((LR->valno->isPHIDef() || !LR->valno->isDefAccurate()) &&
TargetRegisterInfo::isPhysicalRegister(li.reg) &&
*tri_->getSuperRegisters(li.reg)) {
// It's a sub-register live interval, we may not have precise information.
*tri_->getSuperRegisters(LHS.reg))
// Imprecise sub-register information. Can't handle it.
return false;
- assert(0 && "No copies from the RHS?");
+ LLVM_UNREACHABLE("No copies from the RHS?");
} else {
LHSValNo = EliminatedLHSVals[0];
}
// Okay, the final step is to loop over the RHS live intervals, adding them to
// the LHS.
- LHSValNo->hasPHIKill |= VNI->hasPHIKill;
+ if (VNI->hasPHIKill())
+ LHSValNo->setHasPHIKill(true);
LHS.addKills(LHSValNo, VNI->kills);
LHS.MergeRangesInAsValue(RHS, LHSValNo);
LHS.weight += RHS.weight;
- if (RHS.preference && !LHS.preference)
- LHS.preference = RHS.preference;
+
+ // Update regalloc hint if both are virtual registers.
+ if (TargetRegisterInfo::isVirtualRegister(LHS.reg) &&
+ TargetRegisterInfo::isVirtualRegister(RHS.reg)) {
+ std::pair<unsigned, unsigned> RHSPref = mri_->getRegAllocationHint(RHS.reg);
+ std::pair<unsigned, unsigned> LHSPref = mri_->getRegAllocationHint(LHS.reg);
+ if (RHSPref != LHSPref)
+ mri_->setRegAllocationHint(LHS.reg, RHSPref.first, RHSPref.second);
+ }
// Update the liveintervals of sub-registers.
if (TargetRegisterInfo::isPhysicalRegister(LHS.reg))
for (LiveInterval::vni_iterator i = LHS.vni_begin(), e = LHS.vni_end();
i != e; ++i) {
VNInfo *VNI = *i;
- if (VNI->def == ~1U || VNI->copy == 0) // Src not defined by a copy?
+ if (VNI->isUnused() || VNI->copy == 0) // Src not defined by a copy?
continue;
// DstReg is known to be a register in the LHS interval. If the src is
for (LiveInterval::vni_iterator i = RHS.vni_begin(), e = RHS.vni_end();
i != e; ++i) {
VNInfo *VNI = *i;
- if (VNI->def == ~1U || VNI->copy == 0) // Src not defined by a copy?
+ if (VNI->isUnused() || VNI->copy == 0) // Src not defined by a copy?
continue;
// DstReg is known to be a register in the RHS interval. If the src is
i != e; ++i) {
VNInfo *VNI = *i;
unsigned VN = VNI->id;
- if (LHSValNoAssignments[VN] >= 0 || VNI->def == ~1U)
+ if (LHSValNoAssignments[VN] >= 0 || VNI->isUnused())
continue;
ComputeUltimateVN(VNI, NewVNInfo,
LHSValsDefinedFromRHS, RHSValsDefinedFromLHS,
i != e; ++i) {
VNInfo *VNI = *i;
unsigned VN = VNI->id;
- if (RHSValNoAssignments[VN] >= 0 || VNI->def == ~1U)
+ if (RHSValNoAssignments[VN] >= 0 || VNI->isUnused())
continue;
// If this value number isn't a copy from the LHS, it's a new number.
if (RHSValsDefinedFromLHS.find(VNI) == RHSValsDefinedFromLHS.end()) {
VNInfo *VNI = I->first;
unsigned LHSValID = LHSValNoAssignments[VNI->id];
LiveInterval::removeKill(NewVNInfo[LHSValID], VNI->def);
- NewVNInfo[LHSValID]->hasPHIKill |= VNI->hasPHIKill;
+ if (VNI->hasPHIKill())
+ NewVNInfo[LHSValID]->setHasPHIKill(true);
RHS.addKills(NewVNInfo[LHSValID], VNI->kills);
}
VNInfo *VNI = I->first;
unsigned RHSValID = RHSValNoAssignments[VNI->id];
LiveInterval::removeKill(NewVNInfo[RHSValID], VNI->def);
- NewVNInfo[RHSValID]->hasPHIKill |= VNI->hasPHIKill;
+ if (VNI->hasPHIKill())
+ NewVNInfo[RHSValID]->setHasPHIKill(true);
LHS.addKills(NewVNInfo[RHSValID], VNI->kills);
}
if ((RHS.ranges.size() > LHS.ranges.size() &&
TargetRegisterInfo::isVirtualRegister(LHS.reg)) ||
TargetRegisterInfo::isPhysicalRegister(RHS.reg)) {
- RHS.join(LHS, &RHSValNoAssignments[0], &LHSValNoAssignments[0], NewVNInfo);
+ RHS.join(LHS, &RHSValNoAssignments[0], &LHSValNoAssignments[0], NewVNInfo,
+ mri_);
Swapped = true;
} else {
- LHS.join(RHS, &LHSValNoAssignments[0], &RHSValNoAssignments[0], NewVNInfo);
+ LHS.join(RHS, &LHSValNoAssignments[0], &RHSValNoAssignments[0], NewVNInfo,
+ mri_);
Swapped = false;
}
return true;
static bool isZeroLengthInterval(LiveInterval *li) {
for (LiveInterval::Ranges::const_iterator
i = li->ranges.begin(), e = li->ranges.end(); i != e; ++i)
- if (i->end - i->start > LiveIntervals::InstrSlots::NUM)
+ if (i->end - i->start > LiveInterval::InstrSlots::NUM)
return false;
return true;
}
return false;
LiveInterval &DstInt = li_->getInterval(DstReg);
const LiveRange *DstLR = DstInt.getLiveRangeContaining(CopyIdx);
+ // If the valno extends beyond this basic block, then it's not safe to delete
+ // the val# or else livein information won't be correct.
+ MachineBasicBlock *EndMBB = li_->getMBBFromIndex(DstLR->end);
+ if (EndMBB != MBB)
+ return false;
DstInt.removeValNo(DstLR->valno);
CopyMI->setDesc(tii_->get(TargetInstrInfo::IMPLICIT_DEF));
for (int i = CopyMI->getNumOperands() - 1, e = 0; i > e; --i)
CopyMI->RemoveOperand(i);
+ CopyMI->getOperand(0).setIsUndef();
bool NoUse = mri_->use_empty(SrcReg);
if (NoUse) {
- for (MachineRegisterInfo::reg_iterator I = mri_->reg_begin(SrcReg),
- E = mri_->reg_end(); I != E; ) {
- assert(I.getOperand().isDef());
- MachineInstr *DefMI = &*I;
- ++I;
+ for (MachineRegisterInfo::reg_iterator RI = mri_->reg_begin(SrcReg),
+ RE = mri_->reg_end(); RI != RE; ) {
+ assert(RI.getOperand().isDef());
+ MachineInstr *DefMI = &*RI;
+ ++RI;
// The implicit_def source has no other uses, delete it.
assert(DefMI->getOpcode() == TargetInstrInfo::IMPLICIT_DEF);
li_->RemoveMachineInstrFromMaps(DefMI);
DefMI->eraseFromParent();
}
}
+
+ // Mark uses of implicit_def isUndef.
+ for (MachineRegisterInfo::use_iterator RI = mri_->use_begin(DstReg),
+ RE = mri_->use_end(); RI != RE; ++RI) {
+ assert((*RI).getParent() == MBB);
+ RI.getOperand().setIsUndef();
+ }
+
++I;
return true;
}
}
// Slightly prefer live interval that has been assigned a preferred reg.
- if (LI.preference)
+ std::pair<unsigned, unsigned> Hint = mri_->getRegAllocationHint(LI.reg);
+ if (Hint.first || Hint.second)
LI.weight *= 1.01F;
// Divide the weight of the interval by its size. This encourages
projects / oota-llvm.git / blobdiff