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");
IntB.addRange(LiveRange(FillerStart, FillerEnd, BValNo));
// If the IntB live range is assigned to a physical register, and if that
- // physreg has aliases,
+ // physreg has sub-registers, update their live intervals as well.
if (TargetRegisterInfo::isPhysicalRegister(IntB.reg)) {
- // Update the liveintervals of sub-registers.
- for (const unsigned *AS = tri_->getSubRegisters(IntB.reg); *AS; ++AS) {
- LiveInterval &AliasLI = li_->getInterval(*AS);
- AliasLI.addRange(LiveRange(FillerStart, FillerEnd,
- AliasLI.getNextValue(FillerStart, 0, li_->getVNInfoAllocator())));
+ 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())));
}
}
BExtend[ALR->end] = BLR->end;
// Update uses of IntA of the specific Val# with IntB.
+ bool BHasSubRegs = false;
+ if (TargetRegisterInfo::isPhysicalRegister(IntB.reg))
+ BHasSubRegs = *tri_->getSubRegisters(IntB.reg);
for (MachineRegisterInfo::use_iterator UI = mri_->use_begin(IntA.reg),
UE = mri_->use_end(); UI != UE;) {
MachineOperand &UseMO = UI.getOperand();
DOUT << "\nExtending: "; IntB.print(DOUT, tri_);
// Remove val#'s defined by copies that will be coalesced away.
- for (unsigned i = 0, e = BDeadValNos.size(); i != e; ++i)
+ for (unsigned i = 0, e = BDeadValNos.size(); i != e; ++i) {
+ VNInfo *DeadVNI = BDeadValNos[i];
+ if (BHasSubRegs) {
+ for (const unsigned *SR = tri_->getSubRegisters(IntB.reg); *SR; ++SR) {
+ LiveInterval &SRLI = li_->getInterval(*SR);
+ const LiveRange *SRLR = SRLI.getLiveRangeContaining(DeadVNI->def);
+ SRLI.removeValNo(SRLR->valno);
+ }
+ }
IntB.removeValNo(BDeadValNos[i]);
+ }
// Extend BValNo by merging in IntA live ranges of AValNo. Val# definition
// is updated. Kills are also updated.
if (EI != BExtend.end())
End = EI->second;
IntB.addRange(LiveRange(AI->start, End, ValNo));
+
+ // If the IntB live range is assigned to a physical register, and if that
+ // physreg has sub-registers, update their live intervals as well.
+ if (BHasSubRegs) {
+ for (const unsigned *SR = tri_->getSubRegisters(IntB.reg); *SR; ++SR) {
+ LiveInterval &SRLI = li_->getInterval(*SR);
+ SRLI.MergeInClobberRange(AI->start, End, li_->getVNInfoAllocator());
+ }
+ }
}
IntB.addKills(ValNo, BKills);
ValNo->hasPHIKill = BHasPHIKill;
// of last use.
LastUse->setIsKill();
removeRange(li, li_->getDefIndex(LastUseIdx), LR->end, li_, tri_);
+ li.addKill(LR->valno, LastUseIdx+1);
unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
if (tii_->isMoveInstr(*LastUseMI, SrcReg, DstReg, SrcSubIdx, DstSubIdx) &&
DstReg == li.reg) {
if (UseMO.isKill()) {
MachineInstr *UseMI = UseMO.getParent();
unsigned UseIdx = li_->getUseIndex(li_->getInstructionIndex(UseMI));
- if (JoinedCopies.count(UseMI))
- continue;
const LiveRange *UI = LI.getLiveRangeContaining(UseIdx);
if (!UI || !LI.isKill(UI->valno, UseIdx+1))
UseMO.setIsKill(false);
// If there is a last use in the same bb, we can't remove the live range.
// Shorten the live interval and return.
- if (TrimLiveIntervalToLastUse(CopyIdx, CopyMI->getParent(), li, LR))
+ MachineBasicBlock *CopyMBB = CopyMI->getParent();
+ if (TrimLiveIntervalToLastUse(CopyIdx, CopyMBB, li, LR))
return false;
+ MachineBasicBlock *StartMBB = li_->getMBBFromIndex(RemoveStart);
+ if (!isSameOrFallThroughBB(StartMBB, CopyMBB, tii_))
+ // If the live range starts in another mbb and the copy mbb is not a fall
+ // through mbb, then we can only cut the range from the beginning of the
+ // copy mbb.
+ RemoveStart = li_->getMBBStartIdx(CopyMBB) + 1;
+
if (LR->valno->def == RemoveStart) {
// If the def MI defines the val# and this copy is the only kill of the
// val#, then propagate the dead marker.
- if (!li.isOnlyLROfValNo(LR)) {
- if (li.isKill(LR->valno, RemoveEnd))
- li.removeKill(LR->valno, RemoveEnd);
- } else {
+ if (li.isOnlyLROfValNo(LR)) {
PropagateDeadness(li, CopyMI, RemoveStart, li_, tri_);
++numDeadValNo;
}
+ if (li.isKill(LR->valno, RemoveEnd))
+ li.removeKill(LR->valno, RemoveEnd);
}
- removeRange(li, RemoveStart, LR->end, li_, tri_);
+ removeRange(li, RemoveStart, RemoveEnd, li_, tri_);
return removeIntervalIfEmpty(li, li_, tri_);
}
LastUse = MO;
}
}
- if (LastUse)
+ if (LastUse) {
LastUse->setIsKill();
- else {
+ li.addKill(VNI, LastUseIdx+1);
+ } else {
// Remove dead implicit_def's.
while (!ImpDefs.empty()) {
MachineInstr *ImpDef = ImpDefs.back();
}
}
-/// 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;
}
}
- if (MI->getOpcode() == TargetInstrInfo::INSERT_SUBREG) {
+ if (MI->getOpcode() == TargetInstrInfo::INSERT_SUBREG ||
+ MI->getOpcode() == TargetInstrInfo::SUBREG_TO_REG) {
SubIdx = MI->getOperand(3).getImm();
if (VirtReg == MI->getOperand(0).getReg()) {
if (!tri_->getSubReg(PhysReg, SubIdx))
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);
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();
- } else if (isInsSubReg) {
+ 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;
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;
MachineBasicBlock *CopyMBB = CopyMI->getParent();
unsigned RealDstReg = 0;
unsigned RealSrcReg = 0;
- if (isExtSubReg || isInsSubReg) {
+ if (isExtSubReg || isInsSubReg || isSubRegToReg) {
SubIdx = CopyMI->getOperand(isExtSubReg ? 2 : 3).getImm();
if (SrcIsPhys && isExtSubReg) {
// r1024 = EXTRACT_SUBREG EAX, 0 then r1024 is really going to be
} else
SrcReg = tri_->getSubReg(SrcReg, SubIdx);
SubIdx = 0;
- } else if (DstIsPhys && isInsSubReg) {
+ } else if (DstIsPhys && (isInsSubReg || isSubRegToReg)) {
// EAX = INSERT_SUBREG EAX, r1024, 0
unsigned SrcSubIdx = CopyMI->getOperand(2).getSubReg();
if (SrcSubIdx) {
} else
DstReg = tri_->getSubReg(DstReg, SubIdx);
SubIdx = 0;
- } else if ((DstIsPhys && isExtSubReg) || (SrcIsPhys && isInsSubReg)) {
- if (CopyMI->getOperand(1).getSubReg()) {
+ } else if ((DstIsPhys && isExtSubReg) ||
+ (SrcIsPhys && (isInsSubReg || isSubRegToReg))) {
+ if (!isSubRegToReg && CopyMI->getOperand(1).getSubReg()) {
DOUT << "\tSrc of extract_subreg already coalesced with reg"
<< " of a super-class.\n";
return false; // Not coalescable.
// Process moves where one of the registers have a sub-register index.
MachineOperand *DstMO = CopyMI->findRegisterDefOperand(DstReg);
- if (DstMO->getSubReg())
- // FIXME: Can we handle this?
- return false;
MachineOperand *SrcMO = CopyMI->findRegisterUseOperand(SrcReg);
- SubIdx = SrcMO->getSubReg();
+ SubIdx = DstMO->getSubReg();
if (SubIdx) {
- // This is not a extract_subreg but it looks like one.
- // e.g. %cl = MOV16rr %reg1024:2
- isExtSubReg = true;
- if (DstIsPhys) {
- if (!CanJoinExtractSubRegToPhysReg(DstReg, SrcReg, SubIdx,RealDstReg))
+ if (SrcMO->getSubReg())
+ // FIXME: can we handle this?
+ return false;
+ // This is not an insert_subreg but it looks like one.
+ // e.g. %reg1024:4 = MOV32rr %EAX
+ isInsSubReg = true;
+ if (SrcIsPhys) {
+ if (!CanJoinInsertSubRegToPhysReg(DstReg, SrcReg, SubIdx, RealSrcReg))
return false; // Not coalescable
SubIdx = 0;
}
+ } else {
+ SubIdx = SrcMO->getSubReg();
+ if (SubIdx) {
+ // This is not a extract_subreg but it looks like one.
+ // e.g. %cl = MOV16rr %reg1024:1
+ isExtSubReg = true;
+ if (DstIsPhys) {
+ if (!CanJoinExtractSubRegToPhysReg(DstReg, SrcReg, SubIdx,RealDstReg))
+ return false; // Not coalescable
+ SubIdx = 0;
+ }
+ }
}
const TargetRegisterClass *SrcRC= SrcIsPhys ? 0 : mri_->getRegClass(SrcReg);
return false;
}
Limit = allocatableRCRegs_[DstRC].count();
- } else if (!SrcIsPhys && !SrcIsPhys) {
- 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;
+ } else if (!SrcIsPhys && !DstIsPhys) {
+ 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
DOUT << " and "; DstInt.print(DOUT, tri_);
DOUT << ": ";
+ // Save a copy of the virtual register live interval. We'll manually
+ // merge this into the "real" physical register live interval this is
+ // coalesced with.
+ LiveInterval *SavedLI = 0;
+ if (RealDstReg)
+ SavedLI = li_->dupInterval(&SrcInt);
+ else if (RealSrcReg)
+ SavedLI = li_->dupInterval(&DstInt);
+
// Check if it is necessary to propagate "isDead" property.
- if (!isExtSubReg && !isInsSubReg) {
+ if (!isExtSubReg && !isInsSubReg && !isSubRegToReg) {
MachineOperand *mopd = CopyMI->findRegisterDefOperand(DstReg, false);
bool isDead = mopd->isDead();
// 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)) {
+ DstInt.preference = 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)) {
+ SrcInt.preference = 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)) {
+ JoinVInt.preference = JoinPReg;
+ ++numAborts;
+ DOUT << "\tMay tie down a physical register, abort!\n";
+ Again = true; // May be possible to coalesce later.
+ return false;
+ }
}
}
}
// If definition of source is defined by trivial computation, try
// rematerializing it.
- if (!isExtSubReg && !isInsSubReg &&
+ if (!isExtSubReg && !isInsSubReg && !isSubRegToReg &&
ReMaterializeTrivialDef(SrcInt, DstInt.reg, CopyMI))
return true;
// If we can eliminate the copy without merging the live ranges, do so now.
- if (!isExtSubReg && !isInsSubReg &&
+ if (!isExtSubReg && !isInsSubReg && !isSubRegToReg &&
(AdjustCopiesBackFrom(SrcInt, DstInt, CopyMI) ||
RemoveCopyByCommutingDef(SrcInt, DstInt, CopyMI))) {
JoinedCopies.insert(CopyMI);
if (RealDstReg || RealSrcReg) {
LiveInterval &RealInt =
li_->getOrCreateInterval(RealDstReg ? RealDstReg : RealSrcReg);
- SmallSet<const VNInfo*, 4> CopiedValNos;
- for (LiveInterval::Ranges::const_iterator I = ResSrcInt->ranges.begin(),
- E = ResSrcInt->ranges.end(); I != E; ++I) {
- const LiveRange *DstLR = ResDstInt->getLiveRangeContaining(I->start);
- assert(DstLR && "Invalid joined interval!");
- const VNInfo *DstValNo = DstLR->valno;
- if (CopiedValNos.insert(DstValNo)) {
- VNInfo *ValNo = RealInt.getNextValue(DstValNo->def, DstValNo->copy,
- li_->getVNInfoAllocator());
- ValNo->hasPHIKill = DstValNo->hasPHIKill;
- RealInt.addKills(ValNo, DstValNo->kills);
- RealInt.MergeValueInAsValue(*ResDstInt, DstValNo, ValNo);
- }
+ for (LiveInterval::const_vni_iterator I = SavedLI->vni_begin(),
+ E = SavedLI->vni_end(); I != E; ++I) {
+ const VNInfo *ValNo = *I;
+ VNInfo *NewValNo = RealInt.getNextValue(ValNo->def, ValNo->copy,
+ li_->getVNInfoAllocator());
+ NewValNo->hasPHIKill = ValNo->hasPHIKill;
+ NewValNo->redefByEC = ValNo->redefByEC;
+ RealInt.addKills(NewValNo, ValNo->kills);
+ RealInt.MergeValueInAsValue(*SavedLI, ValNo, NewValNo);
}
-
+ RealInt.weight += SavedLI->weight;
DstReg = RealDstReg ? RealDstReg : RealSrcReg;
}
// If this is a EXTRACT_SUBREG, make sure the result of coalescing is the
// larger super-register.
- if ((isExtSubReg || isInsSubReg) && !SrcIsPhys && !DstIsPhys) {
- if ((isExtSubReg && !Swapped) || (isInsSubReg && Swapped)) {
+ if ((isExtSubReg || isInsSubReg || isSubRegToReg) &&
+ !SrcIsPhys && !DstIsPhys) {
+ if ((isExtSubReg && !Swapped) ||
+ ((isInsSubReg || isSubRegToReg) && Swapped)) {
ResSrcInt->Copy(*ResDstInt, li_->getVNInfoAllocator());
std::swap(SrcReg, DstReg);
std::swap(ResSrcInt, ResDstInt);
// being merged.
li_->removeInterval(SrcReg);
+ // Manually deleted the live interval copy.
+ if (SavedLI) {
+ SavedLI->clear();
+ delete SavedLI;
+ }
+
if (isEmpty) {
// Now the copy is being coalesced away, the val# previously defined
// by the copy is being defined by an IMPLICIT_DEF which defines a zero
// If resulting interval has a preference that no longer fits because of subreg
// coalescing, just clear the preference.
- if (ResDstInt->preference && (isExtSubReg || isInsSubReg) &&
+ if (ResDstInt->preference && (isExtSubReg || isInsSubReg || isSubRegToReg) &&
TargetRegisterInfo::isVirtualRegister(ResDstInt->reg)) {
const TargetRegisterClass *RC = mri_->getRegClass(ResDstInt->reg);
if (!RC->contains(ResDstInt->preference))
// vr1024 = op
// = vr1025
// Even though vr1025 is copied from vr1024, it's not safe to
- // coalesced them since live range of vr1025 intersects the
+ // coalesce them since the live range of vr1025 intersects the
// def of vr1024. This happens because vr1025 is assigned the
// value of the previous iteration of vr1024.
return false;
LHS.weight += RHS.weight;
if (RHS.preference && !LHS.preference)
LHS.preference = RHS.preference;
-
+
+ // Update the liveintervals of sub-registers.
+ if (TargetRegisterInfo::isPhysicalRegister(LHS.reg))
+ for (const unsigned *AS = tri_->getSubRegisters(LHS.reg); *AS; ++AS)
+ li_->getOrCreateInterval(*AS).MergeInClobberRanges(LHS,
+ li_->getVNInfoAllocator());
+
return true;
}
if (Inst->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG) {
DstReg = Inst->getOperand(0).getReg();
SrcReg = Inst->getOperand(1).getReg();
- } else if (Inst->getOpcode() == TargetInstrInfo::INSERT_SUBREG) {
+ } else if (Inst->getOpcode() == TargetInstrInfo::INSERT_SUBREG ||
+ Inst->getOpcode() == TargetInstrInfo::SUBREG_TO_REG) {
DstReg = Inst->getOperand(0).getReg();
SrcReg = Inst->getOperand(2).getReg();
} else if (!tii_->isMoveInstr(*Inst, SrcReg, DstReg, SrcSubIdx, DstSubIdx))
unsigned Idx = li_->getInstructionIndex(UseMI);
if (Idx >= Start && Idx < End && Idx >= UseIdx) {
LastUse = &Use;
- UseIdx = Idx;
+ UseIdx = li_->getUseIndex(Idx);
}
}
return LastUse;
MachineOperand &Use = MI->getOperand(i);
if (Use.isReg() && Use.isUse() && Use.getReg() &&
tri_->regsOverlap(Use.getReg(), Reg)) {
- UseIdx = e;
+ UseIdx = li_->getUseIndex(e);
return &Use;
}
}
// Delete all coalesced copies.
if (!tii_->isMoveInstr(*MI, SrcReg, DstReg, SrcSubIdx, DstSubIdx)) {
assert((MI->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG ||
- MI->getOpcode() == TargetInstrInfo::INSERT_SUBREG) &&
+ MI->getOpcode() == TargetInstrInfo::INSERT_SUBREG ||
+ MI->getOpcode() == TargetInstrInfo::SUBREG_TO_REG) &&
"Unrecognized copy instruction");
DstReg = MI->getOperand(0).getReg();
}
projects / oota-llvm.git / blobdiff