// See PR3149:
// 172 %ECX<def> = MOV32rr %reg1039<kill>
// 180 INLINEASM <es:subl $5,$1
- // sbbl $3,$0>, 10, %EAX<def>, 14, %ECX<earlyclobber,def>, 9, %EAX<kill>,
+ // sbbl $3,$0>, 10, %EAX<def>, 14, %ECX<earlyclobber,def>, 9,
+ // %EAX<kill>,
// 36, <fi#0>, 1, %reg0, 0, 9, %ECX<kill>, 36, <fi#1>, 1, %reg0, 0
// 188 %EAX<def> = MOV32rr %EAX<kill>
// 196 %ECX<def> = MOV32rr %ECX<kill>
for (const unsigned* SR = tri_->getSubRegisters(IntB.reg); *SR; ++SR)
if (li_->hasInterval(*SR) && IntA.overlaps(li_->getInterval(*SR))) {
DEBUG({
- errs() << "Interfere with sub-register ";
- li_->getInterval(*SR).print(errs(), tri_);
+ dbgs() << "Interfere with sub-register ";
+ li_->getInterval(*SR).print(dbgs(), tri_);
});
return false;
}
}
DEBUG({
- errs() << "\nExtending: ";
- IntB.print(errs(), tri_);
+ dbgs() << "\nExtending: ";
+ IntB.print(dbgs(), tri_);
});
SlotIndex FillerStart = ValLR->end, FillerEnd = BLR->start;
// We are about to delete CopyMI, so need to remove it as the 'instruction
- // that defines this value #'. Update the the valnum with the new defining
+ // that defines this value #'. Update the valnum with the new defining
// instruction #.
BValNo->def = FillerStart;
BValNo->setCopy(0);
IntB.MergeValueNumberInto(BValNo, ValLR->valno);
}
DEBUG({
- errs() << " result = ";
- IntB.print(errs(), tri_);
- errs() << "\n";
+ dbgs() << " result = ";
+ IntB.print(dbgs(), tri_);
+ dbgs() << "\n";
});
// If the source instruction was killing the source register before the
}
}
-/// RemoveCopyByCommutingDef - We found a non-trivially-coalescable copy with IntA
-/// being the source and IntB being the dest, thus this defines a value number
-/// in IntB. If the source value number (in IntA) is defined by a commutable
-/// instruction and its other operand is coalesced to the copy dest register,
-/// see if we can transform the copy into a noop by commuting the definition. For
-/// example,
+/// RemoveCopyByCommutingDef - We found a non-trivially-coalescable copy with
+/// IntA being the source and IntB being the dest, thus this defines a value
+/// number in IntB. If the source value number (in IntA) is defined by a
+/// commutable instruction and its other operand is coalesced to the copy dest
+/// register, see if we can transform the copy into a noop by commuting the
+/// definition. For example,
///
/// A3 = op A2 B0<kill>
/// ...
// If some of the uses of IntA.reg is already coalesced away, return false.
// It's not possible to determine whether it's safe to perform the coalescing.
- for (MachineRegisterInfo::use_iterator UI = mri_->use_begin(IntA.reg),
- UE = mri_->use_end(); UI != UE; ++UI) {
+ for (MachineRegisterInfo::use_nodbg_iterator UI =
+ mri_->use_nodbg_begin(IntA.reg),
+ UE = mri_->use_nodbg_end(); UI != UE; ++UI) {
MachineInstr *UseMI = &*UI;
SlotIndex UseIdx = li_->getInstructionIndex(UseMI);
LiveInterval::iterator ULR = IntA.FindLiveRangeContaining(UseIdx);
++UI;
if (JoinedCopies.count(UseMI))
continue;
+ if (UseMI->isDebugValue()) {
+ // FIXME These don't have an instruction index. Not clear we have enough
+ // info to decide whether to do this replacement or not. For now do it.
+ UseMO.setReg(NewReg);
+ continue;
+ }
SlotIndex UseIdx = li_->getInstructionIndex(UseMI).getUseIndex();
LiveInterval::iterator ULR = IntA.FindLiveRangeContaining(UseIdx);
if (ULR == IntA.end() || ULR->valno != AValNo)
// We need to insert a new liverange: [ALR.start, LastUse). It may be we can
// simply extend BLR if CopyMI doesn't end the range.
DEBUG({
- errs() << "\nExtending: ";
- IntB.print(errs(), tri_);
+ dbgs() << "\nExtending: ";
+ IntB.print(dbgs(), tri_);
});
// Remove val#'s defined by copies that will be coalesced away.
if (BHasSubRegs) {
for (const unsigned *SR = tri_->getSubRegisters(IntB.reg); *SR; ++SR) {
LiveInterval &SRLI = li_->getInterval(*SR);
- SRLI.MergeInClobberRange(*li_, AI->start, End, li_->getVNInfoAllocator());
+ SRLI.MergeInClobberRange(*li_, AI->start, End,
+ li_->getVNInfoAllocator());
}
}
}
ValNo->setHasPHIKill(BHasPHIKill);
DEBUG({
- errs() << " result = ";
- IntB.print(errs(), tri_);
- errs() << '\n';
- errs() << "\nShortening: ";
- IntA.print(errs(), tri_);
+ dbgs() << " result = ";
+ IntB.print(dbgs(), tri_);
+ dbgs() << '\n';
+ dbgs() << "\nShortening: ";
+ IntA.print(dbgs(), tri_);
});
IntA.removeValNo(AValNo);
DEBUG({
- errs() << " result = ";
- IntA.print(errs(), tri_);
- errs() << '\n';
+ dbgs() << " result = ";
+ IntA.print(dbgs(), tri_);
+ dbgs() << '\n';
});
++numCommutes;
return false;
if (TID.getNumDefs() != 1)
return false;
- if (DefMI->getOpcode() != TargetInstrInfo::IMPLICIT_DEF) {
+ if (!DefMI->isImplicitDef()) {
// Make sure the copy destination register class fits the instruction
// definition register class. The mismatch can happen as a result of earlier
// extract_subreg, insert_subreg, subreg_to_reg coalescing.
checkForDeadDef = true;
}
- MachineBasicBlock::iterator MII = next(MachineBasicBlock::iterator(CopyMI));
+ MachineBasicBlock::iterator MII =
+ llvm::next(MachineBasicBlock::iterator(CopyMI));
tii_->reMaterialize(*MBB, MII, DstReg, DstSubIdx, DefMI, tri_);
MachineInstr *NewMI = prior(MII);
SubIdx = 0;
}
+ // Copy the register use-list before traversing it. We may be adding operands
+ // and invalidating pointers.
+ SmallVector<std::pair<MachineInstr*, unsigned>, 32> reglist;
for (MachineRegisterInfo::reg_iterator I = mri_->reg_begin(SrcReg),
- E = mri_->reg_end(); I != E; ) {
- MachineOperand &O = I.getOperand();
- MachineInstr *UseMI = &*I;
- ++I;
+ E = mri_->reg_end(); I != E; ++I)
+ reglist.push_back(std::make_pair(&*I, I.getOperandNo()));
+
+ for (unsigned N=0; N != reglist.size(); ++N) {
+ MachineInstr *UseMI = reglist[N].first;
+ MachineOperand &O = UseMI->getOperand(reglist[N].second);
unsigned OldSubIdx = O.getSubReg();
if (DstIsPhys) {
unsigned UseDstReg = DstReg;
O.setReg(UseDstReg);
O.setSubReg(0);
+ if (OldSubIdx) {
+ // Def and kill of subregister of a virtual register actually defs and
+ // kills the whole register. Add imp-defs and imp-kills as needed.
+ if (O.isDef()) {
+ if(O.isDead())
+ UseMI->addRegisterDead(DstReg, tri_, true);
+ else
+ UseMI->addRegisterDefined(DstReg, tri_);
+ } else if (!O.isUndef() &&
+ (O.isKill() ||
+ UseMI->isRegTiedToDefOperand(&O-&UseMI->getOperand(0))))
+ UseMI->addRegisterKilled(DstReg, tri_, true);
+ }
continue;
}
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)))
+ (((float)std::distance(mri_->use_nodbg_begin(DstInt.reg),
+ mri_->use_nodbg_end()) / Length) <
+ (1.0 / Threshold)))
return false;
// If the virtual register live interval extends into a loop, turn down
if (SuccMBB == CopyMBB)
continue;
if (DstInt.overlaps(li_->getMBBStartIdx(SuccMBB),
- li_->getMBBEndIdx(SuccMBB).getNextIndex().getBaseIndex()))
+ li_->getMBBEndIdx(SuccMBB)))
return false;
}
}
MachineBasicBlock *CopyMBB,
LiveInterval &DstInt,
LiveInterval &SrcInt) {
- // If the virtual register live interval is long but it has low use desity,
+ // If the virtual register live interval is long but it has low use density,
// 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)))
+ (((float)std::distance(mri_->use_nodbg_begin(SrcInt.reg),
+ mri_->use_nodbg_end()) / Length) <
+ (1.0 / Threshold)))
return false;
if (SrcInt.empty())
if (PredMBB == SMBB)
continue;
if (SrcInt.overlaps(li_->getMBBStartIdx(PredMBB),
- li_->getMBBEndIdx(PredMBB).getNextIndex().getBaseIndex()))
+ li_->getMBBEndIdx(PredMBB)))
return false;
}
}
LiveInterval &SmallInt = li_->getInterval(SmallReg);
unsigned LargeSize = li_->getApproximateInstructionCount(LargeInt);
unsigned SmallSize = li_->getApproximateInstructionCount(SmallInt);
- if (SmallSize > Threshold || LargeSize > Threshold)
- if ((float)std::distance(mri_->use_begin(SmallReg),
- mri_->use_end()) / SmallSize <
- (float)std::distance(mri_->use_begin(LargeReg),
- mri_->use_end()) / LargeSize)
+ if (LargeSize > Threshold) {
+ unsigned SmallUses = std::distance(mri_->use_nodbg_begin(SmallReg),
+ mri_->use_nodbg_end());
+ unsigned LargeUses = std::distance(mri_->use_nodbg_begin(LargeReg),
+ mri_->use_nodbg_end());
+ if (SmallUses*LargeSize < LargeUses*SmallSize)
return false;
+ }
return true;
}
for (MachineRegisterInfo::reg_iterator I = mri_->reg_begin(VirtReg),
E = mri_->reg_end(); I != E; ++I) {
MachineOperand &O = I.getOperand();
+ if (O.isDebug())
+ continue;
MachineInstr *MI = &*I;
if (MI == CopyMI || JoinedCopies.count(MI))
continue;
unsigned SubIdx = O.getSubReg();
if (SubIdx && !tri_->getSubReg(PhysReg, SubIdx))
return true;
- if (MI->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG) {
+ if (MI->isExtractSubreg()) {
SubIdx = MI->getOperand(2).getImm();
if (O.isUse() && !tri_->getSubReg(PhysReg, SubIdx))
return true;
return true;
}
}
- if (MI->getOpcode() == TargetInstrInfo::INSERT_SUBREG ||
- MI->getOpcode() == TargetInstrInfo::SUBREG_TO_REG) {
+ if (MI->isInsertSubreg() || MI->isSubregToReg()) {
SubIdx = MI->getOperand(3).getImm();
if (VirtReg == MI->getOperand(0).getReg()) {
if (!tri_->getSubReg(PhysReg, SubIdx))
if (li_->hasInterval(RealDstReg) &&
RHS.overlaps(li_->getInterval(RealDstReg))) {
DEBUG({
- errs() << "Interfere with register ";
- li_->getInterval(RealDstReg).print(errs(), tri_);
+ dbgs() << "Interfere with register ";
+ li_->getInterval(RealDstReg).print(dbgs(), tri_);
});
return false; // Not coalescable
}
for (const unsigned* SR = tri_->getSubRegisters(RealDstReg); *SR; ++SR)
if (li_->hasInterval(*SR) && RHS.overlaps(li_->getInterval(*SR))) {
DEBUG({
- errs() << "Interfere with sub-register ";
- li_->getInterval(*SR).print(errs(), tri_);
+ dbgs() << "Interfere with sub-register ";
+ li_->getInterval(*SR).print(dbgs(), tri_);
});
return false; // Not coalescable
}
if (li_->hasInterval(RealSrcReg) &&
RHS.overlaps(li_->getInterval(RealSrcReg))) {
DEBUG({
- errs() << "Interfere with register ";
- li_->getInterval(RealSrcReg).print(errs(), tri_);
+ dbgs() << "Interfere with register ";
+ li_->getInterval(RealSrcReg).print(dbgs(), tri_);
});
return false; // Not coalescable
}
for (const unsigned* SR = tri_->getSubRegisters(RealSrcReg); *SR; ++SR)
if (li_->hasInterval(*SR) && RHS.overlaps(li_->getInterval(*SR))) {
DEBUG({
- errs() << "Interfere with sub-register ";
- li_->getInterval(*SR).print(errs(), tri_);
+ dbgs() << "Interfere with sub-register ";
+ li_->getInterval(*SR).print(dbgs(), tri_);
});
return false; // Not coalescable
}
if (JoinedCopies.count(CopyMI) || ReMatCopies.count(CopyMI))
return false; // Already done.
- DEBUG(errs() << li_->getInstructionIndex(CopyMI) << '\t' << *CopyMI);
+ DEBUG(dbgs() << li_->getInstructionIndex(CopyMI) << '\t' << *CopyMI);
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;
+ bool isExtSubReg = CopyMI->isExtractSubreg();
+ bool isInsSubReg = CopyMI->isInsertSubreg();
+ bool isSubRegToReg = CopyMI->isSubregToReg();
unsigned SubIdx = 0;
if (isExtSubReg) {
DstReg = CopyMI->getOperand(0).getReg();
if (SrcSubIdx && SrcSubIdx != DstSubIdx) {
// r1025 = INSERT_SUBREG r1025, r1024<2>, 2 Then r1024 has already been
// coalesced to a larger register so the subreg indices cancel out.
- DEBUG(errs() << "\tSource of insert_subreg or subreg_to_reg is already "
+ DEBUG(dbgs() << "\tSource of insert_subreg or subreg_to_reg is already "
"coalesced to another register.\n");
return false; // Not coalescable.
}
- } else if (!tii_->isMoveInstr(*CopyMI, SrcReg, DstReg, SrcSubIdx, DstSubIdx)){
+ } else if (tii_->isMoveInstr(*CopyMI, SrcReg, DstReg, SrcSubIdx, DstSubIdx)) {
+ if (SrcSubIdx && DstSubIdx && SrcSubIdx != DstSubIdx) {
+ // e.g. %reg16404:1<def> = MOV8rr %reg16412:2<kill>
+ Again = true;
+ return false; // Not coalescable.
+ }
+ } else {
llvm_unreachable("Unrecognized copy instruction!");
}
// If they are already joined we continue.
if (SrcReg == DstReg) {
- DEBUG(errs() << "\tCopy already coalesced.\n");
+ DEBUG(dbgs() << "\tCopy already coalesced.\n");
return false; // Not coalescable.
}
// If they are both physical registers, we cannot join them.
if (SrcIsPhys && DstIsPhys) {
- DEBUG(errs() << "\tCan not coalesce physregs.\n");
+ DEBUG(dbgs() << "\tCan not coalesce physregs.\n");
return false; // Not coalescable.
}
// We only join virtual registers with allocatable physical registers.
if (SrcIsPhys && !allocatableRegs_[SrcReg]) {
- DEBUG(errs() << "\tSrc reg is unallocatable physreg.\n");
+ DEBUG(dbgs() << "\tSrc reg is unallocatable physreg.\n");
return false; // Not coalescable.
}
if (DstIsPhys && !allocatableRegs_[DstReg]) {
- DEBUG(errs() << "\tDst reg is unallocatable physreg.\n");
+ DEBUG(dbgs() << "\tDst reg is unallocatable physreg.\n");
return false; // Not coalescable.
}
DstSubRC = DstRC->getSubRegisterRegClass(DstSubIdx);
assert(DstSubRC && "Illegal subregister index");
if (!DstSubRC->contains(SrcSubReg)) {
- DEBUG(errs() << "\tIncompatible destination regclass: "
+ DEBUG(dbgs() << "\tIncompatible destination regclass: "
<< tri_->getName(SrcSubReg) << " not in "
<< DstSubRC->getName() << ".\n");
return false; // Not coalescable.
SrcSubRC = SrcRC->getSubRegisterRegClass(SrcSubIdx);
assert(SrcSubRC && "Illegal subregister index");
if (!SrcSubRC->contains(DstSubReg)) {
- DEBUG(errs() << "\tIncompatible source regclass: "
+ DEBUG(dbgs() << "\tIncompatible source regclass: "
<< tri_->getName(DstSubReg) << " not in "
<< SrcSubRC->getName() << ".\n");
(void)DstSubReg;
// r1024<2> = EXTRACT_SUBREG EAX, 2. Then r1024 has already been
// coalesced to a larger register so the subreg indices cancel out.
if (DstSubIdx != SubIdx) {
- DEBUG(errs() << "\t Sub-register indices mismatch.\n");
+ DEBUG(dbgs() << "\t Sub-register indices mismatch.\n");
return false; // Not coalescable.
}
} else
// EAX = INSERT_SUBREG EAX, r1024<2>, 2 Then r1024 has already been
// coalesced to a larger register so the subreg indices cancel out.
if (SrcSubIdx != SubIdx) {
- DEBUG(errs() << "\t Sub-register indices mismatch.\n");
+ DEBUG(dbgs() << "\t Sub-register indices mismatch.\n");
return false; // Not coalescable.
}
} else
} else if ((DstIsPhys && isExtSubReg) ||
(SrcIsPhys && (isInsSubReg || isSubRegToReg))) {
if (!isSubRegToReg && CopyMI->getOperand(1).getSubReg()) {
- DEBUG(errs() << "\tSrc of extract_subreg already coalesced with reg"
+ DEBUG(dbgs() << "\tSrc of extract_subreg already coalesced with reg"
<< " of a super-class.\n");
return false; // Not coalescable.
}
// class as the would be resulting register.
SubIdx = 0;
else {
- DEBUG(errs() << "\t Sub-register indices mismatch.\n");
+ DEBUG(dbgs() << "\t Sub-register indices mismatch.\n");
return false; // Not coalescable.
}
}
NewRC = tri_->getMatchingSuperRegClass(SrcRC, DstRC, SubIdx);
}
if (!NewRC) {
- DEBUG(errs() << "\t Conflicting sub-register indices.\n");
+ DEBUG(dbgs() << "\t Conflicting sub-register indices.\n");
return false; // Not coalescable
}
} else if (!SrcIsPhys && !DstIsPhys) {
NewRC = getCommonSubClass(SrcRC, DstRC);
if (!NewRC) {
- DEBUG(errs() << "\tDisjoint regclasses: "
+ DEBUG(dbgs() << "\tDisjoint regclasses: "
<< SrcRC->getName() << ", "
<< DstRC->getName() << ".\n");
return false; // Not coalescable.
(isExtSubReg || DstRC->isASubClass()) &&
!isWinToJoinCrossClass(LargeReg, SmallReg,
allocatableRCRegs_[NewRC].count())) {
- DEBUG(errs() << "\tSrc/Dest are different register classes.\n");
+ DEBUG(dbgs() << "\tSrc/Dest are different register classes: "
+ << SrcRC->getName() << "/"
+ << DstRC->getName() << " -> "
+ << NewRC->getName() << ".\n");
// Allow the coalescer to try again in case either side gets coalesced to
// a physical register that's compatible with the other side. e.g.
// r1024 = MOV32to32_ r1025
"Register mapping is horribly broken!");
DEBUG({
- errs() << "\t\tInspecting "; SrcInt.print(errs(), tri_);
- errs() << " and "; DstInt.print(errs(), tri_);
- errs() << ": ";
+ dbgs() << "\t\tInspecting "; SrcInt.print(dbgs(), tri_);
+ dbgs() << " and "; DstInt.print(dbgs(), tri_);
+ dbgs() << ": ";
});
// Save a copy of the virtual register live interval. We'll manually
if (!isWinToJoinVRWithSrcPhysReg(CopyMI, CopyMBB, DstInt, SrcInt)) {
mri_->setRegAllocationHint(DstInt.reg, 0, SrcReg);
++numAborts;
- DEBUG(errs() << "\tMay tie down a physical register, abort!\n");
+ DEBUG(dbgs() << "\tMay tie down a physical register, abort!\n");
Again = true; // May be possible to coalesce later.
return false;
}
if (!isWinToJoinVRWithDstPhysReg(CopyMI, CopyMBB, DstInt, SrcInt)) {
mri_->setRegAllocationHint(SrcInt.reg, 0, DstReg);
++numAborts;
- DEBUG(errs() << "\tMay tie down a physical register, abort!\n");
+ DEBUG(dbgs() << "\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.
+ // If the virtual register live interval is long but it has low use
+ // density, 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;
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)) {
+ (((float)std::distance(mri_->use_nodbg_begin(JoinVReg),
+ mri_->use_nodbg_end()) / Length) < Ratio)) {
mri_->setRegAllocationHint(JoinVInt.reg, 0, JoinPReg);
++numAborts;
- DEBUG(errs() << "\tMay tie down a physical register, abort!\n");
+ DEBUG(dbgs() << "\tMay tie down a physical register, abort!\n");
Again = true; // May be possible to coalesce later.
return false;
}
// Only coalesce an empty interval (defined by implicit_def) with
// another interval which has a valno defined by the CopyMI and the CopyMI
// is a kill of the implicit def.
- DEBUG(errs() << "Not profitable!\n");
+ DEBUG(dbgs() << "Not profitable!\n");
return false;
}
}
// Otherwise, we are unable to join the intervals.
- DEBUG(errs() << "Interference!\n");
+ DEBUG(dbgs() << "Interference!\n");
Again = true; // May be possible to coalesce later.
return false;
}
UpdateRegDefsUses(SrcReg, DstReg, SubIdx);
+ // If we have extended the live range of a physical register, make sure we
+ // update live-in lists as well.
+ if (TargetRegisterInfo::isPhysicalRegister(DstReg)) {
+ const LiveInterval &VRegInterval = li_->getInterval(SrcReg);
+ SmallVector<MachineBasicBlock*, 16> BlockSeq;
+ for (LiveInterval::const_iterator I = VRegInterval.begin(),
+ E = VRegInterval.end(); I != E; ++I ) {
+ li_->findLiveInMBBs(I->start, I->end, BlockSeq);
+ for (unsigned idx = 0, size = BlockSeq.size(); idx != size; ++idx) {
+ MachineBasicBlock &block = *BlockSeq[idx];
+ if (!block.isLiveIn(DstReg))
+ block.addLiveIn(DstReg);
+ }
+ BlockSeq.clear();
+ }
+ }
+
// SrcReg is guarateed to be the register whose live interval that is
// being merged.
li_->removeInterval(SrcReg);
}
DEBUG({
- errs() << "\n\t\tJoined. Result = ";
- ResDstInt->print(errs(), tri_);
- errs() << "\n";
+ dbgs() << "\n\t\tJoined. Result = ";
+ ResDstInt->print(dbgs(), tri_);
+ dbgs() << "\n";
});
++numJoins;
unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
if (TII->isMoveInstr(*MI, SrcReg, DstReg, SrcSubIdx, DstSubIdx))
;
- else if (MI->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG) {
+ else if (MI->isExtractSubreg()) {
DstReg = MI->getOperand(0).getReg();
SrcReg = MI->getOperand(1).getReg();
- } else if (MI->getOpcode() == TargetInstrInfo::SUBREG_TO_REG ||
- MI->getOpcode() == TargetInstrInfo::INSERT_SUBREG) {
+ } else if (MI->isSubregToReg() ||
+ MI->isInsertSubreg()) {
DstReg = MI->getOperand(0).getReg();
SrcReg = MI->getOperand(2).getReg();
} else
if (Overlaps) {
// If we haven't already recorded that this value # is safe, check it.
if (!InVector(LHSIt->valno, EliminatedLHSVals)) {
+ // If it's re-defined by an early clobber somewhere in the live range,
+ // then conservatively abort coalescing.
+ if (LHSIt->valno->hasRedefByEC())
+ return false;
// Copy from the RHS?
if (!RangeIsDefinedByCopyFromReg(LHS, LHSIt, RHS.reg))
return false; // Nope, bail out.
// if coalescing succeeds. Just skip the liverange.
if (++LHSIt == LHSEnd) break;
} else {
+ // If it's re-defined by an early clobber somewhere in the live range,
+ // then conservatively abort coalescing.
+ if (LHSIt->valno->hasRedefByEC())
+ return false;
// Otherwise, if this is a copy from the RHS, mark it as being merged
// in.
if (RangeIsDefinedByCopyFromReg(LHS, LHSIt, RHS.reg)) {
for (const unsigned* SR = tri_->getSubRegisters(LHS.reg); *SR; ++SR)
if (li_->hasInterval(*SR) && RHS.overlaps(li_->getInterval(*SR))) {
DEBUG({
- errs() << "Interfere with sub-register ";
- li_->getInterval(*SR).print(errs(), tri_);
+ dbgs() << "Interfere with sub-register ";
+ li_->getInterval(*SR).print(dbgs(), tri_);
});
return false;
}
for (const unsigned* SR = tri_->getSubRegisters(RHS.reg); *SR; ++SR)
if (li_->hasInterval(*SR) && LHS.overlaps(li_->getInterval(*SR))) {
DEBUG({
- errs() << "Interfere with sub-register ";
- li_->getInterval(*SR).print(errs(), tri_);
+ dbgs() << "Interfere with sub-register ";
+ li_->getInterval(*SR).print(dbgs(), tri_);
});
return false;
}
continue;
// Figure out the value # from the RHS.
- LHSValsDefinedFromRHS[VNI]=
- RHS.getLiveRangeContaining(VNI->def.getPrevSlot())->valno;
+ LiveRange *lr = RHS.getLiveRangeContaining(VNI->def.getPrevSlot());
+ assert(lr && "Cannot find live range");
+ LHSValsDefinedFromRHS[VNI] = lr->valno;
}
// Loop over the value numbers of the RHS, seeing if any are defined from
continue;
// Figure out the value # from the LHS.
- RHSValsDefinedFromLHS[VNI]=
- LHS.getLiveRangeContaining(VNI->def.getPrevSlot())->valno;
+ LiveRange *lr = LHS.getLiveRangeContaining(VNI->def.getPrevSlot());
+ assert(lr && "Cannot find live range");
+ RHSValsDefinedFromLHS[VNI] = lr->valno;
}
LHSValNoAssignments.resize(LHS.getNumValNums(), -1);
if (LHSValNoAssignments[I->valno->id] !=
RHSValNoAssignments[J->valno->id])
return false;
+ // If it's re-defined by an early clobber somewhere in the live range,
+ // then conservatively abort coalescing.
+ if (NewVNInfo[LHSValNoAssignments[I->valno->id]]->hasRedefByEC())
+ return false;
}
if (I->end < J->end) {
struct DepthMBBCompare {
typedef std::pair<unsigned, MachineBasicBlock*> DepthMBBPair;
bool operator()(const DepthMBBPair &LHS, const DepthMBBPair &RHS) const {
- if (LHS.first > RHS.first) return true; // Deeper loops first
- return LHS.first == RHS.first &&
- LHS.second->getNumber() < RHS.second->getNumber();
+ // Deeper loops first
+ if (LHS.first != RHS.first)
+ return LHS.first > RHS.first;
+
+ // Prefer blocks that are more connected in the CFG. This takes care of
+ // the most difficult copies first while intervals are short.
+ unsigned cl = LHS.second->pred_size() + LHS.second->succ_size();
+ unsigned cr = RHS.second->pred_size() + RHS.second->succ_size();
+ if (cl != cr)
+ return cl > cr;
+
+ // As a last resort, sort by block number.
+ return LHS.second->getNumber() < RHS.second->getNumber();
}
};
}
void SimpleRegisterCoalescing::CopyCoalesceInMBB(MachineBasicBlock *MBB,
std::vector<CopyRec> &TryAgain) {
- DEBUG(errs() << ((Value*)MBB->getBasicBlock())->getName() << ":\n");
+ DEBUG(dbgs() << MBB->getName() << ":\n");
std::vector<CopyRec> VirtCopies;
std::vector<CopyRec> PhysCopies;
// If this isn't a copy nor a extract_subreg, we can't join intervals.
unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
- if (Inst->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG) {
+ bool isInsUndef = false;
+ if (Inst->isExtractSubreg()) {
DstReg = Inst->getOperand(0).getReg();
SrcReg = Inst->getOperand(1).getReg();
- } else if (Inst->getOpcode() == TargetInstrInfo::INSERT_SUBREG ||
- Inst->getOpcode() == TargetInstrInfo::SUBREG_TO_REG) {
+ } else if (Inst->isInsertSubreg()) {
+ DstReg = Inst->getOperand(0).getReg();
+ SrcReg = Inst->getOperand(2).getReg();
+ if (Inst->getOperand(1).isUndef())
+ isInsUndef = true;
+ } else if (Inst->isInsertSubreg() || Inst->isSubregToReg()) {
DstReg = Inst->getOperand(0).getReg();
SrcReg = Inst->getOperand(2).getReg();
} else if (!tii_->isMoveInstr(*Inst, SrcReg, DstReg, SrcSubIdx, DstSubIdx))
bool SrcIsPhys = TargetRegisterInfo::isPhysicalRegister(SrcReg);
bool DstIsPhys = TargetRegisterInfo::isPhysicalRegister(DstReg);
- if (li_->hasInterval(SrcReg) && li_->getInterval(SrcReg).empty())
+ if (isInsUndef ||
+ (li_->hasInterval(SrcReg) && li_->getInterval(SrcReg).empty()))
ImpDefCopies.push_back(CopyRec(Inst, 0));
else if (SrcIsPhys || DstIsPhys)
PhysCopies.push_back(CopyRec(Inst, 0));
VirtCopies.push_back(CopyRec(Inst, 0));
}
- // Try coalescing implicit copies first, followed by copies to / from
- // physical registers, then finally copies from virtual registers to
- // virtual registers.
+ // Try coalescing implicit copies and insert_subreg <undef> first,
+ // followed by copies to / from physical registers, then finally copies
+ // from virtual registers to virtual registers.
for (unsigned i = 0, e = ImpDefCopies.size(); i != e; ++i) {
CopyRec &TheCopy = ImpDefCopies[i];
bool Again = false;
}
void SimpleRegisterCoalescing::joinIntervals() {
- DEBUG(errs() << "********** JOINING INTERVALS ***********\n");
+ DEBUG(dbgs() << "********** JOINING INTERVALS ***********\n");
std::vector<CopyRec> TryAgainList;
if (loopInfo->empty()) {
return !RegClassA->contains(RegB);
}
-/// lastRegisterUse - Returns the last use of the specific register between
-/// cycles Start and End or NULL if there are no uses.
+/// lastRegisterUse - Returns the last (non-debug) use of the specific register
+/// between cycles Start and End or NULL if there are no uses.
MachineOperand *
SimpleRegisterCoalescing::lastRegisterUse(SlotIndex Start,
SlotIndex End,
UseIdx = SlotIndex();
if (TargetRegisterInfo::isVirtualRegister(Reg)) {
MachineOperand *LastUse = NULL;
- for (MachineRegisterInfo::use_iterator I = mri_->use_begin(Reg),
- E = mri_->use_end(); I != E; ++I) {
+ for (MachineRegisterInfo::use_nodbg_iterator I = mri_->use_nodbg_begin(Reg),
+ E = mri_->use_nodbg_end(); I != E; ++I) {
MachineOperand &Use = I.getOperand();
MachineInstr *UseMI = Use.getParent();
unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
return NULL;
}
-
void SimpleRegisterCoalescing::printRegName(unsigned reg) const {
if (TargetRegisterInfo::isPhysicalRegister(reg))
- errs() << tri_->getName(reg);
+ dbgs() << tri_->getName(reg);
else
- errs() << "%reg" << reg;
+ dbgs() << "%reg" << reg;
}
void SimpleRegisterCoalescing::releaseMemory() {
ReMatDefs.clear();
}
-/// Returns true if the given live interval is zero length.
-static bool isZeroLengthInterval(LiveInterval *li, LiveIntervals *li_) {
- for (LiveInterval::Ranges::const_iterator
- i = li->ranges.begin(), e = li->ranges.end(); i != e; ++i)
- if (i->end.getPrevIndex() > i->start)
- return false;
- return true;
-}
-
-
-void SimpleRegisterCoalescing::CalculateSpillWeights() {
- SmallSet<unsigned, 4> Processed;
- for (MachineFunction::iterator mbbi = mf_->begin(), mbbe = mf_->end();
- mbbi != mbbe; ++mbbi) {
- MachineBasicBlock* MBB = mbbi;
- SlotIndex MBBEnd = li_->getMBBEndIdx(MBB);
- MachineLoop* loop = loopInfo->getLoopFor(MBB);
- unsigned loopDepth = loop ? loop->getLoopDepth() : 0;
- bool isExiting = loop ? loop->isLoopExiting(MBB) : false;
-
- for (MachineBasicBlock::const_iterator mii = MBB->begin(), mie = MBB->end();
- mii != mie; ++mii) {
- const MachineInstr *MI = mii;
- if (tii_->isIdentityCopy(*MI))
- continue;
-
- if (MI->getOpcode() == TargetInstrInfo::IMPLICIT_DEF)
- continue;
-
- for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
- const MachineOperand &mopi = MI->getOperand(i);
- if (!mopi.isReg() || mopi.getReg() == 0)
- continue;
- unsigned Reg = mopi.getReg();
- if (!TargetRegisterInfo::isVirtualRegister(mopi.getReg()))
- continue;
- // Multiple uses of reg by the same instruction. It should not
- // contribute to spill weight again.
- if (!Processed.insert(Reg))
- continue;
-
- bool HasDef = mopi.isDef();
- bool HasUse = !HasDef;
- for (unsigned j = i+1; j != e; ++j) {
- const MachineOperand &mopj = MI->getOperand(j);
- if (!mopj.isReg() || mopj.getReg() != Reg)
- continue;
- HasDef |= mopj.isDef();
- HasUse |= mopj.isUse();
- if (HasDef && HasUse)
- break;
- }
-
- LiveInterval &RegInt = li_->getInterval(Reg);
- float Weight = li_->getSpillWeight(HasDef, HasUse, loopDepth);
- if (HasDef && isExiting) {
- // Looks like this is a loop count variable update.
- SlotIndex DefIdx = li_->getInstructionIndex(MI).getDefIndex();
- const LiveRange *DLR =
- li_->getInterval(Reg).getLiveRangeContaining(DefIdx);
- if (DLR->end > MBBEnd)
- Weight *= 3.0F;
- }
- RegInt.weight += Weight;
- }
- Processed.clear();
- }
- }
-
- for (LiveIntervals::iterator I = li_->begin(), E = li_->end(); I != E; ++I) {
- LiveInterval &LI = *I->second;
- if (TargetRegisterInfo::isVirtualRegister(LI.reg)) {
- // If the live interval length is essentially zero, i.e. in every live
- // range the use follows def immediately, it doesn't make sense to spill
- // it and hope it will be easier to allocate for this li.
- if (isZeroLengthInterval(&LI, li_)) {
- LI.weight = HUGE_VALF;
- continue;
- }
-
- bool isLoad = false;
- SmallVector<LiveInterval*, 4> SpillIs;
- if (li_->isReMaterializable(LI, SpillIs, isLoad)) {
- // If all of the definitions of the interval are re-materializable,
- // it is a preferred candidate for spilling. If non of the defs are
- // loads, then it's potentially very cheap to re-materialize.
- // FIXME: this gets much more complicated once we support non-trivial
- // re-materialization.
- if (isLoad)
- LI.weight *= 0.9F;
- else
- LI.weight *= 0.5F;
- }
-
- // Slightly prefer live interval that has been assigned a preferred reg.
- 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
- // spilling of intervals that are large and have few uses, and
- // discourages spilling of small intervals with many uses.
- LI.weight /= li_->getApproximateInstructionCount(LI) * InstrSlots::NUM;
- }
- }
-}
-
-
bool SimpleRegisterCoalescing::runOnMachineFunction(MachineFunction &fn) {
mf_ = &fn;
mri_ = &fn.getRegInfo();
AA = &getAnalysis<AliasAnalysis>();
loopInfo = &getAnalysis<MachineLoopInfo>();
- DEBUG(errs() << "********** SIMPLE REGISTER COALESCING **********\n"
+ DEBUG(dbgs() << "********** SIMPLE REGISTER COALESCING **********\n"
<< "********** Function: "
<< ((Value*)mf_->getFunction())->getName() << '\n');
if (EnableJoining) {
joinIntervals();
DEBUG({
- errs() << "********** INTERVALS POST JOINING **********\n";
- for (LiveIntervals::iterator I = li_->begin(), E = li_->end(); I != E; ++I){
- I->second->print(errs(), tri_);
- errs() << "\n";
+ dbgs() << "********** INTERVALS POST JOINING **********\n";
+ for (LiveIntervals::iterator I = li_->begin(), E = li_->end();
+ I != E; ++I){
+ I->second->print(dbgs(), tri_);
+ dbgs() << "\n";
}
});
}
// Delete all coalesced copies.
bool DoDelete = true;
if (!tii_->isMoveInstr(*MI, SrcReg, DstReg, SrcSubIdx, DstSubIdx)) {
- assert((MI->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG ||
- MI->getOpcode() == TargetInstrInfo::INSERT_SUBREG ||
- MI->getOpcode() == TargetInstrInfo::SUBREG_TO_REG) &&
- "Unrecognized copy instruction");
+ assert((MI->isExtractSubreg() || MI->isInsertSubreg() ||
+ MI->isSubregToReg()) && "Unrecognized copy instruction");
DstReg = MI->getOperand(0).getReg();
if (TargetRegisterInfo::isPhysicalRegister(DstReg))
// Do not delete extract_subreg, insert_subreg of physical
DoDelete = true;
}
if (!DoDelete)
- mii = next(mii);
+ mii = llvm::next(mii);
else {
li_->RemoveMachineInstrFromMaps(MI);
mii = mbbi->erase(mii);
}
}
- CalculateSpillWeights();
-
DEBUG(dump());
return true;
}