// Get the location that B is defined at. Two options: either this value has
// an unknown definition point or it is defined at CopyIdx. If unknown, we
// can't process it.
- if (!BValNo->reg) return false;
- assert(BValNo->def == CopyIdx &&
- "Copy doesn't define the value?");
+ if (!BValNo->copy) return false;
+ assert(BValNo->def == CopyIdx && "Copy doesn't define the value?");
// AValNo is the value number in A that defines the copy, A3 in the example.
LiveInterval::iterator ALR = IntA.FindLiveRangeContaining(CopyIdx-1);
// If AValNo is defined as a copy from IntB, we can potentially process this.
// Get the instruction that defines this value number.
- unsigned SrcReg = AValNo->reg;
+ unsigned SrcReg = li_->getVNInfoSourceReg(AValNo);
if (!SrcReg) return false; // Not defined by a copy.
// If the value number is not defined by a copy instruction, ignore it.
-
+
// If the source register comes from an interval other than IntB, we can't
// handle this.
- if (rep(SrcReg) != IntB.reg) return false;
+ if (SrcReg != IntB.reg) return false;
// Get the LiveRange in IntB that this value number starts with.
LiveInterval::iterator ValLR = IntB.FindLiveRangeContaining(AValNo->def-1);
// 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
// instruction #.
- BValNo->def = FillerStart;
- BValNo->reg = 0;
+ BValNo->def = FillerStart;
+ BValNo->copy = NULL;
// Okay, we can merge them. We need to insert a new liverange:
// [ValLR.end, BLR.begin) of either value number, then we merge the
return true;
}
+/// HasOtherReachingDefs - Return true if there are definitions of IntB
+/// other than BValNo val# that can reach uses of AValno val# of IntA.
+bool SimpleRegisterCoalescing::HasOtherReachingDefs(LiveInterval &IntA,
+ LiveInterval &IntB,
+ VNInfo *AValNo,
+ VNInfo *BValNo) {
+ for (LiveInterval::iterator AI = IntA.begin(), AE = IntA.end();
+ AI != AE; ++AI) {
+ if (AI->valno != AValNo) continue;
+ LiveInterval::Ranges::iterator BI =
+ std::upper_bound(IntB.ranges.begin(), IntB.ranges.end(), AI->start);
+ if (BI != IntB.ranges.begin())
+ --BI;
+ for (; BI != IntB.ranges.end() && AI->end >= BI->start; ++BI) {
+ if (BI->valno == BValNo)
+ continue;
+ if (BI->start <= AI->start && BI->end > AI->start)
+ return true;
+ if (BI->start > AI->start && BI->start < AI->end)
+ return true;
+ }
+ }
+ return false;
+}
+
/// 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
unsigned CopyIdx = li_->getDefIndex(li_->getInstructionIndex(CopyMI));
- // BValNo is a value number in B that is defined by a copy from A. 'B3' in
+ // FIXME: For now, only eliminate the copy by commuting its def when the
+ // source register is a virtual register. We want to guard against cases
+ // where the copy is a back edge copy and commuting the def lengthen the
+ // live interval of the source register to the entire loop.
+ if (TargetRegisterInfo::isPhysicalRegister(IntA.reg))
+ return false;
+
+ // BValNo is a value number in B that is defined by a copy from A. 'B3' in
// the example above.
LiveInterval::iterator BLR = IntB.FindLiveRangeContaining(CopyIdx);
VNInfo *BValNo = BLR->valno;
// Get the location that B is defined at. Two options: either this value has
// an unknown definition point or it is defined at CopyIdx. If unknown, we
// can't process it.
- if (!BValNo->reg) return false;
+ if (!BValNo->copy) return false;
assert(BValNo->def == CopyIdx && "Copy doesn't define the value?");
// AValNo is the value number in A that defines the copy, A3 in the example.
LiveInterval::iterator ALR = IntA.FindLiveRangeContaining(CopyIdx-1);
VNInfo *AValNo = ALR->valno;
- if (AValNo->def == ~0U || AValNo->def == ~1U)
+ // 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)
return false;
MachineInstr *DefMI = li_->getInstructionFromIndex(AValNo->def);
const TargetInstrDesc &TID = DefMI->getDesc();
- if (!TID.isCommutable())
- return false;
- int Idx = -1;
- for (unsigned i = 0, e = DefMI->getNumOperands(); i != e; ++i) {
- MachineOperand &MO = DefMI->getOperand(i);
- if (!MO.isRegister()) continue;
- unsigned Reg = MO.getReg();
- if (Reg && TargetRegisterInfo::isVirtualRegister(Reg)) {
- if (rep(Reg) == IntA.reg) {
- // If the dest register comes from an interval other than IntA, we
- // can't handle this.
- if (Reg != IntA.reg)
- return false;
- continue;
- }
- if (Idx != -1)
- // FIXME: Being overly careful here. We just need to figure out the
- // which register operand will become the new def.
- return false;
- Idx = i;
- }
- }
- if (Idx == -1)
- // Something like %reg1024 = add %reg1024, %reg1024
+ unsigned NewDstIdx;
+ if (!TID.isCommutable() ||
+ !tii_->CommuteChangesDestination(DefMI, NewDstIdx))
return false;
- MachineOperand &MO = DefMI->getOperand(Idx);
- unsigned NewReg = MO.getReg();
- if (rep(NewReg) != IntB.reg || !MO.isKill())
+ MachineOperand &NewDstMO = DefMI->getOperand(NewDstIdx);
+ unsigned NewReg = NewDstMO.getReg();
+ if (NewReg != IntB.reg || !NewDstMO.isKill())
return false;
// Make sure there are no other definitions of IntB that would reach the
// uses which the new definition can reach.
- for (LiveInterval::iterator AI = IntA.begin(), AE = IntA.end();
- AI != AE; ++AI) {
- if (AI->valno != AValNo) continue;
- LiveInterval::Ranges::iterator BI =
- std::upper_bound(IntB.ranges.begin(), IntB.ranges.end(), AI->start);
- if (BI != IntB.ranges.begin())
- --BI;
- for (; BI != IntB.ranges.end() && AI->end >= BI->start; ++BI) {
- if (BI->valno == BLR->valno)
- continue;
- if (BI->start <= AI->start && BI->end > AI->start)
- return false;
- if (BI->start > AI->start && BI->start < AI->end)
- return false;
- }
- }
+ if (HasOtherReachingDefs(IntA, IntB, AValNo, BValNo))
+ return false;
- // Commute def machine instr.
+ // At this point we have decided that it is legal to do this
+ // transformation. Start by commuting the instruction.
MachineBasicBlock *MBB = DefMI->getParent();
MachineInstr *NewMI = tii_->commuteInstruction(DefMI);
+ if (!NewMI)
+ return false;
if (NewMI != DefMI) {
li_->ReplaceMachineInstrInMaps(DefMI, NewMI);
MBB->insert(DefMI, NewMI);
for (MachineRegisterInfo::use_iterator UI = mri_->use_begin(IntA.reg),
UE = mri_->use_end(); UI != UE;) {
MachineOperand &UseMO = UI.getOperand();
+ MachineInstr *UseMI = &*UI;
++UI;
- MachineInstr *UseMI = UseMO.getParent();
+ if (JoinedCopies.count(UseMI))
+ continue;
unsigned UseIdx = li_->getInstructionIndex(UseMI);
LiveInterval::iterator ULR = IntA.FindLiveRangeContaining(UseIdx);
if (ULR->valno != AValNo)
continue;
UseMO.setReg(NewReg);
+ if (UseMI == CopyMI)
+ continue;
if (UseMO.isKill())
BKills.push_back(li_->getUseIndex(UseIdx)+1);
- if (UseMI != CopyMI) {
- unsigned SrcReg, DstReg;
- if (!tii_->isMoveInstr(*UseMI, SrcReg, DstReg))
- continue;
- unsigned repDstReg = rep(DstReg);
- if (repDstReg != IntB.reg) {
- // Update dst register interval val# since its source register has
- // changed.
- LiveInterval &DLI = li_->getInterval(repDstReg);
- LiveInterval::iterator DLR =
- DLI.FindLiveRangeContaining(li_->getDefIndex(UseIdx));
- DLR->valno->reg = NewReg;
- ChangedCopies.insert(UseMI);
- } else {
- // This copy will become a noop. If it's defining a new val#,
- // remove that val# as well. However this live range is being
- // extended to the end of the existing live range defined by the copy.
- unsigned DefIdx = li_->getDefIndex(UseIdx);
- LiveInterval::iterator DLR = IntB.FindLiveRangeContaining(DefIdx);
- BHasPHIKill |= DLR->valno->hasPHIKill;
- assert(DLR->valno->def == DefIdx);
- BDeadValNos.push_back(DLR->valno);
- BExtend[DLR->start] = DLR->end;
- JoinedCopies.insert(UseMI);
- // If this is a kill but it's going to be removed, the last use
- // of the same val# is the new kill.
- if (UseMO.isKill()) {
- BKills.pop_back();
- }
+ unsigned SrcReg, DstReg;
+ if (!tii_->isMoveInstr(*UseMI, SrcReg, DstReg))
+ continue;
+ if (DstReg == IntB.reg) {
+ // This copy will become a noop. If it's defining a new val#,
+ // remove that val# as well. However this live range is being
+ // extended to the end of the existing live range defined by the copy.
+ unsigned DefIdx = li_->getDefIndex(UseIdx);
+ LiveInterval::iterator DLR = IntB.FindLiveRangeContaining(DefIdx);
+ BHasPHIKill |= DLR->valno->hasPHIKill;
+ assert(DLR->valno->def == DefIdx);
+ BDeadValNos.push_back(DLR->valno);
+ BExtend[DLR->start] = DLR->end;
+ JoinedCopies.insert(UseMI);
+ // If this is a kill but it's going to be removed, the last use
+ // of the same val# is the new kill.
+ if (UseMO.isKill()) {
+ BKills.pop_back();
}
}
}
return true;
}
-/// AddSubRegIdxPairs - Recursively mark all the registers represented by the
-/// specified register as sub-registers. The recursion level is expected to be
-/// shallow.
-void SimpleRegisterCoalescing::AddSubRegIdxPairs(unsigned Reg, unsigned SubIdx) {
- std::vector<unsigned> &JoinedRegs = r2rRevMap_[Reg];
- for (unsigned i = 0, e = JoinedRegs.size(); i != e; ++i) {
- SubRegIdxes.push_back(std::make_pair(JoinedRegs[i], SubIdx));
- AddSubRegIdxPairs(JoinedRegs[i], SubIdx);
+/// RemoveUnnecessaryKills - Remove kill markers that are no longer accurate
+/// due to live range lengthening as the result of coalescing.
+void SimpleRegisterCoalescing::RemoveUnnecessaryKills(unsigned Reg,
+ LiveInterval &LI) {
+ for (MachineRegisterInfo::use_iterator UI = mri_->use_begin(Reg),
+ UE = mri_->use_end(); UI != UE; ++UI) {
+ MachineOperand &UseMO = UI.getOperand();
+ if (UseMO.isKill()) {
+ MachineInstr *UseMI = UseMO.getParent();
+ unsigned UseIdx = li_->getUseIndex(li_->getInstructionIndex(UseMI));
+ if (JoinedCopies.count(UseMI))
+ continue;
+ LiveInterval::const_iterator UI = LI.FindLiveRangeContaining(UseIdx);
+ assert(UI != LI.end());
+ if (!LI.isKill(UI->valno, UseIdx+1))
+ UseMO.setIsKill(false);
+ }
}
}
if (MBB != L->getLoopLatch())
return false;
- DstReg = rep(DstReg);
LiveInterval &LI = li_->getInterval(DstReg);
unsigned DefIdx = li_->getInstructionIndex(CopyMI);
LiveInterval::const_iterator DstLR =
return false;
}
+/// UpdateRegDefsUses - Replace all defs and uses of SrcReg to DstReg and
+/// update the subregister number if it is not zero. If DstReg is a
+/// physical register and the existing subregister number of the def / use
+/// being updated is not zero, make sure to set it to the correct physical
+/// subregister.
+void
+SimpleRegisterCoalescing::UpdateRegDefsUses(unsigned SrcReg, unsigned DstReg,
+ unsigned SubIdx) {
+ bool DstIsPhys = TargetRegisterInfo::isPhysicalRegister(DstReg);
+ if (DstIsPhys && SubIdx) {
+ // Figure out the real physical register we are updating with.
+ DstReg = tri_->getSubReg(DstReg, SubIdx);
+ SubIdx = 0;
+ }
+
+ for (MachineRegisterInfo::reg_iterator I = mri_->reg_begin(SrcReg),
+ E = mri_->reg_end(); I != E; ) {
+ MachineOperand &O = I.getOperand();
+ ++I;
+ if (DstIsPhys) {
+ unsigned UseSubIdx = O.getSubReg();
+ unsigned UseDstReg = DstReg;
+ if (UseSubIdx)
+ UseDstReg = tri_->getSubReg(DstReg, UseSubIdx);
+ O.setReg(UseDstReg);
+ O.setSubReg(0);
+ } else {
+ unsigned OldSubIdx = O.getSubReg();
+ assert((!SubIdx || !OldSubIdx) && "Conflicting sub-register index!");
+ if (SubIdx)
+ O.setSubReg(SubIdx);
+ O.setReg(DstReg);
+ }
+ }
+}
+
/// 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;
- // Get representative registers.
- unsigned SrcReg = TheCopy.SrcReg;
- unsigned DstReg = TheCopy.DstReg;
-
- // CopyMI has been modified due to commuting.
- if (ChangedCopies.count(CopyMI)) {
- if (tii_->isMoveInstr(*CopyMI, SrcReg, DstReg))
- ;
- else if (CopyMI->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG) {
- DstReg = CopyMI->getOperand(0).getReg();
- SrcReg = CopyMI->getOperand(1).getReg();
- } else
- assert(0 && "Unrecognized move instruction!");
- TheCopy.SrcReg = SrcReg;
- TheCopy.DstReg = DstReg;
- ChangedCopies.erase(CopyMI);
+ unsigned SrcReg;
+ unsigned DstReg;
+ bool isExtSubReg = CopyMI->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG;
+ unsigned SubIdx = 0;
+ if (isExtSubReg) {
+ DstReg = CopyMI->getOperand(0).getReg();
+ SrcReg = CopyMI->getOperand(1).getReg();
+ } else if (!tii_->isMoveInstr(*CopyMI, SrcReg, DstReg)) {
+ assert(0 && "Unrecognized copy instruction!");
+ return false;
}
- unsigned repSrcReg = rep(SrcReg);
- unsigned repDstReg = rep(DstReg);
-
// If they are already joined we continue.
- if (repSrcReg == repDstReg) {
+ if (SrcReg == DstReg) {
DOUT << "\tCopy already coalesced.\n";
return false; // Not coalescable.
}
- bool SrcIsPhys = TargetRegisterInfo::isPhysicalRegister(repSrcReg);
- bool DstIsPhys = TargetRegisterInfo::isPhysicalRegister(repDstReg);
+ bool SrcIsPhys = TargetRegisterInfo::isPhysicalRegister(SrcReg);
+ bool DstIsPhys = TargetRegisterInfo::isPhysicalRegister(DstReg);
// If they are both physical registers, we cannot join them.
if (SrcIsPhys && DstIsPhys) {
}
// We only join virtual registers with allocatable physical registers.
- if (SrcIsPhys && !allocatableRegs_[repSrcReg]) {
+ if (SrcIsPhys && !allocatableRegs_[SrcReg]) {
DOUT << "\tSrc reg is unallocatable physreg.\n";
return false; // Not coalescable.
}
- if (DstIsPhys && !allocatableRegs_[repDstReg]) {
+ if (DstIsPhys && !allocatableRegs_[DstReg]) {
DOUT << "\tDst reg is unallocatable physreg.\n";
return false; // Not coalescable.
}
- bool isExtSubReg = CopyMI->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG;
unsigned RealDstReg = 0;
if (isExtSubReg) {
- unsigned SubIdx = CopyMI->getOperand(2).getImm();
- if (SrcIsPhys)
+ SubIdx = CopyMI->getOperand(2).getImm();
+ if (SrcIsPhys) {
// r1024 = EXTRACT_SUBREG EAX, 0 then r1024 is really going to be
// coalesced with AX.
- repSrcReg = tri_->getSubReg(repSrcReg, SubIdx);
- else if (DstIsPhys) {
+ SrcReg = tri_->getSubReg(SrcReg, SubIdx);
+ SubIdx = 0;
+ } else if (DstIsPhys) {
// If this is a extract_subreg where dst is a physical register, e.g.
// cl = EXTRACT_SUBREG reg1024, 1
// then create and update the actual physical register allocated to RHS.
- const TargetRegisterClass *RC = mri_->getRegClass(repSrcReg);
- for (const unsigned *SRs = tri_->getSuperRegisters(repDstReg);
+ const TargetRegisterClass *RC = mri_->getRegClass(SrcReg);
+ for (const unsigned *SRs = tri_->getSuperRegisters(DstReg);
unsigned SR = *SRs; ++SRs) {
- if (repDstReg == tri_->getSubReg(SR, SubIdx) &&
+ if (DstReg == tri_->getSubReg(SR, SubIdx) &&
RC->contains(SR)) {
RealDstReg = SR;
break;
// For this type of EXTRACT_SUBREG, conservatively
// check if the live interval of the source register interfere with the
// actual super physical register we are trying to coalesce with.
- LiveInterval &RHS = li_->getInterval(repSrcReg);
+ LiveInterval &RHS = li_->getInterval(SrcReg);
if (li_->hasInterval(RealDstReg) &&
RHS.overlaps(li_->getInterval(RealDstReg))) {
DOUT << "Interfere with register ";
DEBUG(li_->getInterval(*SR).print(DOUT, tri_));
return false; // Not coalescable
}
+ SubIdx = 0;
} else {
- unsigned SrcSize= li_->getInterval(repSrcReg).getSize() / InstrSlots::NUM;
- unsigned DstSize= li_->getInterval(repDstReg).getSize() / InstrSlots::NUM;
- const TargetRegisterClass *RC=mf_->getRegInfo().getRegClass(repDstReg);
+ unsigned SrcSize= li_->getInterval(SrcReg).getSize() / InstrSlots::NUM;
+ unsigned DstSize= li_->getInterval(DstReg).getSize() / InstrSlots::NUM;
+ const TargetRegisterClass *RC = mri_->getRegClass(DstReg);
unsigned Threshold = allocatableRCRegs_[RC].count();
// Be conservative. If both sides are virtual registers, do not coalesce
// if this will cause a high use density interval to target a smaller set
// of registers.
if (DstSize > Threshold || SrcSize > Threshold) {
- LiveVariables::VarInfo &svi = lv_->getVarInfo(repSrcReg);
- LiveVariables::VarInfo &dvi = lv_->getVarInfo(repDstReg);
+ LiveVariables::VarInfo &svi = lv_->getVarInfo(SrcReg);
+ LiveVariables::VarInfo &dvi = lv_->getVarInfo(DstReg);
if ((float)dvi.NumUses / DstSize < (float)svi.NumUses / SrcSize) {
Again = true; // May be possible to coalesce later.
return false;
}
}
}
- } else if (differingRegisterClasses(repSrcReg, repDstReg)) {
+ } else if (differingRegisterClasses(SrcReg, DstReg)) {
+ // FIXME: What if the resul of a EXTRACT_SUBREG is then coalesced
+ // with another? If it's the resulting destination register, then
+ // the subidx must be propagated to uses (but only those defined
+ // by the EXTRACT_SUBREG). If it's being coalesced into another
+ // register, it should be safe because register is assumed to have
+ // the register class of the super-register.
+
// If they are not of the same register class, we cannot join them.
DOUT << "\tSrc/Dest are different register classes.\n";
// Allow the coalescer to try again in case either side gets coalesced to
return false;
}
- LiveInterval &SrcInt = li_->getInterval(repSrcReg);
- LiveInterval &DstInt = li_->getInterval(repDstReg);
- assert(SrcInt.reg == repSrcReg && DstInt.reg == repDstReg &&
+ LiveInterval &SrcInt = li_->getInterval(SrcReg);
+ LiveInterval &DstInt = li_->getInterval(DstReg);
+ assert(SrcInt.reg == SrcReg && DstInt.reg == DstReg &&
"Register mapping is horribly broken!");
DOUT << "\t\tInspecting "; SrcInt.print(DOUT, tri_);
if (SrcEnd > li_->getDefIndex(CopyIdx)) {
isDead = false;
} else {
- MachineOperand *MOU;
- MachineInstr *LastUse= lastRegisterUse(SrcStart, CopyIdx, repSrcReg, MOU);
+ unsigned LastUseIdx;
+ MachineOperand *LastUse =
+ lastRegisterUse(SrcStart, CopyIdx, SrcReg, LastUseIdx);
if (LastUse) {
// Shorten the liveinterval to the end of last use.
- MOU->setIsKill();
+ LastUse->setIsKill();
isDead = false;
isShorten = true;
- RemoveStart = li_->getDefIndex(li_->getInstructionIndex(LastUse));
- RemoveEnd = SrcEnd;
+ RemoveStart = li_->getDefIndex(LastUseIdx);
+ RemoveEnd = SrcEnd;
} else {
MachineInstr *SrcMI = li_->getInstructionFromIndex(SrcStart);
if (SrcMI) {
- MachineOperand *mops = findDefOperand(SrcMI, repSrcReg);
+ MachineOperand *mops = findDefOperand(SrcMI, SrcReg);
if (mops)
// A dead def should have a single cycle interval.
++RemoveStart;
// think twice about coalescing them!
if (!mopd->isDead() && (SrcIsPhys || DstIsPhys) && !isExtSubReg) {
LiveInterval &JoinVInt = SrcIsPhys ? DstInt : SrcInt;
- unsigned JoinVReg = SrcIsPhys ? repDstReg : repSrcReg;
- unsigned JoinPReg = SrcIsPhys ? repSrcReg : repDstReg;
- const TargetRegisterClass *RC = mf_->getRegInfo().getRegClass(JoinVReg);
+ 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 (isDead) {
// Result of the copy is dead. Propagate this property.
if (SrcStart == 0) {
- assert(TargetRegisterInfo::isPhysicalRegister(repSrcReg) &&
+ assert(TargetRegisterInfo::isPhysicalRegister(SrcReg) &&
"Live-in must be a physical register!");
// Live-in to the function but dead. Remove it from entry live-in set.
// JoinIntervals may end up swapping the two intervals.
- mf_->begin()->removeLiveIn(repSrcReg);
+ mf_->begin()->removeLiveIn(SrcReg);
} else {
MachineInstr *SrcMI = li_->getInstructionFromIndex(SrcStart);
if (SrcMI) {
- MachineOperand *mops = findDefOperand(SrcMI, repSrcReg);
+ MachineOperand *mops = findDefOperand(SrcMI, SrcReg);
if (mops)
mops->setIsDead();
}
return true;
}
-
// Otherwise, we are unable to join the intervals.
DOUT << "Interference!\n";
Again = true; // May be possible to coalesce later.
LiveInterval *ResSrcInt = &SrcInt;
LiveInterval *ResDstInt = &DstInt;
if (Swapped) {
- std::swap(repSrcReg, repDstReg);
+ std::swap(SrcReg, DstReg);
std::swap(ResSrcInt, ResDstInt);
}
- assert(TargetRegisterInfo::isVirtualRegister(repSrcReg) &&
+ assert(TargetRegisterInfo::isVirtualRegister(SrcReg) &&
"LiveInterval::join didn't work right!");
// If we're about to merge live ranges into a physical register live range,
// we have to update any aliased register's live ranges to indicate that they
// have clobbered values for this range.
- if (TargetRegisterInfo::isPhysicalRegister(repDstReg)) {
+ if (TargetRegisterInfo::isPhysicalRegister(DstReg)) {
// Unset unnecessary kills.
if (!ResDstInt->containsOneValue()) {
for (LiveInterval::Ranges::const_iterator I = ResSrcInt->begin(),
E = ResSrcInt->end(); I != E; ++I)
- unsetRegisterKills(I->start, I->end, repDstReg);
+ unsetRegisterKills(I->start, I->end, DstReg);
}
// If this is a extract_subreg where dst is a physical register, e.g.
assert(DstLR != ResDstInt->end() && "Invalid joined interval!");
const VNInfo *DstValNo = DstLR->valno;
if (CopiedValNos.insert(DstValNo)) {
- VNInfo *ValNo = RealDstInt.getNextValue(DstValNo->def, DstValNo->reg,
+ VNInfo *ValNo = RealDstInt.getNextValue(DstValNo->def, DstValNo->copy,
li_->getVNInfoAllocator());
ValNo->hasPHIKill = DstValNo->hasPHIKill;
RealDstInt.addKills(ValNo, DstValNo->kills);
RealDstInt.MergeValueInAsValue(*ResDstInt, DstValNo, ValNo);
}
}
- repDstReg = RealDstReg;
+ DstReg = RealDstReg;
}
// Update the liveintervals of sub-registers.
- for (const unsigned *AS = tri_->getSubRegisters(repDstReg); *AS; ++AS)
+ for (const unsigned *AS = tri_->getSubRegisters(DstReg); *AS; ++AS)
li_->getOrCreateInterval(*AS).MergeInClobberRanges(*ResSrcInt,
li_->getVNInfoAllocator());
} else {
// Merge use info if the destination is a virtual register.
- LiveVariables::VarInfo& dVI = lv_->getVarInfo(repDstReg);
- LiveVariables::VarInfo& sVI = lv_->getVarInfo(repSrcReg);
+ LiveVariables::VarInfo& dVI = lv_->getVarInfo(DstReg);
+ LiveVariables::VarInfo& sVI = lv_->getVarInfo(SrcReg);
dVI.NumUses += sVI.NumUses;
}
- // Remember these liveintervals have been joined.
- JoinedLIs.set(repSrcReg - TargetRegisterInfo::FirstVirtualRegister);
- if (TargetRegisterInfo::isVirtualRegister(repDstReg))
- JoinedLIs.set(repDstReg - TargetRegisterInfo::FirstVirtualRegister);
-
+ // If this is a EXTRACT_SUBREG, make sure the result of coalescing is the
+ // larger super-register.
if (isExtSubReg && !SrcIsPhys && !DstIsPhys) {
if (!Swapped) {
- // Make sure we allocate the larger super-register.
ResSrcInt->Copy(*ResDstInt, li_->getVNInfoAllocator());
- std::swap(repSrcReg, repDstReg);
+ std::swap(SrcReg, DstReg);
std::swap(ResSrcInt, ResDstInt);
}
- unsigned SubIdx = CopyMI->getOperand(2).getImm();
- SubRegIdxes.push_back(std::make_pair(repSrcReg, SubIdx));
- AddSubRegIdxPairs(repSrcReg, SubIdx);
}
if (NewHeuristic) {
+ // Add all copies that define val# in the source interval into the queue.
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) {
- MachineInstr *CopyMI = li_->getInstructionFromIndex(vni->def);
- unsigned SrcReg, DstReg;
- if (CopyMI &&
- JoinedCopies.count(CopyMI) == 0 &&
- tii_->isMoveInstr(*CopyMI, SrcReg, DstReg)) {
- unsigned LoopDepth = loopInfo->getLoopDepth(CopyMI->getParent());
- JoinQueue->push(CopyRec(CopyMI, SrcReg, DstReg, LoopDepth,
- isBackEdgeCopy(CopyMI, DstReg)));
- }
+ if (!vni->def || vni->def == ~1U || vni->def == ~0U)
+ continue;
+ MachineInstr *CopyMI = li_->getInstructionFromIndex(vni->def);
+ unsigned NewSrcReg, NewDstReg;
+ if (CopyMI &&
+ JoinedCopies.count(CopyMI) == 0 &&
+ tii_->isMoveInstr(*CopyMI, NewSrcReg, NewDstReg)) {
+ unsigned LoopDepth = loopInfo->getLoopDepth(CopyMI->getParent());
+ JoinQueue->push(CopyRec(CopyMI, LoopDepth,
+ isBackEdgeCopy(CopyMI, DstReg)));
}
}
}
DOUT << "\n\t\tJoined. Result = "; ResDstInt->print(DOUT, tri_);
DOUT << "\n";
- // repSrcReg is guarateed to be the register whose live interval that is
+ // Remember to delete the copy instruction.
+ JoinedCopies.insert(CopyMI);
+
+ // Some live range has been lengthened due to colaescing, eliminate the
+ // unnecessary kills.
+ RemoveUnnecessaryKills(SrcReg, *ResDstInt);
+ if (TargetRegisterInfo::isVirtualRegister(DstReg))
+ RemoveUnnecessaryKills(DstReg, *ResDstInt);
+
+ // SrcReg is guarateed to be the register whose live interval that is
// being merged.
- li_->removeInterval(repSrcReg);
- r2rMap_[repSrcReg] = repDstReg;
- r2rRevMap_[repDstReg].push_back(repSrcReg);
+ li_->removeInterval(SrcReg);
+ UpdateRegDefsUses(SrcReg, DstReg, SubIdx);
- // Finally, delete the copy instruction.
- JoinedCopies.insert(CopyMI);
++numJoins;
return true;
}
// If we haven't already recorded that this value # is safe, check it.
if (!InVector(LHSIt->valno, EliminatedLHSVals)) {
// Copy from the RHS?
- unsigned SrcReg = LHSIt->valno->reg;
- if (rep(SrcReg) != RHS.reg)
+ unsigned SrcReg = li_->getVNInfoSourceReg(LHSIt->valno);
+ if (SrcReg != RHS.reg)
return false; // Nope, bail out.
EliminatedLHSVals.push_back(LHSIt->valno);
} else {
// Otherwise, if this is a copy from the RHS, mark it as being merged
// in.
- if (rep(LHSIt->valno->reg) == RHS.reg) {
+ if (li_->getVNInfoSourceReg(LHSIt->valno) == RHS.reg) {
EliminatedLHSVals.push_back(LHSIt->valno);
// We know this entire LHS live range is okay, so skip it now.
// RHS into, update the value number info for the LHS to indicate that the
// value number is defined where the RHS value number was.
const VNInfo *VNI = RHS.getValNumInfo(0);
- LHSValNo->def = VNI->def;
- LHSValNo->reg = VNI->reg;
+ LHSValNo->def = VNI->def;
+ LHSValNo->copy = VNI->copy;
// Okay, the final step is to loop over the RHS live intervals, adding them to
// the LHS.
int RHSValID = -1;
VNInfo *RHSValNoInfo = NULL;
VNInfo *RHSValNoInfo0 = RHS.getValNumInfo(0);
- unsigned RHSSrcReg = RHSValNoInfo0->reg;
- if ((RHSSrcReg == 0 || rep(RHSSrcReg) != LHS.reg)) {
+ unsigned RHSSrcReg = li_->getVNInfoSourceReg(RHSValNoInfo0);
+ if ((RHSSrcReg == 0 || RHSSrcReg != LHS.reg)) {
// If RHS is not defined as a copy from the LHS, we can use simpler and
// faster checks to see if the live ranges are coalescable. This joiner
// can't swap the LHS/RHS intervals though.
i != e; ++i) {
VNInfo *VNI = *i;
unsigned VN = VNI->id;
- if (unsigned LHSSrcReg = VNI->reg) {
- if (rep(LHSSrcReg) != RHS.reg) {
+ if (unsigned LHSSrcReg = li_->getVNInfoSourceReg(VNI)) {
+ if (LHSSrcReg != RHS.reg) {
// If this is not a copy from the RHS, its value number will be
// unmodified by the coalescing.
NewVNInfo[VN] = VNI;
for (LiveInterval::vni_iterator i = LHS.vni_begin(), e = LHS.vni_end();
i != e; ++i) {
VNInfo *VNI = *i;
- unsigned ValSrcReg = VNI->reg;
- if (VNI->def == ~1U ||ValSrcReg == 0) // Src not defined by a copy?
+ if (VNI->def == ~1U || 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
// from the RHS interval, we can use its value #.
- if (rep(ValSrcReg) != RHS.reg)
+ if (li_->getVNInfoSourceReg(VNI) != RHS.reg)
continue;
// Figure out the value # from the RHS.
for (LiveInterval::vni_iterator i = RHS.vni_begin(), e = RHS.vni_end();
i != e; ++i) {
VNInfo *VNI = *i;
- unsigned ValSrcReg = VNI->reg;
- if (VNI->def == ~1U || ValSrcReg == 0) // Src not defined by a copy?
+ if (VNI->def == ~1U || 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
// from the LHS interval, we can use its value #.
- if (rep(ValSrcReg) != LHS.reg)
+ if (li_->getVNInfoSourceReg(VNI) != LHS.reg)
continue;
// Figure out the value # from the LHS.
// Inner loops first.
if (left.LoopDepth > right.LoopDepth)
return false;
- else if (left.LoopDepth == right.LoopDepth) {
+ else if (left.LoopDepth == right.LoopDepth)
if (left.isBackEdge && !right.isBackEdge)
return false;
- else if (left.isBackEdge == right.isBackEdge) {
- // Join virtuals to physical registers first.
- bool LDstIsPhys = TargetRegisterInfo::isPhysicalRegister(left.DstReg);
- bool LSrcIsPhys = TargetRegisterInfo::isPhysicalRegister(left.SrcReg);
- bool LIsPhys = LDstIsPhys || LSrcIsPhys;
- bool RDstIsPhys = TargetRegisterInfo::isPhysicalRegister(right.DstReg);
- bool RSrcIsPhys = TargetRegisterInfo::isPhysicalRegister(right.SrcReg);
- bool RIsPhys = RDstIsPhys || RSrcIsPhys;
- if (LIsPhys && !RIsPhys)
- return false;
- else if (LIsPhys == RIsPhys) {
- // Join shorter intervals first.
- unsigned LSize = 0;
- unsigned RSize = 0;
- if (LIsPhys) {
- LSize = LDstIsPhys ? 0 : JPQ->getRepIntervalSize(left.DstReg);
- LSize += LSrcIsPhys ? 0 : JPQ->getRepIntervalSize(left.SrcReg);
- RSize = RDstIsPhys ? 0 : JPQ->getRepIntervalSize(right.DstReg);
- RSize += RSrcIsPhys ? 0 : JPQ->getRepIntervalSize(right.SrcReg);
- } else {
- LSize = std::min(JPQ->getRepIntervalSize(left.DstReg),
- JPQ->getRepIntervalSize(left.SrcReg));
- RSize = std::min(JPQ->getRepIntervalSize(right.DstReg),
- JPQ->getRepIntervalSize(right.SrcReg));
- }
- if (LSize < RSize)
- return false;
- }
- }
- }
return true;
}
} else if (!tii_->isMoveInstr(*Inst, SrcReg, DstReg))
continue;
- unsigned repSrcReg = rep(SrcReg);
- unsigned repDstReg = rep(DstReg);
- bool SrcIsPhys = TargetRegisterInfo::isPhysicalRegister(repSrcReg);
- bool DstIsPhys = TargetRegisterInfo::isPhysicalRegister(repDstReg);
+ bool SrcIsPhys = TargetRegisterInfo::isPhysicalRegister(SrcReg);
+ bool DstIsPhys = TargetRegisterInfo::isPhysicalRegister(DstReg);
if (NewHeuristic) {
- JoinQueue->push(CopyRec(Inst, SrcReg, DstReg, LoopDepth,
- isBackEdgeCopy(Inst, DstReg)));
+ JoinQueue->push(CopyRec(Inst, LoopDepth, isBackEdgeCopy(Inst, DstReg)));
} else {
if (SrcIsPhys || DstIsPhys)
- PhysCopies.push_back(CopyRec(Inst, SrcReg, DstReg, 0, false));
+ PhysCopies.push_back(CopyRec(Inst, 0, false));
else
- VirtCopies.push_back(CopyRec(Inst, SrcReg, DstReg, 0, false));
+ VirtCopies.push_back(CopyRec(Inst, 0, false));
}
}
if (NewHeuristic)
JoinQueue = new JoinPriorityQueue<CopyRecSort>(this);
- JoinedLIs.resize(li_->getNumIntervals());
- JoinedLIs.reset();
-
std::vector<CopyRec> TryAgainList;
if (loopInfo->begin() == loopInfo->end()) {
// If there are no loops in the function, join intervals in function order.
}
}
- // Some live range has been lengthened due to colaescing, eliminate the
- // unnecessary kills.
- int RegNum = JoinedLIs.find_first();
- while (RegNum != -1) {
- unsigned Reg = RegNum + TargetRegisterInfo::FirstVirtualRegister;
- unsigned repReg = rep(Reg);
- LiveInterval &LI = li_->getInterval(repReg);
- LiveVariables::VarInfo& svi = lv_->getVarInfo(Reg);
- for (unsigned i = 0, e = svi.Kills.size(); i != e; ++i) {
- MachineInstr *Kill = svi.Kills[i];
- // Suppose vr1 = op vr2, x
- // and vr1 and vr2 are coalesced. vr2 should still be marked kill
- // unless it is a two-address operand.
- if (li_->isRemoved(Kill) || hasRegisterDef(Kill, repReg))
- continue;
- if (LI.liveAt(li_->getInstructionIndex(Kill) + InstrSlots::NUM))
- unsetRegisterKill(Kill, repReg);
- }
- RegNum = JoinedLIs.find_next(RegNum);
- }
-
if (NewHeuristic)
- delete JoinQueue;
-
- DOUT << "*** Register mapping ***\n";
- for (unsigned i = 0, e = r2rMap_.size(); i != e; ++i)
- if (r2rMap_[i]) {
- DOUT << " reg " << i << " -> ";
- DEBUG(printRegName(r2rMap_[i]));
- DOUT << "\n";
- }
+ delete JoinQueue;
}
/// Return true if the two specified registers belong to different register
if (TargetRegisterInfo::isPhysicalRegister(RegA)) {
assert(TargetRegisterInfo::isVirtualRegister(RegB) &&
"Shouldn't consider two physregs!");
- return !mf_->getRegInfo().getRegClass(RegB)->contains(RegA);
+ return !mri_->getRegClass(RegB)->contains(RegA);
}
// Compare against the regclass for the second reg.
- const TargetRegisterClass *RegClass = mf_->getRegInfo().getRegClass(RegA);
+ const TargetRegisterClass *RegClass = mri_->getRegClass(RegA);
if (TargetRegisterInfo::isVirtualRegister(RegB))
- return RegClass != mf_->getRegInfo().getRegClass(RegB);
+ return RegClass != mri_->getRegClass(RegB);
else
return !RegClass->contains(RegB);
}
-/// FIXME: Make use MachineRegisterInfo use information for virtual registers.
/// lastRegisterUse - Returns the last use of the specific register between
-/// cycles Start and End. It also returns the use operand by reference. It
-/// returns NULL if there are no uses.
-MachineInstr *
+/// cycles Start and End or NULL if there are no uses.
+MachineOperand *
SimpleRegisterCoalescing::lastRegisterUse(unsigned Start, unsigned End,
- unsigned Reg, MachineOperand *&MOU) {
+ unsigned Reg, unsigned &UseIdx) const{
+ UseIdx = 0;
+ if (TargetRegisterInfo::isVirtualRegister(Reg)) {
+ MachineOperand *LastUse = NULL;
+ for (MachineRegisterInfo::use_iterator I = mri_->use_begin(Reg),
+ E = mri_->use_end(); I != E; ++I) {
+ MachineOperand &Use = I.getOperand();
+ MachineInstr *UseMI = Use.getParent();
+ unsigned Idx = li_->getInstructionIndex(UseMI);
+ if (Idx >= Start && Idx < End && Idx >= UseIdx) {
+ LastUse = &Use;
+ UseIdx = Idx;
+ }
+ }
+ return LastUse;
+ }
+
int e = (End-1) / InstrSlots::NUM * InstrSlots::NUM;
int s = Start;
while (e >= s) {
return NULL;
for (unsigned i = 0, NumOps = MI->getNumOperands(); i != NumOps; ++i) {
- MachineOperand &MO = MI->getOperand(i);
- if (MO.isRegister() && MO.isUse() && MO.getReg() &&
- tri_->regsOverlap(rep(MO.getReg()), Reg)) {
- MOU = &MO;
- return MI;
+ MachineOperand &Use = MI->getOperand(i);
+ if (Use.isRegister() && Use.isUse() && Use.getReg() &&
+ tri_->regsOverlap(Use.getReg(), Reg)) {
+ UseIdx = e;
+ return &Use;
}
}
/// findDefOperand - Returns the MachineOperand that is a def of the specific
/// register. It returns NULL if the def is not found.
MachineOperand *SimpleRegisterCoalescing::findDefOperand(MachineInstr *MI,
- unsigned Reg) {
+ unsigned Reg) const {
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
MachineOperand &MO = MI->getOperand(i);
if (MO.isRegister() && MO.isDef() &&
- tri_->regsOverlap(rep(MO.getReg()), Reg))
+ tri_->regsOverlap(MO.getReg(), Reg))
return &MO;
}
return NULL;
}
-/// unsetRegisterKill - Unset IsKill property of all uses of specific register
-/// of the specific instruction.
-void SimpleRegisterCoalescing::unsetRegisterKill(MachineInstr *MI,
- unsigned Reg) {
- for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
- MachineOperand &MO = MI->getOperand(i);
- if (MO.isRegister() && MO.isKill() && MO.getReg() &&
- tri_->regsOverlap(rep(MO.getReg()), Reg))
- MO.setIsKill(false);
- }
-}
-
/// unsetRegisterKills - Unset IsKill property of all uses of specific register
/// between cycles Start and End.
void SimpleRegisterCoalescing::unsetRegisterKills(unsigned Start, unsigned End,
for (unsigned i = 0, NumOps = MI->getNumOperands(); i != NumOps; ++i) {
MachineOperand &MO = MI->getOperand(i);
if (MO.isRegister() && MO.isKill() && MO.getReg() &&
- tri_->regsOverlap(rep(MO.getReg()), Reg)) {
+ tri_->regsOverlap(MO.getReg(), Reg)) {
MO.setIsKill(false);
}
}
}
}
-/// hasRegisterDef - True if the instruction defines the specific register.
-///
-bool SimpleRegisterCoalescing::hasRegisterDef(MachineInstr *MI, unsigned Reg) {
- for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
- MachineOperand &MO = MI->getOperand(i);
- if (MO.isRegister() && MO.isDef() &&
- tri_->regsOverlap(rep(MO.getReg()), Reg))
- return true;
- }
- return false;
-}
-
void SimpleRegisterCoalescing::printRegName(unsigned reg) const {
if (TargetRegisterInfo::isPhysicalRegister(reg))
cerr << tri_->getName(reg);
}
void SimpleRegisterCoalescing::releaseMemory() {
- for (unsigned i = 0, e = r2rMap_.size(); i != e; ++i)
- r2rRevMap_[i].clear();
- r2rRevMap_.clear();
- r2rMap_.clear();
- JoinedLIs.clear();
- SubRegIdxes.clear();
JoinedCopies.clear();
- ChangedCopies.clear();
}
static bool isZeroLengthInterval(LiveInterval *li) {
allocatableRCRegs_.insert(std::make_pair(*I,
tri_->getAllocatableSet(fn, *I)));
- MachineRegisterInfo &RegInfo = mf_->getRegInfo();
- r2rMap_.grow(RegInfo.getLastVirtReg());
- r2rRevMap_.grow(RegInfo.getLastVirtReg());
-
// Join (coalesce) intervals if requested.
- IndexedMap<unsigned, VirtReg2IndexFunctor> RegSubIdxMap;
if (EnableJoining) {
joinIntervals();
DOUT << "********** INTERVALS POST JOINING **********\n";
(*I)->eraseFromParent();
++numPeep;
}
-
- // Transfer sub-registers info to MachineRegisterInfo now that coalescing
- // information is complete.
- RegSubIdxMap.grow(RegInfo.getLastVirtReg()+1);
- while (!SubRegIdxes.empty()) {
- std::pair<unsigned, unsigned> RI = SubRegIdxes.back();
- SubRegIdxes.pop_back();
- RegSubIdxMap[RI.first] = RI.second;
- }
}
- // perform a final pass over the instructions and compute spill
- // weights, coalesce virtual registers and remove identity moves.
+ // Perform a final pass over the instructions and compute spill weights
+ // and remove identity moves.
for (MachineFunction::iterator mbbi = mf_->begin(), mbbe = mf_->end();
mbbi != mbbe; ++mbbi) {
MachineBasicBlock* mbb = mbbi;
for (MachineBasicBlock::iterator mii = mbb->begin(), mie = mbb->end();
mii != mie; ) {
// if the move will be an identity move delete it
- unsigned srcReg, dstReg, RegRep;
- if (tii_->isMoveInstr(*mii, srcReg, dstReg) &&
- (RegRep = rep(srcReg)) == rep(dstReg)) {
+ unsigned srcReg, dstReg;
+ if (tii_->isMoveInstr(*mii, srcReg, dstReg) && srcReg == dstReg) {
// remove from def list
- LiveInterval &RegInt = li_->getOrCreateInterval(RegRep);
+ LiveInterval &RegInt = li_->getOrCreateInterval(srcReg);
MachineOperand *MO = mii->findRegisterDefOperand(dstReg);
// If def of this move instruction is dead, remove its live range from
// the dstination register's live interval.
LiveInterval::iterator MLR = RegInt.FindLiveRangeContaining(MoveIdx);
RegInt.removeRange(MLR->start, MoveIdx+1, true);
if (RegInt.empty())
- li_->removeInterval(RegRep);
+ li_->removeInterval(srcReg);
}
li_->RemoveMachineInstrFromMaps(mii);
mii = mbbi->erase(mii);
const MachineOperand &mop = mii->getOperand(i);
if (mop.isRegister() && mop.getReg() &&
TargetRegisterInfo::isVirtualRegister(mop.getReg())) {
- // replace register with representative register
- unsigned OrigReg = mop.getReg();
- unsigned reg = rep(OrigReg);
- unsigned SubIdx = RegSubIdxMap[OrigReg];
- if (SubIdx && TargetRegisterInfo::isPhysicalRegister(reg))
- mii->getOperand(i).setReg(tri_->getSubReg(reg, SubIdx));
- else {
- mii->getOperand(i).setReg(reg);
- mii->getOperand(i).setSubReg(SubIdx);
- }
-
+ unsigned reg = mop.getReg();
// Multiple uses of reg by the same instruction. It should not
// contribute to spill weight again.
if (UniqueUses.count(reg) != 0)
projects / oota-llvm.git / blobdiff