for (const unsigned* SR = tri_->getSubRegisters(IntB.reg); *SR; ++SR)
if (li_->hasInterval(*SR) && IntA.overlaps(li_->getInterval(*SR))) {
DEBUG({
- dbgs() << "Interfere with sub-register ";
+ dbgs() << "\t\tInterfere with sub-register ";
li_->getInterval(*SR).print(dbgs(), tri_);
});
return false;
}
DEBUG({
- dbgs() << "\nExtending: ";
+ dbgs() << "Extending: ";
IntB.print(dbgs(), tri_);
});
// If the copy instruction was killing the destination register before the
// merge, find the last use and trim the live range. That will also add the
// isKill marker.
- if (CopyMI->killsRegister(IntA.reg))
+ if (ALR->valno->isKill(CopyIdx))
TrimLiveIntervalToLastUse(CopyUseIdx, CopyMI->getParent(), IntA, ALR);
++numExtends;
for (; BI != IntB.ranges.end() && AI->end >= BI->start; ++BI) {
if (BI->valno == BValNo)
continue;
+ // When BValNo is null, we're looking for a dummy clobber-value for a subreg.
+ if (!BValNo && !BI->valno->isDefAccurate() && !BI->valno->getCopy())
+ continue;
if (BI->start <= AI->start && BI->end > AI->start)
return true;
if (BI->start > AI->start && BI->start < AI->end)
if (HasOtherReachingDefs(IntA, IntB, AValNo, BValNo))
return false;
+ bool BHasSubRegs = false;
+ if (TargetRegisterInfo::isPhysicalRegister(IntB.reg))
+ BHasSubRegs = *tri_->getSubRegisters(IntB.reg);
+
+ // Abort if the subregisters of IntB.reg have values that are not simply the
+ // clobbers from the superreg.
+ if (BHasSubRegs)
+ for (const unsigned *SR = tri_->getSubRegisters(IntB.reg); *SR; ++SR)
+ if (HasOtherReachingDefs(IntA, li_->getInterval(*SR), AValNo, 0))
+ return false;
+
// 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_nodbg_iterator UI =
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();
unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
if (!tii_->isMoveInstr(*UseMI, SrcReg, DstReg, SrcSubIdx, DstSubIdx))
continue;
- if (DstReg == IntB.reg) {
+ if (DstReg == IntB.reg && DstSubIdx == 0) {
// 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.
// 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({
- dbgs() << "\nExtending: ";
+ dbgs() << "Extending: ";
IntB.print(dbgs(), tri_);
});
DEBUG({
dbgs() << " result = ";
IntB.print(dbgs(), tri_);
- dbgs() << '\n';
dbgs() << "\nShortening: ";
IntA.print(dbgs(), tri_);
});
LR->valno->addKill(LastUseIdx.getDefIndex());
unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
if (tii_->isMoveInstr(*LastUseMI, SrcReg, DstReg, SrcSubIdx, DstSubIdx) &&
- DstReg == li.reg) {
+ DstReg == li.reg && DstSubIdx == 0) {
// Last use is itself an identity code.
int DeadIdx = LastUseMI->findRegisterDefOperandIdx(li.reg, false, tri_);
LastUseMI->getOperand(DeadIdx).setIsDead();
// kill.
bool checkForDeadDef = false;
MachineBasicBlock *MBB = CopyMI->getParent();
- if (CopyMI->killsRegister(SrcInt.reg))
+ if (SrcLR->valno->isKill(DefIdx))
if (!TrimLiveIntervalToLastUse(CopyIdx, MBB, SrcInt, SrcLR)) {
checkForDeadDef = true;
}
unsigned CopySrcReg, CopyDstReg, CopySrcSubIdx, CopyDstSubIdx;
if (tii_->isMoveInstr(*UseMI, CopySrcReg, CopyDstReg,
CopySrcSubIdx, CopyDstSubIdx) &&
+ CopySrcSubIdx == 0 &&
+ CopyDstSubIdx == 0 &&
CopySrcReg != CopyDstReg &&
CopySrcReg == SrcReg && CopyDstReg != UseDstReg) {
// If the use is a copy and it won't be coalesced away, and its source
UseMI->isRegTiedToDefOperand(&O-&UseMI->getOperand(0))))
UseMI->addRegisterKilled(DstReg, tri_, true);
}
+ DEBUG(dbgs() << "\t\tupdated: " << li_->getInstructionIndex(UseMI)
+ << "\t" << *UseMI);
continue;
}
assert(OldSubIdx < SubIdx && "Conflicting sub-register index!");
else if (SubIdx)
O.setSubReg(SubIdx);
- // Remove would-be duplicated kill marker.
- if (O.isKill() && UseMI->killsRegister(DstReg))
- O.setIsKill(false);
O.setReg(DstReg);
+ DEBUG(dbgs() << "\t\tupdated: " << li_->getInstructionIndex(UseMI)
+ << "\t" << *UseMI);
+
// After updating the operand, check if the machine instruction has
// become a copy. If so, update its val# information.
if (JoinedCopies.count(UseMI))
}
}
-/// 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())
- continue;
- MachineInstr *UseMI = UseMO.getParent();
- SlotIndex UseIdx =
- li_->getInstructionIndex(UseMI).getUseIndex();
- const LiveRange *LR = LI.getLiveRangeContaining(UseIdx);
- if (!LR ||
- (!LR->valno->isKill(UseIdx.getDefIndex()) &&
- LR->valno->def != UseIdx.getDefIndex())) {
- // Interesting problem. After coalescing reg1027's def and kill are both
- // at the same point: %reg1027,0.000000e+00 = [56,814:0) 0@70-(814)
- //
- // bb5:
- // 60 %reg1027<def> = t2MOVr %reg1027, 14, %reg0, %reg0
- // 68 %reg1027<def> = t2LDRi12 %reg1027<kill>, 8, 14, %reg0
- // 76 t2CMPzri %reg1038<kill,undef>, 0, 14, %reg0, %CPSR<imp-def>
- // 84 %reg1027<def> = t2MOVr %reg1027, 14, %reg0, %reg0
- // 96 t2Bcc mbb<bb5,0x2030910>, 1, %CPSR<kill>
- //
- // Do not remove the kill marker on t2LDRi12.
- UseMO.setIsKill(false);
- }
- }
-}
-
/// removeIntervalIfEmpty - Check if the live interval of a physical register
/// is empty, if so remove it and also remove the empty intervals of its
/// sub-registers. Return true if live interval is removed.
unsigned Threshold = allocatableRCRegs_[RC].count() * 2;
unsigned Length = li_->getApproximateInstructionCount(DstInt);
if (Length > Threshold &&
- (((float)std::distance(mri_->use_nodbg_begin(DstInt.reg),
- mri_->use_nodbg_end()) / Length) <
- (1.0 / Threshold)))
+ std::distance(mri_->use_nodbg_begin(DstInt.reg),
+ mri_->use_nodbg_end()) * Threshold < Length)
return false;
// If the virtual register live interval extends into a loop, turn down
unsigned Threshold = allocatableRCRegs_[RC].count() * 2;
unsigned Length = li_->getApproximateInstructionCount(SrcInt);
if (Length > Threshold &&
- (((float)std::distance(mri_->use_nodbg_begin(SrcInt.reg),
- mri_->use_nodbg_end()) / Length) <
- (1.0 / Threshold)))
+ std::distance(mri_->use_nodbg_begin(SrcInt.reg),
+ mri_->use_nodbg_end()) * Threshold < Length)
return false;
if (SrcInt.empty())
mri_->use_nodbg_end());
unsigned DstUses = std::distance(mri_->use_nodbg_begin(DstReg),
mri_->use_nodbg_end());
- float NewDensity = ((float)(SrcUses + DstUses) / (SrcSize + DstSize)) /
- NewRCCount;
+ unsigned NewUses = SrcUses + DstUses;
+ unsigned NewSize = SrcSize + DstSize;
if (SrcRC != NewRC && SrcSize > NewRCCount) {
unsigned SrcRCCount = allocatableRCRegs_[SrcRC].count();
- float Density = ((float)SrcUses / SrcSize) / SrcRCCount;
- if (NewDensity > Density * 2.0f)
+ if (NewUses*SrcSize*SrcRCCount > 2*SrcUses*NewSize*NewRCCount)
return false;
}
if (DstRC != NewRC && DstSize > NewRCCount) {
unsigned DstRCCount = allocatableRCRegs_[DstRC].count();
- float Density = ((float)DstUses / DstSize) / DstRCCount;
- if (NewDensity > Density * 2.0f)
+ if (NewUses*DstSize*DstRCCount > 2*DstUses*NewSize*NewRCCount)
return false;
}
return true;
unsigned &RealDstReg) {
const TargetRegisterClass *RC = mri_->getRegClass(SrcReg);
RealDstReg = tri_->getMatchingSuperReg(DstReg, SubIdx, RC);
- assert(RealDstReg && "Invalid extract_subreg instruction!");
+ if (!RealDstReg) {
+ DEBUG(dbgs() << "\tIncompatible source regclass: "
+ << "none of the super-registers of " << tri_->getName(DstReg)
+ << " are in " << RC->getName() << ".\n");
+ return false;
+ }
LiveInterval &RHS = li_->getInterval(SrcReg);
// For this type of EXTRACT_SUBREG, conservatively
if (li_->hasInterval(RealDstReg) &&
RHS.overlaps(li_->getInterval(RealDstReg))) {
DEBUG({
- dbgs() << "Interfere with register ";
+ dbgs() << "\t\tInterfere with register ";
li_->getInterval(RealDstReg).print(dbgs(), tri_);
});
return false; // Not coalescable
!tri_->isSubRegister(DstReg, *SR) &&
li_->hasInterval(*SR) && RHS.overlaps(li_->getInterval(*SR))) {
DEBUG({
- dbgs() << "Interfere with sub-register ";
+ dbgs() << "\t\tInterfere with sub-register ";
li_->getInterval(*SR).print(dbgs(), tri_);
});
return false; // Not coalescable
unsigned &RealSrcReg) {
const TargetRegisterClass *RC = mri_->getRegClass(DstReg);
RealSrcReg = tri_->getMatchingSuperReg(SrcReg, SubIdx, RC);
- assert(RealSrcReg && "Invalid extract_subreg instruction!");
+ if (!RealSrcReg) {
+ DEBUG(dbgs() << "\tIncompatible destination regclass: "
+ << "none of the super-registers of " << tri_->getName(SrcReg)
+ << " are in " << RC->getName() << ".\n");
+ return false;
+ }
LiveInterval &LHS = li_->getInterval(DstReg);
if (li_->hasInterval(RealSrcReg) &&
LHS.overlaps(li_->getInterval(RealSrcReg))) {
DEBUG({
- dbgs() << "Interfere with register ";
+ dbgs() << "\t\tInterfere with register ";
li_->getInterval(RealSrcReg).print(dbgs(), tri_);
});
return false; // Not coalescable
!tri_->isSubRegister(SrcReg, *SR) &&
li_->hasInterval(*SR) && LHS.overlaps(li_->getInterval(*SR))) {
DEBUG({
- dbgs() << "Interfere with sub-register ";
+ dbgs() << "\t\tInterfere with sub-register ";
li_->getInterval(*SR).print(dbgs(), tri_);
});
return false; // Not coalescable
return false; // Not coalescable.
}
+ // We cannot handle dual subreg indices and mismatched classes at the same
+ // time.
+ if (SrcSubIdx && DstSubIdx && differingRegisterClasses(SrcReg, DstReg)) {
+ DEBUG(dbgs() << "\tCannot handle subreg indices and mismatched classes.\n");
+ return false;
+ }
+
// Check that a physical source register is compatible with dst regclass
if (SrcIsPhys) {
unsigned SrcSubReg = SrcSubIdx ?
assert(DstSubRC && "Illegal subregister index");
if (!DstSubRC->contains(SrcSubReg)) {
DEBUG(dbgs() << "\tIncompatible destination regclass: "
- << tri_->getName(SrcSubReg) << " not in "
+ << "none of the super-registers of "
+ << tri_->getName(SrcSubReg) << " are in "
<< DstSubRC->getName() << ".\n");
return false; // Not coalescable.
}
assert(SrcSubRC && "Illegal subregister index");
if (!SrcSubRC->contains(DstSubReg)) {
DEBUG(dbgs() << "\tIncompatible source regclass: "
- << tri_->getName(DstSubReg) << " not in "
+ << "none of the super-registers of "
+ << tri_->getName(DstSubReg) << " are in "
<< SrcSubRC->getName() << ".\n");
(void)DstSubReg;
return false; // Not coalescable.
}
if (!isWinToJoinCrossClass(SrcReg, DstReg, SrcRC, DstRC, NewRC)) {
- DEBUG(dbgs() << "\tAvoid coalescing to constrainted register class: "
+ DEBUG(dbgs() << "\tAvoid coalescing to constrained register class: "
<< SrcRC->getName() << "/"
<< DstRC->getName() << " -> "
<< NewRC->getName() << ".\n");
// class is more restrictive (fewer register, smaller size). Check if it's
// worth doing the merge.
if (!isWinToJoinCrossClass(SrcReg, DstReg, SrcRC, DstRC, NewRC)) {
- DEBUG(dbgs() << "\tAvoid coalescing to constrainted register class: "
+ DEBUG(dbgs() << "\tAvoid coalescing to constrained register class: "
<< SrcRC->getName() << "/"
<< DstRC->getName() << " -> "
<< NewRC->getName() << ".\n");
"Register mapping is horribly broken!");
DEBUG({
- dbgs() << "\t\tInspecting "; SrcInt.print(dbgs(), tri_);
- dbgs() << " and "; DstInt.print(dbgs(), tri_);
- dbgs() << ": ";
+ dbgs() << "\t\tInspecting ";
+ if (SrcRC) dbgs() << SrcRC->getName() << ": ";
+ SrcInt.print(dbgs(), tri_);
+ dbgs() << "\n\t\t and ";
+ if (DstRC) dbgs() << DstRC->getName() << ": ";
+ DstInt.print(dbgs(), tri_);
+ dbgs() << "\n";
});
// Save a copy of the virtual register live interval. We'll manually
const TargetRegisterClass *RC = mri_->getRegClass(JoinVReg);
unsigned Threshold = allocatableRCRegs_[RC].count() * 2;
unsigned Length = li_->getApproximateInstructionCount(JoinVInt);
- float Ratio = 1.0 / Threshold;
if (Length > Threshold &&
- (((float)std::distance(mri_->use_nodbg_begin(JoinVReg),
- mri_->use_nodbg_end()) / Length) < Ratio)) {
+ std::distance(mri_->use_nodbg_begin(JoinVReg),
+ mri_->use_nodbg_end()) * Threshold < Length) {
// Before giving up coalescing, if definition of source is defined by
// trivial computation, try rematerializing it.
if (ReMaterializeTrivialDef(SrcInt, DstReg, DstSubIdx, CopyMI))
// 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(dbgs() << "Not profitable!\n");
+ DEBUG(dbgs() << "\tNot profitable!\n");
return false;
}
} else if (!JoinIntervals(DstInt, SrcInt, Swapped)) {
(AdjustCopiesBackFrom(SrcInt, DstInt, CopyMI) ||
RemoveCopyByCommutingDef(SrcInt, DstInt, CopyMI))) {
JoinedCopies.insert(CopyMI);
- DEBUG(dbgs() << "Trivial!\n");
+ DEBUG(dbgs() << "\tTrivial!\n");
return true;
}
// Otherwise, we are unable to join the intervals.
- DEBUG(dbgs() << "Interference!\n");
+ DEBUG(dbgs() << "\tInterference!\n");
Again = true; // May be possible to coalesce later.
return false;
}
// 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);
-
UpdateRegDefsUses(SrcReg, DstReg, SubIdx);
// If we have extended the live range of a physical register, make sure we
}
DEBUG({
- dbgs() << "\n\t\tJoined. Result = ";
+ dbgs() << "\t\tJoined. Result = ";
ResDstInt->print(dbgs(), tri_);
dbgs() << "\n";
});
for (const unsigned* SR = tri_->getSubRegisters(LHS.reg); *SR; ++SR)
if (li_->hasInterval(*SR) && RHS.overlaps(li_->getInterval(*SR))) {
DEBUG({
- dbgs() << "Interfere with sub-register ";
+ dbgs() << "\tInterfere 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({
- dbgs() << "Interfere with sub-register ";
+ dbgs() << "\tInterfere with sub-register ";
li_->getInterval(*SR).print(dbgs(), tri_);
});
return false;
MachineInstr *UseMI = Use.getParent();
unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
if (tii_->isMoveInstr(*UseMI, SrcReg, DstReg, SrcSubIdx, DstSubIdx) &&
- SrcReg == DstReg)
+ SrcReg == DstReg && SrcSubIdx == DstSubIdx)
// Ignore identity copies.
continue;
SlotIndex Idx = li_->getInstructionIndex(UseMI);
// Ignore identity copies.
unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
if (!(tii_->isMoveInstr(*MI, SrcReg, DstReg, SrcSubIdx, DstSubIdx) &&
- SrcReg == DstReg))
+ SrcReg == DstReg && SrcSubIdx == DstSubIdx))
for (unsigned i = 0, NumOps = MI->getNumOperands(); i != NumOps; ++i) {
MachineOperand &Use = MI->getOperand(i);
if (Use.isReg() && Use.isUse() && Use.getReg() &&
return NULL;
}
-void SimpleRegisterCoalescing::printRegName(unsigned reg) const {
- if (TargetRegisterInfo::isPhysicalRegister(reg))
- dbgs() << tri_->getName(reg);
- else
- dbgs() << "%reg" << reg;
-}
-
void SimpleRegisterCoalescing::releaseMemory() {
JoinedCopies.clear();
ReMatCopies.clear();
// If the move will be an identity move delete it
bool isMove= tii_->isMoveInstr(*MI, SrcReg, DstReg, SrcSubIdx, DstSubIdx);
- if (isMove && SrcReg == DstReg) {
+ if (isMove && SrcReg == DstReg && SrcSubIdx == DstSubIdx) {
if (li_->hasInterval(SrcReg)) {
LiveInterval &RegInt = li_->getInterval(SrcReg);
// If def of this move instruction is dead, remove its live range
li_->RemoveMachineInstrFromMaps(MI);
mii = mbbi->erase(mii);
++numPeep;
- } else {
- ++mii;
+ continue;
+ }
+
+ ++mii;
+
+ // Check for now unnecessary kill flags.
+ if (li_->isNotInMIMap(MI)) continue;
+ SlotIndex UseIdx = li_->getInstructionIndex(MI).getUseIndex();
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ MachineOperand &MO = MI->getOperand(i);
+ if (!MO.isReg() || !MO.isKill()) continue;
+ unsigned reg = MO.getReg();
+ if (!reg || !li_->hasInterval(reg)) continue;
+ LiveInterval &LI = li_->getInterval(reg);
+ const LiveRange *LR = LI.getLiveRangeContaining(UseIdx);
+ if (!LR ||
+ (!LR->valno->isKill(UseIdx.getDefIndex()) &&
+ LR->valno->def != UseIdx.getDefIndex()))
+ MO.setIsKill(false);
}
}
}
projects / oota-llvm.git / blobdiff