- Change the horrible N^2 isRegReDefinedByTwoAddr. Now callers must supply the operand index of def machineoperand and at most one full scan of non-implicit operands is needed.

- Change local register allocator to use the new isRegReDefinedByTwoAddr instead of reinventing the wheel.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53394 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2008-07-10 07:35:43 +00:00
parent 5dcc41f5b3
commit ef0732d25a
5 changed files with 24 additions and 37 deletions

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@ -328,14 +328,14 @@ namespace llvm {
/// handleVirtualRegisterDef)
void handleRegisterDef(MachineBasicBlock *MBB,
MachineBasicBlock::iterator MI, unsigned MIIdx,
MachineOperand& MO);
MachineOperand& MO, unsigned MOIdx);
/// handleVirtualRegisterDef - update intervals for a virtual
/// register def
void handleVirtualRegisterDef(MachineBasicBlock *MBB,
MachineBasicBlock::iterator MI,
unsigned MIIdx, MachineOperand& MO,
LiveInterval& interval);
unsigned MOIdx, LiveInterval& interval);
/// handlePhysicalRegisterDef - update intervals for a physical register
/// def.

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@ -207,9 +207,9 @@ public:
/// none is found.
int findFirstPredOperandIdx() const;
/// isRegReDefinedByTwoAddr - Returns true if the Reg re-definition is due
/// to two addr elimination.
bool isRegReDefinedByTwoAddr(unsigned Reg) const;
/// isRegReDefinedByTwoAddr - Given the defined register and the operand index,
/// check if the register def is a re-definition due to two addr elimination.
bool isRegReDefinedByTwoAddr(unsigned Reg, unsigned DefIdx) const;
/// copyKillDeadInfo - Copies kill / dead operand properties from MI.
///

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@ -298,6 +298,7 @@ void LiveIntervals::printRegName(unsigned reg) const {
void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock *mbb,
MachineBasicBlock::iterator mi,
unsigned MIIdx, MachineOperand& MO,
unsigned MOIdx,
LiveInterval &interval) {
DOUT << "\t\tregister: "; DEBUG(printRegName(interval.reg));
LiveVariables::VarInfo& vi = lv_->getVarInfo(interval.reg);
@ -390,7 +391,7 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock *mbb,
// must be due to phi elimination or two addr elimination. If this is
// the result of two address elimination, then the vreg is one of the
// def-and-use register operand.
if (mi->isRegReDefinedByTwoAddr(interval.reg)) {
if (mi->isRegReDefinedByTwoAddr(interval.reg, MOIdx)) {
// If this is a two-address definition, then we have already processed
// the live range. The only problem is that we didn't realize there
// are actually two values in the live interval. Because of this we
@ -553,9 +554,10 @@ exit:
void LiveIntervals::handleRegisterDef(MachineBasicBlock *MBB,
MachineBasicBlock::iterator MI,
unsigned MIIdx,
MachineOperand& MO) {
MachineOperand& MO,
unsigned MOIdx) {
if (TargetRegisterInfo::isVirtualRegister(MO.getReg()))
handleVirtualRegisterDef(MBB, MI, MIIdx, MO,
handleVirtualRegisterDef(MBB, MI, MIIdx, MO, MOIdx,
getOrCreateInterval(MO.getReg()));
else if (allocatableRegs_[MO.getReg()]) {
MachineInstr *CopyMI = NULL;
@ -660,7 +662,7 @@ void LiveIntervals::computeIntervals() {
MachineOperand &MO = MI->getOperand(i);
// handle register defs - build intervals
if (MO.isRegister() && MO.getReg() && MO.isDef())
handleRegisterDef(MBB, MI, MIIndex, MO);
handleRegisterDef(MBB, MI, MIIndex, MO, i);
}
MIIndex += InstrSlots::NUM;

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@ -623,20 +623,15 @@ int MachineInstr::findFirstPredOperandIdx() const {
return -1;
}
/// isRegReDefinedByTwoAddr - Returns true if the Reg re-definition is due
/// to two addr elimination.
bool MachineInstr::isRegReDefinedByTwoAddr(unsigned Reg) const {
/// isRegReDefinedByTwoAddr - Given the defined register and the operand index,
/// check if the register def is a re-definition due to two addr elimination.
bool MachineInstr::isRegReDefinedByTwoAddr(unsigned Reg, unsigned DefIdx) const{
const TargetInstrDesc &TID = getDesc();
for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
const MachineOperand &MO1 = getOperand(i);
if (MO1.isRegister() && MO1.isDef() && MO1.getReg() == Reg) {
for (unsigned j = i+1; j < e; ++j) {
const MachineOperand &MO2 = getOperand(j);
if (MO2.isRegister() && MO2.isUse() && MO2.getReg() == Reg &&
TID.getOperandConstraint(j, TOI::TIED_TO) == (int)i)
return true;
}
}
for (unsigned i = 0, e = TID.getNumOperands(); i != e; ++i) {
const MachineOperand &MO = getOperand(i);
if (MO.isRegister() && MO.isUse() && MO.getReg() == Reg &&
TID.getOperandConstraint(i, TOI::TIED_TO) == (int)DefIdx)
return true;
}
return false;
}

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@ -604,25 +604,15 @@ void RALocal::ComputeLocalLiveness(MachineBasicBlock& MBB) {
if (last != LastUseDef.end()) {
// Check if this is a two address instruction. If so, then
// the def does not kill the use.
if (last->second.first == I) {
bool isTwoAddr = false;
for (unsigned j = i+1, je = I->getDesc().getNumOperands();
j < je; ++j) {
const MachineOperand &MO2 = I->getOperand(j);
if (MO2.isRegister() && MO2.isUse() &&
MO2.getReg() == MO.getReg() &&
I->getDesc().getOperandConstraint(j, TOI::TIED_TO) == (int)i)
isTwoAddr = true;
}
if (isTwoAddr) continue;
}
if (last->second.first == I &&
I->isRegReDefinedByTwoAddr(MO.getReg(), i))
continue;
MachineOperand& lastUD =
last->second.first->getOperand(last->second.second);
if (lastUD.isDef())
lastUD.setIsDead(true);
else if (lastUD.isUse())
else
lastUD.setIsKill(true);
}
@ -677,7 +667,7 @@ void RALocal::ComputeLocalLiveness(MachineBasicBlock& MBB) {
if (isPhysReg || !usedOutsideBlock) {
if (MO.isUse())
MO.setIsKill(true);
else if (MI->getOperand(idx).isDef())
else
MO.setIsDead(true);
}
}