// Pointer to the next DomainValue in a chain. When two DomainValues are
// merged, Victim.Next is set to point to Victor, so old DomainValue
- // references can be updated by folowing the chain.
+ // references can be updated by following the chain.
DomainValue *Next;
// Twiddleable instructions using or defining these registers.
assert(!MI->isDebugValue() && "Won't process debug values");
const MCInstrDesc &MCID = MI->getDesc();
for (unsigned i = 0,
- e = MCID.isVariadic() ? MI->getNumOperands() : MCID.getNumDefs();
+ e = MI->isVariadic() ? MI->getNumOperands() : MCID.getNumDefs();
i != e; ++i) {
MachineOperand &MO = MI->getOperand(i);
if (!MO.isReg())
DEBUG(dbgs() << TRI->getName(RC->getRegister(rx)) << ":\t" << CurInstr
<< '\t' << *MI);
+ // How many instructions since rx was last written?
+ unsigned Clearance = CurInstr - LiveRegs[rx].Def;
LiveRegs[rx].Def = CurInstr;
// Kill off domains redefined by generic instructions.
if (Kill)
kill(rx);
+
+ // Verify clearance before partial register updates.
+ unsigned Pref = TII->getPartialRegUpdateClearance(MI, i, TRI);
+ if (!Pref)
+ continue;
+ DEBUG(dbgs() << "Clearance: " << Clearance << ", want " << Pref);
+ if (Pref > Clearance) {
+ DEBUG(dbgs() << ": Break dependency.\n");
+ TII->breakPartialRegDependency(MI, i, TRI);
+ continue;
+ }
+
+ // The current clearance seems OK, but we may be ignoring a def from a
+ // back-edge.
+ if (!SeenUnknownBackEdge || Pref <= unsigned(CurInstr)) {
+ DEBUG(dbgs() << ": OK.\n");
+ continue;
+ }
+
+ // A def from an unprocessed back-edge may make us break this dependency.
+ DEBUG(dbgs() << ": Wait for back-edge to resolve.\n");
}
++CurInstr;
while (!Regs.empty()) {
if (!dv) {
dv = Regs.pop_back_val().Value;
+ // Force the first dv to match the current instruction.
+ dv->AvailableDomains = dv->getCommonDomains(available);
+ assert(dv->AvailableDomains && "Domain should have been filtered");
continue;
}
}
// dv is the DomainValue we are going to use for this instruction.
- if (!dv)
+ if (!dv) {
dv = alloc();
- dv->AvailableDomains = available;
+ dv->AvailableDomains = available;
+ }
dv->Instrs.push_back(mi);
- // Finally set all defs and non-collapsed uses to dv.
- for (unsigned i = 0, e = mi->getDesc().getNumOperands(); i != e; ++i) {
- MachineOperand &mo = mi->getOperand(i);
+ // Finally set all defs and non-collapsed uses to dv. We must iterate through
+ // all the operators, including imp-def ones.
+ for (MachineInstr::mop_iterator ii = mi->operands_begin(),
+ ee = mi->operands_end();
+ ii != ee; ++ii) {
+ MachineOperand &mo = *ii;
if (!mo.isReg()) continue;
int rx = regIndex(mo.getReg());
if (rx < 0) continue;
bool anyregs = false;
for (TargetRegisterClass::const_iterator I = RC->begin(), E = RC->end();
I != E; ++I)
- if (MF->getRegInfo().isPhysRegUsed(*I)) {
+ if (MF->getRegInfo().isPhysRegOrOverlapUsed(*I)) {
anyregs = true;
break;
}
// or -1.
AliasMap.resize(TRI->getNumRegs(), -1);
for (unsigned i = 0, e = RC->getNumRegs(); i != e; ++i)
- for (const unsigned *AI = TRI->getOverlaps(RC->getRegister(i)); *AI; ++AI)
+ for (MCRegAliasIterator AI(RC->getRegister(i), TRI, true);
+ AI.isValid(); ++AI)
AliasMap[*AI] = i;
}
for (unsigned i = 0, e = Loops.size(); i != e; ++i) {
MachineBasicBlock *MBB = Loops[i];
enterBasicBlock(MBB);
+ for (MachineBasicBlock::iterator I = MBB->begin(), E = MBB->end(); I != E;
+ ++I)
+ if (!I->isDebugValue())
+ processDefs(I, false);
leaveBasicBlock(MBB);
}