SpillerOpt("spiller",
cl::desc("Spiller to use: (default: local)"),
cl::Prefix,
- cl::values(clEnumVal(simple, " simple spiller"),
- clEnumVal(local, " local spiller"),
+ cl::values(clEnumVal(simple, "simple spiller"),
+ clEnumVal(local, "local spiller"),
clEnumValEnd),
cl::init(local));
LowSpillSlot = SS;
if (HighSpillSlot == NO_STACK_SLOT || SS > HighSpillSlot)
HighSpillSlot = SS;
- I->second = SS;
+ EmergencySpillSlots[RC] = SS;
return SS;
}
/// marked kill, then it must be due to register reuse. Transfer the kill info
/// over.
static void UpdateKills(MachineInstr &MI, BitVector &RegKills,
- std::vector<MachineOperand*> &KillOps) {
+ std::vector<MachineOperand*> &KillOps,
+ const TargetRegisterInfo* TRI) {
const TargetInstrDesc &TID = MI.getDesc();
for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
MachineOperand &MO = MI.getOperand(i);
unsigned Reg = MO.getReg();
RegKills.reset(Reg);
KillOps[Reg] = NULL;
+ // It also defines (or partially define) aliases.
+ for (const unsigned *AS = TRI->getAliasSet(Reg); *AS; ++AS) {
+ RegKills.reset(*AS);
+ KillOps[*AS] = NULL;
+ }
}
}
Spills.addAvailable(NewOp.StackSlotOrReMat, MI, NewPhysReg);
--MII;
- UpdateKills(*MII, RegKills, KillOps);
+ UpdateKills(*MII, RegKills, KillOps, TRI);
DOUT << '\t' << *MII;
DOUT << "Reuse undone!\n";
}
// This invalidates Phys.
Spills.ClobberPhysReg(Phys);
- UpdateKills(*prior(MII), RegKills, KillOps);
+ UpdateKills(*prior(MII), RegKills, KillOps, TRI);
DOUT << '\t' << *prior(MII);
}
}
}
// Process all of the spilled uses and all non spilled reg references.
+ SmallVector<int, 2> PotentialDeadStoreSlots;
for (unsigned j = 0, e = VirtUseOps.size(); j != e; ++j) {
unsigned i = VirtUseOps[j];
MachineOperand &MO = MI.getOperand(i);
unsigned RReg = SubIdx ? TRI->getSubReg(Phys, SubIdx) : Phys;
MI.getOperand(i).setReg(RReg);
if (VRM.isImplicitlyDefined(VirtReg))
- BuildMI(MBB, &MI, TII->get(TargetInstrInfo::IMPLICIT_DEF), RReg);
+ BuildMI(MBB, &MI, MI.getDebugLoc(),
+ TII->get(TargetInstrInfo::IMPLICIT_DEF), RReg);
continue;
}
if (MI.getOperand(i).isKill() &&
ReuseSlot <= VirtRegMap::MAX_STACK_SLOT) {
- // This was the last use and the spilled value is still available
- // for reuse. That means the spill was unnecessary!
- MachineInstr* DeadStore = MaybeDeadStores[ReuseSlot];
- if (DeadStore) {
- DOUT << "Removed dead store:\t" << *DeadStore;
- InvalidateKills(*DeadStore, RegKills, KillOps);
- VRM.RemoveMachineInstrFromMaps(DeadStore);
- MBB.erase(DeadStore);
- MaybeDeadStores[ReuseSlot] = NULL;
- ++NumDSE;
- }
+
+ // The store of this spilled value is potentially dead, but we
+ // won't know for certain until we've confirmed that the re-use
+ // above is valid, which means waiting until the other operands
+ // are processed. For now we just track the spill slot, we'll
+ // remove it after the other operands are processed if valid.
+
+ PotentialDeadStoreSlots.push_back(ReuseSlot);
}
continue;
} // CanReuse
TII->copyRegToReg(MBB, &MI, DesignatedReg, PhysReg, RC, RC);
MachineInstr *CopyMI = prior(MII);
- UpdateKills(*CopyMI, RegKills, KillOps);
+ UpdateKills(*CopyMI, RegKills, KillOps, TRI);
// This invalidates DesignatedReg.
Spills.ClobberPhysReg(DesignatedReg);
MI.getOperand(i).setIsKill();
unsigned RReg = SubIdx ? TRI->getSubReg(PhysReg, SubIdx) : PhysReg;
MI.getOperand(i).setReg(RReg);
- UpdateKills(*prior(MII), RegKills, KillOps);
+ UpdateKills(*prior(MII), RegKills, KillOps, TRI);
DOUT << '\t' << *prior(MII);
}
+ // Ok - now we can remove stores that have been confirmed dead.
+ for (unsigned j = 0, e = PotentialDeadStoreSlots.size(); j != e; ++j) {
+ // This was the last use and the spilled value is still available
+ // for reuse. That means the spill was unnecessary!
+ int PDSSlot = PotentialDeadStoreSlots[j];
+ MachineInstr* DeadStore = MaybeDeadStores[PDSSlot];
+ if (DeadStore) {
+ DOUT << "Removed dead store:\t" << *DeadStore;
+ InvalidateKills(*DeadStore, RegKills, KillOps);
+ VRM.RemoveMachineInstrFromMaps(DeadStore);
+ MBB.erase(DeadStore);
+ MaybeDeadStores[PDSSlot] = NULL;
+ ++NumDSE;
+ }
+ }
+
+
DOUT << '\t' << MI;
// super-register is needed below.
if (KillOpnd && !KillOpnd->getSubReg() &&
TII->unfoldMemoryOperand(MF, &MI, PhysReg, false, true,NewMIs)){
- MBB.insert(MII, NewMIs[0]);
+ MBB.insert(MII, NewMIs[0]);
NewStore = NewMIs[1];
MBB.insert(MII, NewStore);
VRM.addSpillSlotUse(SS, NewStore);
if (!TargetRegisterInfo::isVirtualRegister(VirtReg)) {
// Check to see if this is a noop copy. If so, eliminate the
// instruction before considering the dest reg to be changed.
- unsigned Src, Dst;
- if (TII->isMoveInstr(MI, Src, Dst) && Src == Dst) {
+ unsigned Src, Dst, SrcSR, DstSR;
+ if (TII->isMoveInstr(MI, Src, Dst, SrcSR, DstSR) && Src == Dst) {
++NumDCE;
DOUT << "Removing now-noop copy: " << MI;
SmallVector<unsigned, 2> KillRegs;
InvalidateKills(MI, RegKills, KillOps, &KillRegs);
if (MO.isDead() && !KillRegs.empty()) {
- // Source register or an implicit super-register use is killed.
- assert(KillRegs[0] == Dst || TRI->isSubRegister(KillRegs[0], Dst));
+ // Source register or an implicit super/sub-register use is killed.
+ assert(KillRegs[0] == Dst ||
+ TRI->isSubRegister(KillRegs[0], Dst) ||
+ TRI->isSuperRegister(KillRegs[0], Dst));
// Last def is now dead.
TransferDeadness(&MBB, Dist, Src, RegKills, KillOps);
}
// Check to see if this is a noop copy. If so, eliminate the
// instruction before considering the dest reg to be changed.
{
- unsigned Src, Dst;
- if (TII->isMoveInstr(MI, Src, Dst) && Src == Dst) {
+ unsigned Src, Dst, SrcSR, DstSR;
+ if (TII->isMoveInstr(MI, Src, Dst, SrcSR, DstSR) && Src == Dst) {
++NumDCE;
DOUT << "Removing now-noop copy: " << MI;
InvalidateKills(MI, RegKills, KillOps);
VRM.RemoveMachineInstrFromMaps(&MI);
MBB.erase(&MI);
Erased = true;
- UpdateKills(*LastStore, RegKills, KillOps);
+ UpdateKills(*LastStore, RegKills, KillOps, TRI);
goto ProcessNextInst;
}
}
DistanceMap.insert(std::make_pair(&MI, Dist++));
if (!Erased && !BackTracked) {
for (MachineBasicBlock::iterator II = &MI; II != NextMII; ++II)
- UpdateKills(*II, RegKills, KillOps);
+ UpdateKills(*II, RegKills, KillOps, TRI);
}
MII = NextMII;
}
projects / oota-llvm.git / blobdiff