Revert r68073. It's causing a failure in the Apple-style builds.

llvm-svn: 68092
This commit is contained in:
Bill Wendling 2009-03-31 08:26:26 +00:00
parent 95a32aa18b
commit 4706abded2
6 changed files with 96 additions and 47 deletions

View File

@ -253,15 +253,6 @@ public:
/// it returns end()
iterator getFirstTerminator();
/// isOnlyReachableViaFallthough - Return true if this basic block has
/// exactly one predecessor and the control transfer mechanism between
/// the predecessor and this block is a fall-through.
bool isOnlyReachableByFallthrough() const {
return !pred_empty() &&
next(pred_begin()) == pred_end() &&
(*pred_begin())->getFirstTerminator() == (*pred_begin())->end();
}
void pop_front() { Insts.pop_front(); }
void pop_back() { Insts.pop_back(); }
void push_back(MachineInstr *MI) { Insts.push_back(MI); }

View File

@ -578,6 +578,20 @@ bool LocalSpiller::runOnMachineFunction(MachineFunction &MF, VirtRegMap &VRM) {
DOUT << "**** Post Machine Instrs ****\n";
DEBUG(MF.dump());
// See if any of the spills we added are actually dead and can be deleted.
for (std::vector<MachineInstr*> >::iterator
I = AddedSpills.begin(), E = AddedSpills.end(); I != E; ++I) {
MachineInstr *MI = *I;
if (VRM.OnlyUseOfStackSlot(MI)) {
MachineBasicBlock *MBB = MI->getParent();
DOUT << "Removed dead store:\t" << *MI;
VRM.RemoveMachineInstrFromMaps(MI);
MBB->erase(MI);
++NumDSE;
}
}
// Mark unused spill slots.
MachineFrameInfo *MFI = MF.getFrameInfo();
int SS = VRM.getLowSpillSlot();
@ -588,6 +602,7 @@ bool LocalSpiller::runOnMachineFunction(MachineFunction &MF, VirtRegMap &VRM) {
++NumDSS;
}
AddedSpills.clear();
return true;
}
@ -798,9 +813,50 @@ bool LocalSpiller::CommuteToFoldReload(MachineBasicBlock &MBB,
return false;
}
void LocalSpiller::RemoveDeadStore(MachineInstr *Store,
MachineBasicBlock &MBB,
MachineBasicBlock::iterator &MII,
SmallSet<MachineInstr*, 4> &ReMatDefs,
BitVector &RegKills,
std::vector<MachineOperand*> &KillOps,
VirtRegMap &VRM) {
// If there is a dead store to this stack slot, nuke it now.
DOUT << "Removed dead store:\t" << *Store;
++NumDSE;
SmallVector<unsigned, 2> KillRegs;
InvalidateKills(*Store, RegKills, KillOps, &KillRegs);
MachineBasicBlock::iterator PrevMII = Store;
bool CheckDef = PrevMII != MBB.begin();
if (CheckDef) --PrevMII;
VRM.RemoveMachineInstrFromMaps(Store);
MBB.erase(Store);
if (CheckDef) {
// Look at defs of killed registers on the store. Mark the defs as dead
// since the store has been deleted and they aren't being reused.
for (unsigned j = 0, ee = KillRegs.size(); j != ee; ++j) {
bool HasOtherDef = false;
if (InvalidateRegDef(PrevMII, *MII, KillRegs[j], HasOtherDef)) {
MachineInstr *DeadDef = PrevMII;
if (ReMatDefs.count(DeadDef) && !HasOtherDef) {
// FIXME: This assumes a remat def does not have side effects.
VRM.RemoveMachineInstrFromMaps(DeadDef);
MBB.erase(DeadDef);
++NumDRM;
}
}
}
}
}
/// SpillRegToStackSlot - Spill a register to a specified stack slot. Check if
/// the last store to the same slot is now dead. If so, remove the last store.
void LocalSpiller::SpillRegToStackSlot(MachineBasicBlock &MBB,
void
LocalSpiller::SpillRegToStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator &MII,
int Idx, unsigned PhysReg, int StackSlot,
const TargetRegisterClass *RC,
@ -816,36 +872,8 @@ void LocalSpiller::SpillRegToStackSlot(MachineBasicBlock &MBB,
DOUT << "Store:\t" << *StoreMI;
// If there is a dead store to this stack slot, nuke it now.
if (LastStore) {
DOUT << "Removed dead store:\t" << *LastStore;
++NumDSE;
SmallVector<unsigned, 2> KillRegs;
InvalidateKills(*LastStore, RegKills, KillOps, &KillRegs);
MachineBasicBlock::iterator PrevMII = LastStore;
bool CheckDef = PrevMII != MBB.begin();
if (CheckDef)
--PrevMII;
VRM.RemoveMachineInstrFromMaps(LastStore);
MBB.erase(LastStore);
if (CheckDef) {
// Look at defs of killed registers on the store. Mark the defs
// as dead since the store has been deleted and they aren't
// being reused.
for (unsigned j = 0, ee = KillRegs.size(); j != ee; ++j) {
bool HasOtherDef = false;
if (InvalidateRegDef(PrevMII, *MII, KillRegs[j], HasOtherDef)) {
MachineInstr *DeadDef = PrevMII;
if (ReMatDefs.count(DeadDef) && !HasOtherDef) {
// FIXME: This assumes a remat def does not have side
// effects.
VRM.RemoveMachineInstrFromMaps(DeadDef);
MBB.erase(DeadDef);
++NumDRM;
}
}
}
}
}
if (LastStore)
RemoveDeadStore(LastStore, MBB, MII, ReMatDefs, RegKills, KillOps, VRM);
LastStore = next(MII);
@ -1060,6 +1088,7 @@ void LocalSpiller::RewriteMBB(MachineBasicBlock &MBB, VirtRegMap &VRM,
if (VRM.isSpillPt(&MI)) {
std::vector<std::pair<unsigned,bool> > &SpillRegs =
VRM.getSpillPtSpills(&MI);
for (unsigned i = 0, e = SpillRegs.size(); i != e; ++i) {
unsigned VirtReg = SpillRegs[i].first;
bool isKill = SpillRegs[i].second;
@ -1073,7 +1102,9 @@ void LocalSpiller::RewriteMBB(MachineBasicBlock &MBB, VirtRegMap &VRM,
VRM.addSpillSlotUse(StackSlot, StoreMI);
DOUT << "Store:\t" << *StoreMI;
VRM.virtFolded(VirtReg, StoreMI, VirtRegMap::isMod);
AddedSpills.push_back(StoreMI);
}
NextMII = next(MII);
}

View File

@ -285,6 +285,7 @@ namespace llvm {
const TargetRegisterInfo *TRI;
const TargetInstrInfo *TII;
DenseMap<MachineInstr*, unsigned> DistanceMap;
std::vector<MachineInstr*> AddedSpills;
public:
bool runOnMachineFunction(MachineFunction &MF, VirtRegMap &VRM);
private:
@ -305,6 +306,14 @@ namespace llvm {
std::vector<MachineOperand*> &KillOps,
const TargetRegisterInfo *TRI,
VirtRegMap &VRM);
void RemoveDeadStore(MachineInstr *Store,
MachineBasicBlock &MBB,
MachineBasicBlock::iterator &MII,
SmallSet<MachineInstr*, 4> &ReMatDefs,
BitVector &RegKills,
std::vector<MachineOperand*> &KillOps,
VirtRegMap &VRM);
void SpillRegToStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator &MII,
int Idx, unsigned PhysReg, int StackSlot,

View File

@ -188,7 +188,7 @@ void VirtRegMap::RemoveMachineInstrFromMaps(MachineInstr *MI) {
if (MF->getFrameInfo()->isFixedObjectIndex(FI))
continue;
// This stack reference was produced by instruction selection and
// is not a spill
// is not a spill.
if (FI < LowSpillSlot)
continue;
assert((unsigned)FI-LowSpillSlot < SpillSlotToUsesMap.size()
@ -201,6 +201,27 @@ void VirtRegMap::RemoveMachineInstrFromMaps(MachineInstr *MI) {
EmergencySpillMap.erase(MI);
}
bool VirtRegMap::OnlyUseOfStackSlot(const MachineInstr *MI) const {
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
const MachineOperand &MO = MI->getOperand(i);
if (!MO.isFI())
continue;
int FI = MO.getIndex();
if (MF->getFrameInfo()->isFixedObjectIndex(FI))
continue;
// This stack reference was produced by instruction selection and
// is not a spill.
if (FI < LowSpillSlot)
continue;
assert((unsigned)FI-LowSpillSlot < SpillSlotToUsesMap.size()
&& "Invalid spill slot");
if (SpillSlotToUsesMap[FI - LowSpillSlot].size() != 1)
return false;
}
return true;
}
void VirtRegMap::print(std::ostream &OS, const Module* M) const {
const TargetRegisterInfo* TRI = MF->getTarget().getRegisterInfo();

View File

@ -430,6 +430,8 @@ namespace llvm {
/// the folded instruction map and spill point map.
void RemoveMachineInstrFromMaps(MachineInstr *MI);
bool OnlyUseOfStackSlot(const MachineInstr *MI) const;
void print(std::ostream &OS, const Module* M = 0) const;
void print(std::ostream *OS) const { if (OS) print(*OS); }
void dump() const;

View File

@ -238,12 +238,7 @@ bool X86ATTAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
I != E; ++I) {
// Print a label for the basic block.
if (!VerboseAsm && (I->pred_empty() || I->isOnlyReachableByFallthrough())) {
// This is an entry block or a block that's only reachable via a
// fallthrough edge. In non-VerboseAsm mode, don't print the label.
assert((I->pred_empty() || (*I->pred_begin())->isLayoutSuccessor(I)) &&
"Fall-through predecessor not adjacent to its successor!");
} else {
if (!I->pred_empty()) {
printBasicBlockLabel(I, true, true, VerboseAsm);
O << '\n';
}