bool UnpackMachineBundles::runOnMachineFunction(MachineFunction &MF) {
bool Changed = false;
for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I) {
MachineBasicBlock *MBB = &*I;
for (MachineBasicBlock::instr_iterator MII = MBB->instr_begin(),
MIE = MBB->instr_end(); MII != MIE; ) {
MachineInstr *MI = &*MII;
// Remove BUNDLE instruction and the InsideBundle flags from bundled
// instructions.
if (MI->isBundle()) {
while (++MII != MIE && MII->isBundledWithPred()) {
MII->unbundleFromPred();
for (unsigned i = 0, e = MII->getNumOperands(); i != e; ++i) {
MachineOperand &MO = MII->getOperand(i);
if (MO.isReg() && MO.isInternalRead())
MO.setIsInternalRead(false);
}
}
MI->eraseFromParent();
Changed = true;
continue;
}
++MII;
}
}
return Changed;
}
ClauseFile
MakeALUClause(MachineBasicBlock &MBB, MachineBasicBlock::iterator &I)
const {
MachineBasicBlock::iterator ClauseHead = I;
std::vector<MachineInstr *> ClauseContent;
I++;
for (MachineBasicBlock::instr_iterator E = MBB.instr_end(); I != E;) {
if (IsTrivialInst(I)) {
++I;
continue;
}
if (!I->isBundle() && !TII->isALUInstr(I->getOpcode()))
break;
std::vector<int64_t> Literals;
if (I->isBundle()) {
MachineInstr *DeleteMI = I;
MachineBasicBlock::instr_iterator BI = I.getInstrIterator();
while (++BI != E && BI->isBundledWithPred()) {
BI->unbundleFromPred();
for (unsigned i = 0, e = BI->getNumOperands(); i != e; ++i) {
MachineOperand &MO = BI->getOperand(i);
if (MO.isReg() && MO.isInternalRead())
MO.setIsInternalRead(false);
}
getLiteral(BI, Literals);
ClauseContent.push_back(BI);
}
I = BI;
DeleteMI->eraseFromParent();
} else {
getLiteral(I, Literals);
ClauseContent.push_back(I);
I++;
}
for (unsigned i = 0, e = Literals.size(); i < e; i+=2) {
unsigned literal0 = Literals[i];
unsigned literal2 = (i + 1 < e)?Literals[i + 1]:0;
MachineInstr *MILit = BuildMI(MBB, I, I->getDebugLoc(),
TII->get(AMDGPU::LITERALS))
.addImm(literal0)
.addImm(literal2);
ClauseContent.push_back(MILit);
}
}
ClauseHead->getOperand(7).setImm(ClauseContent.size() - 1);
return ClauseFile(ClauseHead, ClauseContent);
}
bool Thumb2SizeReduce::ReduceMBB(MachineBasicBlock &MBB) {
bool Modified = false;
// Yes, CPSR could be livein.
bool LiveCPSR = MBB.isLiveIn(ARM::CPSR);
MachineInstr *BundleMI = 0;
CPSRDef = 0;
HighLatencyCPSR = false;
// Check predecessors for the latest CPSRDef.
for (MachineBasicBlock::pred_iterator
I = MBB.pred_begin(), E = MBB.pred_end(); I != E; ++I) {
const MBBInfo &PInfo = BlockInfo[(*I)->getNumber()];
if (!PInfo.Visited) {
// Since blocks are visited in RPO, this must be a back-edge.
continue;
}
if (PInfo.HighLatencyCPSR) {
HighLatencyCPSR = true;
break;
}
}
// If this BB loops back to itself, conservatively avoid narrowing the
// first instruction that does partial flag update.
bool IsSelfLoop = MBB.isSuccessor(&MBB);
MachineBasicBlock::instr_iterator MII = MBB.instr_begin(),E = MBB.instr_end();
MachineBasicBlock::instr_iterator NextMII;
for (; MII != E; MII = NextMII) {
NextMII = llvm::next(MII);
MachineInstr *MI = &*MII;
if (MI->isBundle()) {
BundleMI = MI;
continue;
}
if (MI->isDebugValue())
continue;
LiveCPSR = UpdateCPSRUse(*MI, LiveCPSR);
// Does NextMII belong to the same bundle as MI?
bool NextInSameBundle = NextMII != E && NextMII->isBundledWithPred();
if (ReduceMI(MBB, MI, LiveCPSR, IsSelfLoop)) {
Modified = true;
MachineBasicBlock::instr_iterator I = prior(NextMII);
MI = &*I;
// Removing and reinserting the first instruction in a bundle will break
// up the bundle. Fix the bundling if it was broken.
if (NextInSameBundle && !NextMII->isBundledWithPred())
NextMII->bundleWithPred();
}
if (!NextInSameBundle && MI->isInsideBundle()) {
// FIXME: Since post-ra scheduler operates on bundles, the CPSR kill
// marker is only on the BUNDLE instruction. Process the BUNDLE
// instruction as we finish with the bundled instruction to work around
// the inconsistency.
if (BundleMI->killsRegister(ARM::CPSR))
LiveCPSR = false;
MachineOperand *MO = BundleMI->findRegisterDefOperand(ARM::CPSR);
if (MO && !MO->isDead())
LiveCPSR = true;
}
bool DefCPSR = false;
LiveCPSR = UpdateCPSRDef(*MI, LiveCPSR, DefCPSR);
if (MI->isCall()) {
// Calls don't really set CPSR.
CPSRDef = 0;
HighLatencyCPSR = false;
IsSelfLoop = false;
} else if (DefCPSR) {
// This is the last CPSR defining instruction.
CPSRDef = MI;
HighLatencyCPSR = isHighLatencyCPSR(CPSRDef);
IsSelfLoop = false;
}
}
MBBInfo &Info = BlockInfo[MBB.getNumber()];
Info.HighLatencyCPSR = HighLatencyCPSR;
Info.Visited = true;
return Modified;
}