void BT::runEdgeQueue(BitVector &BlockScanned) {
while (!FlowQ.empty()) {
CFGEdge Edge = FlowQ.front();
FlowQ.pop();
if (EdgeExec.count(Edge))
return;
EdgeExec.insert(Edge);
ReachedBB.insert(Edge.second);
const MachineBasicBlock &B = *MF.getBlockNumbered(Edge.second);
MachineBasicBlock::const_iterator It = B.begin(), End = B.end();
// Visit PHI nodes first.
while (It != End && It->isPHI()) {
const MachineInstr &PI = *It++;
InstrExec.insert(&PI);
visitPHI(PI);
}
// If this block has already been visited through a flow graph edge,
// then the instructions have already been processed. Any updates to
// the cells would now only happen through visitUsesOf...
if (BlockScanned[Edge.second])
return;
BlockScanned[Edge.second] = true;
// Visit non-branch instructions.
while (It != End && !It->isBranch()) {
const MachineInstr &MI = *It++;
InstrExec.insert(&MI);
visitNonBranch(MI);
}
// If block end has been reached, add the fall-through edge to the queue.
if (It == End) {
MachineFunction::const_iterator BIt = B.getIterator();
MachineFunction::const_iterator Next = std::next(BIt);
if (Next != MF.end() && B.isSuccessor(&*Next)) {
int ThisN = B.getNumber();
int NextN = Next->getNumber();
FlowQ.push(CFGEdge(ThisN, NextN));
}
} else {
// Handle the remaining sequence of branches. This function will update
// the work queue.
visitBranchesFrom(*It);
}
} // while (!FlowQ->empty())
}
void BT::run() {
reset();
assert(FlowQ.empty());
typedef GraphTraits<const MachineFunction*> MachineFlowGraphTraits;
const MachineBasicBlock *Entry = MachineFlowGraphTraits::getEntryNode(&MF);
unsigned MaxBN = 0;
for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
I != E; ++I) {
assert(I->getNumber() >= 0 && "Disconnected block");
unsigned BN = I->getNumber();
if (BN > MaxBN)
MaxBN = BN;
}
// Keep track of visited blocks.
BitVector BlockScanned(MaxBN+1);
int EntryN = Entry->getNumber();
// Generate a fake edge to get something to start with.
FlowQ.push(CFGEdge(-1, EntryN));
while (!FlowQ.empty()) {
CFGEdge Edge = FlowQ.front();
FlowQ.pop();
if (EdgeExec.count(Edge))
continue;
EdgeExec.insert(Edge);
const MachineBasicBlock &B = *MF.getBlockNumbered(Edge.second);
MachineBasicBlock::const_iterator It = B.begin(), End = B.end();
// Visit PHI nodes first.
while (It != End && It->isPHI()) {
const MachineInstr &PI = *It++;
InstrExec.insert(&PI);
visitPHI(PI);
}
// If this block has already been visited through a flow graph edge,
// then the instructions have already been processed. Any updates to
// the cells would now only happen through visitUsesOf...
if (BlockScanned[Edge.second])
continue;
BlockScanned[Edge.second] = true;
// Visit non-branch instructions.
while (It != End && !It->isBranch()) {
const MachineInstr &MI = *It++;
InstrExec.insert(&MI);
visitNonBranch(MI);
}
// If block end has been reached, add the fall-through edge to the queue.
if (It == End) {
MachineFunction::const_iterator BIt = B.getIterator();
MachineFunction::const_iterator Next = std::next(BIt);
if (Next != MF.end() && B.isSuccessor(&*Next)) {
int ThisN = B.getNumber();
int NextN = Next->getNumber();
FlowQ.push(CFGEdge(ThisN, NextN));
}
} else {
// Handle the remaining sequence of branches. This function will update
// the work queue.
visitBranchesFrom(*It);
}
} // while (!FlowQ->empty())
if (Trace)
print_cells(dbgs() << "Cells after propagation:\n");
}