Make CalcLatency() non-recursive.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43017 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2007-10-15 21:33:22 +00:00
parent 82f209e421
commit 4859e277f7

View File

@ -443,22 +443,57 @@ int LatencyPriorityQueue::CalcLatency(const SUnit &SU) {
int &Latency = Latencies[SU.NodeNum];
if (Latency != -1)
return Latency;
int MaxSuccLatency = 0;
for (SUnit::const_succ_iterator I = SU.Succs.begin(), E = SU.Succs.end();
I != E; ++I)
MaxSuccLatency = std::max(MaxSuccLatency, CalcLatency(*I->Dep));
return Latency = MaxSuccLatency + SU.Latency;
std::vector<const SUnit*> WorkList;
WorkList.push_back(&SU);
while (!WorkList.empty()) {
const SUnit *Cur = WorkList.back();
bool AllDone = true;
int MaxSuccLatency = 0;
for (SUnit::const_succ_iterator I = Cur->Succs.begin(),E = Cur->Succs.end();
I != E; ++I) {
int SuccLatency = Latencies[I->Dep->NodeNum];
if (SuccLatency == -1) {
AllDone = false;
WorkList.push_back(I->Dep);
} else {
MaxSuccLatency = std::max(MaxSuccLatency, SuccLatency);
}
}
if (AllDone) {
Latencies[Cur->NodeNum] = MaxSuccLatency + Cur->Latency;
WorkList.pop_back();
}
}
return Latency;
}
/// CalculatePriorities - Calculate priorities of all scheduling units.
void LatencyPriorityQueue::CalculatePriorities() {
Latencies.assign(SUnits->size(), -1);
NumNodesSolelyBlocking.assign(SUnits->size(), 0);
for (unsigned i = 0, e = SUnits->size(); i != e; ++i)
CalcLatency((*SUnits)[i]);
// For each node, calculate the maximal path from the node to the exit.
std::vector<std::pair<const SUnit*, unsigned> > WorkList;
for (unsigned i = 0, e = SUnits->size(); i != e; ++i) {
const SUnit *SU = &(*SUnits)[i];
if (SU->Succs.size() == 0)
WorkList.push_back(std::make_pair(SU, 0U));
}
while (!WorkList.empty()) {
const SUnit *SU = WorkList.back().first;
unsigned SuccLat = WorkList.back().second;
WorkList.pop_back();
int &Latency = Latencies[SU->NodeNum];
if (Latency == -1 || (SU->Latency + SuccLat) > (unsigned)Latency) {
Latency = SU->Latency + SuccLat;
for (SUnit::const_pred_iterator I = SU->Preds.begin(),E = SU->Preds.end();
I != E; ++I)
WorkList.push_back(std::make_pair(I->Dep, Latency));
}
}
}
/// getSingleUnscheduledPred - If there is exactly one unscheduled predecessor