ScheduleDAG: Cleanup; NFC
- Fix doxygen comments (do not repeat documented name, remove definition
comment if there is already one at the declaration, add \p, ...)
- Add some const modifiers
- Use range based for
llvm-svn: 295688
diff --git a/llvm/lib/CodeGen/ScheduleDAG.cpp b/llvm/lib/CodeGen/ScheduleDAG.cpp
index 5c17746..01c056c 100644
--- a/llvm/lib/CodeGen/ScheduleDAG.cpp
+++ b/llvm/lib/CodeGen/ScheduleDAG.cpp
@@ -7,8 +7,8 @@
//
//===----------------------------------------------------------------------===//
//
-// This implements the ScheduleDAG class, which is a base class used by
-// scheduling implementation classes.
+/// \file Implements the ScheduleDAG class, which is a base class used by
+/// scheduling implementation classes.
//
//===----------------------------------------------------------------------===//
@@ -46,45 +46,39 @@
ScheduleDAG::~ScheduleDAG() {}
-/// Clear the DAG state (e.g. between scheduling regions).
void ScheduleDAG::clearDAG() {
SUnits.clear();
EntrySU = SUnit();
ExitSU = SUnit();
}
-/// getInstrDesc helper to handle SDNodes.
const MCInstrDesc *ScheduleDAG::getNodeDesc(const SDNode *Node) const {
if (!Node || !Node->isMachineOpcode()) return nullptr;
return &TII->get(Node->getMachineOpcode());
}
-/// addPred - This adds the specified edge as a pred of the current node if
-/// not already. It also adds the current node as a successor of the
-/// specified node.
bool SUnit::addPred(const SDep &D, bool Required) {
// If this node already has this dependence, don't add a redundant one.
- for (SmallVectorImpl<SDep>::iterator I = Preds.begin(), E = Preds.end();
- I != E; ++I) {
+ for (SDep &PredDep : Preds) {
// Zero-latency weak edges may be added purely for heuristic ordering. Don't
// add them if another kind of edge already exists.
- if (!Required && I->getSUnit() == D.getSUnit())
+ if (!Required && PredDep.getSUnit() == D.getSUnit())
return false;
- if (I->overlaps(D)) {
- // Extend the latency if needed. Equivalent to removePred(I) + addPred(D).
- if (I->getLatency() < D.getLatency()) {
- SUnit *PredSU = I->getSUnit();
+ if (PredDep.overlaps(D)) {
+ // Extend the latency if needed. Equivalent to
+ // removePred(PredDep) + addPred(D).
+ if (PredDep.getLatency() < D.getLatency()) {
+ SUnit *PredSU = PredDep.getSUnit();
// Find the corresponding successor in N.
- SDep ForwardD = *I;
+ SDep ForwardD = PredDep;
ForwardD.setSUnit(this);
- for (SmallVectorImpl<SDep>::iterator II = PredSU->Succs.begin(),
- EE = PredSU->Succs.end(); II != EE; ++II) {
- if (*II == ForwardD) {
- II->setLatency(D.getLatency());
+ for (SDep &SuccDep : PredSU->Succs) {
+ if (SuccDep == ForwardD) {
+ SuccDep.setLatency(D.getLatency());
break;
}
}
- I->setLatency(D.getLatency());
+ PredDep.setLatency(D.getLatency());
}
return false;
}
@@ -127,51 +121,46 @@
return true;
}
-/// removePred - This removes the specified edge as a pred of the current
-/// node if it exists. It also removes the current node as a successor of
-/// the specified node.
void SUnit::removePred(const SDep &D) {
// Find the matching predecessor.
- for (SmallVectorImpl<SDep>::iterator I = Preds.begin(), E = Preds.end();
- I != E; ++I)
- if (*I == D) {
- // Find the corresponding successor in N.
- SDep P = D;
- P.setSUnit(this);
- SUnit *N = D.getSUnit();
- SmallVectorImpl<SDep>::iterator Succ = find(N->Succs, P);
- assert(Succ != N->Succs.end() && "Mismatching preds / succs lists!");
- N->Succs.erase(Succ);
- Preds.erase(I);
- // Update the bookkeeping.
- if (P.getKind() == SDep::Data) {
- assert(NumPreds > 0 && "NumPreds will underflow!");
- assert(N->NumSuccs > 0 && "NumSuccs will underflow!");
- --NumPreds;
- --N->NumSuccs;
- }
- if (!N->isScheduled) {
- if (D.isWeak())
- --WeakPredsLeft;
- else {
- assert(NumPredsLeft > 0 && "NumPredsLeft will underflow!");
- --NumPredsLeft;
- }
- }
- if (!isScheduled) {
- if (D.isWeak())
- --N->WeakSuccsLeft;
- else {
- assert(N->NumSuccsLeft > 0 && "NumSuccsLeft will underflow!");
- --N->NumSuccsLeft;
- }
- }
- if (P.getLatency() != 0) {
- this->setDepthDirty();
- N->setHeightDirty();
- }
- return;
+ SmallVectorImpl<SDep>::iterator I = find(Preds, D);
+ if (I == Preds.end())
+ return;
+ // Find the corresponding successor in N.
+ SDep P = D;
+ P.setSUnit(this);
+ SUnit *N = D.getSUnit();
+ SmallVectorImpl<SDep>::iterator Succ = find(N->Succs, P);
+ assert(Succ != N->Succs.end() && "Mismatching preds / succs lists!");
+ N->Succs.erase(Succ);
+ Preds.erase(I);
+ // Update the bookkeeping.
+ if (P.getKind() == SDep::Data) {
+ assert(NumPreds > 0 && "NumPreds will underflow!");
+ assert(N->NumSuccs > 0 && "NumSuccs will underflow!");
+ --NumPreds;
+ --N->NumSuccs;
+ }
+ if (!N->isScheduled) {
+ if (D.isWeak())
+ --WeakPredsLeft;
+ else {
+ assert(NumPredsLeft > 0 && "NumPredsLeft will underflow!");
+ --NumPredsLeft;
}
+ }
+ if (!isScheduled) {
+ if (D.isWeak())
+ --N->WeakSuccsLeft;
+ else {
+ assert(N->NumSuccsLeft > 0 && "NumSuccsLeft will underflow!");
+ --N->NumSuccsLeft;
+ }
+ }
+ if (P.getLatency() != 0) {
+ this->setDepthDirty();
+ N->setHeightDirty();
+ }
}
void SUnit::setDepthDirty() {
@@ -181,9 +170,8 @@
do {
SUnit *SU = WorkList.pop_back_val();
SU->isDepthCurrent = false;
- for (SUnit::const_succ_iterator I = SU->Succs.begin(),
- E = SU->Succs.end(); I != E; ++I) {
- SUnit *SuccSU = I->getSUnit();
+ for (SDep &SuccDep : SU->Succs) {
+ SUnit *SuccSU = SuccDep.getSUnit();
if (SuccSU->isDepthCurrent)
WorkList.push_back(SuccSU);
}
@@ -197,18 +185,14 @@
do {
SUnit *SU = WorkList.pop_back_val();
SU->isHeightCurrent = false;
- for (SUnit::const_pred_iterator I = SU->Preds.begin(),
- E = SU->Preds.end(); I != E; ++I) {
- SUnit *PredSU = I->getSUnit();
+ for (SDep &PredDep : SU->Preds) {
+ SUnit *PredSU = PredDep.getSUnit();
if (PredSU->isHeightCurrent)
WorkList.push_back(PredSU);
}
} while (!WorkList.empty());
}
-/// setDepthToAtLeast - Update this node's successors to reflect the
-/// fact that this node's depth just increased.
-///
void SUnit::setDepthToAtLeast(unsigned NewDepth) {
if (NewDepth <= getDepth())
return;
@@ -217,9 +201,6 @@
isDepthCurrent = true;
}
-/// setHeightToAtLeast - Update this node's predecessors to reflect the
-/// fact that this node's height just increased.
-///
void SUnit::setHeightToAtLeast(unsigned NewHeight) {
if (NewHeight <= getHeight())
return;
@@ -228,8 +209,7 @@
isHeightCurrent = true;
}
-/// ComputeDepth - Calculate the maximal path from the node to the exit.
-///
+/// Calculates the maximal path from the node to the exit.
void SUnit::ComputeDepth() {
SmallVector<SUnit*, 8> WorkList;
WorkList.push_back(this);
@@ -238,12 +218,11 @@
bool Done = true;
unsigned MaxPredDepth = 0;
- for (SUnit::const_pred_iterator I = Cur->Preds.begin(),
- E = Cur->Preds.end(); I != E; ++I) {
- SUnit *PredSU = I->getSUnit();
+ for (const SDep &PredDep : Cur->Preds) {
+ SUnit *PredSU = PredDep.getSUnit();
if (PredSU->isDepthCurrent)
MaxPredDepth = std::max(MaxPredDepth,
- PredSU->Depth + I->getLatency());
+ PredSU->Depth + PredDep.getLatency());
else {
Done = false;
WorkList.push_back(PredSU);
@@ -261,8 +240,7 @@
} while (!WorkList.empty());
}
-/// ComputeHeight - Calculate the maximal path from the node to the entry.
-///
+/// Calculates the maximal path from the node to the entry.
void SUnit::ComputeHeight() {
SmallVector<SUnit*, 8> WorkList;
WorkList.push_back(this);
@@ -271,12 +249,11 @@
bool Done = true;
unsigned MaxSuccHeight = 0;
- for (SUnit::const_succ_iterator I = Cur->Succs.begin(),
- E = Cur->Succs.end(); I != E; ++I) {
- SUnit *SuccSU = I->getSUnit();
+ for (const SDep &SuccDep : Cur->Succs) {
+ SUnit *SuccSU = SuccDep.getSUnit();
if (SuccSU->isHeightCurrent)
MaxSuccHeight = std::max(MaxSuccHeight,
- SuccSU->Height + I->getLatency());
+ SuccSU->Height + SuccDep.getLatency());
else {
Done = false;
WorkList.push_back(SuccSU);
@@ -320,8 +297,6 @@
OS << "SU(" << NodeNum << ")";
}
-/// SUnit - Scheduling unit. It's an wrapper around either a single SDNode or
-/// a group of nodes flagged together.
LLVM_DUMP_METHOD void SUnit::dump(const ScheduleDAG *G) const {
print(dbgs(), G);
dbgs() << ": ";
@@ -344,41 +319,39 @@
if (Preds.size() != 0) {
dbgs() << " Predecessors:\n";
- for (SUnit::const_succ_iterator I = Preds.begin(), E = Preds.end();
- I != E; ++I) {
+ for (const SDep &SuccDep : Preds) {
dbgs() << " ";
- switch (I->getKind()) {
+ switch (SuccDep.getKind()) {
case SDep::Data: dbgs() << "data "; break;
case SDep::Anti: dbgs() << "anti "; break;
case SDep::Output: dbgs() << "out "; break;
case SDep::Order: dbgs() << "ord "; break;
}
- I->getSUnit()->print(dbgs(), G);
- if (I->isArtificial())
+ SuccDep.getSUnit()->print(dbgs(), G);
+ if (SuccDep.isArtificial())
dbgs() << " *";
- dbgs() << ": Latency=" << I->getLatency();
- if (I->isAssignedRegDep())
- dbgs() << " Reg=" << PrintReg(I->getReg(), G->TRI);
+ dbgs() << ": Latency=" << SuccDep.getLatency();
+ if (SuccDep.isAssignedRegDep())
+ dbgs() << " Reg=" << PrintReg(SuccDep.getReg(), G->TRI);
dbgs() << "\n";
}
}
if (Succs.size() != 0) {
dbgs() << " Successors:\n";
- for (SUnit::const_succ_iterator I = Succs.begin(), E = Succs.end();
- I != E; ++I) {
+ for (const SDep &SuccDep : Succs) {
dbgs() << " ";
- switch (I->getKind()) {
+ switch (SuccDep.getKind()) {
case SDep::Data: dbgs() << "data "; break;
case SDep::Anti: dbgs() << "anti "; break;
case SDep::Output: dbgs() << "out "; break;
case SDep::Order: dbgs() << "ord "; break;
}
- I->getSUnit()->print(dbgs(), G);
- if (I->isArtificial())
+ SuccDep.getSUnit()->print(dbgs(), G);
+ if (SuccDep.isArtificial())
dbgs() << " *";
- dbgs() << ": Latency=" << I->getLatency();
- if (I->isAssignedRegDep())
- dbgs() << " Reg=" << PrintReg(I->getReg(), G->TRI);
+ dbgs() << ": Latency=" << SuccDep.getLatency();
+ if (SuccDep.isAssignedRegDep())
+ dbgs() << " Reg=" << PrintReg(SuccDep.getReg(), G->TRI);
dbgs() << "\n";
}
}
@@ -386,47 +359,44 @@
#endif
#ifndef NDEBUG
-/// VerifyScheduledDAG - Verify that all SUnits were scheduled and that
-/// their state is consistent. Return the number of scheduled nodes.
-///
unsigned ScheduleDAG::VerifyScheduledDAG(bool isBottomUp) {
bool AnyNotSched = false;
unsigned DeadNodes = 0;
- for (unsigned i = 0, e = SUnits.size(); i != e; ++i) {
- if (!SUnits[i].isScheduled) {
- if (SUnits[i].NumPreds == 0 && SUnits[i].NumSuccs == 0) {
+ for (const SUnit &SUnit : SUnits) {
+ if (!SUnit.isScheduled) {
+ if (SUnit.NumPreds == 0 && SUnit.NumSuccs == 0) {
++DeadNodes;
continue;
}
if (!AnyNotSched)
dbgs() << "*** Scheduling failed! ***\n";
- SUnits[i].dump(this);
+ SUnit.dump(this);
dbgs() << "has not been scheduled!\n";
AnyNotSched = true;
}
- if (SUnits[i].isScheduled &&
- (isBottomUp ? SUnits[i].getHeight() : SUnits[i].getDepth()) >
+ if (SUnit.isScheduled &&
+ (isBottomUp ? SUnit.getHeight() : SUnit.getDepth()) >
unsigned(INT_MAX)) {
if (!AnyNotSched)
dbgs() << "*** Scheduling failed! ***\n";
- SUnits[i].dump(this);
+ SUnit.dump(this);
dbgs() << "has an unexpected "
<< (isBottomUp ? "Height" : "Depth") << " value!\n";
AnyNotSched = true;
}
if (isBottomUp) {
- if (SUnits[i].NumSuccsLeft != 0) {
+ if (SUnit.NumSuccsLeft != 0) {
if (!AnyNotSched)
dbgs() << "*** Scheduling failed! ***\n";
- SUnits[i].dump(this);
+ SUnit.dump(this);
dbgs() << "has successors left!\n";
AnyNotSched = true;
}
} else {
- if (SUnits[i].NumPredsLeft != 0) {
+ if (SUnit.NumPredsLeft != 0) {
if (!AnyNotSched)
dbgs() << "*** Scheduling failed! ***\n";
- SUnits[i].dump(this);
+ SUnit.dump(this);
dbgs() << "has predecessors left!\n";
AnyNotSched = true;
}
@@ -437,36 +407,33 @@
}
#endif
-/// InitDAGTopologicalSorting - create the initial topological
-/// ordering from the DAG to be scheduled.
-///
-/// The idea of the algorithm is taken from
-/// "Online algorithms for managing the topological order of
-/// a directed acyclic graph" by David J. Pearce and Paul H.J. Kelly
-/// This is the MNR algorithm, which was first introduced by
-/// A. Marchetti-Spaccamela, U. Nanni and H. Rohnert in
-/// "Maintaining a topological order under edge insertions".
-///
-/// Short description of the algorithm:
-///
-/// Topological ordering, ord, of a DAG maps each node to a topological
-/// index so that for all edges X->Y it is the case that ord(X) < ord(Y).
-///
-/// This means that if there is a path from the node X to the node Z,
-/// then ord(X) < ord(Z).
-///
-/// This property can be used to check for reachability of nodes:
-/// if Z is reachable from X, then an insertion of the edge Z->X would
-/// create a cycle.
-///
-/// The algorithm first computes a topological ordering for the DAG by
-/// initializing the Index2Node and Node2Index arrays and then tries to keep
-/// the ordering up-to-date after edge insertions by reordering the DAG.
-///
-/// On insertion of the edge X->Y, the algorithm first marks by calling DFS
-/// the nodes reachable from Y, and then shifts them using Shift to lie
-/// immediately after X in Index2Node.
void ScheduleDAGTopologicalSort::InitDAGTopologicalSorting() {
+ // The idea of the algorithm is taken from
+ // "Online algorithms for managing the topological order of
+ // a directed acyclic graph" by David J. Pearce and Paul H.J. Kelly
+ // This is the MNR algorithm, which was first introduced by
+ // A. Marchetti-Spaccamela, U. Nanni and H. Rohnert in
+ // "Maintaining a topological order under edge insertions".
+ //
+ // Short description of the algorithm:
+ //
+ // Topological ordering, ord, of a DAG maps each node to a topological
+ // index so that for all edges X->Y it is the case that ord(X) < ord(Y).
+ //
+ // This means that if there is a path from the node X to the node Z,
+ // then ord(X) < ord(Z).
+ //
+ // This property can be used to check for reachability of nodes:
+ // if Z is reachable from X, then an insertion of the edge Z->X would
+ // create a cycle.
+ //
+ // The algorithm first computes a topological ordering for the DAG by
+ // initializing the Index2Node and Node2Index arrays and then tries to keep
+ // the ordering up-to-date after edge insertions by reordering the DAG.
+ //
+ // On insertion of the edge X->Y, the algorithm first marks by calling DFS
+ // the nodes reachable from Y, and then shifts them using Shift to lie
+ // immediately after X in Index2Node.
unsigned DAGSize = SUnits.size();
std::vector<SUnit*> WorkList;
WorkList.reserve(DAGSize);
@@ -477,18 +444,17 @@
// Initialize the data structures.
if (ExitSU)
WorkList.push_back(ExitSU);
- for (unsigned i = 0, e = DAGSize; i != e; ++i) {
- SUnit *SU = &SUnits[i];
- int NodeNum = SU->NodeNum;
- unsigned Degree = SU->Succs.size();
+ for (SUnit &SU : SUnits) {
+ int NodeNum = SU.NodeNum;
+ unsigned Degree = SU.Succs.size();
// Temporarily use the Node2Index array as scratch space for degree counts.
Node2Index[NodeNum] = Degree;
// Is it a node without dependencies?
if (Degree == 0) {
- assert(SU->Succs.empty() && "SUnit should have no successors");
+ assert(SU.Succs.empty() && "SUnit should have no successors");
// Collect leaf nodes.
- WorkList.push_back(SU);
+ WorkList.push_back(&SU);
}
}
@@ -498,9 +464,8 @@
WorkList.pop_back();
if (SU->NodeNum < DAGSize)
Allocate(SU->NodeNum, --Id);
- for (SUnit::const_pred_iterator I = SU->Preds.begin(), E = SU->Preds.end();
- I != E; ++I) {
- SUnit *SU = I->getSUnit();
+ for (const SDep &PredDep : SU->Preds) {
+ SUnit *SU = PredDep.getSUnit();
if (SU->NodeNum < DAGSize && !--Node2Index[SU->NodeNum])
// If all dependencies of the node are processed already,
// then the node can be computed now.
@@ -512,19 +477,15 @@
#ifndef NDEBUG
// Check correctness of the ordering
- for (unsigned i = 0, e = DAGSize; i != e; ++i) {
- SUnit *SU = &SUnits[i];
- for (SUnit::const_pred_iterator I = SU->Preds.begin(), E = SU->Preds.end();
- I != E; ++I) {
- assert(Node2Index[SU->NodeNum] > Node2Index[I->getSUnit()->NodeNum] &&
+ for (SUnit &SU : SUnits) {
+ for (const SDep &PD : SU.Preds) {
+ assert(Node2Index[SU.NodeNum] > Node2Index[PD.getSUnit()->NodeNum] &&
"Wrong topological sorting");
}
}
#endif
}
-/// AddPred - Updates the topological ordering to accommodate an edge
-/// to be added from SUnit X to SUnit Y.
void ScheduleDAGTopologicalSort::AddPred(SUnit *Y, SUnit *X) {
int UpperBound, LowerBound;
LowerBound = Node2Index[Y->NodeNum];
@@ -541,16 +502,10 @@
}
}
-/// RemovePred - Updates the topological ordering to accommodate an
-/// an edge to be removed from the specified node N from the predecessors
-/// of the current node M.
void ScheduleDAGTopologicalSort::RemovePred(SUnit *M, SUnit *N) {
// InitDAGTopologicalSorting();
}
-/// DFS - Make a DFS traversal to mark all nodes reachable from SU and mark
-/// all nodes affected by the edge insertion. These nodes will later get new
-/// topological indexes by means of the Shift method.
void ScheduleDAGTopologicalSort::DFS(const SUnit *SU, int UpperBound,
bool &HasLoop) {
std::vector<const SUnit*> WorkList;
@@ -561,8 +516,9 @@
SU = WorkList.back();
WorkList.pop_back();
Visited.set(SU->NodeNum);
- for (int I = SU->Succs.size()-1; I >= 0; --I) {
- unsigned s = SU->Succs[I].getSUnit()->NodeNum;
+ for (const SDep &SuccDep
+ : make_range(SU->Succs.rbegin(), SU->Succs.rend())) {
+ unsigned s = SuccDep.getSUnit()->NodeNum;
// Edges to non-SUnits are allowed but ignored (e.g. ExitSU).
if (s >= Node2Index.size())
continue;
@@ -572,14 +528,12 @@
}
// Visit successors if not already and in affected region.
if (!Visited.test(s) && Node2Index[s] < UpperBound) {
- WorkList.push_back(SU->Succs[I].getSUnit());
+ WorkList.push_back(SuccDep.getSUnit());
}
}
} while (!WorkList.empty());
}
-/// Shift - Renumber the nodes so that the topological ordering is
-/// preserved.
void ScheduleDAGTopologicalSort::Shift(BitVector& Visited, int LowerBound,
int UpperBound) {
std::vector<int> L;
@@ -599,28 +553,24 @@
}
}
- for (unsigned j = 0; j < L.size(); ++j) {
- Allocate(L[j], i - shift);
+ for (unsigned LI : L) {
+ Allocate(LI, i - shift);
i = i + 1;
}
}
-/// WillCreateCycle - Returns true if adding an edge to TargetSU from SU will
-/// create a cycle. If so, it is not safe to call AddPred(TargetSU, SU).
bool ScheduleDAGTopologicalSort::WillCreateCycle(SUnit *TargetSU, SUnit *SU) {
// Is SU reachable from TargetSU via successor edges?
if (IsReachable(SU, TargetSU))
return true;
- for (SUnit::pred_iterator
- I = TargetSU->Preds.begin(), E = TargetSU->Preds.end(); I != E; ++I)
- if (I->isAssignedRegDep() &&
- IsReachable(SU, I->getSUnit()))
+ for (const SDep &PredDep : TargetSU->Preds)
+ if (PredDep.isAssignedRegDep() &&
+ IsReachable(SU, PredDep.getSUnit()))
return true;
return false;
}
-/// IsReachable - Checks if SU is reachable from TargetSU.
bool ScheduleDAGTopologicalSort::IsReachable(const SUnit *SU,
const SUnit *TargetSU) {
// If insertion of the edge SU->TargetSU would create a cycle
@@ -638,7 +588,6 @@
return HasLoop;
}
-/// Allocate - assign the topological index to the node n.
void ScheduleDAGTopologicalSort::Allocate(int n, int index) {
Node2Index[n] = index;
Index2Node[index] = n;