Revert "[NFC][ScheduleDAG] Remove unused EntrySU SUnit"
This reverts commit 0345d88de654259ae90494bf9b015416e2cccacb.
Google internal backend uses EntrySU, we are looking into removing
dependency on it.
Differential Revision: https://reviews.llvm.org/D88018
diff --git a/llvm/lib/CodeGen/MachineScheduler.cpp b/llvm/lib/CodeGen/MachineScheduler.cpp
index dbb2f3f..b6d0d9a 100644
--- a/llvm/lib/CodeGen/MachineScheduler.cpp
+++ b/llvm/lib/CodeGen/MachineScheduler.cpp
@@ -680,7 +680,7 @@
PredSU->BotReadyCycle = SU->BotReadyCycle + PredEdge->getLatency();
--PredSU->NumSuccsLeft;
- if (PredSU->NumSuccsLeft == 0)
+ if (PredSU->NumSuccsLeft == 0 && PredSU != &EntrySU)
SchedImpl->releaseBottomNode(PredSU);
}
@@ -853,7 +853,7 @@
NextClusterSucc = nullptr;
NextClusterPred = nullptr;
- // Release all DAG roots for scheduling, not including ExitSU.
+ // Release all DAG roots for scheduling, not including EntrySU/ExitSU.
//
// Nodes with unreleased weak edges can still be roots.
// Release top roots in forward order.
@@ -867,6 +867,7 @@
SchedImpl->releaseBottomNode(*I);
}
+ releaseSuccessors(&EntrySU);
releasePredecessors(&ExitSU);
SchedImpl->registerRoots();
@@ -1167,6 +1168,8 @@
void ScheduleDAGMILive::dump() const {
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+ if (EntrySU.getInstr() != nullptr)
+ dumpNodeAll(EntrySU);
for (const SUnit &SU : SUnits) {
dumpNodeAll(SU);
if (ShouldTrackPressure) {
diff --git a/llvm/lib/CodeGen/MacroFusion.cpp b/llvm/lib/CodeGen/MacroFusion.cpp
index 4243dcf..d2ee21c 100644
--- a/llvm/lib/CodeGen/MacroFusion.cpp
+++ b/llvm/lib/CodeGen/MacroFusion.cpp
@@ -109,21 +109,23 @@
// Make the FirstSU also dependent on the dependencies of the SecondSU to
// prevent them from being scheduled between the FirstSU and the SecondSU.
- for (const SDep &SI : SecondSU.Preds) {
- SUnit *SU = SI.getSUnit();
- if (SI.isWeak() || isHazard(SI) || &FirstSU == SU || FirstSU.isSucc(SU))
- continue;
- LLVM_DEBUG(dbgs() << " Bind "; DAG.dumpNodeName(*SU); dbgs() << " - ";
- DAG.dumpNodeName(FirstSU); dbgs() << '\n';);
- DAG.addEdge(&FirstSU, SDep(SU, SDep::Artificial));
- }
- // ExitSU comes last by design, which acts like an implicit dependency
- // between ExitSU and any bottom root in the graph. We should transfer
- // this to FirstSU as well.
- if (&SecondSU == &DAG.ExitSU) {
- for (SUnit &SU : DAG.SUnits) {
- if (SU.Succs.empty())
- DAG.addEdge(&FirstSU, SDep(&SU, SDep::Artificial));
+ if (&FirstSU != &DAG.EntrySU) {
+ for (const SDep &SI : SecondSU.Preds) {
+ SUnit *SU = SI.getSUnit();
+ if (SI.isWeak() || isHazard(SI) || &FirstSU == SU || FirstSU.isSucc(SU))
+ continue;
+ LLVM_DEBUG(dbgs() << " Bind "; DAG.dumpNodeName(*SU); dbgs() << " - ";
+ DAG.dumpNodeName(FirstSU); dbgs() << '\n';);
+ DAG.addEdge(&FirstSU, SDep(SU, SDep::Artificial));
+ }
+ // ExitSU comes last by design, which acts like an implicit dependency
+ // between ExitSU and any bottom root in the graph. We should transfer
+ // this to FirstSU as well.
+ if (&SecondSU == &DAG.ExitSU) {
+ for (SUnit &SU : DAG.SUnits) {
+ if (SU.Succs.empty())
+ DAG.addEdge(&FirstSU, SDep(&SU, SDep::Artificial));
+ }
}
}
diff --git a/llvm/lib/CodeGen/PostRASchedulerList.cpp b/llvm/lib/CodeGen/PostRASchedulerList.cpp
index d6af437..b85f00a 100644
--- a/llvm/lib/CodeGen/PostRASchedulerList.cpp
+++ b/llvm/lib/CodeGen/PostRASchedulerList.cpp
@@ -527,6 +527,9 @@
// blocks are a single region).
HazardRec->Reset();
+ // Release any successors of the special Entry node.
+ ReleaseSuccessors(&EntrySU);
+
// Add all leaves to Available queue.
for (unsigned i = 0, e = SUnits.size(); i != e; ++i) {
// It is available if it has no predecessors.
diff --git a/llvm/lib/CodeGen/ScheduleDAG.cpp b/llvm/lib/CodeGen/ScheduleDAG.cpp
index 0e9c4e6..60f8eec 100644
--- a/llvm/lib/CodeGen/ScheduleDAG.cpp
+++ b/llvm/lib/CodeGen/ScheduleDAG.cpp
@@ -63,6 +63,7 @@
void ScheduleDAG::clearDAG() {
SUnits.clear();
+ EntrySU = SUnit();
ExitSU = SUnit();
}
@@ -351,7 +352,9 @@
}
LLVM_DUMP_METHOD void ScheduleDAG::dumpNodeName(const SUnit &SU) const {
- if (&SU == &ExitSU)
+ if (&SU == &EntrySU)
+ dbgs() << "EntrySU";
+ else if (&SU == &ExitSU)
dbgs() << "ExitSU";
else
dbgs() << "SU(" << SU.NodeNum << ")";
@@ -653,7 +656,7 @@
for (int I = SU->Preds.size()-1; I >= 0; --I) {
const SUnit *Pred = SU->Preds[I].getSUnit();
unsigned s = Pred->NodeNum;
- // Edges to non-SUnits are allowed but ignored (e.g. ExitSU).
+ // Edges to non-SUnits are allowed but ignored (e.g. EntrySU).
if (Pred->isBoundaryNode())
continue;
if (Node2Index[s] == LowerBound) {
diff --git a/llvm/lib/CodeGen/ScheduleDAGInstrs.cpp b/llvm/lib/CodeGen/ScheduleDAGInstrs.cpp
index 9fb24ed..10453c4 100644
--- a/llvm/lib/CodeGen/ScheduleDAGInstrs.cpp
+++ b/llvm/lib/CodeGen/ScheduleDAGInstrs.cpp
@@ -1167,6 +1167,8 @@
void ScheduleDAGInstrs::dump() const {
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+ if (EntrySU.getInstr() != nullptr)
+ dumpNodeAll(EntrySU);
for (const SUnit &SU : SUnits)
dumpNodeAll(SU);
if (ExitSU.getInstr() != nullptr)
@@ -1177,7 +1179,9 @@
std::string ScheduleDAGInstrs::getGraphNodeLabel(const SUnit *SU) const {
std::string s;
raw_string_ostream oss(s);
- if (SU == &ExitSU)
+ if (SU == &EntrySU)
+ oss << "<entry>";
+ else if (SU == &ExitSU)
oss << "<exit>";
else
SU->getInstr()->print(oss, /*IsStandalone=*/true);
diff --git a/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp b/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp
index e2a9d7c..2902c96 100644
--- a/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp
@@ -150,8 +150,8 @@
--PredSU->NumSuccsLeft;
// If all the node's successors are scheduled, this node is ready
- // to be scheduled.
- if (PredSU->NumSuccsLeft == 0) {
+ // to be scheduled. Ignore the special EntrySU node.
+ if (PredSU->NumSuccsLeft == 0 && PredSU != &EntrySU) {
PredSU->isAvailable = true;
AvailableQueue.push(PredSU);
}
diff --git a/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp b/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
index 73f09e6..7a5e8ac 100644
--- a/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
@@ -415,8 +415,8 @@
}
// If all the node's successors are scheduled, this node is ready
- // to be scheduled.
- if (PredSU->NumSuccsLeft == 0) {
+ // to be scheduled. Ignore the special EntrySU node.
+ if (PredSU->NumSuccsLeft == 0 && PredSU != &EntrySU) {
PredSU->isAvailable = true;
unsigned Height = PredSU->getHeight();
diff --git a/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp b/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
index db9f4e3..76fb034 100644
--- a/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
@@ -696,6 +696,8 @@
void ScheduleDAGSDNodes::dump() const {
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+ if (EntrySU.getNode() != nullptr)
+ dumpNodeAll(EntrySU);
for (const SUnit &SU : SUnits)
dumpNodeAll(SU);
if (ExitSU.getNode() != nullptr)
diff --git a/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGVLIW.cpp b/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGVLIW.cpp
index 05d3eaa..e7bac73 100644
--- a/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGVLIW.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGVLIW.cpp
@@ -166,6 +166,9 @@
void ScheduleDAGVLIW::listScheduleTopDown() {
unsigned CurCycle = 0;
+ // Release any successors of the special Entry node.
+ releaseSuccessors(&EntrySU);
+
// All leaves to AvailableQueue.
for (unsigned i = 0, e = SUnits.size(); i != e; ++i) {
// It is available if it has no predecessors.
diff --git a/llvm/lib/Target/AMDGPU/GCNMinRegStrategy.cpp b/llvm/lib/Target/AMDGPU/GCNMinRegStrategy.cpp
index 417abc4..884b2e1 100644
--- a/llvm/lib/Target/AMDGPU/GCNMinRegStrategy.cpp
+++ b/llvm/lib/Target/AMDGPU/GCNMinRegStrategy.cpp
@@ -248,6 +248,7 @@
for (auto SU : TopRoots) {
RQ.push_back(*new (Alloc.Allocate()) Candidate(SU, StepNo));
}
+ releaseSuccessors(&DAG.EntrySU, StepNo);
while (!RQ.empty()) {
LLVM_DEBUG(dbgs() << "\n=== Picking candidate, Step = " << StepNo
diff --git a/llvm/lib/Target/AMDGPU/SIMachineScheduler.h b/llvm/lib/Target/AMDGPU/SIMachineScheduler.h
index cfa6734..0a8abbb 100644
--- a/llvm/lib/Target/AMDGPU/SIMachineScheduler.h
+++ b/llvm/lib/Target/AMDGPU/SIMachineScheduler.h
@@ -455,6 +455,7 @@
MachineRegisterInfo *getMRI() { return &MRI; }
const TargetRegisterInfo *getTRI() { return TRI; }
ScheduleDAGTopologicalSort *GetTopo() { return &Topo; }
+ SUnit &getEntrySU() { return EntrySU; }
SUnit& getExitSU() { return ExitSU; }
void restoreSULinksLeft();