MIsched: Improve the interface to SchedDFS analysis (subtrees).
Allow the strategy to select SchedDFS. Allow the results of SchedDFS
to affect initialization of the scheduler state.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173425 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineScheduler.cpp b/lib/CodeGen/MachineScheduler.cpp
index 3e5935c..aa59915 100644
--- a/lib/CodeGen/MachineScheduler.cpp
+++ b/lib/CodeGen/MachineScheduler.cpp
@@ -510,10 +510,19 @@
postprocessDAG();
+ SmallVector<SUnit*, 8> TopRoots, BotRoots;
+ findRootsAndBiasEdges(TopRoots, BotRoots);
+
+ // Initialize the strategy before modifying the DAG.
+ // This may initialize a DFSResult to be used for queue priority.
+ SchedImpl->initialize(this);
+
DEBUG(for (unsigned su = 0, e = SUnits.size(); su != e; ++su)
SUnits[su].dumpAll(this));
+ if (ViewMISchedDAGs) viewGraph();
- initQueues();
+ // Initialize ready queues now that the DAG and priority data are finalized.
+ initQueues(TopRoots, BotRoots);
bool IsTopNode = false;
while (SUnit *SU = SchedImpl->pickNode(IsTopNode)) {
@@ -561,25 +570,18 @@
}
}
-void ScheduleDAGMI::initDFSResult() {
+void ScheduleDAGMI::computeDFSResult() {
if (!DFSResult)
DFSResult = new SchedDFSResult(/*BottomU*/true, MinSubtreeSize);
DFSResult->clear();
- DFSResult->resize(SUnits.size());
ScheduledTrees.clear();
-}
-
-void ScheduleDAGMI::computeDFSResult(ArrayRef<SUnit*> Roots) {
- DFSResult->compute(Roots);
+ DFSResult->resize(SUnits.size());
+ DFSResult->compute(SUnits);
ScheduledTrees.resize(DFSResult->getNumSubtrees());
}
-// Release all DAG roots for scheduling.
-//
-// Nodes with unreleased weak edges can still be roots.
-void ScheduleDAGMI::releaseRoots() {
- SmallVector<SUnit*, 16> BotRoots;
-
+void ScheduleDAGMI::findRootsAndBiasEdges(SmallVectorImpl<SUnit*> &TopRoots,
+ SmallVectorImpl<SUnit*> &BotRoots) {
for (std::vector<SUnit>::iterator
I = SUnits.begin(), E = SUnits.end(); I != E; ++I) {
SUnit *SU = &(*I);
@@ -589,28 +591,33 @@
// A SUnit is ready to top schedule if it has no predecessors.
if (!I->NumPredsLeft && SU != &EntrySU)
- SchedImpl->releaseTopNode(SU);
+ TopRoots.push_back(SU);
// A SUnit is ready to bottom schedule if it has no successors.
if (!I->NumSuccsLeft && SU != &ExitSU)
BotRoots.push_back(SU);
}
- // Release bottom roots in reverse order so the higher priority nodes appear
- // first. This is more natural and slightly more efficient.
- for (SmallVectorImpl<SUnit*>::const_reverse_iterator
- I = BotRoots.rbegin(), E = BotRoots.rend(); I != E; ++I)
- SchedImpl->releaseBottomNode(*I);
}
/// Identify DAG roots and setup scheduler queues.
-void ScheduleDAGMI::initQueues() {
+void ScheduleDAGMI::initQueues(ArrayRef<SUnit*> TopRoots,
+ ArrayRef<SUnit*> BotRoots) {
NextClusterSucc = NULL;
NextClusterPred = NULL;
- // Initialize the strategy before modifying the DAG.
- SchedImpl->initialize(this);
-
// Release all DAG roots for scheduling, not including EntrySU/ExitSU.
- releaseRoots();
+ //
+ // Nodes with unreleased weak edges can still be roots.
+ // Release top roots in forward order.
+ for (SmallVectorImpl<SUnit*>::const_iterator
+ I = TopRoots.begin(), E = TopRoots.end(); I != E; ++I) {
+ SchedImpl->releaseTopNode(*I);
+ }
+ // Release bottom roots in reverse order so the higher priority nodes appear
+ // first. This is more natural and slightly more efficient.
+ for (SmallVectorImpl<SUnit*>::const_reverse_iterator
+ I = BotRoots.rbegin(), E = BotRoots.rend(); I != E; ++I) {
+ SchedImpl->releaseBottomNode(*I);
+ }
releaseSuccessors(&EntrySU);
releasePredecessors(&ExitSU);
@@ -1216,7 +1223,7 @@
Top.init(DAG, SchedModel, &Rem);
Bot.init(DAG, SchedModel, &Rem);
- DAG->initDFSResult();
+ DAG->computeDFSResult();
// Initialize resource counts.
@@ -1278,8 +1285,6 @@
Rem.CriticalPath = (*I)->getDepth();
}
DEBUG(dbgs() << "Critical Path: " << Rem.CriticalPath << '\n');
-
- DAG->computeDFSResult(Bot.Available.elements());
}
/// Does this SU have a hazard within the current instruction group.
@@ -2140,14 +2145,13 @@
virtual void initialize(ScheduleDAGMI *dag) {
DAG = dag;
- DAG->initDFSResult();
+ DAG->computeDFSResult();
Cmp.DFSResult = DAG->getDFSResult();
Cmp.ScheduledTrees = &DAG->getScheduledTrees();
ReadyQ.clear();
}
virtual void registerRoots() {
- DAG->computeDFSResult(ReadyQ);
// Restore the heap in ReadyQ with the updated DFS results.
std::make_heap(ReadyQ.begin(), ReadyQ.end(), Cmp);
}