misched: Infrastructure for weak DAG edges.
This adds support for weak DAG edges to the general scheduling
infrastructure in preparation for MachineScheduler support for
heuristics based on weak edges.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167738 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/PostRASchedulerList.cpp b/lib/CodeGen/PostRASchedulerList.cpp
index d57bc73..4284c42 100644
--- a/lib/CodeGen/PostRASchedulerList.cpp
+++ b/lib/CodeGen/PostRASchedulerList.cpp
@@ -111,9 +111,6 @@
/// added to the AvailableQueue.
std::vector<SUnit*> PendingQueue;
- /// Topo - A topological ordering for SUnits.
- ScheduleDAGTopologicalSort Topo;
-
/// HazardRec - The hazard recognizer to use.
ScheduleHazardRecognizer *HazardRec;
@@ -198,7 +195,7 @@
AliasAnalysis *AA, const RegisterClassInfo &RCI,
TargetSubtargetInfo::AntiDepBreakMode AntiDepMode,
SmallVectorImpl<const TargetRegisterClass*> &CriticalPathRCs)
- : ScheduleDAGInstrs(MF, MLI, MDT, /*IsPostRA=*/true), Topo(SUnits), AA(AA),
+ : ScheduleDAGInstrs(MF, MLI, MDT, /*IsPostRA=*/true), AA(AA),
LiveRegs(TRI->getNumRegs())
{
const TargetMachine &TM = MF.getTarget();
@@ -580,10 +577,14 @@
//===----------------------------------------------------------------------===//
/// ReleaseSucc - Decrement the NumPredsLeft count of a successor. Add it to
-/// the PendingQueue if the count reaches zero. Also update its cycle bound.
+/// the PendingQueue if the count reaches zero.
void SchedulePostRATDList::ReleaseSucc(SUnit *SU, SDep *SuccEdge) {
SUnit *SuccSU = SuccEdge->getSUnit();
+ if (SuccEdge->isArtificial()) {
+ --SuccSU->WeakPredsLeft;
+ return;
+ }
#ifndef NDEBUG
if (SuccSU->NumPredsLeft == 0) {
dbgs() << "*** Scheduling failed! ***\n";
@@ -653,8 +654,7 @@
// Add all leaves to Available queue.
for (unsigned i = 0, e = SUnits.size(); i != e; ++i) {
// It is available if it has no predecessors.
- bool available = SUnits[i].Preds.empty();
- if (available) {
+ if (!SUnits[i].NumPredsLeft && !SUnits[i].isAvailable) {
AvailableQueue.push(&SUnits[i]);
SUnits[i].isAvailable = true;
}