AvailableQueue->push(SU);
}
+// FIXME: This is probably too slow!
+static void isReachable(SUnit *SU, SUnit *TargetSU,
+ SmallPtrSet<SUnit*, 32> &Visited, bool &Reached) {
+ if (Reached) return;
+ if (SU == TargetSU) {
+ Reached = true;
+ return;
+ }
+ if (!Visited.insert(SU)) return;
+
+ for (SUnit::pred_iterator I = SU->Preds.begin(), E = SU->Preds.end(); I != E;
+ ++I)
+ isReachable(I->Dep, TargetSU, Visited, Reached);
+}
+
+static bool isReachable(SUnit *SU, SUnit *TargetSU) {
+ SmallPtrSet<SUnit*, 32> Visited;
+ bool Reached = false;
+ isReachable(SU, TargetSU, Visited, Reached);
+ return Reached;
+}
+
+/// willCreateCycle - Returns true if adding an edge from SU to TargetSU will
+/// create a cycle.
+static bool willCreateCycle(SUnit *SU, SUnit *TargetSU) {
+ if (isReachable(TargetSU, SU))
+ return true;
+ for (SUnit::pred_iterator I = SU->Preds.begin(), E = SU->Preds.end();
+ I != E; ++I)
+ if (I->Cost < 0 && isReachable(TargetSU, I->Dep))
+ return true;
+ return false;
+}
+
/// BacktrackBottomUp - Backtrack scheduling to a previous cycle specified in
/// BTCycle in order to schedule a specific node. Returns the last unscheduled
/// SUnit. Also returns if a successor is unscheduled in the process.
return N->getValueType(NumRes);
}
-// FIXME: This is probably too slow!
-static void isReachable(SUnit *SU, SUnit *TargetSU,
- SmallPtrSet<SUnit*, 32> &Visited, bool &Reached) {
- if (Reached) return;
- if (SU == TargetSU) {
- Reached = true;
- return;
- }
- if (!Visited.insert(SU)) return;
-
- for (SUnit::pred_iterator I = SU->Preds.begin(), E = SU->Preds.end(); I != E;
- ++I)
- isReachable(I->Dep, TargetSU, Visited, Reached);
-}
-
-static bool isReachable(SUnit *SU, SUnit *TargetSU) {
- SmallPtrSet<SUnit*, 32> Visited;
- bool Reached = false;
- isReachable(SU, TargetSU, Visited, Reached);
- return Reached;
-}
-
/// DelayForLiveRegsBottomUp - Returns true if it is necessary to delay
/// scheduling of the given node to satisfy live physical register dependencies.
/// If the specific node is the last one that's available to schedule, do
}
SUnit *OldSU = Sequence[LiveCycle];
- if (!isReachable(Sequence[LiveCycle], SU)) {
+ if (!willCreateCycle(SU, OldSU)) {
// If CycleBound is greater than backtrack cycle, then some of SU
// successors are going to be unscheduled.
bool SuccUnsched = SU->CycleBound > LiveCycle;