Prune the flow propagation graph on-the-fly in argument propagator
Change-Id: I1e986618a5d0bb7e56796df3ef985758abcc33f2
diff --git a/src/main/java/com/android/tools/r8/optimize/argumentpropagation/propagation/InParameterFlowPropagator.java b/src/main/java/com/android/tools/r8/optimize/argumentpropagation/propagation/InParameterFlowPropagator.java
index 1f8637a..98277f4 100644
--- a/src/main/java/com/android/tools/r8/optimize/argumentpropagation/propagation/InParameterFlowPropagator.java
+++ b/src/main/java/com/android/tools/r8/optimize/argumentpropagation/propagation/InParameterFlowPropagator.java
@@ -28,6 +28,7 @@
import it.unimi.dsi.fastutil.ints.Int2ReferenceMap;
import it.unimi.dsi.fastutil.ints.Int2ReferenceOpenHashMap;
import java.util.ArrayDeque;
+import java.util.ArrayList;
import java.util.Deque;
import java.util.IdentityHashMap;
import java.util.List;
@@ -73,9 +74,6 @@
// p3, and then p1, then the processing of p1 could cause p2 to change, which means that we
// need to reprocess p2 and then p3. If we always process leaves in the graph first, we would
// process p1, then p2, then p3, and then be done.
- // TODO(b/190154391): Prune the graph on-the-fly. If the argument information for a parameter
- // becomes unknown, we could consider clearing its predecessors since none of the predecessors
- // could contribute any information even if they change.
while (!worklist.isEmpty()) {
ParameterNode parameterNode = worklist.removeLast();
parameterNode.unsetPending();
@@ -98,9 +96,19 @@
if (parameterState.isBottom()) {
return;
}
+ List<ParameterNode> newlyUnknownParameterNodes = new ArrayList<>();
for (ParameterNode successorNode : parameterNode.getSuccessors()) {
- successorNode.addState(
- appView, parameterState.asNonEmpty(), () -> affectedNodeConsumer.accept(successorNode));
+ ParameterState newParameterState =
+ successorNode.addState(
+ appView,
+ parameterState.asNonEmpty(),
+ () -> affectedNodeConsumer.accept(successorNode));
+ if (newParameterState.isUnknown()) {
+ newlyUnknownParameterNodes.add(successorNode);
+ }
+ }
+ for (ParameterNode newlyUnknownParameterNode : newlyUnknownParameterNodes) {
+ newlyUnknownParameterNode.clearPredecessors();
}
}
@@ -307,7 +315,7 @@
return pending;
}
- void addState(
+ ParameterState addState(
AppView<AppInfoWithLiveness> appView,
NonEmptyParameterState parameterStateToAdd,
Action onChangedAction) {
@@ -319,6 +327,7 @@
setState(newParameterState);
onChangedAction.execute();
}
+ return newParameterState;
}
void setPending() {
