Remove redundant init class instructions
Change-Id: I462cd6e63fab090f3f059e886de49b96a5f068a4
diff --git a/src/main/java/com/android/tools/r8/ir/optimize/RedundantFieldLoadAndStoreElimination.java b/src/main/java/com/android/tools/r8/ir/optimize/RedundantFieldLoadAndStoreElimination.java
index 0e3dfdb..50bea08 100644
--- a/src/main/java/com/android/tools/r8/ir/optimize/RedundantFieldLoadAndStoreElimination.java
+++ b/src/main/java/com/android/tools/r8/ir/optimize/RedundantFieldLoadAndStoreElimination.java
@@ -29,6 +29,7 @@
import com.android.tools.r8.ir.code.Instruction;
import com.android.tools.r8.ir.code.InstructionListIterator;
import com.android.tools.r8.ir.code.InvokeDirect;
+import com.android.tools.r8.ir.code.InvokeStatic;
import com.android.tools.r8.ir.code.NewInstance;
import com.android.tools.r8.ir.code.Phi;
import com.android.tools.r8.ir.code.StaticGet;
@@ -243,13 +244,12 @@
}
} else if (instruction.isInvokeDirect()) {
handleInvokeDirect(instruction.asInvokeDirect());
+ } else if (instruction.isInvokeStatic()) {
+ handleInvokeStatic(instruction.asInvokeStatic());
} else if (instruction.isInvokeMethod() || instruction.isInvokeCustom()) {
killAllNonFinalActiveFields();
} else if (instruction.isNewInstance()) {
- NewInstance newInstance = instruction.asNewInstance();
- if (newInstance.clazz.classInitializationMayHaveSideEffectsInContext(appView, method)) {
- killAllNonFinalActiveFields();
- }
+ handleNewInstance(instruction.asNewInstance());
} else {
// If the current instruction could trigger a method invocation, it could also cause
// field values to change. In that case, it must be handled above.
@@ -258,6 +258,7 @@
// Clear the field writes.
if (instruction.instructionInstanceCanThrow(appView, method)) {
activeState.clearMostRecentFieldWrites();
+ activeState.clearMostRecentInitClass();
}
// If this assertion fails for a new instruction we need to determine if that
@@ -394,6 +395,23 @@
});
}
+ private void handleInvokeStatic(InvokeStatic invoke) {
+ if (appView.hasClassHierarchy()) {
+ ProgramMethod resolvedMethod =
+ appView
+ .appInfo()
+ .withClassHierarchy()
+ .unsafeResolveMethodDueToDexFormat(invoke.getInvokedMethod())
+ .getResolvedProgramMethod();
+ if (resolvedMethod != null) {
+ markClassAsInitialized(resolvedMethod.getHolderType());
+ markMostRecentInitClassForRemoval(resolvedMethod.getHolderType());
+ }
+ }
+
+ killAllNonFinalActiveFields();
+ }
+
private void handleInitClass(InstructionListIterator instructionIterator, InitClass initClass) {
assert !initClass.outValue().hasAnyUsers();
@@ -406,11 +424,28 @@
}
DexType clazz = initClass.getClassValue();
- if (!activeState.markClassAsInitialized(clazz)) {
+ if (markClassAsInitialized(clazz)) {
+ if (release) {
+ activeState.setMostRecentInitClass(initClass);
+ }
+ } else {
instructionIterator.removeOrReplaceByDebugLocalRead();
}
}
+ private boolean markClassAsInitialized(DexType type) {
+ return activeState.markClassAsInitialized(type);
+ }
+
+ private void markMostRecentInitClassForRemoval(DexType initializedType) {
+ InitClass mostRecentInitClass = activeState.getMostRecentInitClass();
+ if (mostRecentInitClass != null && mostRecentInitClass.getClassValue() == initializedType) {
+ instructionsToRemove
+ .computeIfAbsent(mostRecentInitClass.getBlock(), ignoreKey(Sets::newIdentityHashSet))
+ .add(mostRecentInitClass);
+ }
+ }
+
private void handleInstanceGet(
InstructionListIterator it,
InstanceGet instanceGet,
@@ -431,9 +466,18 @@
}
activeState.putNonFinalInstanceField(fieldAndObject, new ExistingValue(instanceGet.value()));
+ activeState.clearMostRecentInitClass();
clearMostRecentInstanceFieldWrite(instanceGet, field);
}
+ private void handleNewInstance(NewInstance newInstance) {
+ markClassAsInitialized(newInstance.getType());
+ markMostRecentInitClassForRemoval(newInstance.getType());
+ if (newInstance.getType().classInitializationMayHaveSideEffectsInContext(appView, method)) {
+ killAllNonFinalActiveFields();
+ }
+ }
+
private void clearMostRecentInstanceFieldWrite(InstanceGet instanceGet, DexClassAndField field) {
// If the instruction can throw, we need to clear all most-recent-writes, since subsequent field
// writes (if any) are not guaranteed to be executed.
@@ -494,6 +538,8 @@
}
}
}
+
+ activeState.clearMostRecentInitClass();
}
private void handleStaticGet(
@@ -501,6 +547,8 @@
StaticGet staticGet,
DexClassAndField field,
AssumeRemover assumeRemover) {
+ markClassAsInitialized(field.getHolderType());
+
if (staticGet.outValue().hasLocalInfo()) {
killNonFinalActiveFields(staticGet);
clearMostRecentStaticFieldWrite(staticGet, field);
@@ -532,6 +580,9 @@
applyObjectState(staticGet.outValue(), singleFieldValue.getObjectState());
}
}
+
+ markMostRecentInitClassForRemoval(field.getHolderType());
+ activeState.clearMostRecentInitClass();
}
private void clearMostRecentStaticFieldWrite(StaticGet staticGet, DexClassAndField field) {
@@ -545,6 +596,8 @@
}
private void handleStaticPut(StaticPut staticPut, DexClassAndField field) {
+ markClassAsInitialized(field.getHolderType());
+
// A field put on a different class can cause <clinit> to run and change static field values.
killNonFinalActiveFields(staticPut);
@@ -573,6 +626,9 @@
}
}
}
+
+ markMostRecentInitClassForRemoval(field.getHolderType());
+ activeState.clearMostRecentInitClass();
}
private void applyObjectState(Value value, ObjectState objectState) {
@@ -593,6 +649,7 @@
activeState.clearNonFinalInstanceFields();
activeState.clearNonFinalStaticFields();
activeState.clearMostRecentFieldWrites();
+ activeState.clearMostRecentInitClass();
}
private void killNonFinalActiveFields(Instruction instruction) {
@@ -714,6 +771,7 @@
}
if (!block.hasUniqueSuccessorWithUniquePredecessor()) {
state.clearMostRecentFieldWrites();
+ state.clearMostRecentInitClass();
}
ensureCapacity(state);
activeStateAtExit.put(block, state);
@@ -753,6 +811,8 @@
private LinkedHashMap<DexField, FieldValue> nonFinalStaticFieldValues;
+ private InitClass mostRecentInitClass;
+
private LinkedHashMap<FieldAndObject, InstancePut> mostRecentInstanceFieldWrites;
private LinkedHashMap<DexField, StaticPut> mostRecentStaticFieldWrites;
@@ -787,6 +847,7 @@
nonFinalStaticFieldValues = new LinkedHashMap<>();
nonFinalStaticFieldValues.putAll(state.nonFinalStaticFieldValues);
}
+ mostRecentInitClass = state.mostRecentInitClass;
if (state.mostRecentInstanceFieldWrites != null
&& !state.mostRecentInstanceFieldWrites.isEmpty()) {
mostRecentInstanceFieldWrites = new LinkedHashMap<>();
@@ -885,6 +946,7 @@
} else {
nonFinalStaticFieldValues = null;
}
+ assert mostRecentInitClass == null;
assert mostRecentInstanceFieldWrites == null;
assert mostRecentStaticFieldWrites == null;
}
@@ -899,10 +961,6 @@
initializedClasses.removeIf(not(other::contains));
}
- public boolean isClassInitialized(DexType clazz) {
- return initializedClasses != null && initializedClasses.contains(clazz);
- }
-
public boolean isEmpty() {
return isEmpty(finalInstanceFieldValues)
&& isEmpty(finalStaticFieldValues)
@@ -1082,6 +1140,20 @@
nonFinalStaticFieldValues.put(field, value);
}
+ public InitClass getMostRecentInitClass() {
+ return mostRecentInitClass;
+ }
+
+ public void setMostRecentInitClass(InitClass initClass) {
+ mostRecentInitClass = initClass;
+ }
+
+ public InitClass clearMostRecentInitClass() {
+ InitClass result = mostRecentInitClass;
+ mostRecentInitClass = null;
+ return result;
+ }
+
public int size() {
return size(finalInstanceFieldValues)
+ size(finalStaticFieldValues)
diff --git a/src/test/java/com/android/tools/r8/ir/optimize/redundantfieldloadelimination/RedundantInitClassBeforeInvokeStaticTest.java b/src/test/java/com/android/tools/r8/ir/optimize/redundantfieldloadelimination/RedundantInitClassBeforeInvokeStaticTest.java
index b2ea2ce..d7e4296 100644
--- a/src/test/java/com/android/tools/r8/ir/optimize/redundantfieldloadelimination/RedundantInitClassBeforeInvokeStaticTest.java
+++ b/src/test/java/com/android/tools/r8/ir/optimize/redundantfieldloadelimination/RedundantInitClassBeforeInvokeStaticTest.java
@@ -45,7 +45,7 @@
assertThat(greeterClassSubject, isPresent());
assertThat(greeterClassSubject.uniqueMethodWithName("hello"), isAbsent());
assertThat(greeterClassSubject.uniqueMethodWithName("world"), isPresent());
- assertEquals(1, greeterClassSubject.allFields().size());
+ assertEquals(0, greeterClassSubject.allFields().size());
})
.run(parameters.getRuntime(), Main.class)
.assertSuccessWithOutputLines("Hello world!");
