Tests for extending redundant field load elimination to final fields
Bug: 152196923
Change-Id: Idbb63335184b4199a5ab5d5d3949ba9ea5ddae1d
diff --git a/src/test/java/com/android/tools/r8/ir/optimize/redundantfieldloadelimination/RedundantFinalInstanceFieldLoadAfterStoreTest.java b/src/test/java/com/android/tools/r8/ir/optimize/redundantfieldloadelimination/RedundantFinalInstanceFieldLoadAfterStoreTest.java
new file mode 100644
index 0000000..4958163
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/ir/optimize/redundantfieldloadelimination/RedundantFinalInstanceFieldLoadAfterStoreTest.java
@@ -0,0 +1,144 @@
+package com.android.tools.r8.ir.optimize.redundantfieldloadelimination;
+
+import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertEquals;
+
+import com.android.tools.r8.NeverClassInline;
+import com.android.tools.r8.NeverInline;
+import com.android.tools.r8.NeverPropagateValue;
+import com.android.tools.r8.TestBase;
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.TestParametersCollection;
+import com.android.tools.r8.ir.optimize.redundantfieldloadelimination.RedundantFinalStaticFieldLoadAfterStoreTest.A;
+import com.android.tools.r8.utils.codeinspector.ClassSubject;
+import com.android.tools.r8.utils.codeinspector.CodeInspector;
+import com.android.tools.r8.utils.codeinspector.FieldSubject;
+import com.android.tools.r8.utils.codeinspector.FoundFieldSubject;
+import com.android.tools.r8.utils.codeinspector.FoundMethodSubject;
+import com.android.tools.r8.utils.codeinspector.InstructionSubject;
+import com.android.tools.r8.utils.codeinspector.MethodSubject;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameters;
+
+@RunWith(Parameterized.class)
+public class RedundantFinalInstanceFieldLoadAfterStoreTest extends TestBase {
+
+ private final TestParameters parameters;
+
+ @Parameters(name = "{0}")
+ public static TestParametersCollection data() {
+ return getTestParameters().withAllRuntimesAndApiLevels().build();
+ }
+
+ public RedundantFinalInstanceFieldLoadAfterStoreTest(TestParameters parameters) {
+ this.parameters = parameters;
+ }
+
+ @Test
+ public void test() throws Exception {
+ testForR8(parameters.getBackend())
+ .addInnerClasses(RedundantFinalInstanceFieldLoadAfterStoreTest.class)
+ .addKeepMainRule(TestClass.class)
+ .enableInliningAnnotations()
+ .enableMemberValuePropagationAnnotations()
+ .enableNeverClassInliningAnnotations()
+ .setMinApi(parameters.getApiLevel())
+ .compile()
+ .inspect(this::inspect)
+ .run(parameters.getRuntime(), TestClass.class)
+ .assertSuccessWithOutputLines("0", "42", "42", "42");
+ }
+
+ private void inspect(CodeInspector inspector) {
+ ClassSubject aClassSubject = inspector.clazz(A.class);
+ assertThat(aClassSubject, isPresent());
+
+ FieldSubject fFieldSubject = aClassSubject.uniqueFieldWithName("f");
+ assertThat(fFieldSubject, isPresent());
+
+ MethodSubject initMethodSubject = aClassSubject.init();
+ assertThat(initMethodSubject, isPresent());
+ // TODO(b/152196923): Should be 0.
+ assertEquals(
+ 2,
+ countInstanceGetInstructions(
+ initMethodSubject.asFoundMethodSubject(), fFieldSubject.asFoundFieldSubject()));
+
+ MethodSubject mMethodSubject = aClassSubject.uniqueMethodWithName("m");
+ assertThat(mMethodSubject, isPresent());
+ assertEquals(
+ 2,
+ countInstanceGetInstructions(
+ mMethodSubject.asFoundMethodSubject(), fFieldSubject.asFoundFieldSubject()));
+ }
+
+ private long countInstanceGetInstructions(
+ FoundMethodSubject methodSubject, FoundFieldSubject fieldSubject) {
+ return methodSubject
+ .streamInstructions()
+ .filter(InstructionSubject::isInstanceGet)
+ .map(InstructionSubject::getField)
+ .filter(fieldSubject.getField().field::equals)
+ .count();
+ }
+
+ static class TestClass {
+
+ public static void main(String[] args) {
+ new A();
+ }
+ }
+
+ @NeverClassInline
+ static class A {
+
+ @NeverPropagateValue final long f;
+
+ static volatile boolean read;
+ static volatile boolean initialized;
+
+ A() {
+ fork();
+ waitUntilRead();
+ f = System.currentTimeMillis() > 0 ? 42 : 0;
+ initialized = true;
+ killNonFinalActiveFields();
+ System.out.println(f); // Redundant, since `f` is final and guaranteed to be initialized.
+ killNonFinalActiveFields();
+ System.out.println(f); // Redundant, since `f` is final and guaranteed to be initialized.
+ }
+
+ @NeverInline
+ void m() {
+ System.out.println(f);
+ read = true;
+ waitUntilInitialized();
+ System.out.println(f); // Not redundant, since `f` is not guaranteed to be initialized.
+ }
+
+ void fork() {
+ new Thread(this::m).start();
+ }
+
+ void killNonFinalActiveFields() {
+ if (System.currentTimeMillis() < 0) {
+ System.out.println(this);
+ }
+ }
+
+ void waitUntilInitialized() {
+ while (!initialized) {
+ Thread.yield();
+ }
+ }
+
+ void waitUntilRead() {
+ while (!read) {
+ Thread.yield();
+ }
+ }
+ }
+}
diff --git a/src/test/java/com/android/tools/r8/ir/optimize/redundantfieldloadelimination/RedundantFinalStaticFieldLoadAfterStoreTest.java b/src/test/java/com/android/tools/r8/ir/optimize/redundantfieldloadelimination/RedundantFinalStaticFieldLoadAfterStoreTest.java
new file mode 100644
index 0000000..8f3ed33
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/ir/optimize/redundantfieldloadelimination/RedundantFinalStaticFieldLoadAfterStoreTest.java
@@ -0,0 +1,119 @@
+package com.android.tools.r8.ir.optimize.redundantfieldloadelimination;
+
+import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertEquals;
+
+import com.android.tools.r8.NeverInline;
+import com.android.tools.r8.NeverPropagateValue;
+import com.android.tools.r8.TestBase;
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.TestParametersCollection;
+import com.android.tools.r8.utils.codeinspector.ClassSubject;
+import com.android.tools.r8.utils.codeinspector.CodeInspector;
+import com.android.tools.r8.utils.codeinspector.FieldSubject;
+import com.android.tools.r8.utils.codeinspector.FoundFieldSubject;
+import com.android.tools.r8.utils.codeinspector.FoundMethodSubject;
+import com.android.tools.r8.utils.codeinspector.InstructionSubject;
+import com.android.tools.r8.utils.codeinspector.MethodSubject;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameters;
+
+@RunWith(Parameterized.class)
+public class RedundantFinalStaticFieldLoadAfterStoreTest extends TestBase {
+
+ private final TestParameters parameters;
+
+ @Parameters(name = "{0}")
+ public static TestParametersCollection data() {
+ return getTestParameters().withAllRuntimesAndApiLevels().build();
+ }
+
+ public RedundantFinalStaticFieldLoadAfterStoreTest(TestParameters parameters) {
+ this.parameters = parameters;
+ }
+
+ @Test
+ public void test() throws Exception {
+ testForR8(parameters.getBackend())
+ .addInnerClasses(RedundantFinalStaticFieldLoadAfterStoreTest.class)
+ .addKeepMainRule(TestClass.class)
+ .enableInliningAnnotations()
+ .enableMemberValuePropagationAnnotations()
+ .setMinApi(parameters.getApiLevel())
+ .compile()
+ .inspect(this::inspect)
+ .run(parameters.getRuntime(), TestClass.class)
+ .assertSuccessWithOutputLines("42", "42", "42", "42");
+ }
+
+ private void inspect(CodeInspector inspector) {
+ ClassSubject aClassSubject = inspector.clazz(A.class);
+ assertThat(aClassSubject, isPresent());
+
+ FieldSubject fFieldSubject = aClassSubject.uniqueFieldWithName("f");
+ assertThat(fFieldSubject, isPresent());
+
+ MethodSubject initMethodSubject = aClassSubject.clinit();
+ assertThat(initMethodSubject, isPresent());
+ // TODO(b/152196923): Should be 0.
+ assertEquals(
+ 2,
+ countStaticGetInstructions(
+ initMethodSubject.asFoundMethodSubject(), fFieldSubject.asFoundFieldSubject()));
+
+ MethodSubject mMethodSubject = aClassSubject.uniqueMethodWithName("m");
+ assertThat(mMethodSubject, isPresent());
+ // TODO(b/152196923): Should be 0.
+ assertEquals(
+ 2,
+ countStaticGetInstructions(
+ mMethodSubject.asFoundMethodSubject(), fFieldSubject.asFoundFieldSubject()));
+ }
+
+ private long countStaticGetInstructions(
+ FoundMethodSubject methodSubject, FoundFieldSubject fieldSubject) {
+ return methodSubject
+ .streamInstructions()
+ .filter(InstructionSubject::isStaticGet)
+ .map(InstructionSubject::getField)
+ .filter(fieldSubject.getField().field::equals)
+ .count();
+ }
+
+ static class TestClass {
+
+ public static void main(String[] args) {
+ A.m();
+ }
+ }
+
+ static class A {
+
+ @NeverPropagateValue static final long f;
+
+ static {
+ f = System.currentTimeMillis() > 0 ? 42 : 0;
+ killNonFinalActiveFields();
+ System.out.println(f); // Redundant, since `f` is final and guaranteed to be initialized.
+ killNonFinalActiveFields();
+ System.out.println(f); // Redundant, since `f` is final and guaranteed to be initialized.
+ }
+
+ @NeverInline
+ static void m() {
+ System.out.println(A.f);
+ killNonFinalActiveFields();
+ System.out.println(A.f); // Redundant, since `f` is guaranteed to be initialized.
+ }
+
+ @NeverInline
+ static void killNonFinalActiveFields() {
+ if (System.currentTimeMillis() < 0) {
+ System.out.println(A.class);
+ }
+ }
+ }
+}
