| // Copyright (c) 2021, the R8 project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| 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.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()); |
| assertEquals( |
| 0, |
| 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().getReference()::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. |
| } |
| |
| @NeverInline |
| void fork() { |
| new Thread(this::m).start(); |
| } |
| |
| @NeverInline |
| void killNonFinalActiveFields() { |
| if (System.currentTimeMillis() < 0) { |
| System.out.println(this); |
| } |
| } |
| |
| @NeverInline |
| void waitUntilInitialized() { |
| while (!initialized) { |
| Thread.yield(); |
| } |
| } |
| |
| @NeverInline |
| void waitUntilRead() { |
| while (!read) { |
| Thread.yield(); |
| } |
| } |
| } |
| } |