commit a280003e4e2e37a1dc0e64ff871e6d9b48140ecd
author Christoffer Quist Adamsen <christofferqa@google.com> Mon Mar 09 16:30:13 2020 +0100
committer Christoffer Quist Adamsen <christofferqa@google.com> Mon Mar 09 16:30:13 2020 +0100
tree 1fd884f238d6e3462c38ae7c493f9e91f7d9e398
parent 45ee94b27f0b91a6bc5f5932abd607aab593c150

Add an optimizer for Object.getClass()

Change-Id: Id201dc50c6b285a7b10a24135de08eed59a27bd9

src/main/java/com/android/tools/r8/ir/optimize/library/LibraryMethodOptimizer.java

diff --git a/src/main/java/com/android/tools/r8/ir/optimize/library/LibraryMethodOptimizer.java b/src/main/java/com/android/tools/r8/ir/optimize/library/LibraryMethodOptimizer.java
index d61b6ae..f3d7cc6 100644
--- a/src/main/java/com/android/tools/r8/ir/optimize/library/LibraryMethodOptimizer.java
+++ b/src/main/java/com/android/tools/r8/ir/optimize/library/LibraryMethodOptimizer.java
@@ -34,6 +34,7 @@
   public LibraryMethodOptimizer(AppView<?> appView) {
     this.appView = appView;
     register(new BooleanMethodOptimizer(appView));
+    register(new ObjectMethodOptimizer(appView));
     register(new ObjectsMethodOptimizer(appView));
     register(new StringMethodOptimizer(appView));
 

src/main/java/com/android/tools/r8/ir/optimize/library/ObjectMethodOptimizer.java

diff --git a/src/main/java/com/android/tools/r8/ir/optimize/library/ObjectMethodOptimizer.java b/src/main/java/com/android/tools/r8/ir/optimize/library/ObjectMethodOptimizer.java
new file mode 100644
index 0000000..1674baf
--- /dev/null
+++ b/src/main/java/com/android/tools/r8/ir/optimize/library/ObjectMethodOptimizer.java
@@ -0,0 +1,48 @@
+// Copyright (c) 2020, 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.library;
+
+import com.android.tools.r8.graph.AppView;
+import com.android.tools.r8.graph.DexEncodedMethod;
+import com.android.tools.r8.graph.DexItemFactory;
+import com.android.tools.r8.graph.DexType;
+import com.android.tools.r8.ir.code.IRCode;
+import com.android.tools.r8.ir.code.InstructionListIterator;
+import com.android.tools.r8.ir.code.InvokeMethod;
+import com.android.tools.r8.ir.code.Value;
+import java.util.Set;
+
+public class ObjectMethodOptimizer implements LibraryMethodModelCollection {
+
+  private final DexItemFactory dexItemFactory;
+
+  ObjectMethodOptimizer(AppView<?> appView) {
+    this.dexItemFactory = appView.dexItemFactory();
+  }
+
+  @Override
+  public DexType getType() {
+    return dexItemFactory.objectType;
+  }
+
+  @Override
+  public void optimize(
+      IRCode code,
+      InstructionListIterator instructionIterator,
+      InvokeMethod invoke,
+      DexEncodedMethod singleTarget,
+      Set<Value> affectedValues) {
+    if (singleTarget.method == dexItemFactory.objectMembers.getClass) {
+      optimizeGetClass(instructionIterator, invoke);
+    }
+  }
+
+  private void optimizeGetClass(InstructionListIterator instructionIterator, InvokeMethod invoke) {
+    if ((!invoke.hasOutValue() || !invoke.outValue().hasAnyUsers())
+        && invoke.inValues().get(0).isNeverNull()) {
+      instructionIterator.removeOrReplaceByDebugLocalRead();
+    }
+  }
+}