Fix load store elimination bug in the presence of null[i].

Due to the dex specification, we can be in a state where
two array get with the same dex register inputs are typed
differently.

bug:27683874

Change-Id: Ia821fd32e86c306093372249e7686332a7584263

1 files changed, 42 insertions, 0 deletions

diff --git a/test/586-checker-null-array-get/src/Main.java b/test/586-checker-null-array-get/src/Main.java
new file mode 100644
index 0000000000..4b03ff28eb
--- /dev/null
+++ b/test/586-checker-null-array-get/src/Main.java
@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+public class Main {
+  public static Object[] getObjectArray() { return null; }
+  public static long[] getLongArray() { return null; }
+
+  public static void main(String[] args) {
+    try {
+      foo();
+      throw new Error("Expected NullPointerException");
+    } catch (NullPointerException e) {
+      // Expected.
+    }
+  }
+
+  /// CHECK-START: void Main.foo() load_store_elimination (after)
+  /// CHECK-DAG: <<Null:l\d+>>  NullConstant
+  /// CHECK-DAG: <<Check:l\d+>> NullCheck [<<Null>>]
+  /// CHECK-DAG: <<Get1:j\d+>>  ArrayGet [<<Check>>,{{i\d+}}]
+  /// CHECK-DAG: <<Get2:l\d+>>  ArrayGet [<<Check>>,{{i\d+}}]
+  public static void foo() {
+    longField = getLongArray()[0];
+    objectField = getObjectArray()[0];
+  }
+
+  public static long longField;
+  public static Object objectField;
+}