Remove bogus DCHECK in BCE.

When creating a phi for the array length when we add HDeoptimization
nodes, we might update accesses in inner loops to use that phi instead
of the array length. The BCE phase was not expecting this case.

Bug: 21034044

(cherry picked from commit 3cde6227678cf62e06bca264671d1e957456ac3d)

Change-Id: I639f4ea6f5889726142041a42736183f162c7437

3 files changed, 44 insertions, 0 deletions

diff --git a/test/499-bce-phi-array-length/expected.txt b/test/499-bce-phi-array-length/expected.txt
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/test/499-bce-phi-array-length/expected.txt
diff --git a/test/499-bce-phi-array-length/info.txt b/test/499-bce-phi-array-length/info.txt
new file mode 100644
index 0000000..ee52699
--- /dev/null
+++ b/test/499-bce-phi-array-length/info.txt
@@ -0,0 +1,2 @@
+Regression test for BCE phase of optimizing. See Main.java
+for a description of the bug.
diff --git a/test/499-bce-phi-array-length/src/Main.java b/test/499-bce-phi-array-length/src/Main.java
new file mode 100644
index 0000000..c8c84a1
--- /dev/null
+++ b/test/499-bce-phi-array-length/src/Main.java
@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2015 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 int foo(int start, int[] array) {
+    int result = 0;
+    // We will create HDeoptimize nodes for this first loop, and a phi
+    // for the array length which will only be used within the loop.
+    for (int i = start; i < 3; i++) {
+      result += array[i];
+      for (int j = 0; j < 2; ++j) {
+        // The HBoundsCheck for this array access will be updated to access
+        // the array length phi created for the deoptimization checks of the
+        // first loop. This crashed the compiler which used to DCHECK an array
+        // length in a bounds check cannot be a phi.
+        result += array[j];
+      }
+    }
+    return result;
+  }
+
+  public static void main(String[] args) {
+    int[] a = new int[] { 1, 2, 3, 4, 5 };
+    int result = foo(1, a);
+    if (result != 11) {
+      throw new Error("Got " + result + ", expected " + 11);
+    }
+  }
+}