Fix a bug in reference type propagation.
The upper bound of a bound type is always exact, so we should
not use it for setting the type of the bound type.
bug:28730986
Change-Id: I214b8c3493838c22805555f88e8dc87cf9221376
diff --git a/compiler/optimizing/reference_type_propagation.cc b/compiler/optimizing/reference_type_propagation.cc
index f2394f6..15f4928 100644
--- a/compiler/optimizing/reference_type_propagation.cc
+++ b/compiler/optimizing/reference_type_propagation.cc
@@ -809,7 +809,11 @@
// Make sure that we don't go over the bounded type.
ReferenceTypeInfo upper_bound_rti = instr->GetUpperBound();
if (!upper_bound_rti.IsSupertypeOf(new_rti)) {
- new_rti = upper_bound_rti;
+ // Note that the input might be exact, in which case we know the branch leading
+ // to the bound type is dead. We play it safe by not marking the bound type as
+ // exact.
+ bool is_exact = upper_bound_rti.GetTypeHandle()->CannotBeAssignedFromOtherTypes();
+ new_rti = ReferenceTypeInfo::Create(upper_bound_rti.GetTypeHandle(), is_exact);
}
instr->SetReferenceTypeInfo(new_rti);
}
diff --git a/test/603-checker-instanceof/expected.txt b/test/603-checker-instanceof/expected.txt
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/test/603-checker-instanceof/expected.txt
diff --git a/test/603-checker-instanceof/info.txt b/test/603-checker-instanceof/info.txt
new file mode 100644
index 0000000..5907abc
--- /dev/null
+++ b/test/603-checker-instanceof/info.txt
@@ -0,0 +1,2 @@
+Regression test for the compiler that used to wrongly optimize
+an instanceof.
diff --git a/test/603-checker-instanceof/src/Main.java b/test/603-checker-instanceof/src/Main.java
new file mode 100644
index 0000000..ddf4b92
--- /dev/null
+++ b/test/603-checker-instanceof/src/Main.java
@@ -0,0 +1,48 @@
+/*
+ * 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.
+ */
+
+class SuperClass {
+}
+
+class ChildClass extends SuperClass {
+}
+
+public class Main {
+
+ /// CHECK-START: void Main.main(java.lang.String[]) builder (after)
+ /// CHECK: BoundType klass:SuperClass can_be_null:false exact:false
+
+ /// CHECK-START: void Main.main(java.lang.String[]) builder (after)
+ /// CHECK-NOT: BoundType klass:SuperClass can_be_null:false exact:true
+ public static void main(String[] args) {
+ Object obj = new ChildClass();
+
+ // We need a fixed point iteration to hit the bogus type update
+ // of 'obj' below, so create a loop that updates the type of 'obj'.
+ for (int i = 1; i < 1; i++) {
+ obj = new Object();
+ }
+
+ if (obj instanceof SuperClass) {
+ // We used to wrongly type obj as an exact SuperClass from this point,
+ // meaning we were statically determining that the following instanceof
+ // would always fail.
+ if (!(obj instanceof ChildClass)) {
+ throw new Error("Expected a ChildClass, got " + obj.getClass());
+ }
+ }
+ }
+}