/*
* 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 void foo(Object o, int a) {
Object result = null;
if (o instanceof Main) {
// The compiler optimizes the type of `o` by introducing
// a `HBoundType` in this block.
while (a != 3) {
if (a == 2) {
a++;
result = o;
continue;
} else if (willInline()) {
// This block will be detected as dead after inlining.
result = new Object();
continue;
}
result = new Object();
}
// The compiler produces a phi at the back edge for `result`.
// Before dead block elimination, the phi has three inputs:
// result = (new Object(), new Object(), HBoundType)
//
// After dead block elimination, the phi has now two inputs:
// result = (new Object(), HBoundType)
//
// Our internal data structure for linking users and inputs expect
// the input index stored in that data structure to be the index
// in the inputs array. So the index before dead block elimination
// of the `HBoundType` would be 2. Dead block elimination must update
// that index to be 1.
}
System.out.println(result.getClass());
}
public static boolean willInline() {
return false;
}
public static void main(String[] args) {
foo(new Main(), 2);
}
}