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      1 /*
      2  * Copyright (C) 2015 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 public class Main {
     18 
     19   private static int willInline(int a, int b) {
     20     return a & b;
     21   }
     22 
     23   static int[] a = new int[4];
     24   static int field = 42;
     25 
     26   public static void main(String[] args) throws Exception {
     27     // The order of optimizations that would lead to the problem was:
     28     // 1) Inlining of `willInline`.
     29     // 2) Bounds check elimination inserting a deopt at a[0] and removing the HBoundsCheck.
     30     // 3) Instruction simplifier simpilifying the inlined willInline to just `field`.
     31     //
     32     // At this point, if the environment of the HDeoptimization instruction was
     33     // just a pointer to the one in a[0], the uses lists would have not been updated
     34     // and the HBoundsCheck being dead code after the HDeoptimization, the simplifcation
     35     // at step 3) would not updated that environment.
     36     int inEnv = willInline(field, field);
     37     int doAdds = a[0] + a[1] + a[2] + a[3];
     38 
     39     if (inEnv != 42) {
     40       throw new Error("Expected 42");
     41     }
     42 
     43     if (doAdds != 0) {
     44       throw new Error("Expected 0");
     45     }
     46   }
     47 }
     48