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 
18 public class Main {
19   public static int FIBCOUNT = 64;
20   public static int[] fibs;
21 
22   /// CHECK-START-X86_64: int Main.test() disassembly (after)
23   /// CHECK-DAG:   <<Zero:i\d+>>        IntConstant 0
24   //
25   /// CHECK:                            If
26   /// CHECK-NEXT:                       cmp
27   /// CHECK-NEXT:                       jle/ng
28   //
29   /// CHECK-DAG:   <<Fibs:l\d+>>        StaticFieldGet
30   /// CHECK-DAG:                        NullCheck [<<Fibs>>]
31   /// CHECK-NOT:                        jmp
32   /// CHECK-DAG:   <<FibsAtZero:i\d+>>  ArrayGet [<<Fibs>>,<<Zero>>]
33   /// CHECK-DAG:                        Return [<<FibsAtZero>>]
34   //
35   // Checks that there is no conditional jump over a `jmp`
36   // instruction. The `ArrayGet` instruction is in the next block.
37   //
38   // Note that the `StaticFieldGet` HIR instruction above (captured as
39   // `Fibs`) can produce a `jmp` x86-64 instruction when read barriers
40   // are enabled (to jump into the read barrier slow path), which is
41   // different from the `jmp` in the `CHECK-NOT` assertion.
test()42   public static int test() {
43     for (int i = 1; ; i++) {
44       if (i >= FIBCOUNT) {
45         return fibs[0];
46       }
47       fibs[i] = (i + fibs[(i - 1)]);
48     }
49   }
50 
main(String[] args)51   public static void main(String[] args) {
52     fibs = new int[FIBCOUNT];
53     fibs[0] = 1;
54     test();
55   }
56 }
57