1/*
2 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24/*
25 * @test
26 * @bug 8048170
27 * @summary Following range check smearing, range check cannot be replaced by dominating identical test.
28 *
29 * @run main/othervm -XX:-BackgroundCompilation -XX:-UseOnStackReplacement
30 *                   compiler.rangechecks.TestRangeCheckSmearingLoopOpts
31 */
32
33package compiler.rangechecks;
34
35public class TestRangeCheckSmearingLoopOpts {
36
37    static int dummy;
38
39    static int m1(int[] array, int i) {
40        for (;;) {
41            for (;;) {
42                if (array[i] < 0) { // range check (i+0) dominates equivalent check below
43                    break;
44                }
45                i++;
46            }
47
48            // A control flow that stops IfNode::up_one_dom()
49            if ((i % 2)== 0) {
50                if ((array[i] % 2) == 0) {
51                    dummy = i;
52                }
53            }
54
55            // IfNode::Ideal will rewrite some range checks if Compile::allow_range_check_smearing
56            if (array[i-1] == 9) {    // range check (i-1) unchanged
57                int res = array[i-3]; // range check (i-3) unchanged
58                res += array[i];      // range check (i+0) unchanged
59                res += array[i-2];    // removed redundant range check
60                // the previous access might be hoisted by
61                // PhaseIdealLoop::split_if_with_blocks_post because
62                // it appears to have the same guard, but it also
63                // depends on the previous guards
64                return res;
65            }
66            i++;
67        }
68    }
69
70    static public void main(String[] args) {
71        int[] array = { 0, 1, 2, -3, 4, 5, -2, 7, 8, 9, -1 };
72        for (int i = 0; i < 20000; i++) {
73            m1(array, 0);
74        }
75        array[0] = -1;
76        try {
77            m1(array, 0);
78        } catch(ArrayIndexOutOfBoundsException aioobe) {}
79    }
80}
81