1 /*

     2  * Copyright (c) 2019, Red Hat, Inc. 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 8229483

    27  * @summary Sinking load out of loop may trigger: assert(found_sfpt) failed: no node in loop that's not input to safepoint

    28  *

    29  * @run main/othervm -XX:-TieredCompilation -XX:-BackgroundCompilation -XX:-UseOnStackReplacement -XX:LoopMaxUnroll=0 AntiDependentLoadInOuterStripMinedLoop

    30  *

    31  */

    32 

    33 public class AntiDependentLoadInOuterStripMinedLoop {

    34     private static int field;

    35     private static volatile int barrier;

    36 

    37     public static void main(String[] args) {

    38         int[] array = new int[1];

    39         A a = new A();

    40         for (int i = 0; i < 20_000; i++) {

    41             test1(array);

    42             test2(a, array);

    43             test2_helper(array, 0, 0);

    44         }

    45     }

    46 

    47     private static int test1(int[] array) {

    48         int res = 1;

    49 

    50         for (int i = 0; i < 10; i++) {

    51             barrier = 1;

    52             // field load doesn't float higher than here

    53 

    54             for (int j = 0; j < 2000; j++) {

    55                 array[0] = j;  // seen as anti dependence by C2 during loop opts, sunk out of loop

    56                 res *= j;

    57             }

    58         }

    59 

    60         return field + res + field * 2;

    61     }

    62 

    63     private static int test2(A a, int[] array) {

    64         int ignore = a.field;

    65         int res = 1;

    66 

    67         int k = 0;

    68         for (k = 0; k < 2; k++) {

    69         }

    70 

    71         for (int i = 0; i < 10; i++) {

    72             barrier = 1;

    73 

    74             for (int j = 0; j < 2000; j++) {

    75                 test2_helper(array, k, j);

    76                 res *= j;

    77             }

    78         }

    79 

    80         return a.field + res + a.field * 2;

    81     }

    82 

    83     private static void test2_helper(int[] array, int k, int j) {

    84         if (k == 2) {

    85             array[0] = j;

    86         }

    87     }

    88 

    89     private static class A {

    90         public int field;

    91     }

    92 }