| /* | |
| * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved. | |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |
| * | |
| * This code is free software; you can redistribute it and/or modify it | |
| * under the terms of the GNU General Public License version 2 only, as | |
| * published by the Free Software Foundation. | |
| * | |
| * This code is distributed in the hope that it will be useful, but WITHOUT | |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| * version 2 for more details (a copy is included in the LICENSE file that | |
| * accompanied this code). | |
| * | |
| * You should have received a copy of the GNU General Public License version | |
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| */ | |
| /* | |
| * @test | |
| * @bug 8296318 | |
| * @summary Loops inside infinite loops may not be detected, thus a region may still | |
| * be the loop head, even if it is not a LoopNode. | |
| * @run main/othervm -Xcomp -XX:-TieredCompilation | |
| * -XX:CompileCommand=compileonly,TestUndetectedLoopInInfiniteLoop::test* | |
| * -XX:PerMethodTrapLimit=0 | |
| * TestUndetectedLoopInInfiniteLoop | |
| */ | |
| public class TestUndetectedLoopInInfiniteLoop { | |
| public static void main (String[] args) { | |
| test(true, false); | |
| } | |
| public static void test(boolean flag, boolean flag2) { | |
| int x = 0; | |
| if (flag2) { // runtime check, avoid infinite loop | |
| while (true) { // infinite loop (no exit) | |
| if (flag) { | |
| x++; | |
| } | |
| do { // inner loop | |
| // assert for this block | |
| // Region | |
| // Phi -> SubI -> XorI ---> Phi | |
| x = (x - 1) ^ 1; | |
| // Problem: this looks like a loop, but we have no LoopNode | |
| // We have no LoopNode, because this is all in an infinite | |
| // loop, and during PhaseIdealLoop::build_loop_tree we do not | |
| // attach the loops of an infinite loop to the loop tree, | |
| // and hence we do not get to call beautify_loop on these loops | |
| // which would have turned the Region into a LoopNode. | |
| } while (x < 0); | |
| } | |
| } | |
| } | |
| } |