/* * Copyright (c) 2019, 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 * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ /** * @test * @bug 8228772 * @summary Test correct insertion of anti-dependencies if load is already control dependent on membar. * @run main/othervm -Xbatch -XX:-TieredCompilation * -XX:CompileCommand=inline,compiler.controldependency.TestAntiDependentMembar::hitSearchLimit * compiler.controldependency.TestAntiDependentMembar * @run main/othervm -Xbatch -XX:-TieredCompilation * -XX:CompileCommand=inline,compiler.controldependency.TestAntiDependentMembar::hitSearchLimit * -XX:+UnlockDiagnosticVMOptions -XX:+IgnoreUnrecognizedVMOptions -XX:DominatorSearchLimit=0 * compiler.controldependency.TestAntiDependentMembar */ package compiler.controldependency; public class TestAntiDependentMembar { static volatile int step1 = 0; static volatile int step2 = 0; public static int test1(int count, int b1, int b2) { int[] result = {0}; // Complex control flow to generate Region with 4 paths and therefore bail out of Node::dominates if (b1 == 0) { count += 1; } else if (b1 == 1) { if (b2 == 1) { count += 2; } } for (int i = 0; i < count; ++i) { // Volatile field write adds a membar step1 = i; // Load that is dependent on the membar result[0] += count; } return result[0]; } // Same as test1 but bailing out of Node::dominates due to hitting DominatorSearchLimit public static int test2(int count) { int[] result = {0}; // Large method with regions to hit the DominatorSearchLimit hitSearchLimit(); for (int i = 0; i < count; ++i) { step1 = i; result[0] += count; } return result[0]; } // Same as test2 but with multiple membars before the load public static int test3(int count) { int[] result = {0}; hitSearchLimit(); for (int i = 0; i < count; ++i) { step1 = i; step2 = i; step1 = i; step2 = i; result[0] += count; } return result[0]; } public static void main(String[] args) { for (int i = 0; i < 50_000; ++i) { test1(10, 0, 0); test1(10, 1, 1); test1(10, 1, 0); test1(10, 0, 1); test2(10); test3(10); } } public static void hitSearchLimit() { step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; step1++; step2++; } }