/* * Copyright (c) 2018, Red Hat Inc. 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 8204479 * @summary Bitwise AND on byte value sometimes produces wrong result * * @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -XX:-TieredCompilation * -XX:-UseOnStackReplacement -XX:-BackgroundCompilation -Xcomp -XX:-Inline * compiler.c2.TestUnsignedByteCompare */ package compiler.c2; public class TestUnsignedByteCompare { static int p, n; static void report(byte[] ba, int i, boolean failed) { // Enable for debugging: // System.out.println((failed ? "Failed" : "Passed") + " with: " + ba[i] + " at " + i); } static void m1(byte[] ba) { for (int i = 0; i < ba.length; i++) { if ((ba[i] & 0xFF) < 0x10) { p++; report(ba, i, true); } else { n++; report(ba, i, false); } } } static void m2(byte[] ba) { for (int i = 0; i < ba.length; i++) { if (((ba[i] & 0xFF) & 0x80) < 0) { p++; report(ba, i, true); } else { n++; report(ba, i, false); } } } static public void main(String[] args) { final int tries = 1_000; final int count = 1_000; byte[] ba = new byte[count]; for (int i = 0; i < count; i++) { int v = -(i % 126 + 1); ba[i] = (byte)v; } for (int t = 0; t < tries; t++) { m1(ba); if (p != 0) { throw new IllegalStateException("m1 error: p = " + p + ", n = " + n); } } for (int t = 0; t < tries; t++) { m2(ba); if (p != 0) { throw new IllegalStateException("m2 error: p = " + p + ", n = " + n); } } } }