/* * Copyright 2003 Sun Microsystems, 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, * CA 95054 USA or visit www.sun.com if you need additional information or * have any questions. */ /* * @test * @bug 4495754 * @summary Basic test for long bit twiddling * @author Josh Bloch */ import java.util.Random; import static java.lang.Long.*; public class BitTwiddle { private static final int N = 1000; // # of repetitions per test public static void main(String args[]) { Random rnd = new Random(); if (highestOneBit(0) != 0) throw new RuntimeException("a"); if (highestOneBit(-1) != MIN_VALUE) throw new RuntimeException("b"); if (highestOneBit(1) != 1) throw new RuntimeException("c"); if (lowestOneBit(0) != 0) throw new RuntimeException("d"); if (lowestOneBit(-1) != 1) throw new RuntimeException("e"); if (lowestOneBit(MIN_VALUE) != MIN_VALUE) throw new RuntimeException("f"); for (int i = 0; i < N; i++) { long x = rnd.nextLong(); if (highestOneBit(x) != reverse(lowestOneBit(reverse(x)))) throw new RuntimeException("g: " + toHexString(x)); } if (numberOfLeadingZeros(0) != SIZE) throw new RuntimeException("h"); if (numberOfLeadingZeros(-1) != 0) throw new RuntimeException("i"); if (numberOfLeadingZeros(1) != (SIZE - 1)) throw new RuntimeException("j"); if (numberOfTrailingZeros(0) != SIZE) throw new RuntimeException("k"); if (numberOfTrailingZeros(1) != 0) throw new RuntimeException("l"); if (numberOfTrailingZeros(MIN_VALUE) != (SIZE - 1)) throw new RuntimeException("m"); for (int i = 0; i < N; i++) { long x = rnd.nextLong(); if (numberOfLeadingZeros(x) != numberOfTrailingZeros(reverse(x))) throw new RuntimeException("n: " + toHexString(x)); } if (bitCount(0) != 0) throw new RuntimeException("o"); for (int i = 0; i < SIZE; i++) { long pow2 = 1L << i; if (bitCount(pow2) != 1) throw new RuntimeException("p: " + i); if (bitCount(pow2 -1) != i) throw new RuntimeException("q: " + i); } for (int i = 0; i < N; i++) { long x = rnd.nextLong(); if (bitCount(x) != bitCount(reverse(x))) throw new RuntimeException("r: " + toHexString(x)); } for (int i = 0; i < N; i++) { long x = rnd.nextLong(); int dist = rnd.nextInt(); if (bitCount(x) != bitCount(rotateRight(x, dist))) throw new RuntimeException("s: " + toHexString(x) + toHexString(dist)); if (bitCount(x) != bitCount(rotateLeft(x, dist))) throw new RuntimeException("t: " + toHexString(x) + toHexString(dist)); if (rotateRight(x, dist) != rotateLeft(x, -dist)) throw new RuntimeException("u: " + toHexString(x) + toHexString(dist)); if (rotateRight(x, -dist) != rotateLeft(x, dist)) throw new RuntimeException("v: " + toHexString(x) + toHexString(dist)); } if (signum(0) != 0 || signum(1) != 1 || signum(-1) != -1 || signum(MIN_VALUE) != -1 || signum(MAX_VALUE) != 1) throw new RuntimeException("w"); for (int i = 0; i < N; i++) { long x = rnd.nextLong(); int sign = (x < 0 ? -1 : (x == 0 ? 0 : 1)); if (signum(x) != sign) throw new RuntimeException("x: " + toHexString(x)); } if(reverseBytes(0xaabbccdd11223344L) != 0x44332211ddccbbaaL) throw new RuntimeException("y"); for (int i = 0; i < N; i++) { long x = rnd.nextLong(); if (bitCount(x) != bitCount(reverseBytes(x))) throw new RuntimeException("z: " + toHexString(x)); } } }