--- /dev/null Mon Jan 26 16:11:55 2009 +++ new/test/java/lang/Integer/BitTwiddle.java Mon Jan 26 16:11:54 2009 @@ -0,0 +1,137 @@ +/* + * 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 int bit twiddling + * @author Josh Bloch + * + * @compile -source 1.5 BitTwiddle.java + * @run main BitTwiddle + */ + +import java.util.Random; +import static java.lang.Integer.*; + +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++) { + int x = rnd.nextInt(); + 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++) { + int x = rnd.nextInt(); + 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++) { + int pow2 = 1 << 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++) { + int x = rnd.nextInt(); + if (bitCount(x) != bitCount(reverse(x))) + throw new RuntimeException("r: " + toHexString(x)); + } + + for (int i = 0; i < N; i++) { + int x = rnd.nextInt(); + 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++) { + int x = rnd.nextInt(); + int sign = (x < 0 ? -1 : (x == 0 ? 0 : 1)); + if (signum(x) != sign) + throw new RuntimeException("x: " + toHexString(x)); + } + + if(reverseBytes(0xaabbccdd) != 0xddccbbaa) + throw new RuntimeException("y"); + + for (int i = 0; i < N; i++) { + int x = rnd.nextInt(); + if (bitCount(x) != bitCount(reverseBytes(x))) + throw new RuntimeException("z: " + toHexString(x)); + } + } +}