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 * 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.

 *

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 */

/*

 * @test

 * @library /test/lib

 * @build jdk.test.lib.RandomFactory

 * @run main BitTwiddle

 * @bug     4495754 8078672

 * @summary Basic test for int bit twiddling (use -Dseed=X to set PRNG seed)

 * @author  Josh Bloch

 * @key randomness

 */

import java.util.Random;

import jdk.test.lib.RandomFactory;

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 = RandomFactory.getRandom();

        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();

            String expected = new StringBuilder()

                .append(leftpad(toBinaryString(x), 32))

                .reverse().toString();

            String actual = leftpad(toBinaryString(reverse(x)), 32);

            if (!expected.equals(actual)) {

                throw new RuntimeException("reverse: \n" +

                        expected + " \n" + actual);

            }

        }

        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 (numberOfLeadingZeros(Integer.MAX_VALUE) != 1)

            throw new RuntimeException("lzmax");

        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));

        }

        for (int i = 1, r = SIZE - 1; i != 0; i <<= 1, r--) {

            if (numberOfLeadingZeros(i) != r ||

                numberOfTrailingZeros(i) != (SIZE - r - 1) ||

                numberOfLeadingZeros(i) != numberOfTrailingZeros(reverse(i))) {

                throw new RuntimeException("lzx: " + toHexString(i));

            }

        }

        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));

        }

    }

    private static final String ZEROS = "0".repeat(32);

    private static String leftpad(String s, int width) {

        return ZEROS.substring(0, width - s.length()) + s;

    }

}