user/test/com/google/gwt/emultest/java/math/BigIntegerOperateBitsTest.java

/*
 * Copyright 2009 Google Inc.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements. See the NOTICE file distributed with this
 * work for additional information regarding copyright ownership. The ASF
 * licenses this file to You under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 * 
 * INCLUDES MODIFICATIONS BY GOOGLE.
 */
/**
 * author Elena Semukhina
 */
package com.google.gwt.emultest.java.math;

import com.google.gwt.emultest.java.util.EmulTestBase;

import java.math.BigInteger;

/**
 * Class: java.math.BigInteger Methods: bitLength, shiftLeft, shiftRight,
 * clearBit, flipBit, setBit, testBit.
 */
public class BigIntegerOperateBitsTest extends EmulTestBase {
  /**
   * bitCount() of a negative number.
   */
  public void testBitCountNeg() {
    BigInteger aNumber = new BigInteger(
        "-12378634756382937873487638746283767238657872368748726875");
    assertEquals(87, aNumber.bitCount());
  }

  /**
   * bitCount() of a negative number.
   */
  public void testBitCountPos() {
    BigInteger aNumber = new BigInteger(
        "12378634756343564757582937873487638746283767238657872368748726875");
    assertEquals(107, aNumber.bitCount());
  }

  /**
   * bitCount() of zero.
   */
  public void testBitCountZero() {
    BigInteger aNumber = new BigInteger("0");
    assertEquals(0, aNumber.bitCount());
  }

  /**
   * bitLength() of a negative number.
   */
  public void testBitLengthNegative1() {
    byte aBytes[] = {12, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26, 3, 91};
    int aSign = -1;
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    assertEquals(108, aNumber.bitLength());
  }

  /**
   * bitLength() of a negative number with the leftmost bit set.
   */
  public void testBitLengthNegative2() {
    byte aBytes[] = {-128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = -1;
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    assertEquals(96, aNumber.bitLength());
  }

  /**
   * bitLength() of a negative number which is a power of 2.
   */
  public void testBitLengthNegative3() {
    byte aBytes[] = {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
    int aSign = -1;
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    assertEquals(80, aNumber.bitLength());
  }

  /**
   * bitLength() of a positive number.
   */
  public void testBitLengthPositive1() {
    byte aBytes[] = {12, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26, 3, 91};
    int aSign = 1;
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    assertEquals(108, aNumber.bitLength());
  }

  /**
   * bitLength() of a positive number with the leftmost bit set.
   */
  public void testBitLengthPositive2() {
    byte aBytes[] = {-128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    assertEquals(96, aNumber.bitLength());
  }

  /**
   * bitLength() of a positive number which is a power of 2.
   */
  public void testBitLengthPositive3() {
    byte aBytes[] = {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
    int aSign = 1;
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    assertEquals(81, aNumber.bitLength());
  }

  /**
   * bitLength() of zero.
   */
  public void testBitLengthZero() {
    BigInteger aNumber = new BigInteger("0");
    assertEquals(0, aNumber.bitLength());
  }

  /**
   * clearBit(int n) of a negative n.
   */
  public void testClearBitException() {
    byte aBytes[] = {-1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = -7;
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    try {
      aNumber.clearBit(number);
      fail("ArithmeticException has not been caught");
    } catch (ArithmeticException e) {
      assertEquals("Improper exception message", "Negative bit address",
          e.getMessage());
    }
  }

  /**
   * clearBit(int n) inside a negative number.
   */
  public void testClearBitNegativeInside1() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = -1;
    int number = 15;
    byte rBytes[] = {-2, 127, -57, -101, 1, 75, -90, -46, -92, -4, 14, 92, -26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.clearBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", -1, result.signum());
  }

  /**
   * clearBit(int n) inside a negative number.
   */
  public void testClearBitNegativeInside2() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = -1;
    int number = 44;
    byte rBytes[] = {-2, 127, -57, -101, 1, 75, -90, -62, -92, -4, 14, -36, -26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.clearBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", -1, result.signum());
  }

  /**
   * clearBit(2) in the negative number with all ones in bit representation.
   */
  public void testClearBitNegativeInside3() {
    String as = "-18446744073709551615";
    int number = 2;
    BigInteger aNumber = new BigInteger(as);
    BigInteger result = aNumber.clearBit(number);
    assertEquals(as, result.toString());
  }

  /**
   * clearBit(0) in the negative number of length 1 with all ones in bit
   * representation. the resulting number's length is 2.
   */
  public void testClearBitNegativeInside4() {
    String as = "-4294967295";
    String res = "-4294967296";
    int number = 0;
    BigInteger aNumber = new BigInteger(as);
    BigInteger result = aNumber.clearBit(number);
    assertEquals(res, result.toString());
  }

  /**
   * clearBit(0) in the negative number of length 2 with all ones in bit
   * representation. the resulting number's length is 3.
   */
  public void testClearBitNegativeInside5() {
    String as = "-18446744073709551615";
    String res = "-18446744073709551616";
    int number = 0;
    BigInteger aNumber = new BigInteger(as);
    BigInteger result = aNumber.clearBit(number);
    assertEquals(res, result.toString());
  }

  /**
   * clearBit(int n) outside a negative number.
   */
  public void testClearBitNegativeOutside1() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = -1;
    int number = 150;
    byte rBytes[] = {
        -65, -1, -1, -1, -1, -1, -2, 127, -57, -101, 1, 75, -90, -46, -92, -4,
        14, -36, -26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.clearBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", -1, result.signum());
  }

  /**
   * clearBit(int n) outside a negative number.
   */
  public void testClearBitNegativeOutside2() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = -1;
    int number = 165;
    byte rBytes[] = {
        -33, -1, -1, -1, -1, -1, -1, -1, -2, 127, -57, -101, 1, 75, -90, -46,
        -92, -4, 14, -36, -26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.clearBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", -1, result.signum());
  }

  /**
   * clearBit(int n) inside a positive number.
   */
  public void testClearBitPositiveInside1() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = 20;
    byte rBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -31, 35, 26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.clearBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * clearBit(int n) inside a positive number.
   */
  public void testClearBitPositiveInside2() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = 17;
    byte rBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.clearBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * clearBit(int n) inside a positive number.
   */
  public void testClearBitPositiveInside3() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = 45;
    byte rBytes[] = {1, -128, 56, 100, -2, -76, 89, 13, 91, 3, -15, 35, 26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.clearBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * clearBit(int n) inside a positive number.
   */
  public void testClearBitPositiveInside4() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = 50;
    byte rBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.clearBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * clearBit(int n) inside a positive number.
   */
  public void testClearBitPositiveInside5() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = 63;
    byte rBytes[] = {1, -128, 56, 100, -2, 52, 89, 45, 91, 3, -15, 35, 26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.clearBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * clearBit(int n) outside a positive number.
   */
  public void testClearBitPositiveOutside1() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = 150;
    byte rBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.clearBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * clearBit(int n) outside a positive number.
   */
  public void testClearBitPositiveOutside2() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = 191;
    byte rBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.clearBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * clearBit(int n) the leftmost bit in a negative number.
   */
  public void testClearBitTopNegative() {
    byte aBytes[] = {1, -128, 56, 100, -15, 35, 26};
    int aSign = -1;
    int number = 63;
    byte rBytes[] = {-1, 127, -2, 127, -57, -101, 14, -36, -26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.clearBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", -1, result.signum());
  }

  /**
   * clearBit(int n) outside zero.
   */
  public void testClearBitZero() {
    byte aBytes[] = {0};
    int aSign = 0;
    int number = 0;
    byte rBytes[] = {0};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.clearBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 0, result.signum());
  }

  /**
   * clearBit(int n) outside zero.
   */
  public void testClearBitZeroOutside1() {
    byte aBytes[] = {0};
    int aSign = 0;
    int number = 95;
    byte rBytes[] = {0};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.clearBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 0, result.signum());
  }

  /**
   * flipBit(int n) of a negative n.
   */
  public void testFlipBitException() {
    byte aBytes[] = {-1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = -7;
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    try {
      aNumber.flipBit(number);
      fail("ArithmeticException has not been caught");
    } catch (ArithmeticException e) {
      assertEquals("Improper exception message", "Negative bit address",
          e.getMessage());
    }
  }

  /**
   * flipBit(int n) the leftmost bit in a negative number.
   */
  public void testFlipBitLeftmostNegative() {
    byte aBytes[] = {1, -128, 56, 100, -15, 35, 26};
    int aSign = -1;
    int number = 48;
    byte rBytes[] = {-1, 127, -57, -101, 14, -36, -26, 49};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.flipBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", -1, result.signum());
  }

  /**
   * flipBit(int n) the leftmost bit in a positive number.
   */
  public void testFlipBitLeftmostPositive() {
    byte aBytes[] = {1, -128, 56, 100, -15, 35, 26};
    int aSign = 1;
    int number = 48;
    byte rBytes[] = {0, -128, 56, 100, -15, 35, 26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.flipBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * flipBit(int n) inside a negative number.
   */
  public void testFlipBitNegativeInside1() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = -1;
    int number = 15;
    byte rBytes[] = {-2, 127, -57, -101, 1, 75, -90, -46, -92, -4, 14, 92, -26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.flipBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", -1, result.signum());
  }

  /**
   * flipBit(int n) inside a negative number.
   */
  public void testFlipBitNegativeInside2() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = -1;
    int number = 45;
    byte rBytes[] = {-2, 127, -57, -101, 1, 75, -90, -14, -92, -4, 14, -36, -26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.flipBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", -1, result.signum());
  }

  /**
   * flipBit(int n) inside a negative number with all ones in bit representation.
   */
  public void testFlipBitNegativeInside3() {
    String as = "-18446744073709551615";
    String res = "-18446744073709551611";
    int number = 2;
    BigInteger aNumber = new BigInteger(as);
    BigInteger result = aNumber.flipBit(number);
    assertEquals(res, result.toString());
  }

  /**
   * flipBit(0) in the negative number of length 1 with all ones in bit
   * representation. the resulting number's length is 2.
   */
  public void testFlipBitNegativeInside4() {
    String as = "-4294967295";
    String res = "-4294967296";
    int number = 0;
    BigInteger aNumber = new BigInteger(as);
    BigInteger result = aNumber.flipBit(number);
    assertEquals(res, result.toString());
  }

  /**
   * flipBit(0) in the negative number of length 2 with all ones in bit
   * representation. the resulting number's length is 3.
   */
  public void testFlipBitNegativeInside5() {
    String as = "-18446744073709551615";
    String res = "-18446744073709551616";
    int number = 0;
    BigInteger aNumber = new BigInteger(as);
    BigInteger result = aNumber.flipBit(number);
    assertEquals(res, result.toString());
  }

  /**
   * flipBit(int n) outside a negative number.
   */
  public void testFlipBitNegativeOutside1() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = -1;
    int number = 150;
    byte rBytes[] = {
        -65, -1, -1, -1, -1, -1, -2, 127, -57, -101, 1, 75, -90, -46, -92, -4,
        14, -36, -26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.flipBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", -1, result.signum());
  }

  /**
   * flipBit(int n) outside a negative number.
   */
  public void testFlipBitNegativeOutside2() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = -1;
    int number = 191;
    byte rBytes[] = {
        -1, 127, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -2, 127, -57, -101, 1,
        75, -90, -46, -92, -4, 14, -36, -26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.flipBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", -1, result.signum());
  }

  /**
   * flipBit(int n) inside a positive number.
   */
  public void testFlipBitPositiveInside1() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = 15;
    byte rBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, -93, 26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.flipBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * flipBit(int n) inside a positive number.
   */
  public void testFlipBitPositiveInside2() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = 45;
    byte rBytes[] = {1, -128, 56, 100, -2, -76, 89, 13, 91, 3, -15, 35, 26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.flipBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * flipBit(int n) outside a positive number.
   */
  public void testFlipBitPositiveOutside1() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = 150;
    byte rBytes[] = {
        64, 0, 0, 0, 0, 0, 1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35,
        26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.flipBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * flipBit(int n) outside a positive number.
   */
  public void testFlipBitPositiveOutside2() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = 191;
    byte rBytes[] = {
        0, -128, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -128, 56, 100, -2, -76, 89,
        45, 91, 3, -15, 35, 26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.flipBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * flipBit(int n) zero.
   */
  public void testFlipBitZero() {
    byte aBytes[] = {0};
    int aSign = 0;
    int number = 0;
    byte rBytes[] = {1};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.flipBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * flipBit(int n) outside zero.
   */
  public void testFlipBitZeroOutside1() {
    byte aBytes[] = {0};
    int aSign = 0;
    int number = 62;
    byte rBytes[] = {64, 0, 0, 0, 0, 0, 0, 0};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.flipBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue("incorrect value", resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * flipBit(int n) outside zero.
   */
  public void testFlipBitZeroOutside2() {
    byte aBytes[] = {0};
    int aSign = 0;
    int number = 63;
    byte rBytes[] = {0, -128, 0, 0, 0, 0, 0, 0, 0};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.flipBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue("incorrect value", resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * setBit: check the case when the number of bit to be set can be represented
   * as n * 32 + 31, where n is an arbitrary integer. Here 191 = 5 * 32 + 31.
   */
  public void testSetBitBug1331() {
    BigInteger result = BigInteger.valueOf(0L).setBit(191);
    assertEquals("incorrect value",
        "3138550867693340381917894711603833208051177722232017256448",
        result.toString());
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * setBit(int n) of a negative n.
   */
  public void testSetBitException() {
    byte aBytes[] = {-1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = -7;
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    try {
      aNumber.setBit(number);
      fail("ArithmeticException has not been caught");
    } catch (ArithmeticException e) {
      assertEquals("Improper exception message", "Negative bit address",
          e.getMessage());
    }
  }

  /**
   * setBit(int n) the leftmost bit in a negative number.
   */
  public void testSetBitLeftmostNegative() {
    byte aBytes[] = {1, -128, 56, 100, -15, 35, 26};
    int aSign = -1;
    int number = 48;
    byte rBytes[] = {-1, 127, -57, -101, 14, -36, -26, 49};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.setBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", -1, result.signum());
  }

  /**
   * setBit(int n) inside a negative number.
   */
  public void testSetBitNegativeInside1() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = -1;
    int number = 15;
    byte rBytes[] = {-2, 127, -57, -101, 1, 75, -90, -46, -92, -4, 14, -36, -26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.setBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", -1, result.signum());
  }

  /**
   * setBit(int n) inside a negative number.
   */
  public void testSetBitNegativeInside2() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = -1;
    int number = 44;
    byte rBytes[] = {-2, 127, -57, -101, 1, 75, -90, -46, -92, -4, 14, -36, -26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.setBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", -1, result.signum());
  }

  /**
   * setBit(int n) inside a negative number with all ones in bit representation.
   */
  public void testSetBitNegativeInside3() {
    String as = "-18446744073709551615";
    String res = "-18446744073709551611";
    int number = 2;
    BigInteger aNumber = new BigInteger(as);
    BigInteger result = aNumber.setBit(number);
    assertEquals(res, result.toString());
  }

  /**
   * setBit(0) in the negative number of length 1 with all ones in bit
   * representation. the resulting number's length is 2.
   */
  public void testSetBitNegativeInside4() {
    String as = "-4294967295";
    int number = 0;
    BigInteger aNumber = new BigInteger(as);
    BigInteger result = aNumber.setBit(number);
    assertEquals(as, result.toString());
  }

  /**
   * setBit(0) in the negative number of length 2 with all ones in bit
   * representation. the resulting number's length is 3.
   */
  public void testSetBitNegativeInside5() {
    String as = "-18446744073709551615";
    int number = 0;
    BigInteger aNumber = new BigInteger(as);
    BigInteger result = aNumber.setBit(number);
    assertEquals(as, result.toString());
  }

  /**
   * setBit(int n) outside a negative number.
   */
  public void testSetBitNegativeOutside1() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = -1;
    int number = 150;
    byte rBytes[] = {-2, 127, -57, -101, 1, 75, -90, -46, -92, -4, 14, -36, -26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.setBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", -1, result.signum());
  }

  /**
   * setBit(int n) outside a negative number.
   */
  public void testSetBitNegativeOutside2() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = -1;
    int number = 191;
    byte rBytes[] = {-2, 127, -57, -101, 1, 75, -90, -46, -92, -4, 14, -36, -26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.setBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", -1, result.signum());
  }

  /**
   * setBit(int n) inside a positive number.
   */
  public void testSetBitPositiveInside1() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = 20;
    byte rBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.setBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * setBit(int n) inside a positive number.
   */
  public void testSetBitPositiveInside2() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = 17;
    byte rBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -13, 35, 26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.setBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * setBit(int n) inside a positive number.
   */
  public void testSetBitPositiveInside3() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = 45;
    byte rBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.setBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * setBit(int n) inside a positive number.
   */
  public void testSetBitPositiveInside4() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = 50;
    byte rBytes[] = {1, -128, 56, 100, -2, -76, 93, 45, 91, 3, -15, 35, 26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.setBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * setBit(int n) outside a positive number.
   */
  public void testSetBitPositiveOutside1() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = 150;
    byte rBytes[] = {
        64, 0, 0, 0, 0, 0, 1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35,
        26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.setBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * setBit(int n) outside a positive number.
   */
  public void testSetBitPositiveOutside2() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = 223;
    byte rBytes[] = {
        0, -128, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -128, 56, 100,
        -2, -76, 89, 45, 91, 3, -15, 35, 26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.setBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * setBit(int n) the leftmost bit in a positive number.
   */
  public void testSetBitTopPositive() {
    byte aBytes[] = {1, -128, 56, 100, -15, 35, 26};
    int aSign = 1;
    int number = 63;
    byte rBytes[] = {0, -128, 1, -128, 56, 100, -15, 35, 26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.setBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * setBit(int n) outside zero.
   */
  public void testSetBitZero() {
    byte aBytes[] = {0};
    int aSign = 0;
    int number = 0;
    byte rBytes[] = {1};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.setBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * setBit(int n) outside zero.
   */
  public void testSetBitZeroOutside1() {
    byte aBytes[] = {0};
    int aSign = 0;
    int number = 95;
    byte rBytes[] = {0, -128, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.setBit(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * shiftLeft(int n), n = 0.
   */
  public void testShiftLeft1() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = 0;
    byte rBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.shiftLeft(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * shiftLeft(int n), n < 0.
   */
  public void testShiftLeft2() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = -27;
    byte rBytes[] = {48, 7, 12, -97, -42, -117, 37, -85, 96};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.shiftLeft(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * shiftLeft(int n) a positive number, n > 0.
   */
  public void testShiftLeft3() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = 27;
    byte rBytes[] = {
        12, 1, -61, 39, -11, -94, -55, 106, -40, 31, -119, 24, -48, 0, 0, 0};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.shiftLeft(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * shiftLeft(int n) a positive number, n > 0.
   */
  public void testShiftLeft4() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = 45;
    byte rBytes[] = {
        48, 7, 12, -97, -42, -117, 37, -85, 96, 126, 36, 99, 64, 0, 0, 0, 0, 0};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.shiftLeft(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * shiftLeft(int n) a negative number, n > 0.
   */
  public void testShiftLeft5() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = -1;
    int number = 45;
    byte rBytes[] = {
        -49, -8, -13, 96, 41, 116, -38, 84, -97, -127, -37, -100, -64, 0, 0, 0,
        0, 0};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.shiftLeft(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", -1, result.signum());
  }

  /**
   * shiftRight(int n), n = 0.
   */
  public void testShiftRight1() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = 0;
    byte rBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.shiftRight(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * shiftRight(int n), n < 0.
   */
  public void testShiftRight2() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = -27;
    byte rBytes[] = {
        12, 1, -61, 39, -11, -94, -55, 106, -40, 31, -119, 24, -48, 0, 0, 0};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.shiftRight(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * shiftRight(int n), 0 < n < 32.
   */
  public void testShiftRight3() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = 27;
    byte rBytes[] = {48, 7, 12, -97, -42, -117, 37, -85, 96};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.shiftRight(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * shiftRight(int n), n > 32.
   */
  public void testShiftRight4() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = 45;
    byte rBytes[] = {12, 1, -61, 39, -11, -94, -55};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.shiftRight(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * shiftRight(int n), n is greater than bitLength().
   */
  public void testShiftRight5() {
    byte aBytes[] = {1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = 300;
    byte rBytes[] = {0};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.shiftRight(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 0, result.signum());
  }

  /**
   * shiftRight a negative number; shift distance is NOT multiple of 32; shifted
   * bits are NOT zeroes.
   */
  public void testShiftRightNegNonZeroes() {
    byte aBytes[] = {
        1, -128, 56, 100, -2, -76, 89, 45, 91, 0, 0, 0, 0, 0, 0, 0, 0};
    int aSign = -1;
    int number = 68;
    byte rBytes[] = {-25, -4, 121, -80, 20, -70, 109, 42};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.shiftRight(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", -1, result.signum());
  }

  /**
   * shiftRight a negative number; shift distance is multiple of 32; shifted
   * bits are NOT zeroes.
   */
  public void testShiftRightNegNonZeroesMul32() {
    byte aBytes[] = {
        1, -128, 56, 100, -2, -76, 89, 45, 91, 1, 0, 0, 0, 0, 0, 0, 0};
    int aSign = -1;
    int number = 64;
    byte rBytes[] = {-2, 127, -57, -101, 1, 75, -90, -46, -92};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.shiftRight(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", -1, result.signum());
  }

  /**
   * shiftRight a negative number; shift distance is NOT multiple of 32; shifted
   * bits are zeroes.
   */
  public void testShiftRightNegZeroes() {
    byte aBytes[] = {
        1, -128, 56, 100, -2, -76, 89, 45, 0, 0, 0, 0, 0, 0, 0, 0, 0};
    int aSign = -1;
    int number = 68;
    byte rBytes[] = {-25, -4, 121, -80, 20, -70, 109, 48};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.shiftRight(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", -1, result.signum());
  }

  /**
   * shiftRight a negative number; shift distance is multiple of 32; shifted
   * bits are zeroes.
   */
  public void testShiftRightNegZeroesMul32() {
    byte aBytes[] = {
        1, -128, 56, 100, -2, -76, 89, 45, 91, 0, 0, 0, 0, 0, 0, 0, 0};
    int aSign = -1;
    int number = 64;
    byte rBytes[] = {-2, 127, -57, -101, 1, 75, -90, -46, -91};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.shiftRight(number);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", -1, result.signum());
  }

  /**
   * testBit(int n) of a negative n.
   */
  public void testTestBitException() {
    byte aBytes[] = {-1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = -7;
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    try {
      aNumber.testBit(number);
      fail("ArithmeticException has not been caught");
    } catch (ArithmeticException e) {
      assertEquals("Improper exception message", "Negative bit address",
          e.getMessage());
    }
  }

  /**
   * testBit(int n) of a negative number.
   */
  public void testTestBitNegative1() {
    byte aBytes[] = {-1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = -1;
    int number = 7;
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    assertTrue(aNumber.testBit(number));
  }

  /**
   * testBit(int n) of a positive n.
   */
  public void testTestBitNegative2() {
    byte aBytes[] = {-1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = -1;
    int number = 45;
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    assertTrue(!aNumber.testBit(number));
  }

  /**
   * testBit(int n) of a positive n, n > bitLength().
   */
  public void testTestBitNegative3() {
    byte aBytes[] = {-1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = -1;
    int number = 300;
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    assertTrue(aNumber.testBit(number));
  }

  /**
   * testBit(int n) of a positive number.
   */
  public void testTestBitPositive1() {
    byte aBytes[] = {-1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = 7;
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    assertTrue(!aNumber.testBit(number));
  }

  /**
   * testBit(int n) of a positive number.
   */
  public void testTestBitPositive2() {
    byte aBytes[] = {-1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = 45;
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    assertTrue(aNumber.testBit(number));
  }

  /**
   * testBit(int n) of a positive number, n > bitLength().
   */
  public void testTestBitPositive3() {
    byte aBytes[] = {-1, -128, 56, 100, -2, -76, 89, 45, 91, 3, -15, 35, 26};
    int aSign = 1;
    int number = 300;
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    assertTrue(!aNumber.testBit(number));
  }
}