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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.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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*/
import java.math.BigInteger;
/**
* @test Test for Math.*Exact integer and long methods.
* @bug 6708398
* @summary Basic tests for Math exact arithmetic operations.
*
* @author Roger Riggs
*/
public class ExactArithTests {
/**
* The count of test errors.
*/
private static int errors = 0;
/**
* @param args the command line arguments
*/
public static void main(String[] args) {
testIntegerExact();
testLongExact();
testLongIntExact();
if (errors > 0) {
throw new RuntimeException(errors + " errors found in ExactArithTests.");
}
}
static void fail(String message) {
errors++;
System.err.println(message);
}
/**
* Test Math.addExact, multiplyExact, subtractExact, toIntValue methods
* with {@code int} arguments.
*/
static void testIntegerExact() {
testIntegerExact(0, 0);
testIntegerExact(1, 1);
testIntegerExact(1, -1);
testIntegerExact(-1, 1);
testIntegerExact(1000, 2000);
testIntegerExact(Integer.MIN_VALUE, Integer.MIN_VALUE);
testIntegerExact(Integer.MAX_VALUE, Integer.MAX_VALUE);
testIntegerExact(Integer.MIN_VALUE, 1);
testIntegerExact(Integer.MAX_VALUE, 1);
testIntegerExact(Integer.MIN_VALUE, 2);
testIntegerExact(Integer.MAX_VALUE, 2);
testIntegerExact(Integer.MIN_VALUE, -1);
testIntegerExact(Integer.MAX_VALUE, -1);
testIntegerExact(Integer.MIN_VALUE, -2);
testIntegerExact(Integer.MAX_VALUE, -2);
}
/**
* Test exact arithmetic by comparing with the same operations using long
* and checking that the result is the same as the integer truncation.
* Errors are reported with {@link fail}.
*
* @param x first parameter
* @param y second parameter
*/
static void testIntegerExact(int x, int y) {
try {
// Test addExact
int sum = Math.addExact(x, y);
long sum2 = (long) x + (long) y;
if ((int) sum2 != sum2) {
fail("FAIL: int Math.addExact(" + x + " + " + y + ") = " + sum + "; expected Arithmetic exception");
} else if (sum != sum2) {
fail("FAIL: long Math.addExact(" + x + " + " + y + ") = " + sum + "; expected: " + sum2);
}
} catch (ArithmeticException ex) {
long sum2 = (long) x + (long) y;
if ((int) sum2 == sum2) {
fail("FAIL: int Math.addExact(" + x + " + " + y + ")" + "; Unexpected exception: " + ex);
}
}
try {
// Test subtractExact
int diff = Math.subtractExact(x, y);
long diff2 = (long) x - (long) y;
if ((int) diff2 != diff2) {
fail("FAIL: int Math.subtractExact(" + x + " - " + y + ") = " + diff + "; expected: " + diff2);
}
} catch (ArithmeticException ex) {
long diff2 = (long) x - (long) y;
if ((int) diff2 == diff2) {
fail("FAIL: int Math.subtractExact(" + x + " - " + y + ")" + "; Unexpected exception: " + ex);
}
}
try {
// Test multiplyExact
int product = Math.multiplyExact(x, y);
long m2 = (long) x * (long) y;
if ((int) m2 != m2) {
fail("FAIL: int Math.multiplyExact(" + x + " * " + y + ") = " + product + "; expected: " + m2);
}
} catch (ArithmeticException ex) {
long m2 = (long) x * (long) y;
if ((int) m2 == m2) {
fail("FAIL: int Math.multiplyExact(" + x + " * " + y + ")" + "; Unexpected exception: " + ex);
}
}
try {
// Test incrementExact
int inc = Math.incrementExact(x);
long inc2 = (long) x + 1L;
if ((int) inc2 != inc2) {
fail("FAIL: int Math.incrementExact(" + x + ") = " + inc + "; expected Arithmetic exception");
} else if (inc != inc2) {
fail("FAIL: long Math.incrementExact(" + x + ") = " + inc + "; expected: " + inc2);
}
} catch (ArithmeticException ex) {
long inc2 = (long) x + 1L;
if ((int) inc2 == inc2) {
fail("FAIL: int Math.incrementExact(" + x + ")" + "; Unexpected exception: " + ex);
}
}
try {
// Test decrementExact
int dec = Math.decrementExact(x);
long dec2 = (long) x - 1L;
if ((int) dec2 != dec2) {
fail("FAIL: int Math.decrementExact(" + x + ") = " + dec + "; expected Arithmetic exception");
} else if (dec != dec2) {
fail("FAIL: long Math.decrementExact(" + x + ") = " + dec + "; expected: " + dec2);
}
} catch (ArithmeticException ex) {
long dec2 = (long) x - 1L;
if ((int) dec2 == dec2) {
fail("FAIL: int Math.decrementExact(" + x + ")" + "; Unexpected exception: " + ex);
}
}
try {
// Test negateExact
int neg = Math.negateExact(x);
long neg2 = -((long)x) ;
if ((int) neg2 != neg2) {
fail("FAIL: int Math.negateExact(" + x + ") = " + neg + "; expected Arithmetic exception");
} else if (neg != neg2) {
fail("FAIL: long Math.negateExact(" + x + ") = " + neg + "; expected: " + neg2);
}
} catch (ArithmeticException ex) {
long neg2 = (long) x - 1L;
if ((int) neg2 == neg2) {
fail("FAIL: int Math.negateExact(" + x + ")" + "; Unexpected exception: " + ex);
}
}
}
/**
* Test Math.addExact, multiplyExact, subtractExact, toIntExact methods
* with {@code long} arguments.
*/
static void testLongExact() {
testLongExactTwice(0, 0);
testLongExactTwice(1, 1);
testLongExactTwice(1, -1);
testLongExactTwice(1000, 2000);
testLongExactTwice(Long.MIN_VALUE, Long.MIN_VALUE);
testLongExactTwice(Long.MAX_VALUE, Long.MAX_VALUE);
testLongExactTwice(Long.MIN_VALUE, 1);
testLongExactTwice(Long.MAX_VALUE, 1);
testLongExactTwice(Long.MIN_VALUE, 2);
testLongExactTwice(Long.MAX_VALUE, 2);
testLongExactTwice(Long.MIN_VALUE, -1);
testLongExactTwice(Long.MAX_VALUE, -1);
testLongExactTwice(Long.MIN_VALUE, -2);
testLongExactTwice(Long.MAX_VALUE, -2);
testLongExactTwice(Long.MIN_VALUE/2, 2);
testLongExactTwice(Long.MAX_VALUE, 2);
testLongExactTwice(Integer.MAX_VALUE, Integer.MAX_VALUE);
testLongExactTwice(Integer.MAX_VALUE, -Integer.MAX_VALUE);
testLongExactTwice(Integer.MAX_VALUE+1, Integer.MAX_VALUE+1);
testLongExactTwice(Integer.MAX_VALUE+1, -Integer.MAX_VALUE+1);
testLongExactTwice(Integer.MIN_VALUE-1, Integer.MIN_VALUE-1);
testLongExactTwice(Integer.MIN_VALUE-1, -Integer.MIN_VALUE-1);
testLongExactTwice(Integer.MIN_VALUE/2, 2);
}
/**
* Test each of the exact operations with the arguments and
* with the arguments reversed.
* @param x
* @param y
*/
static void testLongExactTwice(long x, long y) {
testLongExact(x, y);
testLongExact(y, x);
}
/**
* Test long exact arithmetic by comparing with the same operations using BigInteger
* and checking that the result is the same as the long truncation.
* Errors are reported with {@link fail}.
*
* @param x first parameter
* @param y second parameter
*/
static void testLongExact(long x, long y) {
BigInteger resultBig = null;
final BigInteger xBig = BigInteger.valueOf(x);
final BigInteger yBig = BigInteger.valueOf(y);
try {
// Test addExact
resultBig = xBig.add(yBig);
long sum = Math.addExact(x, y);
checkResult("long Math.addExact", x, y, sum, resultBig);
} catch (ArithmeticException ex) {
if (inLongRange(resultBig)) {
fail("FAIL: long Math.addExact(" + x + " + " + y + "); Unexpected exception: " + ex);
}
}
try {
// Test subtractExact
resultBig = xBig.subtract(yBig);
long diff = Math.subtractExact(x, y);
checkResult("long Math.subtractExact", x, y, diff, resultBig);
} catch (ArithmeticException ex) {
if (inLongRange(resultBig)) {
fail("FAIL: long Math.subtractExact(" + x + " - " + y + ")" + "; Unexpected exception: " + ex);
}
}
try {
// Test multiplyExact
resultBig = xBig.multiply(yBig);
long product = Math.multiplyExact(x, y);
checkResult("long Math.multiplyExact", x, y, product, resultBig);
} catch (ArithmeticException ex) {
if (inLongRange(resultBig)) {
fail("FAIL: long Math.multiplyExact(" + x + " * " + y + ")" + "; Unexpected exception: " + ex);
}
}
try {
// Test incrementExact
resultBig = xBig.add(BigInteger.ONE);
long inc = Math.incrementExact(x);
checkResult("long Math.incrementExact", x, 1L, inc, resultBig);
} catch (ArithmeticException ex) {
if (inLongRange(resultBig)) {
fail("FAIL: long Math.incrementExact(" + x + "); Unexpected exception: " + ex);
}
}
try {
// Test decrementExact
resultBig = xBig.subtract(BigInteger.ONE);
long dec = Math.decrementExact(x);
checkResult("long Math.decrementExact", x, 1L, dec, resultBig);
} catch (ArithmeticException ex) {
if (inLongRange(resultBig)) {
fail("FAIL: long Math.decrementExact(" + x + "); Unexpected exception: " + ex);
}
}
try {
// Test negateExact
resultBig = xBig.negate();
long dec = Math.negateExact(x);
checkResult("long Math.negateExact", x, 0L, dec, resultBig);
} catch (ArithmeticException ex) {
if (inLongRange(resultBig)) {
fail("FAIL: long Math.negateExact(" + x + "); Unexpected exception: " + ex);
}
}
try {
// Test toIntExact
int value = Math.toIntExact(x);
if ((long)value != x) {
fail("FAIL: " + "long Math.toIntExact" + "(" + x + ") = " + value + "; expected an arithmetic exception: ");
}
} catch (ArithmeticException ex) {
if (resultBig.bitLength() <= 32) {
fail("FAIL: long Math.toIntExact(" + x + ")" + "; Unexpected exception: " + ex);
}
}
}
/**
* Compare the expected and actual results.
* @param message message for the error
* @param x first argument
* @param y second argument
* @param result actual result value
* @param expected expected result value
*/
static void checkResult(String message, long x, long y, long result, BigInteger expected) {
BigInteger resultBig = BigInteger.valueOf(result);
if (!inLongRange(expected)) {
fail("FAIL: " + message + "(" + x + ", " + y + ") = " + result + "; expected an arithmetic exception: ");
} else if (!resultBig.equals(expected)) {
fail("FAIL: " + message + "(" + x + ", " + y + ") = " + result + "; expected " + expected);
}
}
/**
* Check if the value fits in 64 bits (a long).
* @param value
* @return true if the value fits in 64 bits (including the sign).
*/
static boolean inLongRange(BigInteger value) {
return value.bitLength() <= 63;
}
/**
* Test Math.multiplyExact method with {@code long} and {@code int}
* arguments.
*/
static void testLongIntExact() {
testLongIntExact(0, 0);
testLongIntExact(1, 1);
testLongIntExact(1, -1);
testLongIntExact(1000, 2000);
testLongIntExact(Long.MIN_VALUE, Integer.MIN_VALUE);
testLongIntExact(Long.MAX_VALUE, Integer.MAX_VALUE);
testLongIntExact(Long.MIN_VALUE, 1);
testLongIntExact(Long.MAX_VALUE, 1);
testLongIntExact(Long.MIN_VALUE, 2);
testLongIntExact(Long.MAX_VALUE, 2);
testLongIntExact(Long.MIN_VALUE, -1);
testLongIntExact(Long.MAX_VALUE, -1);
testLongIntExact(Long.MIN_VALUE, -2);
testLongIntExact(Long.MAX_VALUE, -2);
testLongIntExact(Long.MIN_VALUE/2, 2);
testLongIntExact(Long.MAX_VALUE, 2);
testLongIntExact(Integer.MAX_VALUE, Integer.MAX_VALUE);
testLongIntExact(Integer.MAX_VALUE, -Integer.MAX_VALUE);
testLongIntExact((long)Integer.MAX_VALUE+1L, Integer.MAX_VALUE);
testLongIntExact((long)Integer.MAX_VALUE+1L, -Integer.MAX_VALUE+1);
testLongIntExact((long)Integer.MIN_VALUE-1L, Integer.MIN_VALUE);
testLongIntExact((long)Integer.MIN_VALUE-1, Integer.MAX_VALUE);
testLongIntExact(Integer.MIN_VALUE/2, 2);
}
/**
* Test long-int exact arithmetic by comparing with the same operations using BigInteger
* and checking that the result is the same as the long truncation.
* Errors are reported with {@link fail}.
*
* @param x first parameter
* @param y second parameter
*/
static void testLongIntExact(long x, int y) {
BigInteger resultBig = null;
final BigInteger xBig = BigInteger.valueOf(x);
final BigInteger yBig = BigInteger.valueOf(y);
try {
// Test multiplyExact
resultBig = xBig.multiply(yBig);
long product = Math.multiplyExact(x, y);
checkResult("long Math.multiplyExact", x, y, product, resultBig);
} catch (ArithmeticException ex) {
if (inLongRange(resultBig)) {
fail("FAIL: long Math.multiplyExact(" + x + " * " + y + ")" + "; Unexpected exception: " + ex);
}
}
}
}