Quelle ExactArithTests.java Sprache: JAVA

/*
* Copyright (c) 2012, 2019, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/

import java.math.BigInteger;

/**
* @test Test for StrictMath.*Exact integer and long methods.
* @bug 6708398
* @summary Basic tests for StrictMath 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();

        if (errors > 0) {
            throw new RuntimeException(errors + " errors found in ExactArithTests.");
        }
    }

    static void fail(String message) {
        errors++;
        System.err.println(message);
    }

    /**
     * Test StrictMath.addExact, multiplyExact, subtractExact, incrementExact,
     * decrementExact, negateExact 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 = StrictMath.addExact(x, y);
            long sum2 = (long) x + (long) y;
            if ((int) sum2 != sum2) {
                fail("FAIL: int StrictMath.addExact(" + x + " + " + y + ") = " + sum + "; expected Arithmetic exception");
            } else if (sum != sum2) {
                fail("FAIL: long StrictMath.addExact(" + x + " + " + y + ") = " + sum + "; expected: " + sum2);
            }
        } catch (ArithmeticException ex) {
            long sum2 = (long) x + (long) y;
            if ((int) sum2 == sum2) {
                fail("FAIL: int StrictMath.addExact(" + x + " + " + y + ")" + "; Unexpected exception: " + ex);
            }
        }

        try {
            // Test subtractExact
            int diff = StrictMath.subtractExact(x, y);
            long diff2 = (long) x - (long) y;
            if ((int) diff2 != diff2) {
                fail("FAIL: int StrictMath.subtractExact(" + x + " - " + y + ") = " + diff + "; expected: " + diff2);
            }

        } catch (ArithmeticException ex) {
            long diff2 = (long) x - (long) y;
            if ((int) diff2 == diff2) {
                fail("FAIL: int StrictMath.subtractExact(" + x + " - " + y + ")" + "; Unexpected exception: " + ex);
            }
        }

        try {
            // Test multiplyExact
            int product = StrictMath.multiplyExact(x, y);
            long m2 = (long) x * (long) y;
            if ((int) m2 != m2) {
                fail("FAIL: int StrictMath.multiplyExact(" + x + " * " + y + ") = " + product + "; expected: " + m2);
            }
        } catch (ArithmeticException ex) {
            long m2 = (long) x * (long) y;
            if ((int) m2 == m2) {
                fail("FAIL: int StrictMath.multiplyExact(" + x + " * " + y + ")" + "; Unexpected exception: " + ex);
            }
        }

        try {
            // Test incrementExact
            int inc = StrictMath.incrementExact(x);
            long inc2 = (long) x + 1L;
            if ((int) inc2 != inc2) {
                fail("FAIL: int StrictMath.incrementExact(" + x + ") = " + inc + "; expected Arithmetic exception");
            } else if (inc != inc2) {
                fail("FAIL: long StrictMath.incrementExact(" + x + ") = " + inc + "; expected: " + inc2);
            }
        } catch (ArithmeticException ex) {
            long inc2 = (long) x + 1L;
            if ((int) inc2 == inc2) {
                fail("FAIL: int StrictMath.incrementExact(" + x + ")" + "; Unexpected exception: " + ex);
            }
        }

        try {
            // Test decrementExact
            int dec = StrictMath.decrementExact(x);
            long dec2 = (long) x - 1L;
            if ((int) dec2 != dec2) {
                fail("FAIL: int StrictMath.decrementExact(" + x + ") = " + dec + "; expected Arithmetic exception");
            } else if (dec != dec2) {
                fail("FAIL: long StrictMath.decrementExact(" + x + ") = " + dec + "; expected: " + dec2);
            }
        } catch (ArithmeticException ex) {
            long dec2 = (long) x - 1L;
            if ((int) dec2 == dec2) {
                fail("FAIL: int StrictMath.decrementExact(" + x + ")" + "; Unexpected exception: " + ex);
            }
        }

        try {
            // Test negateExact
            int neg = StrictMath.negateExact(x);
            long neg2 = -((long)x);
            if ((int) neg2 != neg2) {
                fail("FAIL: int StrictMath.negateExact(" + x + ") = " + neg + "; expected Arithmetic exception");
            } else if (neg != neg2) {
                fail("FAIL: long StrictMath.negateExact(" + x + ") = " + neg + "; expected: " + neg2);
            }
        } catch (ArithmeticException ex) {
            long neg2 = -((long)x);
            if ((int) neg2 == neg2) {
                fail("FAIL: int StrictMath.negateExact(" + x + ")" + "; Unexpected exception: " + ex);
            }
        }
    }

    /**
     * Test StrictMath.addExact, multiplyExact, subtractExact, incrementExact,
     * decrementExact, negateExact, 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 = StrictMath.addExact(x, y);
            checkResult("long StrictMath.addExact", x, y, sum, resultBig);
        } catch (ArithmeticException ex) {
            if (inLongRange(resultBig)) {
                fail("FAIL: long StrictMath.addExact(" + x + " + " + y + "); Unexpected exception: " + ex);
            }
        }

        try {
            // Test subtractExact
            resultBig = xBig.subtract(yBig);
            long diff = StrictMath.subtractExact(x, y);
            checkResult("long StrictMath.subtractExact", x, y, diff, resultBig);
        } catch (ArithmeticException ex) {
            if (inLongRange(resultBig)) {
                fail("FAIL: long StrictMath.subtractExact(" + x + " - " + y + ")" + "; Unexpected exception: " + ex);
            }
        }

        try {
            // Test multiplyExact
            resultBig = xBig.multiply(yBig);
            long product = StrictMath.multiplyExact(x, y);
            checkResult("long StrictMath.multiplyExact", x, y, product, resultBig);
        } catch (ArithmeticException ex) {
            if (inLongRange(resultBig)) {
                fail("FAIL: long StrictMath.multiplyExact(" + x + " * " + y + ")" + "; Unexpected exception: " + ex);
            }
        }

        try {
            // Test incrementExact
            resultBig = xBig.add(BigInteger.ONE);
            long inc = StrictMath.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 = StrictMath.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 = StrictMath.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 = StrictMath.toIntExact(x);
            if ((long)value != x) {
                fail("FAIL: " + "long StrictMath.toIntExact" + "(" + x + ") = " + value + "; expected an arithmetic exception: ");
            }
        } catch (ArithmeticException ex) {
            if (resultBig.bitLength() <= 32) {
                fail("FAIL: long StrictMath.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;
    }
}

quality89%

¤ Dauer der Verarbeitung: 0.16 Sekunden (vorverarbeitet) ¤

Wurzel

Suchen

Beweissystem der NASA

Beweissystem Isabelle

NIST Cobol Testsuite

Cephes Mathematical Library

Wiener Entwicklungsmethode

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.

Bemerkung:

Die farbliche Syntaxdarstellung ist noch experimentell.