test/jdk/java/lang/Math/ExpCornerCaseTests.java

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * This code is free software; you can redistribute it and/or modify it
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 *
 * 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).
 *
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 * 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
 * @bug 8255368 8240632
 * @summary Tests corner cases of Math.exp
 */

public class ExpCornerCaseTests {
    private ExpCornerCaseTests(){}

    public static void main(String... args) {
        int failures = 0;

        failures += testExpCornerCases();

        if (failures > 0) {
            System.err.printf("Testing exp corner cases incurred %d failures.%n", failures);
            throw new RuntimeException();
        }
    }

    private static int testExpCornerCases() {
        int failures = 0;
        double [][] testCases = {
           {+0x4.0p8,                  Double.POSITIVE_INFINITY},
           {+0x2.71p12,                Double.POSITIVE_INFINITY},

           // Identified special cases in IEEE 754 exp operation
           {+0.0,                      1.0},
           {-0.0,                      1.0},
         };

        for (double[] testCase : testCases) {
            failures += testExp(testCase[0], testCase[1]);
        }

        return failures;
    }

    private static int testExp(double input, double expected) {
        int failures = 0;
        failures += Tests.test("StrictMath.exp", input, StrictMath::exp, expected);
        failures += Tests.test("Math.exp",       input, Math::exp,       expected);
        return failures;
    }
}