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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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 * questions.

 */

/**

 * @test

 * @bug 8015396

 * @summary double a%b returns NaN for some (a,b) (|a| < inf, |b|>0) (on Core i7 980X)

 * @run main ModNaN

 */

public class ModNaN {

    /* This bug was seen in the field for a particular version of the VM,

     * but never reproduced internally, and the reason was never known,

     * nor were the exact circumstances of the failure.

     */

    /*

     * Failed on Windows 7/Core i7 980X/1.6.0_38 (64-bit):

     *

     * NaNs (i.e., when it fails, this is what we expect to see):

     *

     * 8.98846567431158E307 % 1.295163E-318 = NaN

     * (0x7FE0000000000000L % 0x0000000000040000L)

     *

     * 1.7976931348623157E308 % 2.59032E-318 = NaN

     * (0x7FEFFFFFFFFFFFFFL % 0x000000000007FFFFL)

     *

     * 1.7976931348623157E308 % 1.060997895E-314 = NaN

     * (0x7FEFFFFFFFFFFFFFL % 0x000000007FFFFFFFL)

     *

     * 1.7976931348623157E308 % 6.767486E-317 = NaN

     * (0x7FEFFFFFFFFFFFFFL % 0x0000000000d10208L)

     *

     * 1.7976931348623157E308 % 7.528725E-318 = NaN

     * (0x7FEFFFFFFFFFFFFFL % 0x0000000000174077L)

     *

     * These cases did not fail, even when the previous five did:

     * 8.98846567431158E307 % 1.29516E-318 = 2.53E-321

     * (0x7fe0000000000000L % 0x000000000003ffffL)

     *

     * 1.7976931348623157E308 % 2.590327E-318 = 0.0

     * (0x7fefffffffffffffL % 0x0000000000080000L)

     *

     * 1.7976931348623157E308 % 1.060965516E-314 = 9.35818525E-315

     * (0x7fefffffffffffffL % 0x000000007ffeffffL)

     *

     */

    static double[][] bad = new double[][] {

            /*

             * These hex numbers correspond to the base-10 doubles in the

             * comment above; this can be checked by observing the output

             * of testWithPrint.

             */

            new double[] { Double.longBitsToDouble(0x7FE0000000000000L),

                    Double.longBitsToDouble(0x0000000000040000L) },

            new double[] { Double.longBitsToDouble(0x7FEFFFFFFFFFFFFFL),

                    Double.longBitsToDouble(0x000000000007FFFFL) },

            new double[] { Double.longBitsToDouble(0x7FEFFFFFFFFFFFFFL),

                    Double.longBitsToDouble(0x000000007FFFFFFFL) },

            new double[] { Double.longBitsToDouble(0x7FEFFFFFFFFFFFFFL),

                    6.767486E-317 },

            new double[] { Double.longBitsToDouble(0x7FEFFFFFFFFFFFFFL),

                    7.528725E-318 }, };

    static double[][] good = new double[][] {

            new double[] { Double.longBitsToDouble(0x7FE0000000000000L),

                    Double.longBitsToDouble(0x000000000003FFFFL) },

            new double[] { Double.longBitsToDouble(0x7FEFFFFFFFFFFFFFL),

                    Double.longBitsToDouble(0x0000000000080000L) },

            new double[] { Double.longBitsToDouble(0x7FEFFFFFFFFFFFFFL),

                    Double.longBitsToDouble(0x000000007FFEFFFFL) }, };

    public static void main(String[] args) throws InterruptedException {

        int N = 10000;

        testWithPrint();

        for (int i = 0; i < N; i++)

            testStrict();

        for (int i = 0; i < N; i++)

            test();

        Thread.sleep(1000); // pause to let the compiler work

        for (int i = 0; i < 10; i++)

            testStrict();

        for (int i = 0; i < 10; i++)

            test();

    }

    public strictfp static void testWithPrint() {

        for (double[] ab : bad) {

            double a = ab[0];

            double b = ab[1];

            double mod = a % b;

            System.out.println("" + a + "("+toHexRep(a)+") mod " +

                                    b + "("+toHexRep(b)+") yields " +

                                    mod + "("+toHexRep(mod)+")");

        }

        for (double[] ab : good) {

            double a = ab[0];

            double b = ab[1];

            double mod = a % b;

            System.out.println("" + a + "("+toHexRep(a)+") mod " +

                                    b + "("+toHexRep(b)+") yields " +

                                    mod + "("+toHexRep(mod)+")");

        }

    }

    public strictfp static void testStrict() {

        for (double[] ab : bad) {

            double a = ab[0];

            double b = ab[1];

            double mod = a % b;

            check(mod);

        }

        for (double[] ab : good) {

            double a = ab[0];

            double b = ab[1];

            double mod = a % b;

            check(mod);

        }

    }

    public static void test() {

        for (double[] ab : bad) {

            double a = ab[0];

            double b = ab[1];

            double mod = a % b;

            check(mod);

        }

        for (double[] ab : good) {

            double a = ab[0];

            double b = ab[1];

            double mod = a % b;

            check(mod);

        }

    }

    static String toHexRep(double d) {

        return "0x" + Long.toHexString(Double.doubleToRawLongBits(d)) + "L";

    }

    static void check(double mod) {

        if (Double.isNaN(mod)) {

            throw new Error("Saw a NaN, fail");

        }

    }

}