/*

 * Copyright (c) 2004, 2015, 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.

 */

/*

 * @test

 * @bug 4984407 5033578 8134795

 * @summary Tests for {Math, StrictMath}.pow

 * @author Joseph D. Darcy

 */

public class PowTests {

    private PowTests(){}

    static final double infinityD = Double.POSITIVE_INFINITY;

    static int testPowCase(double input1, double input2, double expected) {

        int failures = 0;

        failures += Tests.test("StrictMath.pow(double, double)", input1, input2,

                               StrictMath.pow(input1, input2), expected);

        failures += Tests.test("Math.pow(double, double)", input1, input2,

                               Math.pow(input1, input2), expected);

        return failures;

    }

    static int testStrictPowCase(double input1, double input2, double expected) {

        int failures = 0;

        failures += Tests.test("StrictMath.pow(double, double)", input1, input2,

                               StrictMath.pow(input1, input2), expected);

        return failures;

    }

    static int testNonstrictPowCase(double input1, double input2, double expected) {

        int failures = 0;

        failures += Tests.test("Math.pow(double, double)", input1, input2,

                               Math.pow(input1, input2), expected);

        return failures;

    }

    /*

     * Test for bad negation implementation.

     */

    static int testPow() {

        int failures = 0;

        double [][] testCases = {

            {-0.0,               3.0,   -0.0},

            {-0.0,               4.0,    0.0},

            {-infinityD,        -3.0,   -0.0},

            {-infinityD,        -4.0,    0.0},

        };

        for (double[] testCase : testCases) {

            failures+=testPowCase(testCase[0], testCase[1], testCase[2]);

        }

        return failures;

    }

    /*

     * Test cross-product of different kinds of arguments.

     */

    static int testCrossProduct() {

        int failures = 0;

        double testData[] = {

                                Double.NEGATIVE_INFINITY,

/* > -oo */                     -Double.MAX_VALUE,

/**/                            (double)Long.MIN_VALUE,

/**/                            (double) -((1L<<53)+2L),

                                -0x1.0p65,

                                -0x1.0000000000001p64,

                                -0x1.0p64,

/**/                            (double) -((1L<<53)),

/**/                            (double) -((1L<<53)-1L),

/**/                            -((double)Integer.MAX_VALUE + 4.0),

/**/                            (double)Integer.MIN_VALUE - 1.0,

/**/                            (double)Integer.MIN_VALUE,

/**/                            (double)Integer.MIN_VALUE + 1.0,

                                -0x1.0p31 + 2.0,

                                -0x1.0p31 + 1.0,

                                -0x1.0000000000001p31,

                                -0x1.0p31,

/**/                            -Math.PI,

/**/                            -3.0,

/**/                            -Math.E,

/**/                            -2.0,

/**/                            -1.0000000000000004,

/* < -1.0 */                    -1.0000000000000002, // nextAfter(-1.0, -oo)

                                -1.0,

/* > -1.0 */                    -0.9999999999999999, // nextAfter(-1.0, +oo)

/* > -1.0 */                    -0.9999999999999998,

                                -0x1.fffffp-1,

                                -0x1.ffffeffffffffp-1,

/**/                            -0.5,

/**/                            -1.0/3.0,

/* < 0.0 */                     -Double.MIN_VALUE,

                                -0.0,

                                +0.0,

/* > 0.0 */                     +Double.MIN_VALUE,

/**/                            +1.0/3.0,

/**/                            +0.5,

                                +0x1.ffffeffffffffp-1,

                                +0x1.fffffp-1,

/**/                            +0.9999999999999998,

/* < +1.0 */                    +0.9999999999999999, // nextAfter(-1.0, +oo)

                                +1.0,

/* > 1.0 */                     +1.0000000000000002, // nextAfter(+1.0, +oo)

/**/                            +1.0000000000000004,

/**/                            +2.0,

/**/                            +Math.E,

/**/                            +3.0,

/**/                            +Math.PI,

                                0x1.0p31,

                                0x1.0000000000001p31,

                                0x1.0p31 + 1.0,

                                0x1.0p31 + 2.0,

/**/                            -(double)Integer.MIN_VALUE - 1.0,

/**/                            -(double)Integer.MIN_VALUE,

/**/                            -(double)Integer.MIN_VALUE + 1.0,

/**/                            (double)Integer.MAX_VALUE + 4.0,

/**/                            (double) ((1L<<53)-1L),

/**/                            (double) ((1L<<53)),

/**/                            (double) ((1L<<53)+2L),

                                0x1.0p64,

                                0x1.0000000000001p64,

                                0x1.0p65,

/**/                            -(double)Long.MIN_VALUE,

/* < oo */                      Double.MAX_VALUE,

                                Double.POSITIVE_INFINITY,

                                Double.NaN

    };

        double NaN = Double.NaN;

        for(double x: testData) {

            for(double y: testData) {

                boolean testPass = false;

                double expected=NaN;

                double actual;

                // First, switch on y

                if( Double.isNaN(y)) {

                    expected = NaN;

                } else if (y == 0.0) {

                    expected = 1.0;

                } else if (Double.isInfinite(y) ) {

                    if(y > 0) { // x ^ (+oo)

                        if (Math.abs(x) > 1.0) {

                            expected = Double.POSITIVE_INFINITY;

                        } else if (Math.abs(x) == 1.0) {

                            expected = NaN;

                        } else if (Math.abs(x) < 1.0) {

                            expected = +0.0;

                        } else { // x is NaN

                            assert Double.isNaN(x);

                            expected = NaN;

                        }

                    } else { // x ^ (-oo)

                        if (Math.abs(x) > 1.0) {

                            expected = +0.0;

                        } else if (Math.abs(x) == 1.0) {

                            expected = NaN;

                        } else if (Math.abs(x) < 1.0) {

                            expected = Double.POSITIVE_INFINITY;

                        } else { // x is NaN

                            assert Double.isNaN(x);

                            expected = NaN;

                        }

                    } /* end Double.isInfinite(y) */

                } else if (y == 1.0) {

                    expected = x;

                } else if (Double.isNaN(x)) { // Now start switching on x

                    assert y != 0.0;

                    expected = NaN;

                } else if (x == Double.NEGATIVE_INFINITY) {

                    expected = (y < 0.0) ? f2(y) :f1(y);

                } else if (x == Double.POSITIVE_INFINITY) {

                    expected = (y < 0.0) ? +0.0 : Double.POSITIVE_INFINITY;

                } else if (equivalent(x, +0.0)) {

                    assert y != 0.0;

                    expected = (y < 0.0) ? Double.POSITIVE_INFINITY: +0.0;

                } else if (equivalent(x, -0.0)) {

                    assert y != 0.0;

                    expected = (y < 0.0) ? f1(y): f2(y);

                } else if( x < 0.0) {

                    assert y != 0.0;

                    failures += testStrictPowCase(x, y, f3(x, y));

                    failures += testNonstrictPowCase(x, y, f3ns(x, y));

                    continue;

                } else {

                    // go to next iteration

                    expected = NaN;

                    continue;

                }

                failures += testPowCase(x, y, expected);

            } // y

        } // x

        return failures;

    }

    static boolean equivalent(double a, double b) {

        return Double.compare(a, b) == 0;

    }

    static double f1(double y) {

        return (intClassify(y) == 1)?

            Double.NEGATIVE_INFINITY:

            Double.POSITIVE_INFINITY;

    }

    static double f2(double y) {

        return (intClassify(y) == 1)?-0.0:0.0;

    }

    static double f3(double x, double y) {

        switch( intClassify(y) ) {

        case 0:

            return StrictMath.pow(Math.abs(x), y);

            // break;

        case 1:

            return -StrictMath.pow(Math.abs(x), y);

            // break;

        case -1:

            return Double.NaN;

            // break;

        default:

            throw new AssertionError("Bad classification.");

            // break;

        }

    }

    static double f3ns(double x, double y) {

        switch( intClassify(y) ) {

        case 0:

            return Math.pow(Math.abs(x), y);

            // break;

        case 1:

            return -Math.pow(Math.abs(x), y);

            // break;

        case -1:

            return Double.NaN;

            // break;

        default:

            throw new AssertionError("Bad classification.");

            // break;

        }

    }

    static boolean isFinite(double a) {

        return (0.0 * a  == 0);

    }

    /**

     * Return classification of argument: -1 for non-integers, 0 for

     * even integers, 1 for odd integers.

     */

    static int intClassify(double a) {

        if(!isFinite(a) || // NaNs and infinities

           (a != Math.floor(a) )) { // only integers are fixed-points of floor

                return -1;

        }

        else {

            // Determine if argument is an odd or even integer.

            a = StrictMath.abs(a); // absolute value doesn't affect odd/even

            if(a+1.0 == a) { // a > maximum odd floating-point integer

                return 0; // Large integers are all even

            }

            else { // Convert double -> long and look at low-order bit

                long ell = (long)  a;

                return ((ell & 0x1L) == (long)1)?1:0;

            }

        }

    }

    public static void main(String [] argv) {

        int failures = 0;

        failures += testPow();

        failures += testCrossProduct();

        if (failures > 0) {

            System.err.println("Testing pow incurred "

                               + failures + " failures.");

            throw new RuntimeException();

        }

    }

}