Quelle  CeilAndFloorTests.java   Sprache: JAVA

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import sun.java2d.marlin.FloatMath;

/*
 * @test
 * @summary Check for correct implementation of FloatMath.ceil/floor
 * @run main CeilAndFloorTests
 * @modules java.desktop/sun.java2d.marlin
 */
public class CeilAndFloorTests {

    public static String toHexString(double f) {
        if (!Double.isNaN(f)) {
            return Double.toHexString(f);
        } else {
            return "NaN(0x" + Long.toHexString(Double.doubleToRawLongBits(f)) + ")";
        }
    }

    public static int test(String testName, double input,
                           double result, double expected) {
        if (Double.compare(expected, result) != 0) {
            System.err.println("Failure for " + testName + ":\n" +
                               "\tFor input " + input    + "\t(" + toHexString(input) + ")\n" +
                               "\texpected " + expected + "\t(" + toHexString(expected) + ")\n" +
                               "\tgot " + result   + "\t(" + toHexString(result) + ").");
            return 1;
        }
        else
            return 0;
    }

    public static int test_skip_0(String testName, double input,
                           double result, double expected)
    {
        // floor_int does not distinguish +0f and -0f
        // but it is not critical for Marlin
        if (Double.compare(expected, result) != 0 && (expected != 0.0))
        {
            System.err.println("Failure for " + testName + ":\n" +
                               "\tFor input " + input    + "\t(" + toHexString(input) + ")\n" +
                               "\texpected " + expected + "\t(" + toHexString(expected) + ")\n" +
                               "\tgot " + result   + "\t(" + toHexString(result) + ").");
            return 1;
        }
        else
            return 0;
    }

    private static int testCeilCase(double input, double expected) {
        int failures = 0;
        // int result:
        failures += test("FloatMath.ceil_int", input, FloatMath.ceil_int(input), (int)expected);
        return failures;
    }

    private static int testFloorCase(double input, double expected) {
        int failures = 0;
        // ignore difference between +0f and -0f:
        failures += test_skip_0("FloatMath.floor_int", input, FloatMath.floor_int(input), (int)expected);
        return failures;
    }

    private static int nearIntegerTests() {
        int failures = 0;

        double [] fixedPoints = {
            -0.0,
             0.0,
            -1.0,
             1.0,
            -0x1.0p52,
             0x1.0p52,
            -Float.MAX_VALUE,
             Float.MAX_VALUE,
             Float.NEGATIVE_INFINITY,
             Float.POSITIVE_INFINITY,
             Float.NaN,
        };

        for(double fixedPoint : fixedPoints) {
            failures += testCeilCase(fixedPoint, fixedPoint);
            failures += testFloorCase(fixedPoint, fixedPoint);
        }

        for(int i = Float.MIN_EXPONENT; i <= Float.MAX_EXPONENT; i++) {
            double powerOfTwo   = Math.scalb(1.0f, i);
            double neighborDown = Math.nextDown(powerOfTwo);
            double neighborUp   = Math.nextUp(powerOfTwo);

            if (i < 0) {
                failures += testCeilCase( powerOfTwo,  1.0);
                failures += testCeilCase(-powerOfTwo, -0.0);

                failures += testFloorCase( powerOfTwo,  0.0);
                failures += testFloorCase(-powerOfTwo, -1.0);

                failures += testCeilCase( neighborDown, 1.0);
                failures += testCeilCase(-neighborDown, -0.0);

                failures += testFloorCase( neighborUp,  0.0);
                failures += testFloorCase(-neighborUp, -1.0);
            } else {
                failures += testCeilCase(powerOfTwo, powerOfTwo);
                failures += testFloorCase(powerOfTwo, powerOfTwo);

                if (neighborDown==Math.rint(neighborDown)) {
                    failures += testCeilCase( neighborDown,  neighborDown);
                    failures += testCeilCase(-neighborDown, -neighborDown);

                    failures += testFloorCase( neighborDown, neighborDown);
                    failures += testFloorCase(-neighborDown,-neighborDown);
                } else {
                    failures += testCeilCase( neighborDown, powerOfTwo);
                    failures += testFloorCase(-neighborDown, -powerOfTwo);
                }

                if (neighborUp==Math.rint(neighborUp)) {
                    failures += testCeilCase(neighborUp, neighborUp);
                    failures += testCeilCase(-neighborUp, -neighborUp);

                    failures += testFloorCase(neighborUp, neighborUp);
                    failures += testFloorCase(-neighborUp, -neighborUp);
                } else {
                    failures += testFloorCase(neighborUp, powerOfTwo);
                    failures += testCeilCase(-neighborUp, -powerOfTwo);
                }
            }
        }

        for(int i = -(0x10000); i <= 0x10000; i++) {
            double f = (double) i;
            double neighborDown = Math.nextDown(f);
            double neighborUp   = Math.nextUp(f);

            failures += testCeilCase( f, f);
            failures += testCeilCase(-f, -f);

            failures += testFloorCase( f, f);
            failures += testFloorCase(-f, -f);

            if (Math.abs(f) > 1.0) {
                failures += testCeilCase( neighborDown, f);
                failures += testCeilCase(-neighborDown, -f+1);

                failures += testFloorCase( neighborUp, f);
                failures += testFloorCase(-neighborUp, -f-1);
            }
        }

        return failures;
    }

    public static int roundingTests() {
        int failures = 0;
        double [][] testCases = {
            { Float.MIN_VALUE,                           1.0},
            {-Float.MIN_VALUE,                          -0.0},
            { Math.nextDown(Float.MIN_NORMAL),           1.0},
            {-Math.nextDown(Float.MIN_NORMAL),          -0.0},
            { Float.MIN_NORMAL,                          1.0},
            {-Float.MIN_NORMAL,                         -0.0},

            { 0.1,                                        1.0},
            {-0.1,                                       -0.0},

            { 0.5,                                        1.0},
            {-0.5,                                       -0.0},

            { 1.5,                                        2.0},
            {-1.5,                                       -1.0},

            { 2.5,                                        3.0},
            {-2.5,                                       -2.0},

            { 12.3456789,                                13.0},
            {-12.3456789,                               -12.0},

            { Math.nextDown(1.0),                         1.0},
            { Math.nextDown(-1.0),                       -1.0},

            { Math.nextUp(1.0),                           2.0},
            { Math.nextUp(-1.0),                         -0.0},

            { 0x1.0p22,                                 0x1.0p22},
            {-0x1.0p22,                                -0x1.0p22},

            { Math.nextDown(0x1.0p22),                  0x1.0p22},
            {-Math.nextUp(0x1.0p22),                   -0x1.0p22},

            { Math.nextUp(0x1.0p22),                    0x1.0p22 + 1.0},
            {-Math.nextDown(0x1.0p22),                 -0x1.0p22 + 1.0}
        };

        for(double[] testCase : testCases) {
            failures += testCeilCase(testCase[0], testCase[1]);
            failures += testFloorCase(-testCase[0], -testCase[1]);
        }
        return failures;
    }

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

        System.out.println("nearIntegerTests");
        failures += nearIntegerTests();

        System.out.println("roundingTests");
        failures += roundingTests();

        if (failures > 0) {
            System.err.println("Testing {FloatMath}.ceil/floor incurred "
                               + failures + " failures.");
            throw new RuntimeException();
        }
    }
}