/*-
 * Copyright (c) 2010 David Schultz <das@FreeBSD.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $FreeBSD: src/tools/regression/lib/msun/test-nearbyint.c,v 1.2 2011/10/21 06:36:40 das Exp $
 */

/*
 * Tests for nearbyint{,f,l}()
 *
 * TODO:
 * - adapt tests for rint(3)
 * - tests for harder values (more mantissa bits than float)
 */

#include <assert.h>
#include <fenv.h>
#include <math.h>
#include <stdio.h>

#define ALL_STD_EXCEPT  (FE_DIVBYZERO | FE_INEXACT | FE_INVALID | \
                         FE_OVERFLOW | FE_UNDERFLOW)

static int testnum;

static const int rmodes[] = {
        FE_TONEAREST, FE_DOWNWARD, FE_UPWARD, FE_TOWARDZERO,
};

static const struct {
        float in;
        float out[3];   /* one answer per rounding mode except towardzero */
} tests[] = {
/* input        output (expected) */
    { 0.0,      { 0.0, 0.0, 0.0 }},
    { 0.5,      { 0.0, 0.0, 1.0 }},
    { M_PI,     { 3.0, 3.0, 4.0 }},
    { 65536.5,  { 65536, 65536, 65537 }},
    { INFINITY, { INFINITY, INFINITY, INFINITY }},
    { NAN,      { NAN, NAN, NAN }},
};

static const int ntests = sizeof(tests) / sizeof(tests[0]);

/*
 * Compare d1 and d2 using special rules: NaN == NaN and +0 != -0.
 * Fail an assertion if they differ.
 */
static int
fpequal(long double d1, long double d2)
{

        if (d1 != d2)
                return (isnan(d1) && isnan(d2));
        return (copysignl(1.0, d1) == copysignl(1.0, d2));
}

/* Get the appropriate result for the current rounding mode. */
static float
get_output(int testindex, int rmodeindex, int negative)
{
        double out;

        if (negative) { /* swap downwards and upwards if input is negative */
                if (rmodeindex == 1)
                        rmodeindex = 2;
                else if (rmodeindex == 2)
                        rmodeindex = 1;
        }
        if (rmodeindex == 3) /* FE_TOWARDZERO uses the value for downwards */
                rmodeindex = 1;
        out = tests[testindex].out[rmodeindex];
        return (negative ? -out : out);
}

static void
test_nearby(int testindex)
{
        float in, out;
        int i;

        for (i = 0; i < sizeof(rmodes) / sizeof(rmodes[0]); i++) {
                fesetround(rmodes[i]);
                feclearexcept(ALL_STD_EXCEPT);

                in = tests[testindex].in;
                out = get_output(testindex, i, 0);
                assert(fpequal(out, nearbyintf(in)));
                assert(fpequal(out, nearbyint(in)));
                assert(fpequal(out, nearbyintl(in)));
                assert(fetestexcept(ALL_STD_EXCEPT) == 0);

                in = -tests[testindex].in;
                out = get_output(testindex, i, 1);
                assert(fpequal(out, nearbyintf(in)));
                assert(fpequal(out, nearbyint(in)));
                assert(fpequal(out, nearbyintl(in)));
                assert(fetestexcept(ALL_STD_EXCEPT) == 0);
        }

        printf("ok %d\t\t# nearbyint(+%g)\n", testnum++, in);
}

static void
test_modf(int testindex)
{
        float in, out;
        float ipartf, ipart_expected;
        double ipart;
        long double ipartl;
        int i;

        for (i = 0; i < sizeof(rmodes) / sizeof(rmodes[0]); i++) {
                fesetround(rmodes[i]);
                feclearexcept(ALL_STD_EXCEPT);

                in = tests[testindex].in;
                ipart_expected = tests[testindex].out[1];
                out = copysignf(
                    isinf(ipart_expected) ? 0.0 : in - ipart_expected, in);
                ipartl = ipart = ipartf = 42.0;

                assert(fpequal(out, modff(in, &ipartf)));
                assert(fpequal(ipart_expected, ipartf));
                assert(fpequal(out, modf(in, &ipart)));
                assert(fpequal(ipart_expected, ipart));
                assert(fpequal(out, modfl(in, &ipartl)));
                assert(fpequal(ipart_expected, ipartl));
                assert(fetestexcept(ALL_STD_EXCEPT) == 0);

                in = -in;
                ipart_expected = -ipart_expected;
                out = -out;
                ipartl = ipart = ipartf = 42.0;
                assert(fpequal(out, modff(in, &ipartf)));
                assert(fpequal(ipart_expected, ipartf));
                assert(fpequal(out, modf(in, &ipart)));
                assert(fpequal(ipart_expected, ipart));
                assert(fpequal(out, modfl(in, &ipartl)));
                assert(fpequal(ipart_expected, ipartl));
                assert(fetestexcept(ALL_STD_EXCEPT) == 0);
        }

        printf("ok %d\t\t# modf(+%g)\n", testnum++, in);
}

int
main(int argc, char *argv[])
{
        int i;

        printf("1..%d\n", ntests * 2);
        testnum = 1;
        for (i = 0; i < ntests; i++) {
                test_nearby(i);
                test_modf(i);
        }

        return (0);
}