/*      $OpenBSD: modf_test.c,v 1.2 2023/08/13 06:57:04 miod Exp $      */

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

/* Test for bug introduced in 4.4BSD modf() on sparc */
/* Public domain, 2014, Tobias Ulmer <tobiasu@tmux.org> */

#define BIGFLOAT (5e15) /* Number large enough to trigger the "big" case */

void
modf_sparc(void)
{
        double f, i;

        f = modf(BIGFLOAT, &i);
        assert(i == BIGFLOAT);
        assert(f == 0.0);

        /* Repeat, maybe we were lucky */
        f = modf(BIGFLOAT, &i);
        assert(i == BIGFLOAT);
        assert(f == 0.0);

        /* With negative number, for good measure */
        f = modf(-BIGFLOAT, &i);
        assert(i == -BIGFLOAT);
        assert(f == 0.0);
}

/* Test for modf() behaviour on Inf and Nan */
/* Written by Willemijn Coene.  Public domain */

void
modf_infnan(void)
{
        double f, i;

        f = modf(__builtin_inf(), &i);
        assert(isinf(i));
        assert(signbit(i) == 0);
        assert(f == 0.0);

        f = modf(-__builtin_inf(), &i);
        assert(isinf(i));
        assert(signbit(i) != 0);
        assert(f == -0.0);

        f = modf(NAN, &i);
        assert(isnan(i));
        assert(signbit(i) == 0);
        assert(isnan(f));
        assert(signbit(f) == 0);

        f = modf(-NAN, &i);
        assert(isnan(i));
        assert(signbit(i) != 0);
        assert(isnan(f));
        assert(signbit(f) != 0);
}

int
main(void)
{
        modf_sparc();
        modf_infnan();
}