/*      $NetBSD: t_bit.c,v 1.2 2024/05/06 18:41:23 riastradh Exp $      */

/*
 * Written by Maya Rashish <maya@NetBSD.org>
 * Public domain.
 *
 * Testing signbit{,f,l} function correctly
 */

#include <sys/cdefs.h>
__RCSID("$NetBSD: t_bit.c,v 1.2 2024/05/06 18:41:23 riastradh Exp $");

#include <atf-c.h>
#include <float.h>
#include <math.h>
#include <stdio.h>
#include <stdint.h>
#include <stdbool.h>

static const struct {
        double input;
        bool is_negative;
} values[] = {
        { -1,           true },
        { -123,         true },
        { -123E6,       true },
        { -INFINITY,    true },
        { INFINITY,     false },
        { 123E6,        false },
        { 0,            false },
        { -0.,          true },
        { -FLT_MIN,     true },
        { FLT_MIN,      false },
        /*
         * Cannot be accurately represented as float,
         * but sign should be preserved
         */
        { DBL_MAX,      false },
        { -DBL_MAX,     true },
};

static const struct {
        long double input;
        bool is_negative;
} ldbl_values[] = {
        { -LDBL_MIN,    true },
        { LDBL_MIN,     false },
        { LDBL_MAX,     false },
        { -LDBL_MAX,    true },
};

ATF_TC(signbit);
ATF_TC_HEAD(signbit, tc)
{
        atf_tc_set_md_var(tc, "descr",
            "Check that signbit functions correctly");
}

ATF_TC_BODY(signbit, tc)
{
        unsigned i;

        for (i = 0; i < __arraycount(values); i++) {
                const float iterator_f = values[i].input;
                const double iterator_d = values[i].input;
                const long double iterator_l = values[i].input;

                if (signbit(iterator_f) != values[i].is_negative) {
                        atf_tc_fail("%s:%d iteration %d signbitf is wrong"
                            " about the sign of %f", __func__, __LINE__, i,
                            iterator_f);
                }
                if (signbit(iterator_d) != values[i].is_negative) {
                        atf_tc_fail("%s:%d iteration %d signbit is wrong"
                            "about the sign of %f", __func__, __LINE__, i,
                            iterator_d);
                }
                if (signbit(iterator_l) != values[i].is_negative) {
                        atf_tc_fail("%s:%d iteration %d signbitl is wrong"
                            " about the sign of %Lf", __func__, __LINE__, i,
                            iterator_l);
                }
        }

        for (i = 0; i < __arraycount(ldbl_values); i++) {
                if (signbit(ldbl_values[i].input) !=
                    ldbl_values[i].is_negative) {
                        atf_tc_fail("%s:%d iteration %d signbitl is"
                            "wrong about the sign of %Lf",
                            __func__, __LINE__, i,
                            ldbl_values[i].input);
                }
        }

#ifdef NAN
        ATF_CHECK_EQ(signbit(copysignf(NAN, -1)), true);
        ATF_CHECK_EQ(signbit(copysignf(NAN, +1)), false);
        ATF_CHECK_EQ(signbit(copysign(NAN, -1)), true);
        ATF_CHECK_EQ(signbit(copysign(NAN, +1)), false);
        ATF_CHECK_EQ(signbit(copysignl(NAN, -1)), true);
        ATF_CHECK_EQ(signbit(copysignl(NAN, +1)), false);
#endif
}

ATF_TP_ADD_TCS(tp)
{

        ATF_TP_ADD_TC(tp, signbit);

        return atf_no_error();
}