/* $NetBSD: t_fpsetround.c,v 1.8 2024/10/29 20:04:30 riastradh Exp $ */

/*-
 * Copyright (c) 2011 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Christos Zoulas.
 *
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *        This product includes software developed by the NetBSD
 *        Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */
#include <sys/cdefs.h>
__RCSID("$NetBSD: t_fpsetround.c,v 1.8 2024/10/29 20:04:30 riastradh Exp $");

#include <float.h>
#include <math.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>

#include <atf-c.h>

ATF_TC(fpsetround_basic);
ATF_TC_HEAD(fpsetround_basic, tc)
{

        atf_tc_set_md_var(tc, "descr",
            "Minimal testing of fpgetround(3) and fpsetround(3)");
}

#ifdef _FLOAT_IEEE754
#include <ieeefp.h>

static const struct {
        const char *n;
        int rm;
        int rf;
} rnd[] = {
        { "RN", FP_RN, 1 },
        { "RP", FP_RP, 2 },
        { "RM", FP_RM, 3 },
        { "RZ", FP_RZ, 0 },

};

static const struct {
        const char *n;
        int v[4];
} tst[] = {     /*  RN  RP  RM  RZ */
        {  "1.1", {  1,  1,  2,  1 } },
        {  "1.5", {  1,  2,  2,  1 } },
        {  "1.9", {  1,  2,  2,  1 } },
        {  "2.1", {  2,  2,  3,  2 } },
        {  "2.5", {  2,  2,  3,  2 } },
        {  "2.9", {  2,  3,  3,  2 } },
        { "-1.1", { -1, -1, -1, -2 } },
        { "-1.5", { -1, -2, -1, -2 } },
        { "-1.9", { -1, -2, -1, -2 } },
        { "-2.1", { -2, -2, -2, -3 } },
        { "-2.5", { -2, -2, -2, -3 } },
        { "-2.9", { -2, -3, -2, -3 } },
};

static const char *
getname(int r)
{
        for (size_t i = 0; i < __arraycount(rnd); i++)
                if (rnd[i].rm == r)
                        return rnd[i].n;
        return "*unknown*";
}

static void
test(int r)
{
        int did = 0;
        for (size_t i = 0; i < __arraycount(tst); i++) {
                double d = strtod(tst[i].n, NULL);
                int g = (int)rint(d);
                int e = tst[i].v[r];
                ATF_CHECK_EQ(g, e);
                if (g != e) {
                        if (!did) {
                                fprintf(stderr, "Mode Value Result Expected\n");
                                did = 1;
                        }
                        fprintf(stderr, "%4.4s %-5.5s %6d %8d\n", rnd[r].n,
                            tst[i].n, (int)rint(d), tst[i].v[r]);
                }
        }
}
#endif


ATF_TC_BODY(fpsetround_basic, tc)
{

#ifndef _FLOAT_IEEE754
        atf_tc_skip("Test not applicable on this architecture.");
#else
        int r;

        ATF_CHECK_EQ(r = fpgetround(), FP_RN);
        if (FP_RN != r)
                fprintf(stderr, "default expected=%s got=%s\n", getname(FP_RN),
                    getname(r));
        ATF_CHECK_EQ(FLT_ROUNDS, 1);

        for (size_t i = 0; i < __arraycount(rnd); i++) {
                const size_t j = (i + 1) & 3;
                const int o = rnd[i].rm;
                const int n = rnd[j].rm;

                ATF_CHECK_EQ(r = fpsetround(n), o);
                if (o != r)
                        fprintf(stderr, "set %s expected=%s got=%s\n",
                            getname(n), getname(o), getname(r));
                ATF_CHECK_EQ(r = fpgetround(), n);
                if (n != r)
                        fprintf(stderr, "get expected=%s got=%s\n", getname(n),
                            getname(r));
                ATF_CHECK_EQ(r = FLT_ROUNDS, rnd[j].rf);
                if (r != rnd[j].rf)
                        fprintf(stderr, "rounds expected=%x got=%x\n",
                            rnd[j].rf, r);
                test(r);
        }
#endif /* _FLOAT_IEEE754 */
}

ATF_TC(fpsetround_noftz);
ATF_TC_HEAD(fpsetround_noftz, tc)
{

        atf_tc_set_md_var(tc, "descr",
            "Test fpsetround(3) does not toggle flush-to-zero mode");
}
ATF_TC_BODY(fpsetround_noftz, tc)
{
#if !defined(_FLOAT_IEEE754) || !defined(__DBL_DENORM_MIN__)
        atf_tc_skip("no fpsetround or subnormals");
#else
        volatile double x = DBL_MIN;
        volatile double y;
        int r;

        y = x/2;
        ATF_CHECK_MSG(y != 0, "machine runs flush-to-zero by default");

        /*
         * This curious test is a regression test for:
         *
         * PR port-arm/58782: fpsetround flips all the other fpcsr bits
         * on aarch64
         */

        ATF_CHECK_EQ_MSG((r = fpsetround(FP_RN)), FP_RN,
            "r=%d FP_RN=%d", r, FP_RN);
        y = x/2;
        ATF_CHECK_MSG(y != 0,
            "machine runs flush-to-zero after one fpsetround call");

        ATF_CHECK_EQ_MSG((r = fpsetround(FP_RN)), FP_RN,
            "r=%d FP_RN=%d", r, FP_RN);
        y = x/2;
        ATF_CHECK_MSG(y != 0,
            "machine runs flush-to-zero after two fpsetround calls");
#endif
}

ATF_TP_ADD_TCS(tp)
{

        ATF_TP_ADD_TC(tp, fpsetround_basic);
        ATF_TP_ADD_TC(tp, fpsetround_noftz);

        return atf_no_error();
}