xref: /src/tests/lib/libc/gen/t_fpclassify.c

/* $NetBSD: t_fpclassify.c,v 1.6.2.1 2025/08/02 05:58:04 perseant Exp $ */

/*-
 * Copyright (c) 2011 The NetBSD Foundation, Inc.
 * 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 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 <atf-c.h>

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

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

	atf_tc_set_md_var(tc, "descr", "Test float operations");
}

ATF_TC_BODY(fpclassify_float, tc)
{
	float d0, d1, f;
	int e;

	d0 = FLT_MIN;
	ATF_CHECK_EQ_MSG(fpclassify(d0), FP_NORMAL,
	    "fpclassify(%a)=%d FP_NORMAL=%d",
	    d0, fpclassify(d0), FP_NORMAL);
	f = frexpf(d0, &e);
	ATF_CHECK_EQ_MSG(e, FLT_MIN_EXP,
	    "frexpf(%a) returned normalized %a, exponent %d;"
	    " expected normalized %a, exponent %d",
	    d0, f, e, 0.5, FLT_MIN_EXP);
	ATF_CHECK_EQ_MSG(f, 0.5,
	    "frexpf(%a) returned normalized %a, exponent %d;"
	    " expected normalized %a, exponent %d",
	    d0, f, e, 0.5, FLT_MIN_EXP);
	d1 = d0;

#if __FLT_HAS_DENORM__
	/* shift a "1" bit through the mantissa (skip the implicit bit) */
	for (int i = 1; i < FLT_MANT_DIG; i++) {
		float d2, ip;

		d1 /= 2;
		ATF_CHECK_EQ_MSG(fpclassify(d1), FP_SUBNORMAL,
		    "[%d] fpclassify(%a)=%d FP_SUBNORMAL=%d",
		    i, d1, fpclassify(d1), FP_SUBNORMAL);
		ATF_CHECK_MSG(d1 > 0 && d1 < d0,
		    "[%d] d1=%a d0=%a", i, d1, d0);

		d2 = ldexpf(d0, -i);
		ATF_CHECK_EQ_MSG(d2, d1, "[%d] ldexpf(%a, -%d)=%a != %a",
		    i, d0, i, d2, d1);

		d2 = modff(d1, &ip);
		ATF_CHECK_EQ_MSG(d2, d1,
		    "[%d] modff(%a) returned int %a, frac %a;"
		    " expected int %a, frac %a",
		    i, d1, ip, d2, 0., d1);
		ATF_CHECK_EQ_MSG(ip, 0,
		    "[%d] modff(%a) returned int %a, frac %a;"
		    " expected int %a, frac %a",
		    i, d1, ip, d2, 0., d1);

		f = frexpf(d1, &e);
		ATF_CHECK_EQ_MSG(e, FLT_MIN_EXP - i,
		    "[%d] frexpf(%a) returned normalized %a, exponent %d;"
		    " expected normalized %a, exponent %d",
		    i, d1, f, e, 0.5, FLT_MIN_EXP - i);
		ATF_CHECK_EQ_MSG(f, 0.5,
		    "[%d] frexpf(%a) returned normalized %a, exponent %d;"
		    " expected normalized %a, exponent %d",
		    i, d1, f, e, 0.5, FLT_MIN_EXP - i);
	}
#endif

	d1 /= 2;
	ATF_CHECK_EQ_MSG(fpclassify(d1), FP_ZERO,
	    "fpclassify(%a)=%d FP_ZERO=%d",
	    d1, fpclassify(d1), FP_ZERO);
	f = frexpf(d1, &e);
	ATF_CHECK_EQ_MSG(e, 0,
	    "frexpf(%a) returned normalized %a, exponent %d;"
	    " expected normalized %a, exponent %d",
	    d1, f, e, 0., 0);
	ATF_CHECK_EQ_MSG(f, 0,
	    "frexpf(%a) returned normalized %a, exponent %d;"
	    " expected normalized %a, exponent %d",
	    d1, f, e, 0., 0);
}

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

	atf_tc_set_md_var(tc, "descr", "Test double operations");
}

ATF_TC_BODY(fpclassify_double, tc)
{
	double d0, d1, f;
	int e;

	d0 = DBL_MIN;
	ATF_CHECK_EQ_MSG(fpclassify(d0), FP_NORMAL,
	    "fpclassify(%a)=%d FP_NORMAL=%d",
	    d0, fpclassify(d0), FP_NORMAL);
	f = frexp(d0, &e);
	ATF_CHECK_EQ_MSG(e, DBL_MIN_EXP,
	    "frexp(%a) returned normalized %a, exponent %d;"
	    " expected normalized %a, exponent %d",
	    d0, f, e, 0.5, DBL_MIN_EXP);
	ATF_CHECK_EQ_MSG(f, 0.5,
	    "frexp(%a) returned normalized %a, exponent %d;"
	    " expected normalized %a, exponent %d",
	    d0, f, e, 0.5, DBL_MIN_EXP);
	d1 = d0;

#if __DBL_HAS_DENORM__
	/* shift a "1" bit through the mantissa (skip the implicit bit) */
	for (int i = 1; i < DBL_MANT_DIG; i++) {
		double d2, ip;

		d1 /= 2;
		ATF_CHECK_EQ_MSG(fpclassify(d1), FP_SUBNORMAL,
		    "[%d] fpclassify(%a)=%d FP_SUBNORMAL=%d",
		    i, d1, fpclassify(d1), FP_SUBNORMAL);
		ATF_CHECK_MSG(d1 > 0 && d1 < d0,
		    "[%d] d1=%a d0=%a", i, d1, d0);

		d2 = ldexp(d0, -i);
		ATF_CHECK_EQ_MSG(d2, d1, "[%d] ldexp(%a, -%d)=%a != %a",
		    i, d0, i, d2, d1);

		d2 = modf(d1, &ip);
		ATF_CHECK_EQ_MSG(d2, d1,
		    "[%d] modf(%a) returned int %a, frac %a;"
		    " expected int %a, frac %a",
		    i, d1, ip, d2, 0., d1);
		ATF_CHECK_EQ_MSG(ip, 0,
		    "[%d] modf(%a) returned int %a, frac %a;"
		    " expected int %a, frac %a",
		    i, d1, ip, d2, 0., d1);

		f = frexp(d1, &e);
		ATF_CHECK_EQ_MSG(e, DBL_MIN_EXP - i,
		    "[%d] frexp(%a) returned normalized %a, exponent %d;"
		    " expected normalized %a, exponent %d",
		    i, d1, f, e, 0.5, DBL_MIN_EXP - i);
		ATF_CHECK_EQ_MSG(f, 0.5,
		    "[%d] frexp(%a) returned normalized %a, exponent %d;"
		    " expected normalized %a, exponent %d",
		    i, d1, f, e, 0.5, DBL_MIN_EXP - i);
	}
#endif

	d1 /= 2;
	ATF_CHECK_EQ_MSG(fpclassify(d1), FP_ZERO,
	    "fpclassify(%a)=%d FP_ZERO=%d",
	    d1, fpclassify(d1), FP_ZERO);
	f = frexp(d1, &e);
	ATF_CHECK_EQ_MSG(e, 0,
	    "frexp(%a) returned normalized %a, exponent %d;"
	    " expected normalized %a, exponent %d",
	    d1, f, e, 0., 0);
	ATF_CHECK_EQ_MSG(f, 0,
	    "frexp(%a) returned normalized %a, exponent %d;"
	    " expected normalized %a, exponent %d",
	    d1, f, e, 0., 0);
}

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

	atf_tc_set_md_var(tc, "descr", "Test long double operations");
}

ATF_TC_BODY(fpclassify_long_double, tc)
{
	long double d0, d1, f;
	int e;

	d0 = LDBL_MIN;
	ATF_CHECK_EQ_MSG(fpclassify(d0), FP_NORMAL,
	    "fpclassify(%La)=%d FP_NORMAL=%d",
	    d0, fpclassify(d0), FP_NORMAL);
	f = frexpl(d0, &e);
	ATF_CHECK_EQ_MSG(e, LDBL_MIN_EXP,
	    "frexpl(%La) returned normalized %La, exponent %d;"
	    " expected normalized %La, exponent %d",
	    d0, f, e, 0.5L, LDBL_MIN_EXP);
	ATF_CHECK_EQ_MSG(f, 0.5,
	    "frexpl(%La) returned normalized %La, exponent %d;"
	    " expected normalized %La, exponent %d",
	    d0, f, e, 0.5L, LDBL_MIN_EXP);
	d1 = d0;

#if __LDBL_HAS_DENORM__
	/* shift a "1" bit through the mantissa (skip the implicit bit) */
	for (int i = 1; i < LDBL_MANT_DIG; i++) {
		long double d2, ip;

		d1 /= 2;
		ATF_CHECK_EQ_MSG(fpclassify(d1), FP_SUBNORMAL,
		    "[%d] fpclassify(%La)=%d FP_SUBNORMAL=%d",
		    i, d1, fpclassify(d1), FP_SUBNORMAL);
		ATF_CHECK_MSG(d1 > 0 && d1 < d0,
		    "[%d] d1=%La d0=%La", i, d1, d0);

		d2 = ldexpl(d0, -i);
		ATF_CHECK_EQ_MSG(d2, d1, "[%d] ldexpl(%La, -%d)=%La != %La",
		    i, d0, i, d2, d1);

		d2 = modfl(d1, &ip);
		ATF_CHECK_EQ_MSG(d2, d1,
		    "[%d] modfl(%La) returned int %La, frac %La;"
		    " expected int %La, frac %La",
		    i, d1, ip, d2, 0.L, d1);
		ATF_CHECK_EQ_MSG(ip, 0,
		    "[%d] modfl(%La) returned int %La, frac %La;"
		    " expected int %La, frac %La",
		    i, d1, ip, d2, 0.L, d1);

		f = frexpl(d1, &e);
		ATF_CHECK_EQ_MSG(e, LDBL_MIN_EXP - i,
		    "[%d] frexpl(%La) returned normalized %La, exponent %d;"
		    " expected normalized %La, exponent %d",
		    i, d1, f, e, 0.5L, LDBL_MIN_EXP - i);
		ATF_CHECK_EQ_MSG(f, 0.5,
		    "[%d] frexpl(%La) returned normalized %La, exponent %d;"
		    " expected normalized %La, exponent %d",
		    i, d1, f, e, 0.5L, LDBL_MIN_EXP - i);
	}
#endif

	d1 /= 2;
	ATF_CHECK_EQ_MSG(fpclassify(d1), FP_ZERO,
	    "fpclassify(%La)=%d FP_ZERO=%d",
	    d1, fpclassify(d1), FP_ZERO);
	f = frexpl(d1, &e);
	ATF_CHECK_EQ_MSG(e, 0,
	    "frexpl(%La) returned normalized %La, exponent %d;"
	    " expected normalized %La, exponent %d",
	    d1, f, e, 0.L, 0);
	ATF_CHECK_EQ_MSG(f, 0,
	    "frexpl(%La) returned normalized %La, exponent %d;"
	    " expected normalized %La, exponent %d",
	    d1, f, e, 0.L, 0);
}

ATF_TP_ADD_TCS(tp)
{

	ATF_TP_ADD_TC(tp, fpclassify_float);
	ATF_TP_ADD_TC(tp, fpclassify_double);
	ATF_TP_ADD_TC(tp, fpclassify_long_double);

	return atf_no_error();
}