xref: /freebsd/lib/libc/gen/fpclassify.c (revision b3e7694832e81d7a904a10f525f8797b753bf0d3)

/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2003 Mike Barcroft <mike@FreeBSD.org>
 * Copyright (c) 2002, 2003 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.
 */

#include <sys/endian.h>

#include <machine/float.h>

#include <math.h>
#include <stdint.h>

#include "fpmath.h"

int
__fpclassifyf(float f)
{
	union IEEEf2bits u;

	u.f = f;
	if (u.bits.exp == 0) {
		if (u.bits.man == 0)
			return (FP_ZERO);
		return (FP_SUBNORMAL);
	}
	if (u.bits.exp == 255) {
		if (u.bits.man == 0)
			return (FP_INFINITE);
		return (FP_NAN);
	}
	return (FP_NORMAL);
}

int
__fpclassifyd(double d)
{
	union IEEEd2bits u;

	u.d = d;
	if (u.bits.exp == 0) {
		if ((u.bits.manl | u.bits.manh) == 0)
			return (FP_ZERO);
		return (FP_SUBNORMAL);
	}
	if (u.bits.exp == 2047) {
		if ((u.bits.manl | u.bits.manh) == 0)
			return (FP_INFINITE);
		return (FP_NAN);
	}
	return (FP_NORMAL);
}

int
__fpclassifyl(long double e)
{
	union IEEEl2bits u;

	u.e = e;
	if (u.bits.exp == 0) {
		if ((u.bits.manl | u.bits.manh) == 0)
			return (FP_ZERO);
		return (FP_SUBNORMAL);
	}
	mask_nbit_l(u);		/* Mask normalization bit if applicable. */
#if LDBL_MANT_DIG == 53
	if (u.bits.exp == 2047) {
		if ((u.bits.manl | u.bits.manh) == 0)
			return (FP_INFINITE);
		return (FP_NAN);
	}
#else
	if (u.bits.exp == 32767) {
		if ((u.bits.manl | u.bits.manh) == 0)
			return (FP_INFINITE);
		return (FP_NAN);
	}
#endif
	return (FP_NORMAL);
}