xref: /freebsd-src/lib/libc/gen/isnan.c (revision b3e7694832e81d7a904a10f525f8797b753bf0d3)

/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2004 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 <math.h>

#include "fpmath.h"

/*
 * XXX These routines belong in libm, but they must remain in libc for
 *     binary compat until we can bump libm's major version number.
 *
 * Note this only applies to the dynamic versions of libm and libc, so
 * for the static and profiled versions we stub out the definitions.
 * Otherwise you cannot link statically to libm and libc at the same
 * time, when calling both functions.
 */

#ifdef PIC
/*
 * Because math.h defines __isnan and __isnanf as aliases for compatibility with
 * glibc and CUDA, we have to undefine them here to avoid redefinition errors.
 */
#undef __isnan
#undef __isnanf

__weak_reference(__isnan, isnan);
__weak_reference(__isnanf, isnanf);

int
__isnan(double d)
{
	union IEEEd2bits u;

	u.d = d;
	return (u.bits.exp == 2047 && (u.bits.manl != 0 || u.bits.manh != 0));
}

int
__isnanf(float f)
{
	union IEEEf2bits u;

	u.f = f;
	return (u.bits.exp == 255 && u.bits.man != 0);
}
#endif /* PIC */