relibc_openlibm/bsdsrc/mathimpl.h

/*
 * Copyright (c) 1988, 1993
 *	The Regents of the University of California.  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.
 * 3. Neither the name of the University 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 REGENTS 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 REGENTS 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.
 *
 *	@(#)mathimpl.h	8.1 (Berkeley) 6/4/93
 * $FreeBSD: src/lib/msun/bsdsrc/mathimpl.h,v 1.7 2005/11/18 05:03:12 bde Exp $
 */

#ifndef _MATHIMPL_H_
#define	_MATHIMPL_H_

#include "cdefs-compat.h"
#include "math_private.h"

/*
 * TRUNC() is a macro that sets the trailing 27 bits in the mantissa of an
 * IEEE double variable to zero.  It must be expression-like for syntactic
 * reasons, and we implement this expression using an inline function
 * instead of a pure macro to avoid depending on the gcc feature of
 * statement-expressions.
 */
#define	TRUNC(d)	(_b_trunc(&(d)))

static __inline void
_b_trunc(volatile double *_dp)
{
        //VBS
        //u_int32_t _lw;
	u_int32_t _lw;

	GET_LOW_WORD(_lw, *_dp);
	SET_LOW_WORD(*_dp, _lw & 0xf8000000);
}

struct Double {
	double	a;
	double	b;
};

/*
 * Functions internal to the math package, yet not static.
 */
double	__exp__D(double, double);
struct Double __log__D(double);

#endif /* !_MATHIMPL_H_ */