s_ldexp.c

来自「基于组件方式开发操作系统的OSKIT源代码」· C语言 代码 · 共 33 行

/* @(#)s_ldexp.c 5.1 93/09/24 */
/*
 * ====================================================
 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
 *
 * Developed at SunPro, a Sun Microsystems, Inc. business.
 * Permission to use, copy, modify, and distribute this
 * software is freely granted, provided that this notice
 * is preserved.
 * ====================================================
 */

#ifndef lint
static char rcsid[] = "$Id: s_ldexp.c,v 1.4 1997/02/22 15:11:26 peter Exp $";
#endif

#include "math.h"
#include "math_private.h"
#include <errno.h>

#ifdef __STDC__
	double ldexp(double value, int exp)
#else
	double ldexp(value, exp)
	double value; int exp;
#endif
{
	if(!finite(value)||value==0.0) return value;
	value = scalbn(value,exp);
	if(!finite(value)||value==0.0) errno = ERANGE;
	return value;
}