w_atanhf.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 53 行

/* w_atanhf.c -- float version of w_atanh.c.
 * Conversion to float by Ian Lance Taylor, Cygnus Support, [e-mail].
 */

/*
 * ====================================================
 * 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: w_atanhf.c,v 1.2 1995/05/30 05:50:46 rgrimes Exp $";
#endif

/*
 * wrapper atanhf(x)
 */

#include "math.h"
#include "math_private.h"


#ifdef __STDC__
	float atanhf(float x)		/* wrapper atanhf */
#else
	float atanhf(x)			/* wrapper atanhf */
	float x;
#endif
{
#ifdef _IEEE_LIBM
	return __ieee754_atanhf(x);
#else
	float z,y;
	z = __ieee754_atanhf(x);
	if(_LIB_VERSION == _IEEE_ || isnanf(x)) return z;
	y = fabsf(x);
	if(y>=(float)1.0) {
	    if(y>(float)1.0)
	        /* atanhf(|x|>1) */
	        return (float)__kernel_standard((double)x,(double)x,130);
	    else
	        /* atanhf(|x|==1) */
	        return (float)__kernel_standard((double)x,(double)x,131);
	} else
	    return z;
#endif
}