w_ynf.c

来自「在x86平台上运行不可信任代码的sandbox。」· C语言 代码 · 共 47 行

/* w_ynf.c -- float version of w_yn.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[] = "$FreeBSD: src/lib/msun/src/w_ynf.c,v 1.5 2002/05/28 18:15:04 alfred Exp $";
#endif

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

float
ynf(int n, float x)	/* wrapper ynf */
{
#ifdef _IEEE_LIBM
	return __ieee754_ynf(n,x);
#else
	float z;
	z = __ieee754_ynf(n,x);
	if(_LIB_VERSION == _IEEE_ || isnanf(x) ) return z;
        if(x <= (float)0.0){
                if(x==(float)0.0)
                    /* d= -one/(x-x); */
                    return (float)__kernel_standard((double)n,(double)x,112);
                else
                    /* d = zero/(x-x); */
                    return (float)__kernel_standard((double)n,(double)x,113);
        }
	if(x>(float)X_TLOSS) {
	    /* yn(x>X_TLOSS,n) */
	    return (float)__kernel_standard((double)n,(double)x,139);
	} else
	    return z;
#endif
}