wf_atanh.c

Newlib 嵌入式 C库 标准实现代码

/* wf_atanh.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.
 * ====================================================
 */
/* 
 * wrapper atanhf(x)
 */

#include "fdlibm.h"
#include <errno.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;
	struct exception exc;
	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) */
                exc.type = DOMAIN;
                exc.name = "atanhf";
		exc.err = 0;
		exc.arg1 = exc.arg2 = (double)x;
                exc.retval = 0.0/0.0;
                if (_LIB_VERSION == _POSIX_)
                  errno = EDOM;
                else if (!matherr(&exc)) {
                  errno = EDOM;
                }
	    } else { 
                /* atanhf(|x|=1) */
                exc.type = SING;
                exc.name = "atanhf";
		exc.err = 0;
		exc.arg1 = exc.arg2 = (double)x;
		exc.retval = x/0.0;	/* sign(x)*inf */
                if (_LIB_VERSION == _POSIX_)
                  errno = EDOM;
                else if (!matherr(&exc)) {
                  errno = EDOM;
                }
            }
	    if (exc.err != 0)
              errno = exc.err;
            return (float)exc.retval; 
	} else
	    return z;
#endif
}

#ifdef _DOUBLE_IS_32BITS

#ifdef __STDC__
	double atanh(double x)
#else
	double atanh(x)
	double x;
#endif
{
	return (double) atanhf((float) x);
}

#endif /* defined(_DOUBLE_IS_32BITS) */