Subversion Repositories or1k

/* sf_asinh.c -- float version of s_asinh.c.

 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.

 */

/*

 * ====================================================

 * 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.

 * ====================================================

 */

#include "fdlibm.h"

#ifdef __STDC__

static const float

#else

static float

#endif

one =  1.0000000000e+00, /* 0x3F800000 */

ln2 =  6.9314718246e-01, /* 0x3f317218 */

huge=  1.0000000000e+30;

#ifdef __STDC__

        float asinhf(float x)

#else

        float asinhf(x)

        float x;

#endif

{

        float t,w;

        __int32_t hx,ix;

        GET_FLOAT_WORD(hx,x);

        ix = hx&0x7fffffff;

        if(!FLT_UWORD_IS_FINITE(ix)) return x+x;        /* x is inf or NaN */

        if(ix< 0x31800000) {    /* |x|<2**-28 */

            if(huge+x>one) return x;    /* return x inexact except 0 */

        }

        if(ix>0x4d800000) {     /* |x| > 2**28 */

            w = __ieee754_logf(fabsf(x))+ln2;

        } else if (ix>0x40000000) {     /* 2**28 > |x| > 2.0 */

            t = fabsf(x);

            w = __ieee754_logf((float)2.0*t+one/(__ieee754_sqrtf(x*x+one)+t));

        } else {                /* 2.0 > |x| > 2**-28 */

            t = x*x;

            w =log1pf(fabsf(x)+t/(one+__ieee754_sqrtf(one+t)));

        }

        if(hx>0) return w; else return -w;

}

#ifdef _DOUBLE_IS_32BITS

#ifdef __STDC__

        double asinh(double x)

#else

        double asinh(x)

        double x;

#endif

{

        return (double) asinhf((float) x);

}

#endif /* defined(_DOUBLE_IS_32BITS) */