/*
 * ====================================================
 * 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.
 * ====================================================
 */

/*
 * Float version of k_log.h.  See the latter for most comments.
 */

static const float
/* |(log(1+s)-log(1-s))/s - Lg(s)| < 2**-34.24 (~[-4.95e-11, 4.97e-11]). */
Lg1 =      0xaaaaaa.0p-24,      /* 0.66666662693 */
Lg2 =      0xccce13.0p-25,      /* 0.40000972152 */
Lg3 =      0x91e9ee.0p-25,      /* 0.28498786688 */
Lg4 =      0xf89e26.0p-26;      /* 0.24279078841 */

static inline float
k_log1pf(float f)
{
        float hfsq,s,z,R,w,t1,t2;

        s = f/((float)2.0+f);
        z = s*s;
        w = z*z;
        t1= w*(Lg2+w*Lg4);
        t2= z*(Lg1+w*Lg3);
        R = t2+t1;
        hfsq=(float)0.5*f*f;
        return s*(hfsq+R);
}