1 /* sf_asinh.c -- float version of s_asinh.c.
2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3 */
4
5 /*
6 * ====================================================
7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8 *
9 * Developed at SunPro, a Sun Microsystems, Inc. business.
10 * Permission to use, copy, modify, and distribute this
11 * software is freely granted, provided that this notice
12 * is preserved.
13 * ====================================================
14 */
15
16 #include "fdlibm.h"
17
18 static const float one = 1.0000000000e+00, /* 0x3F800000 */
19 ln2 = 6.9314718246e-01, /* 0x3f317218 */
20 huge = 1.0000000000e+30;
21
22 float
asinhf(float x)23 asinhf(float x)
24 {
25 float t, w;
26 __int32_t hx, ix;
27 GET_FLOAT_WORD(hx, x);
28 ix = hx & 0x7fffffff;
29 if (!FLT_UWORD_IS_FINITE(ix))
30 return x + x; /* x is inf or NaN */
31 if (ix < 0x31800000) { /* |x|<2**-28 */
32 if (huge + x > one)
33 return x; /* return x inexact except 0 */
34 }
35 if (ix > 0x4d800000) { /* |x| > 2**28 */
36 w = logf(fabsf(x)) + ln2;
37 } else if (ix > 0x40000000) { /* 2**28 > |x| > 2.0 */
38 t = fabsf(x);
39 w = logf((float)2.0 * t + one / (sqrtf(x * x + one) + t));
40 } else { /* 2.0 > |x| > 2**-28 */
41 t = x * x;
42 w = log1pf(fabsf(x) + t / (one + sqrtf(one + t)));
43 }
44 if (hx > 0)
45 return w;
46 else
47 return -w;
48 }
49
50 _MATH_ALIAS_f_f(asinh)
51
