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 #ifdef __STDC__
19 static const float
20 #else
21 static float
22 #endif
23 one =  1.0000000000e+00, /* 0x3F800000 */
24 ln2 =  6.9314718246e-01, /* 0x3f317218 */
25 huge=  1.0000000000e+30;
26 
27 #ifdef __STDC__
asinhf(float x)28 	float asinhf(float x)
29 #else
30 	float asinhf(x)
31 	float x;
32 #endif
33 {
34 	float t,w;
35 	__int32_t hx,ix;
36 	GET_FLOAT_WORD(hx,x);
37 	ix = hx&0x7fffffff;
38 	if(ix>=0x7f800000) return x+x;	/* x is inf or NaN */
39 	if(ix< 0x31800000) {	/* |x|<2**-28 */
40 	    if(huge+x>one) return x;	/* return x inexact except 0 */
41 	}
42 	if(ix>0x4d800000) {	/* |x| > 2**28 */
43 	    w = logf(fabsf(x))+ln2;
44 	} else if (ix>0x40000000) {	/* 2**28 > |x| > 2.0 */
45 	    t = fabsf(x);
46 	    w = logf((float)2.0*t+one/(sqrtf(x*x+one)+t));
47 	} else {		/* 2.0 > |x| > 2**-28 */
48 	    t = x*x;
49 	    w =log1pf(fabsf(x)+t/(one+sqrtf(one+t)));
50 	}
51 	if(hx>0) return w; else return -w;
52 }
53 
54 #ifdef _DOUBLE_IS_32BITS
55 
56 #ifdef __STDC__
asinh(double x)57 	double asinh(double x)
58 #else
59 	double asinh(x)
60 	double x;
61 #endif
62 {
63 	return (double) asinhf((float) x);
64 }
65 
66 #endif /* defined(_DOUBLE_IS_32BITS) */
67