xref: /freebsd/lib/msun/src/s_asinhf.c (revision 7bd6fde3951af84ef3b68e4d1eadc1840c2fc1b3)
1 /* s_asinhf.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 #ifndef lint
17 static char rcsid[] = "$FreeBSD$";
18 #endif
19 
20 #include "math.h"
21 #include "math_private.h"
22 
23 static const float
24 one =  1.0000000000e+00, /* 0x3F800000 */
25 ln2 =  6.9314718246e-01, /* 0x3f317218 */
26 huge=  1.0000000000e+30;
27 
28 float
29 asinhf(float x)
30 {
31 	float t,w;
32 	int32_t hx,ix;
33 	GET_FLOAT_WORD(hx,x);
34 	ix = hx&0x7fffffff;
35 	if(ix>=0x7f800000) return x+x;	/* x is inf or NaN */
36 	if(ix< 0x31800000) {	/* |x|<2**-28 */
37 	    if(huge+x>one) return x;	/* return x inexact except 0 */
38 	}
39 	if(ix>0x4d800000) {	/* |x| > 2**28 */
40 	    w = __ieee754_logf(fabsf(x))+ln2;
41 	} else if (ix>0x40000000) {	/* 2**28 > |x| > 2.0 */
42 	    t = fabsf(x);
43 	    w = __ieee754_logf((float)2.0*t+one/(__ieee754_sqrtf(x*x+one)+t));
44 	} else {		/* 2.0 > |x| > 2**-28 */
45 	    t = x*x;
46 	    w =log1pf(fabsf(x)+t/(one+__ieee754_sqrtf(one+t)));
47 	}
48 	if(hx>0) return w; else return -w;
49 }
50