xref: /freebsd/lib/msun/src/s_asinhf.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
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 #include <sys/cdefs.h>
17 #include "math.h"
18 #include "math_private.h"
19 
20 static const float
21 one =  1.0000000000e+00, /* 0x3F800000 */
22 ln2 =  6.9314718246e-01, /* 0x3f317218 */
23 huge=  1.0000000000e+30;
24 
25 float
26 asinhf(float x)
27 {
28 	float t,w;
29 	int32_t hx,ix;
30 	GET_FLOAT_WORD(hx,x);
31 	ix = hx&0x7fffffff;
32 	if(ix>=0x7f800000) return x+x;	/* x is inf or NaN */
33 	if(ix< 0x31800000) {	/* |x|<2**-28 */
34 	    if(huge+x>one) return x;	/* return x inexact except 0 */
35 	}
36 	if(ix>0x4d800000) {	/* |x| > 2**28 */
37 	    w = logf(fabsf(x))+ln2;
38 	} else if (ix>0x40000000) {	/* 2**28 > |x| > 2.0 */
39 	    t = fabsf(x);
40 	    w = logf((float)2.0*t+one/(sqrtf(x*x+one)+t));
41 	} else {		/* 2.0 > |x| > 2**-28 */
42 	    t = x*x;
43 	    w =log1pf(fabsf(x)+t/(one+sqrtf(one+t)));
44 	}
45 	if(hx>0) return w; else return -w;
46 }
47