xref: /netbsd-src/lib/libm/src/s_asinhf.c (revision 9fbd88883c38d0c0fbfcbe66d76fe6b0fab3f9de)
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 #if defined(LIBM_SCCS) && !defined(lint)
18 __RCSID("$NetBSD: s_asinhf.c,v 1.7 1999/07/02 15:37:42 simonb Exp $");
19 #endif
20 
21 #include "math.h"
22 #include "math_private.h"
23 
24 #ifdef __STDC__
25 static const float
26 #else
27 static float
28 #endif
29 one =  1.0000000000e+00, /* 0x3F800000 */
30 ln2 =  6.9314718246e-01, /* 0x3f317218 */
31 huge=  1.0000000000e+30;
32 
33 #ifdef __STDC__
34 	float asinhf(float x)
35 #else
36 	float asinhf(x)
37 	float x;
38 #endif
39 {
40 	float t,w;
41 	int32_t hx,ix;
42 	GET_FLOAT_WORD(hx,x);
43 	ix = hx&0x7fffffff;
44 	if(ix>=0x7f800000) return x+x;	/* x is inf or NaN */
45 	if(ix< 0x31800000) {	/* |x|<2**-28 */
46 	    if(huge+x>one) return x;	/* return x inexact except 0 */
47 	}
48 	if(ix>0x4d800000) {	/* |x| > 2**28 */
49 	    w = __ieee754_logf(fabsf(x))+ln2;
50 	} else if (ix>0x40000000) {	/* 2**28 > |x| > 2.0 */
51 	    t = fabsf(x);
52 	    w = __ieee754_logf((float)2.0*t+one/(__ieee754_sqrtf(x*x+one)+t));
53 	} else {		/* 2.0 > |x| > 2**-28 */
54 	    t = x*x;
55 	    w =log1pf(fabsf(x)+t/(one+__ieee754_sqrtf(one+t)));
56 	}
57 	if(hx>0) return w; else return -w;
58 }
59