s_asinhf.c revision 23579 
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
17static char rcsid[] = "$Id: s_asinhf.c,v 1.4 1997/02/22 15:10:57 peter Exp $";
18#endif
19
20#include "math.h"
21#include "math_private.h"
22
23#ifdef __STDC__
24static const float
25#else
26static float
27#endif
28one =  1.0000000000e+00, /* 0x3F800000 */
29ln2 =  6.9314718246e-01, /* 0x3f317218 */
30huge=  1.0000000000e+30;
31
32#ifdef __STDC__
33	float asinhf(float x)
34#else
35	float asinhf(x)
36	float x;
37#endif
38{
39	float t,w;
40	int32_t hx,ix;
41	GET_FLOAT_WORD(hx,x);
42	ix = hx&0x7fffffff;
43	if(ix>=0x7f800000) return x+x;	/* x is inf or NaN */
44	if(ix< 0x31800000) {	/* |x|<2**-28 */
45	    if(huge+x>one) return x;	/* return x inexact except 0 */
46	}
47	if(ix>0x4d800000) {	/* |x| > 2**28 */
48	    w = __ieee754_logf(fabsf(x))+ln2;
49	} else if (ix>0x40000000) {	/* 2**28 > |x| > 2.0 */
50	    t = fabsf(x);
51	    w = __ieee754_logf((float)2.0*t+one/(__ieee754_sqrtf(x*x+one)+t));
52	} else {		/* 2.0 > |x| > 2**-28 */
53	    t = x*x;
54	    w =log1pf(fabsf(x)+t/(one+__ieee754_sqrtf(one+t)));
55	}
56	if(hx>0) return w; else return -w;
57}
58