1 /* e_sinhf.c -- float version of e_sinh.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 __FBSDID("$FreeBSD$");
18 
19 #include "math.h"
20 #include "math_private.h"
21 
22 static const float one = 1.0, shuge = 1.0e37;
23 
24 float
__ieee754_sinhf(float x)25 __ieee754_sinhf(float x)
26 {
27 	float t,h;
28 	int32_t ix,jx;
29 
30 	GET_FLOAT_WORD(jx,x);
31 	ix = jx&0x7fffffff;
32 
33     /* x is INF or NaN */
34 	if(ix>=0x7f800000) return x+x;
35 
36 	h = 0.5;
37 	if (jx<0) h = -h;
38     /* |x| in [0,9], return sign(x)*0.5*(E+E/(E+1))) */
39 	if (ix < 0x41100000) {		/* |x|<9 */
40 	    if (ix<0x39800000) 		/* |x|<2**-12 */
41 		if(shuge+x>one) return x;/* sinh(tiny) = tiny with inexact */
42 	    t = expm1f(fabsf(x));
43 	    if(ix<0x3f800000) return h*((float)2.0*t-t*t/(t+one));
44 	    return h*(t+t/(t+one));
45 	}
46 
47     /* |x| in [9, logf(maxfloat)] return 0.5*exp(|x|) */
48 	if (ix < 0x42b17217)  return h*__ieee754_expf(fabsf(x));
49 
50     /* |x| in [logf(maxfloat), overflowthresold] */
51 	if (ix<=0x42b2d4fc)
52 	    return h*2.0F*__ldexp_expf(fabsf(x), -1);
53 
54     /* |x| > overflowthresold, sinh(x) overflow */
55 	return x*shuge;
56 }
57