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