1*05a0b428SJohn Marino /* e_sinhf.c -- float version of e_sinh.c.
2*05a0b428SJohn Marino * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3*05a0b428SJohn Marino */
4*05a0b428SJohn Marino
5*05a0b428SJohn Marino /*
6*05a0b428SJohn Marino * ====================================================
7*05a0b428SJohn Marino * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8*05a0b428SJohn Marino *
9*05a0b428SJohn Marino * Developed at SunPro, a Sun Microsystems, Inc. business.
10*05a0b428SJohn Marino * Permission to use, copy, modify, and distribute this
11*05a0b428SJohn Marino * software is freely granted, provided that this notice
12*05a0b428SJohn Marino * is preserved.
13*05a0b428SJohn Marino * ====================================================
14*05a0b428SJohn Marino */
15*05a0b428SJohn Marino
16*05a0b428SJohn Marino #include "math.h"
17*05a0b428SJohn Marino #include "math_private.h"
18*05a0b428SJohn Marino
19*05a0b428SJohn Marino static const float one = 1.0, shuge = 1.0e37;
20*05a0b428SJohn Marino
21*05a0b428SJohn Marino float
sinhf(float x)22*05a0b428SJohn Marino sinhf(float x)
23*05a0b428SJohn Marino {
24*05a0b428SJohn Marino float t,w,h;
25*05a0b428SJohn Marino int32_t ix,jx;
26*05a0b428SJohn Marino
27*05a0b428SJohn Marino GET_FLOAT_WORD(jx,x);
28*05a0b428SJohn Marino ix = jx&0x7fffffff;
29*05a0b428SJohn Marino
30*05a0b428SJohn Marino /* x is INF or NaN */
31*05a0b428SJohn Marino if(ix>=0x7f800000) return x+x;
32*05a0b428SJohn Marino
33*05a0b428SJohn Marino h = 0.5;
34*05a0b428SJohn Marino if (jx<0) h = -h;
35*05a0b428SJohn Marino /* |x| in [0,22], return sign(x)*0.5*(E+E/(E+1))) */
36*05a0b428SJohn Marino if (ix < 0x41b00000) { /* |x|<22 */
37*05a0b428SJohn Marino if (ix<0x31800000) /* |x|<2**-28 */
38*05a0b428SJohn Marino if(shuge+x>one) return x;/* sinh(tiny) = tiny with inexact */
39*05a0b428SJohn Marino t = expm1f(fabsf(x));
40*05a0b428SJohn Marino if(ix<0x3f800000) return h*((float)2.0*t-t*t/(t+one));
41*05a0b428SJohn Marino return h*(t+t/(t+one));
42*05a0b428SJohn Marino }
43*05a0b428SJohn Marino
44*05a0b428SJohn Marino /* |x| in [22, log(maxdouble)] return 0.5*exp(|x|) */
45*05a0b428SJohn Marino if (ix < 0x42b17180) return h*expf(fabsf(x));
46*05a0b428SJohn Marino
47*05a0b428SJohn Marino /* |x| in [log(maxdouble), overflowthresold] */
48*05a0b428SJohn Marino if (ix<=0x42b2d4fc) {
49*05a0b428SJohn Marino w = expf((float)0.5*fabsf(x));
50*05a0b428SJohn Marino t = h*w;
51*05a0b428SJohn Marino return t*w;
52*05a0b428SJohn Marino }
53*05a0b428SJohn Marino
54*05a0b428SJohn Marino /* |x| > overflowthresold, sinh(x) overflow */
55*05a0b428SJohn Marino return x*shuge;
56*05a0b428SJohn Marino }
57