1/* e_coshf.c -- float version of e_cosh.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
| 1/* e_coshf.c -- float version of e_cosh.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[] = "$FreeBSD: head/lib/msun/src/e_coshf.c 152352 2005-11-13 00:08:23Z bde $";
18#endif
| 16#include <sys/cdefs.h>
17__FBSDID("$FreeBSD: head/lib/msun/src/e_coshf.c 176451 2008-02-22 02:30:36Z das $");
|
19
20#include "math.h"
21#include "math_private.h"
22
23static const float one = 1.0, half=0.5, huge = 1.0e30;
24
25float
26__ieee754_coshf(float x)
27{
28 float t,w;
29 int32_t ix;
30
31 GET_FLOAT_WORD(ix,x);
32 ix &= 0x7fffffff;
33
34 /* x is INF or NaN */
35 if(ix>=0x7f800000) return x*x;
36
37 /* |x| in [0,0.5*ln2], return 1+expm1(|x|)^2/(2*exp(|x|)) */
38 if(ix<0x3eb17218) {
39 t = expm1f(fabsf(x));
40 w = one+t;
41 if (ix<0x39800000) return one; /* cosh(tiny) = 1 */
42 return one+(t*t)/(w+w);
43 }
44
45 /* |x| in [0.5*ln2,9], return (exp(|x|)+1/exp(|x|))/2; */
46 if (ix < 0x41100000) {
47 t = __ieee754_expf(fabsf(x));
48 return half*t+half/t;
49 }
50
51 /* |x| in [9, log(maxfloat)] return half*exp(|x|) */
52 if (ix < 0x42b17217) return half*__ieee754_expf(fabsf(x));
53
54 /* |x| in [log(maxfloat), overflowthresold] */
55 if (ix<=0x42b2d4fc) {
56 w = __ieee754_expf(half*fabsf(x));
57 t = half*w;
58 return t*w;
59 }
60
61 /* |x| > overflowthresold, cosh(x) overflow */
62 return huge*huge;
63}
| 18
19#include "math.h"
20#include "math_private.h"
21
22static const float one = 1.0, half=0.5, huge = 1.0e30;
23
24float
25__ieee754_coshf(float x)
26{
27 float t,w;
28 int32_t ix;
29
30 GET_FLOAT_WORD(ix,x);
31 ix &= 0x7fffffff;
32
33 /* x is INF or NaN */
34 if(ix>=0x7f800000) return x*x;
35
36 /* |x| in [0,0.5*ln2], return 1+expm1(|x|)^2/(2*exp(|x|)) */
37 if(ix<0x3eb17218) {
38 t = expm1f(fabsf(x));
39 w = one+t;
40 if (ix<0x39800000) return one; /* cosh(tiny) = 1 */
41 return one+(t*t)/(w+w);
42 }
43
44 /* |x| in [0.5*ln2,9], return (exp(|x|)+1/exp(|x|))/2; */
45 if (ix < 0x41100000) {
46 t = __ieee754_expf(fabsf(x));
47 return half*t+half/t;
48 }
49
50 /* |x| in [9, log(maxfloat)] return half*exp(|x|) */
51 if (ix < 0x42b17217) return half*__ieee754_expf(fabsf(x));
52
53 /* |x| in [log(maxfloat), overflowthresold] */
54 if (ix<=0x42b2d4fc) {
55 w = __ieee754_expf(half*fabsf(x));
56 t = half*w;
57 return t*w;
58 }
59
60 /* |x| > overflowthresold, cosh(x) overflow */
61 return huge*huge;
62}
|