1/* @(#)s_logb.c 5.1 93/09/24 */
2/*
3 * ====================================================
4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
5 *
6 * Developed at SunPro, a Sun Microsystems, Inc. business.
7 * Permission to use, copy, modify, and distribute this
8 * software is freely granted, provided that this notice
9 * is preserved.
10 * ====================================================
11 */
12
13#ifndef lint
| 1/* @(#)s_logb.c 5.1 93/09/24 */
2/*
3 * ====================================================
4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
5 *
6 * Developed at SunPro, a Sun Microsystems, Inc. business.
7 * Permission to use, copy, modify, and distribute this
8 * software is freely granted, provided that this notice
9 * is preserved.
10 * ====================================================
11 */
12
13#ifndef lint
|
14static char rcsid[] = "$FreeBSD: head/lib/msun/src/s_logb.c 21673 1997-01-14 07:20:47Z jkh $";
| 14static char rcsid[] = "$FreeBSD: head/lib/msun/src/s_logb.c 22808 1997-02-16 18:26:31Z bde $";
|
15#endif
16
17/*
18 * double logb(x)
19 * IEEE 754 logb. Included to pass IEEE test suite. Not recommend.
20 * Use ilogb instead.
21 */
22
23#include "math.h"
24#include "math_private.h"
25
26#ifdef __STDC__
| 15#endif
16
17/*
18 * double logb(x)
19 * IEEE 754 logb. Included to pass IEEE test suite. Not recommend.
20 * Use ilogb instead.
21 */
22
23#include "math.h"
24#include "math_private.h"
25
26#ifdef __STDC__
|
27 double logb(double x)
| 27 double __generic_logb(double x)
|
28#else
| 28#else
|
29 double logb(x)
| 29 double __generic_logb(x)
|
30 double x;
31#endif
32{
33 int32_t lx,ix;
34 EXTRACT_WORDS(ix,lx,x);
35 ix &= 0x7fffffff; /* high |x| */
36 if((ix|lx)==0) return -1.0/fabs(x);
37 if(ix>=0x7ff00000) return x*x;
38 if((ix>>=20)==0) /* IEEE 754 logb */
39 return -1022.0;
40 else
41 return (double) (ix-1023);
42}
| 30 double x;
31#endif
32{
33 int32_t lx,ix;
34 EXTRACT_WORDS(ix,lx,x);
35 ix &= 0x7fffffff; /* high |x| */
36 if((ix|lx)==0) return -1.0/fabs(x);
37 if(ix>=0x7ff00000) return x*x;
38 if((ix>>=20)==0) /* IEEE 754 logb */
39 return -1022.0;
40 else
41 return (double) (ix-1023);
42}
|