1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
|
/* ilogbq.c -- __float128 version of s_ilogb.c.
* Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
*/
/*
* ====================================================
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunPro, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
#if defined(LIBM_SCCS) && !defined(lint)
static char rcsid[] = "$NetBSD: $";
#endif
/* ilogbl(__float128 x)
* return the binary exponent of non-zero x
* ilogbl(0) = FP_ILOGB0
* ilogbl(NaN) = FP_ILOGBNAN (no signal is raised)
* ilogbl(+-Inf) = INT_MAX (no signal is raised)
*/
#include <limits.h>
#include <math.h>
#include <errno.h>
#include "quadmath-imp.h"
#ifndef FP_ILOGB0
# define FP_ILOGB0 INT_MIN
#endif
#ifndef FP_ILOGBNAN
# define FP_ILOGBNAN INT_MAX
#endif
int
ilogbq (__float128 x)
{
int64_t hx,lx;
int ix;
GET_FLT128_WORDS64(hx,lx,x);
hx &= 0x7fffffffffffffffLL;
if(hx <= 0x0001000000000000LL) {
if((hx|lx)==0)
{
errno = EDOM;
#ifdef USE_FENV_H
feraiseexcept (FE_INVALID);
#endif
return FP_ILOGB0; /* ilogbl(0) = FP_ILOGB0 */
}
else /* subnormal x */
if(hx==0) {
for (ix = -16431; lx>0; lx<<=1) ix -=1;
} else {
for (ix = -16382, hx<<=15; hx>0; hx<<=1) ix -=1;
}
return ix;
}
else if (hx<0x7fff000000000000LL) return (hx>>48)-0x3fff;
else if (FP_ILOGBNAN != INT_MAX) {
/* ISO C99 requires ilogbl(+-Inf) == INT_MAX. */
if (((hx^0x7fff000000000000LL)|lx) == 0)
{
errno = EDOM;
#ifdef USE_FENV_H
feraiseexcept (FE_INVALID);
#endif
return INT_MAX;
}
}
errno = EDOM;
#ifdef USE_FENV_H
feraiseexcept (FE_INVALID);
#endif
return FP_ILOGBNAN;
}
|
