summaryrefslogtreecommitdiff
path: root/sysdeps/ieee754/ieee754.h
blob: 9e6efe49738c4ba5e144305b954e288333e680a0 (plain)
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
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
/* Copyright (C) 1992, 1995, 1996 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include <endian.h>

union ieee754_float
  {
    float f;

    /* This is the IEEE 754 single-precision format.  */
    struct
      {
#if	__BYTE_ORDER == __BIG_ENDIAN
	unsigned int negative:1;
	unsigned int exponent:8;
	unsigned int mantissa:23;
#endif				/* Big endian.  */
#if	__BYTE_ORDER == __LITTLE_ENDIAN
	unsigned int mantissa:23;
	unsigned int exponent:8;
	unsigned int negative:1;
#endif				/* Little endian.  */
      } ieee;

    /* This format makes it easier to see if a NaN is a signalling NaN.  */
    struct
      {
#if	__BYTE_ORDER == __BIG_ENDIAN
	unsigned int negative:1;
	unsigned int exponent:8;
	unsigned int quiet_nan:1;
	unsigned int mantissa:22;
#endif				/* Big endian.  */
#if	__BYTE_ORDER == __LITTLE_ENDIAN
	unsigned int mantissa:22;
	unsigned int quiet_nan:1;
	unsigned int exponent:8;
	unsigned int negative:1;
#endif				/* Little endian.  */
      } ieee_nan;
  };

#define IEEE754_FLOAT_BIAS	0x7f /* Added to exponent.  */


union ieee754_double
  {
    double d;

    /* This is the IEEE 754 double-precision format.  */
    struct
      {
#if	__BYTE_ORDER == __BIG_ENDIAN
	unsigned int negative:1;
	unsigned int exponent:11;
	/* Together these comprise the mantissa.  */
	unsigned int mantissa0:20;
	unsigned int mantissa1:32;
#endif				/* Big endian.  */
#if	__BYTE_ORDER == __LITTLE_ENDIAN
	/* Together these comprise the mantissa.  */
	unsigned int mantissa1:32;
	unsigned int mantissa0:20;
	unsigned int exponent:11;
	unsigned int negative:1;
#endif				/* Little endian.  */
      } ieee;

    /* This format makes it easier to see if a NaN is a signalling NaN.  */
    struct
      {
#if	__BYTE_ORDER == __BIG_ENDIAN
	unsigned int negative:1;
	unsigned int exponent:11;
	unsigned int quiet_nan:1;
	/* Together these comprise the mantissa.  */
	unsigned int mantissa0:19;
	unsigned int mantissa1:32;
#else
	/* Together these comprise the mantissa.  */
	unsigned int mantissa1:32;
	unsigned int mantissa0:19;
	unsigned int quiet_nan:1;
	unsigned int exponent:11;
	unsigned int negative:1;
#endif
      } ieee_nan;
  };

#define IEEE754_DOUBLE_BIAS	0x3ff /* Added to exponent.  */


union ieee854_long_double
  {
    long double d;

    /* This is the IEEE 854 double-extended-precision format.  */
    struct
      {
#if	__BYTE_ORDER == __BIG_ENDIAN
	unsigned int negative:1;
	unsigned int exponent:15;
	unsigned int empty:16;
	unsigned int mantissa0:32;
	unsigned int mantissa1:32;
#endif
#if	__BYTE_ORDER == __LITTLE_ENDIAN
	unsigned int mantissa1:32;
	unsigned int mantissa0:32;
	unsigned int exponent:15;
	unsigned int negative:1;
	unsigned int empty:16;
#endif
      } ieee;

    /* This is for NaNs in the IEEE 854 double-extended-precision format.  */
    struct
      {
#if	__BYTE_ORDER == __BIG_ENDIAN
	unsigned int negative:1;
	unsigned int exponent:15;
	unsigned int empty:16;
	unsigned int one:1;
	unsigned int quiet_nan:1;
	unsigned int mantissa0:30;
	unsigned int mantissa1:32;
#endif
#if	__BYTE_ORDER == __LITTLE_ENDIAN
	unsigned int mantissa1:32;
	unsigned int mantissa0:30;
	unsigned int quiet_nan:1;
	unsigned int one:1;
	unsigned int exponent:15;
	unsigned int negative:1;
	unsigned int empty:16;
#endif
      } ieee_nan;
  };

#define IEEE854_LONG_DOUBLE_BIAS 0x3fff