dhcpd-pools  2.28
ISC dhcpd lease usage analyser
float+.h
Go to the documentation of this file.
1 /* Supplemental information about the floating-point formats.
2  Copyright (C) 2007, 2009-2015 Free Software Foundation, Inc.
3  Written by Bruno Haible <bruno@clisp.org>, 2007.
4 
5  This program is free software; you can redistribute it and/or modify
6  it under the terms of the GNU General Public License as published by
7  the Free Software Foundation; either version 3, or (at your option)
8  any later version.
9 
10  This program is distributed in the hope that it will be useful,
11  but WITHOUT ANY WARRANTY; without even the implied warranty of
12  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13  GNU General Public License for more details.
14 
15  You should have received a copy of the GNU General Public License
16  along with this program; if not, see <http://www.gnu.org/licenses/>. */
17 
18 #ifndef _FLOATPLUS_H
19 #define _FLOATPLUS_H
20 
21 #include <float.h>
22 #include <limits.h>
23 
24 /* Number of bits in the mantissa of a floating-point number, including the
25  "hidden bit". */
26 #if FLT_RADIX == 2
27 # define FLT_MANT_BIT FLT_MANT_DIG
28 # define DBL_MANT_BIT DBL_MANT_DIG
29 # define LDBL_MANT_BIT LDBL_MANT_DIG
30 #elif FLT_RADIX == 4
31 # define FLT_MANT_BIT (FLT_MANT_DIG * 2)
32 # define DBL_MANT_BIT (DBL_MANT_DIG * 2)
33 # define LDBL_MANT_BIT (LDBL_MANT_DIG * 2)
34 #elif FLT_RADIX == 16
35 # define FLT_MANT_BIT (FLT_MANT_DIG * 4)
36 # define DBL_MANT_BIT (DBL_MANT_DIG * 4)
37 # define LDBL_MANT_BIT (LDBL_MANT_DIG * 4)
38 #endif
39 
40 /* Bit mask that can be used to mask the exponent, as an unsigned number. */
41 #define FLT_EXP_MASK ((FLT_MAX_EXP - FLT_MIN_EXP) | 7)
42 #define DBL_EXP_MASK ((DBL_MAX_EXP - DBL_MIN_EXP) | 7)
43 #define LDBL_EXP_MASK ((LDBL_MAX_EXP - LDBL_MIN_EXP) | 7)
44 
45 /* Number of bits used for the exponent of a floating-point number, including
46  the exponent's sign. */
47 #define FLT_EXP_BIT \
48  (FLT_EXP_MASK < 0x100 ? 8 : \
49  FLT_EXP_MASK < 0x200 ? 9 : \
50  FLT_EXP_MASK < 0x400 ? 10 : \
51  FLT_EXP_MASK < 0x800 ? 11 : \
52  FLT_EXP_MASK < 0x1000 ? 12 : \
53  FLT_EXP_MASK < 0x2000 ? 13 : \
54  FLT_EXP_MASK < 0x4000 ? 14 : \
55  FLT_EXP_MASK < 0x8000 ? 15 : \
56  FLT_EXP_MASK < 0x10000 ? 16 : \
57  FLT_EXP_MASK < 0x20000 ? 17 : \
58  FLT_EXP_MASK < 0x40000 ? 18 : \
59  FLT_EXP_MASK < 0x80000 ? 19 : \
60  FLT_EXP_MASK < 0x100000 ? 20 : \
61  FLT_EXP_MASK < 0x200000 ? 21 : \
62  FLT_EXP_MASK < 0x400000 ? 22 : \
63  FLT_EXP_MASK < 0x800000 ? 23 : \
64  FLT_EXP_MASK < 0x1000000 ? 24 : \
65  FLT_EXP_MASK < 0x2000000 ? 25 : \
66  FLT_EXP_MASK < 0x4000000 ? 26 : \
67  FLT_EXP_MASK < 0x8000000 ? 27 : \
68  FLT_EXP_MASK < 0x10000000 ? 28 : \
69  FLT_EXP_MASK < 0x20000000 ? 29 : \
70  FLT_EXP_MASK < 0x40000000 ? 30 : \
71  FLT_EXP_MASK <= 0x7fffffff ? 31 : \
72  32)
73 #define DBL_EXP_BIT \
74  (DBL_EXP_MASK < 0x100 ? 8 : \
75  DBL_EXP_MASK < 0x200 ? 9 : \
76  DBL_EXP_MASK < 0x400 ? 10 : \
77  DBL_EXP_MASK < 0x800 ? 11 : \
78  DBL_EXP_MASK < 0x1000 ? 12 : \
79  DBL_EXP_MASK < 0x2000 ? 13 : \
80  DBL_EXP_MASK < 0x4000 ? 14 : \
81  DBL_EXP_MASK < 0x8000 ? 15 : \
82  DBL_EXP_MASK < 0x10000 ? 16 : \
83  DBL_EXP_MASK < 0x20000 ? 17 : \
84  DBL_EXP_MASK < 0x40000 ? 18 : \
85  DBL_EXP_MASK < 0x80000 ? 19 : \
86  DBL_EXP_MASK < 0x100000 ? 20 : \
87  DBL_EXP_MASK < 0x200000 ? 21 : \
88  DBL_EXP_MASK < 0x400000 ? 22 : \
89  DBL_EXP_MASK < 0x800000 ? 23 : \
90  DBL_EXP_MASK < 0x1000000 ? 24 : \
91  DBL_EXP_MASK < 0x2000000 ? 25 : \
92  DBL_EXP_MASK < 0x4000000 ? 26 : \
93  DBL_EXP_MASK < 0x8000000 ? 27 : \
94  DBL_EXP_MASK < 0x10000000 ? 28 : \
95  DBL_EXP_MASK < 0x20000000 ? 29 : \
96  DBL_EXP_MASK < 0x40000000 ? 30 : \
97  DBL_EXP_MASK <= 0x7fffffff ? 31 : \
98  32)
99 #define LDBL_EXP_BIT \
100  (LDBL_EXP_MASK < 0x100 ? 8 : \
101  LDBL_EXP_MASK < 0x200 ? 9 : \
102  LDBL_EXP_MASK < 0x400 ? 10 : \
103  LDBL_EXP_MASK < 0x800 ? 11 : \
104  LDBL_EXP_MASK < 0x1000 ? 12 : \
105  LDBL_EXP_MASK < 0x2000 ? 13 : \
106  LDBL_EXP_MASK < 0x4000 ? 14 : \
107  LDBL_EXP_MASK < 0x8000 ? 15 : \
108  LDBL_EXP_MASK < 0x10000 ? 16 : \
109  LDBL_EXP_MASK < 0x20000 ? 17 : \
110  LDBL_EXP_MASK < 0x40000 ? 18 : \
111  LDBL_EXP_MASK < 0x80000 ? 19 : \
112  LDBL_EXP_MASK < 0x100000 ? 20 : \
113  LDBL_EXP_MASK < 0x200000 ? 21 : \
114  LDBL_EXP_MASK < 0x400000 ? 22 : \
115  LDBL_EXP_MASK < 0x800000 ? 23 : \
116  LDBL_EXP_MASK < 0x1000000 ? 24 : \
117  LDBL_EXP_MASK < 0x2000000 ? 25 : \
118  LDBL_EXP_MASK < 0x4000000 ? 26 : \
119  LDBL_EXP_MASK < 0x8000000 ? 27 : \
120  LDBL_EXP_MASK < 0x10000000 ? 28 : \
121  LDBL_EXP_MASK < 0x20000000 ? 29 : \
122  LDBL_EXP_MASK < 0x40000000 ? 30 : \
123  LDBL_EXP_MASK <= 0x7fffffff ? 31 : \
124  32)
125 
126 /* Number of bits used for a floating-point number: the mantissa (not
127  counting the "hidden bit", since it may or may not be explicit), the
128  exponent, and the sign. */
129 #define FLT_TOTAL_BIT ((FLT_MANT_BIT - 1) + FLT_EXP_BIT + 1)
130 #define DBL_TOTAL_BIT ((DBL_MANT_BIT - 1) + DBL_EXP_BIT + 1)
131 #define LDBL_TOTAL_BIT ((LDBL_MANT_BIT - 1) + LDBL_EXP_BIT + 1)
132 
133 /* Number of bytes used for a floating-point number.
134  This can be smaller than the 'sizeof'. For example, on i386 systems,
135  'long double' most often have LDBL_MANT_BIT = 64, LDBL_EXP_BIT = 16, hence
136  LDBL_TOTAL_BIT = 80 bits, i.e. 10 bytes of consecutive memory, but
137  sizeof (long double) = 12 or = 16. */
138 #define SIZEOF_FLT ((FLT_TOTAL_BIT + CHAR_BIT - 1) / CHAR_BIT)
139 #define SIZEOF_DBL ((DBL_TOTAL_BIT + CHAR_BIT - 1) / CHAR_BIT)
140 #define SIZEOF_LDBL ((LDBL_TOTAL_BIT + CHAR_BIT - 1) / CHAR_BIT)
141 
142 /* Verify that SIZEOF_FLT <= sizeof (float) etc. */
143 typedef int verify_sizeof_flt[SIZEOF_FLT <= sizeof (float) ? 1 : -1];
144 typedef int verify_sizeof_dbl[SIZEOF_DBL <= sizeof (double) ? 1 : - 1];
145 typedef int verify_sizeof_ldbl[SIZEOF_LDBL <= sizeof (long double) ? 1 : - 1];
146 
147 #endif /* _FLOATPLUS_H */
int verify_sizeof_flt[SIZEOF_FLT<=sizeof(float)?1:-1]
Definition: float+.h:143
int verify_sizeof_dbl[SIZEOF_DBL<=sizeof(double)?1:-1]
Definition: float+.h:144
int verify_sizeof_ldbl[SIZEOF_LDBL<=sizeof(long double)?1:-1]
Definition: float+.h:145
#define SIZEOF_FLT
Definition: float+.h:138
#define SIZEOF_DBL
Definition: float+.h:139
#define SIZEOF_LDBL
Definition: float+.h:140