diff options
Diffstat (limited to 'gl/float+.h')
-rw-r--r-- | gl/float+.h | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/gl/float+.h b/gl/float+.h new file mode 100644 index 0000000..240fe36 --- /dev/null +++ b/gl/float+.h | |||
@@ -0,0 +1,148 @@ | |||
1 | /* Supplemental information about the floating-point formats. | ||
2 | Copyright (C) 2007 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, write to the Free Software Foundation, | ||
17 | Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ | ||
18 | |||
19 | #ifndef _FLOATPLUS_H | ||
20 | #define _FLOATPLUS_H | ||
21 | |||
22 | #include <float.h> | ||
23 | #include <limits.h> | ||
24 | |||
25 | /* Number of bits in the mantissa of a floating-point number, including the | ||
26 | "hidden bit". */ | ||
27 | #if FLT_RADIX == 2 | ||
28 | # define FLT_MANT_BIT FLT_MANT_DIG | ||
29 | # define DBL_MANT_BIT DBL_MANT_DIG | ||
30 | # define LDBL_MANT_BIT LDBL_MANT_DIG | ||
31 | #elif FLT_RADIX == 4 | ||
32 | # define FLT_MANT_BIT (FLT_MANT_DIG * 2) | ||
33 | # define DBL_MANT_BIT (DBL_MANT_DIG * 2) | ||
34 | # define LDBL_MANT_BIT (LDBL_MANT_DIG * 2) | ||
35 | #elif FLT_RADIX == 16 | ||
36 | # define FLT_MANT_BIT (FLT_MANT_DIG * 4) | ||
37 | # define DBL_MANT_BIT (DBL_MANT_DIG * 4) | ||
38 | # define LDBL_MANT_BIT (LDBL_MANT_DIG * 4) | ||
39 | #endif | ||
40 | |||
41 | /* Bit mask that can be used to mask the exponent, as an unsigned number. */ | ||
42 | #define FLT_EXP_MASK ((FLT_MAX_EXP - FLT_MIN_EXP) | 7) | ||
43 | #define DBL_EXP_MASK ((DBL_MAX_EXP - DBL_MIN_EXP) | 7) | ||
44 | #define LDBL_EXP_MASK ((LDBL_MAX_EXP - LDBL_MIN_EXP) | 7) | ||
45 | |||
46 | /* Number of bits used for the exponent of a floating-point number, including | ||
47 | the exponent's sign. */ | ||
48 | #define FLT_EXP_BIT \ | ||
49 | (FLT_EXP_MASK < 0x100 ? 8 : \ | ||
50 | FLT_EXP_MASK < 0x200 ? 9 : \ | ||
51 | FLT_EXP_MASK < 0x400 ? 10 : \ | ||
52 | FLT_EXP_MASK < 0x800 ? 11 : \ | ||
53 | FLT_EXP_MASK < 0x1000 ? 12 : \ | ||
54 | FLT_EXP_MASK < 0x2000 ? 13 : \ | ||
55 | FLT_EXP_MASK < 0x4000 ? 14 : \ | ||
56 | FLT_EXP_MASK < 0x8000 ? 15 : \ | ||
57 | FLT_EXP_MASK < 0x10000 ? 16 : \ | ||
58 | FLT_EXP_MASK < 0x20000 ? 17 : \ | ||
59 | FLT_EXP_MASK < 0x40000 ? 18 : \ | ||
60 | FLT_EXP_MASK < 0x80000 ? 19 : \ | ||
61 | FLT_EXP_MASK < 0x100000 ? 20 : \ | ||
62 | FLT_EXP_MASK < 0x200000 ? 21 : \ | ||
63 | FLT_EXP_MASK < 0x400000 ? 22 : \ | ||
64 | FLT_EXP_MASK < 0x800000 ? 23 : \ | ||
65 | FLT_EXP_MASK < 0x1000000 ? 24 : \ | ||
66 | FLT_EXP_MASK < 0x2000000 ? 25 : \ | ||
67 | FLT_EXP_MASK < 0x4000000 ? 26 : \ | ||
68 | FLT_EXP_MASK < 0x8000000 ? 27 : \ | ||
69 | FLT_EXP_MASK < 0x10000000 ? 28 : \ | ||
70 | FLT_EXP_MASK < 0x20000000 ? 29 : \ | ||
71 | FLT_EXP_MASK < 0x40000000 ? 30 : \ | ||
72 | FLT_EXP_MASK <= 0x7fffffff ? 31 : \ | ||
73 | 32) | ||
74 | #define DBL_EXP_BIT \ | ||
75 | (DBL_EXP_MASK < 0x100 ? 8 : \ | ||
76 | DBL_EXP_MASK < 0x200 ? 9 : \ | ||
77 | DBL_EXP_MASK < 0x400 ? 10 : \ | ||
78 | DBL_EXP_MASK < 0x800 ? 11 : \ | ||
79 | DBL_EXP_MASK < 0x1000 ? 12 : \ | ||
80 | DBL_EXP_MASK < 0x2000 ? 13 : \ | ||
81 | DBL_EXP_MASK < 0x4000 ? 14 : \ | ||
82 | DBL_EXP_MASK < 0x8000 ? 15 : \ | ||
83 | DBL_EXP_MASK < 0x10000 ? 16 : \ | ||
84 | DBL_EXP_MASK < 0x20000 ? 17 : \ | ||
85 | DBL_EXP_MASK < 0x40000 ? 18 : \ | ||
86 | DBL_EXP_MASK < 0x80000 ? 19 : \ | ||
87 | DBL_EXP_MASK < 0x100000 ? 20 : \ | ||
88 | DBL_EXP_MASK < 0x200000 ? 21 : \ | ||
89 | DBL_EXP_MASK < 0x400000 ? 22 : \ | ||
90 | DBL_EXP_MASK < 0x800000 ? 23 : \ | ||
91 | DBL_EXP_MASK < 0x1000000 ? 24 : \ | ||
92 | DBL_EXP_MASK < 0x2000000 ? 25 : \ | ||
93 | DBL_EXP_MASK < 0x4000000 ? 26 : \ | ||
94 | DBL_EXP_MASK < 0x8000000 ? 27 : \ | ||
95 | DBL_EXP_MASK < 0x10000000 ? 28 : \ | ||
96 | DBL_EXP_MASK < 0x20000000 ? 29 : \ | ||
97 | DBL_EXP_MASK < 0x40000000 ? 30 : \ | ||
98 | DBL_EXP_MASK <= 0x7fffffff ? 31 : \ | ||
99 | 32) | ||
100 | #define LDBL_EXP_BIT \ | ||
101 | (LDBL_EXP_MASK < 0x100 ? 8 : \ | ||
102 | LDBL_EXP_MASK < 0x200 ? 9 : \ | ||
103 | LDBL_EXP_MASK < 0x400 ? 10 : \ | ||
104 | LDBL_EXP_MASK < 0x800 ? 11 : \ | ||
105 | LDBL_EXP_MASK < 0x1000 ? 12 : \ | ||
106 | LDBL_EXP_MASK < 0x2000 ? 13 : \ | ||
107 | LDBL_EXP_MASK < 0x4000 ? 14 : \ | ||
108 | LDBL_EXP_MASK < 0x8000 ? 15 : \ | ||
109 | LDBL_EXP_MASK < 0x10000 ? 16 : \ | ||
110 | LDBL_EXP_MASK < 0x20000 ? 17 : \ | ||
111 | LDBL_EXP_MASK < 0x40000 ? 18 : \ | ||
112 | LDBL_EXP_MASK < 0x80000 ? 19 : \ | ||
113 | LDBL_EXP_MASK < 0x100000 ? 20 : \ | ||
114 | LDBL_EXP_MASK < 0x200000 ? 21 : \ | ||
115 | LDBL_EXP_MASK < 0x400000 ? 22 : \ | ||
116 | LDBL_EXP_MASK < 0x800000 ? 23 : \ | ||
117 | LDBL_EXP_MASK < 0x1000000 ? 24 : \ | ||
118 | LDBL_EXP_MASK < 0x2000000 ? 25 : \ | ||
119 | LDBL_EXP_MASK < 0x4000000 ? 26 : \ | ||
120 | LDBL_EXP_MASK < 0x8000000 ? 27 : \ | ||
121 | LDBL_EXP_MASK < 0x10000000 ? 28 : \ | ||
122 | LDBL_EXP_MASK < 0x20000000 ? 29 : \ | ||
123 | LDBL_EXP_MASK < 0x40000000 ? 30 : \ | ||
124 | LDBL_EXP_MASK <= 0x7fffffff ? 31 : \ | ||
125 | 32) | ||
126 | |||
127 | /* Number of bits used for a floating-point number: the mantissa (not | ||
128 | counting the "hidden bit", since it may or may not be explicit), the | ||
129 | exponent, and the sign. */ | ||
130 | #define FLT_TOTAL_BIT ((FLT_MANT_BIT - 1) + FLT_EXP_BIT + 1) | ||
131 | #define DBL_TOTAL_BIT ((DBL_MANT_BIT - 1) + DBL_EXP_BIT + 1) | ||
132 | #define LDBL_TOTAL_BIT ((LDBL_MANT_BIT - 1) + LDBL_EXP_BIT + 1) | ||
133 | |||
134 | /* Number of bytes used for a floating-point number. | ||
135 | This can be smaller than the 'sizeof'. For example, on i386 systems, | ||
136 | 'long double' most often have LDBL_MANT_BIT = 64, LDBL_EXP_BIT = 16, hence | ||
137 | LDBL_TOTAL_BIT = 80 bits, i.e. 10 bytes of consecutive memory, but | ||
138 | sizeof (long double) = 12 or = 16. */ | ||
139 | #define SIZEOF_FLT ((FLT_TOTAL_BIT + CHAR_BIT - 1) / CHAR_BIT) | ||
140 | #define SIZEOF_DBL ((DBL_TOTAL_BIT + CHAR_BIT - 1) / CHAR_BIT) | ||
141 | #define SIZEOF_LDBL ((LDBL_TOTAL_BIT + CHAR_BIT - 1) / CHAR_BIT) | ||
142 | |||
143 | /* Verify that SIZEOF_FLT <= sizeof (float) etc. */ | ||
144 | typedef int verify_sizeof_flt[2 * (SIZEOF_FLT <= sizeof (float)) - 1]; | ||
145 | typedef int verify_sizeof_dbl[2 * (SIZEOF_DBL <= sizeof (double)) - 1]; | ||
146 | typedef int verify_sizeof_ldbl[2 * (SIZEOF_LDBL <= sizeof (long double)) - 1]; | ||
147 | |||
148 | #endif /* _FLOATPLUS_H */ | ||