diff options
Diffstat (limited to 'gl/intprops.h')
-rw-r--r-- | gl/intprops.h | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/gl/intprops.h b/gl/intprops.h new file mode 100644 index 00000000..34f971cb --- /dev/null +++ b/gl/intprops.h | |||
@@ -0,0 +1,78 @@ | |||
1 | /* intprops.h -- properties of integer types | ||
2 | |||
3 | Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc. | ||
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 2, 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 | /* Written by Paul Eggert. */ | ||
20 | |||
21 | #include <limits.h> | ||
22 | |||
23 | /* The extra casts in the following macros work around compiler bugs, | ||
24 | e.g., in Cray C 5.0.3.0. */ | ||
25 | |||
26 | /* True if the arithmetic type T is an integer type. bool counts as | ||
27 | an integer. */ | ||
28 | #define TYPE_IS_INTEGER(t) ((t) 1.5 == 1) | ||
29 | |||
30 | /* True if negative values of the signed integer type T use two's | ||
31 | complement, ones' complement, or signed magnitude representation, | ||
32 | respectively. Much GNU code assumes two's complement, but some | ||
33 | people like to be portable to all possible C hosts. */ | ||
34 | #define TYPE_TWOS_COMPLEMENT(t) ((t) ~ (t) 0 == (t) -1) | ||
35 | #define TYPE_ONES_COMPLEMENT(t) ((t) ~ (t) 0 == 0) | ||
36 | #define TYPE_SIGNED_MAGNITUDE(t) ((t) ~ (t) 0 < (t) -1) | ||
37 | |||
38 | /* True if the arithmetic type T is signed. */ | ||
39 | #define TYPE_SIGNED(t) (! ((t) 0 < (t) -1)) | ||
40 | |||
41 | /* The maximum and minimum values for the integer type T. These | ||
42 | macros have undefined behavior if T is signed and has padding bits. | ||
43 | If this is a problem for you, please let us know how to fix it for | ||
44 | your host. */ | ||
45 | #define TYPE_MINIMUM(t) \ | ||
46 | ((t) (! TYPE_SIGNED (t) \ | ||
47 | ? (t) 0 \ | ||
48 | : TYPE_SIGNED_MAGNITUDE (t) \ | ||
49 | ? ~ (t) 0 \ | ||
50 | : ~ (t) 0 << (sizeof (t) * CHAR_BIT - 1))) | ||
51 | #define TYPE_MAXIMUM(t) \ | ||
52 | ((t) (! TYPE_SIGNED (t) \ | ||
53 | ? (t) -1 \ | ||
54 | : ~ (~ (t) 0 << (sizeof (t) * CHAR_BIT - 1)))) | ||
55 | |||
56 | /* Return zero if T can be determined to be an unsigned type. | ||
57 | Otherwise, return 1. | ||
58 | When compiling with GCC, INT_STRLEN_BOUND uses this macro to obtain a | ||
59 | tighter bound. Otherwise, it overestimates the true bound by one byte | ||
60 | when applied to unsigned types of size 2, 4, 16, ... bytes. | ||
61 | The symbol signed_type_or_expr__ is private to this header file. */ | ||
62 | #if __GNUC__ >= 2 | ||
63 | # define signed_type_or_expr__(t) TYPE_SIGNED (__typeof__ (t)) | ||
64 | #else | ||
65 | # define signed_type_or_expr__(t) 1 | ||
66 | #endif | ||
67 | |||
68 | /* Bound on length of the string representing an integer type or expression T. | ||
69 | Subtract 1 for the sign bit if T is signed; log10 (2.0) < 146/485; | ||
70 | add 1 for integer division truncation; add 1 more for a minus sign | ||
71 | if needed. */ | ||
72 | #define INT_STRLEN_BOUND(t) \ | ||
73 | ((sizeof (t) * CHAR_BIT - signed_type_or_expr__ (t)) * 146 / 485 \ | ||
74 | + signed_type_or_expr__ (t) + 1) | ||
75 | |||
76 | /* Bound on buffer size needed to represent an integer type or expression T, | ||
77 | including the terminating null. */ | ||
78 | #define INT_BUFSIZE_BOUND(t) (INT_STRLEN_BOUND (t) + 1) | ||