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| 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 3 of the License, or |
| 8 (at your option) 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 /* Written by Paul Eggert. */ |
| 19 |
| 20 #include <limits.h> |
| 21 |
| 22 /* The extra casts in the following macros work around compiler bugs, |
| 23 e.g., in Cray C 5.0.3.0. */ |
| 24 |
| 25 /* True if the arithmetic type T is an integer type. bool counts as |
| 26 an integer. */ |
| 27 #define TYPE_IS_INTEGER(t) ((t) 1.5 == 1) |
| 28 |
| 29 /* True if negative values of the signed integer type T use two's |
| 30 complement, ones' complement, or signed magnitude representation, |
| 31 respectively. Much GNU code assumes two's complement, but some |
| 32 people like to be portable to all possible C hosts. */ |
| 33 #define TYPE_TWOS_COMPLEMENT(t) ((t) ~ (t) 0 == (t) -1) |
| 34 #define TYPE_ONES_COMPLEMENT(t) ((t) ~ (t) 0 == 0) |
| 35 #define TYPE_SIGNED_MAGNITUDE(t) ((t) ~ (t) 0 < (t) -1) |
| 36 |
| 37 /* True if the arithmetic type T is signed. */ |
| 38 #define TYPE_SIGNED(t) (! ((t) 0 < (t) -1)) |
| 39 |
| 40 /* The maximum and minimum values for the integer type T. These |
| 41 macros have undefined behavior if T is signed and has padding bits. |
| 42 If this is a problem for you, please let us know how to fix it for |
| 43 your host. */ |
| 44 #define TYPE_MINIMUM(t) \ |
| 45 ((t) (! TYPE_SIGNED (t) \ |
| 46 ? (t) 0 \ |
| 47 : TYPE_SIGNED_MAGNITUDE (t) \ |
| 48 ? ~ (t) 0 \ |
| 49 : ~ (t) 0 << (sizeof (t) * CHAR_BIT - 1))) |
| 50 #define TYPE_MAXIMUM(t) \ |
| 51 ((t) (! TYPE_SIGNED (t) \ |
| 52 ? (t) -1 \ |
| 53 : ~ (~ (t) 0 << (sizeof (t) * CHAR_BIT - 1)))) |
| 54 |
| 55 /* Return zero if T can be determined to be an unsigned type. |
| 56 Otherwise, return 1. |
| 57 When compiling with GCC, INT_STRLEN_BOUND uses this macro to obtain a |
| 58 tighter bound. Otherwise, it overestimates the true bound by one byte |
| 59 when applied to unsigned types of size 2, 4, 16, ... bytes. |
| 60 The symbol signed_type_or_expr__ is private to this header file. */ |
| 61 #if __GNUC__ >= 2 |
| 62 # define signed_type_or_expr__(t) TYPE_SIGNED (__typeof__ (t)) |
| 63 #else |
| 64 # define signed_type_or_expr__(t) 1 |
| 65 #endif |
| 66 |
| 67 /* Bound on length of the string representing an integer type or expression T. |
| 68 Subtract 1 for the sign bit if T is signed; log10 (2.0) < 146/485; |
| 69 add 1 for integer division truncation; add 1 more for a minus sign |
| 70 if needed. */ |
| 71 #define INT_STRLEN_BOUND(t) \ |
| 72 ((sizeof (t) * CHAR_BIT - signed_type_or_expr__ (t)) * 146 / 485 \ |
| 73 + signed_type_or_expr__ (t) + 1) |
| 74 |
| 75 /* Bound on buffer size needed to represent an integer type or expression T, |
| 76 including the terminating null. */ |
| 77 #define INT_BUFSIZE_BOUND(t) (INT_STRLEN_BOUND (t) + 1) |
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