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- /* intprops.h -- properties of integer types
- Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
- This program is free software: you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 3 of the License, or
- (at your option) any later version.
- This program 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 General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>. */
- /* Written by Paul Eggert. */
- #include <limits.h>
- /* The extra casts in the following macros work around compiler bugs,
- e.g., in Cray C 5.0.3.0. */
- /* True if the arithmetic type T is an integer type. bool counts as
- an integer. */
- #define TYPE_IS_INTEGER(t) ((t) 1.5 == 1)
- /* True if negative values of the signed integer type T use two's
- complement, ones' complement, or signed magnitude representation,
- respectively. Much GNU code assumes two's complement, but some
- people like to be portable to all possible C hosts. */
- #define TYPE_TWOS_COMPLEMENT(t) ((t) ~ (t) 0 == (t) -1)
- #define TYPE_ONES_COMPLEMENT(t) ((t) ~ (t) 0 == 0)
- #define TYPE_SIGNED_MAGNITUDE(t) ((t) ~ (t) 0 < (t) -1)
- /* True if the arithmetic type T is signed. */
- #define TYPE_SIGNED(t) (! ((t) 0 < (t) -1))
- /* The maximum and minimum values for the integer type T. These
- macros have undefined behavior if T is signed and has padding bits.
- If this is a problem for you, please let us know how to fix it for
- your host. */
- #define TYPE_MINIMUM(t) \
- ((t) (! TYPE_SIGNED (t) \
- ? (t) 0 \
- : TYPE_SIGNED_MAGNITUDE (t) \
- ? ~ (t) 0 \
- : ~ (t) 0 << (sizeof (t) * CHAR_BIT - 1)))
- #define TYPE_MAXIMUM(t) \
- ((t) (! TYPE_SIGNED (t) \
- ? (t) -1 \
- : ~ (~ (t) 0 << (sizeof (t) * CHAR_BIT - 1))))
- /* Return zero if T can be determined to be an unsigned type.
- Otherwise, return 1.
- When compiling with GCC, INT_STRLEN_BOUND uses this macro to obtain a
- tighter bound. Otherwise, it overestimates the true bound by one byte
- when applied to unsigned types of size 2, 4, 16, ... bytes.
- The symbol signed_type_or_expr__ is private to this header file. */
- #if __GNUC__ >= 2
- # define signed_type_or_expr__(t) TYPE_SIGNED (__typeof__ (t))
- #else
- # define signed_type_or_expr__(t) 1
- #endif
- /* Bound on length of the string representing an integer type or expression T.
- Subtract 1 for the sign bit if T is signed; log10 (2.0) < 146/485;
- add 1 for integer division truncation; add 1 more for a minus sign
- if needed. */
- #define INT_STRLEN_BOUND(t) \
- ((sizeof (t) * CHAR_BIT - signed_type_or_expr__ (t)) * 146 / 485 \
- + signed_type_or_expr__ (t) + 1)
- /* Bound on buffer size needed to represent an integer type or expression T,
- including the terminating null. */
- #define INT_BUFSIZE_BOUND(t) (INT_STRLEN_BOUND (t) + 1)
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