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/* Bound on length of the string representing an integer type or expression T.
57   Subtract 1 for the sign bit if t is signed; log10 (2.0) < 146/485;
58   add 1 for integer division truncation; add 1 more for a minus sign
59   if needed.  */
60#define INT_STRLEN_BOUND(t) \
61  ((sizeof (t) * CHAR_BIT - 1) * 146 / 485 + 2)
62
63/* Bound on buffer size needed to represent an integer type or expression T,
64   including the terminating null.  */
65#define INT_BUFSIZE_BOUND(t) (INT_STRLEN_BOUND (t) + 1)
66