Annotation of embedaddon/libiconv/srclib/intprops.h, revision 1.1
1.1 ! misho 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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