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Annotation of embedaddon/libiconv/srclib/intprops.h, revision 1.1.1.1

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)