lib/limits.in.h

   1 /* A GNU-like <limits.h>.
   2
   3    Copyright 2016-2017 Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU General Public License
   7    as published by the Free Software Foundation; either version 3, 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 #ifndef _@GUARD_PREFIX@_LIMITS_H
  19
  20 #if __GNUC__ >= 3
  21 @PRAGMA_SYSTEM_HEADER@
  22 #endif
  23 @PRAGMA_COLUMNS@
  24
  25 /* The include_next requires a split double-inclusion guard.  */
  26 #@INCLUDE_NEXT@ @NEXT_LIMITS_H@
  27
  28 #ifndef _@GUARD_PREFIX@_LIMITS_H
  29 #define _@GUARD_PREFIX@_LIMITS_H
  30
  31 /* The number of usable bits in an unsigned or signed integer type
  32    with minimum value MIN and maximum value MAX, as an int expression
  33    suitable in #if.  Cover all known practical hosts.  This
  34    implementation exploits the fact that MAX is 1 less than a power of
  35    2, and merely counts the number of 1 bits in MAX; "COBn" means
  36    "count the number of 1 bits in the low-order n bits").  */
  37 #define _GL_INTEGER_WIDTH(min, max) (((min) < 0) + _GL_COB128 (max))
  38 #define _GL_COB128(n) (_GL_COB64 ((n) >> 31 >> 31 >> 2) + _GL_COB64 (n))
  39 #define _GL_COB64(n) (_GL_COB32 ((n) >> 31 >> 1) + _GL_COB32 (n))
  40 #define _GL_COB32(n) (_GL_COB16 ((n) >> 16) + _GL_COB16 (n))
  41 #define _GL_COB16(n) (_GL_COB8 ((n) >> 8) + _GL_COB8 (n))
  42 #define _GL_COB8(n) (_GL_COB4 ((n) >> 4) + _GL_COB4 (n))
  43 #define _GL_COB4(n) (!!((n) & 8) + !!((n) & 4) + !!((n) & 2) + !!((n) & 1))
  44
  45 /* Macros specified by ISO/IEC TS 18661-1:2014.  */
  46
  47 #if (! defined ULLONG_WIDTH                                             \
  48      && (defined _GNU_SOURCE || defined __STDC_WANT_IEC_60559_BFP_EXT__))
  49 # define CHAR_WIDTH _GL_INTEGER_WIDTH (CHAR_MIN, CHAR_MAX)
  50 # define SCHAR_WIDTH _GL_INTEGER_WIDTH (SCHAR_MIN, SCHAR_MAX)
  51 # define UCHAR_WIDTH _GL_INTEGER_WIDTH (0, UCHAR_MAX)
  52 # define SHRT_WIDTH _GL_INTEGER_WIDTH (SHRT_MIN, SHRT_MAX)
  53 # define USHRT_WIDTH _GL_INTEGER_WIDTH (0, USHRT_MAX)
  54 # define INT_WIDTH _GL_INTEGER_WIDTH (INT_MIN, INT_MAX)
  55 # define UINT_WIDTH _GL_INTEGER_WIDTH (0, UINT_MAX)
  56 # define LONG_WIDTH _GL_INTEGER_WIDTH (LONG_MIN, LONG_MAX)
  57 # define ULONG_WIDTH _GL_INTEGER_WIDTH (0, ULONG_MAX)
  58 # define LLONG_WIDTH _GL_INTEGER_WIDTH (LLONG_MIN, LLONG_MAX)
  59 # define ULLONG_WIDTH _GL_INTEGER_WIDTH (0, ULLONG_MAX)
  60 #endif /* !ULLONG_WIDTH && (_GNU_SOURCE || __STDC_WANT_IEC_60559_BFP_EXT__) */
  61
  62 #endif /* _@GUARD_PREFIX@_LIMITS_H */
  63 #endif /* _@GUARD_PREFIX@_LIMITS_H */