lib/unictype/bitmap.h

   1 /* Three-level bitmap lookup.
   2    Copyright (C) 2000-2002, 2005-2007, 2009-2021 Free Software Foundation, Inc.
   3    Written by Bruno Haible <bruno@clisp.org>, 2000-2002.
   4
   5    This program is free software: you can redistribute it and/or modify it
   6    under the terms of the GNU Lesser General Public License as published
   7    by 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 GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17
  18 static inline int bitmap_lookup (const void *table, ucs4_t uc);
  19
  20 /* These values are currently hardcoded into gen-uni-tables.c, function
  21    output_predicate().  */
  22 #define header_0 16
  23 #define header_2 9
  24 #define header_3 127
  25 #define header_4 15
  26
  27 static inline int
  28 bitmap_lookup (const void *table, ucs4_t uc)
  29 {
  30   unsigned int index1 = uc >> header_0;
  31   if (index1 < ((const int *) table)[0])
  32     {
  33       int lookup1 = ((const int *) table)[1 + index1];
  34       if (lookup1 >= 0)
  35         {
  36           unsigned int index2 = (uc >> header_2) & header_3;
  37           int lookup2 = ((const short *) table)[lookup1 + index2];
  38           if (lookup2 >= 0)
  39             {
  40               unsigned int index3 = (uc >> 5) & header_4;
  41               unsigned int lookup3 = ((const unsigned int *) table)[lookup2 + index3];
  42
  43               return (lookup3 >> (uc & 0x1f)) & 1;
  44             }
  45         }
  46     }
  47   return 0;
  48 }