1 /* Three-level bitmap lookup.
2 Copyright (C) 2000-2002, 2005-2007, 2009-2020 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 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 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 <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-ctype.c. */
21 #define header_0 16
22 #define header_2 9
23 #define header_3 127
24 #define header_4 15
25
26 static inline int
bitmap_lookup(const void * table,ucs4_t uc)27 bitmap_lookup (const void *table, ucs4_t uc)
28 {
29 unsigned int index1 = uc >> header_0;
30 if (index1 < ((const int *) table)[0])
31 {
32 int lookup1 = ((const int *) table)[1 + index1];
33 if (lookup1 >= 0)
34 {
35 unsigned int index2 = (uc >> header_2) & header_3;
36 int lookup2 = ((const short *) table)[lookup1 + index2];
37 if (lookup2 >= 0)
38 {
39 unsigned int index3 = (uc >> 5) & header_4;
40 unsigned int lookup3 = ((const int *) table)[lookup2 + index3];
41
42 return (lookup3 >> (uc & 0x1f)) & 1;
43 }
44 }
45 }
46 return 0;
47 }
48