1/* Copyright (C) 2000-2022 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18#include <stdint.h>
19
20/* Lookup in a table of int32_t, with default value 0. */
21int32_t
22__collidx_table_lookup (const char *table, uint32_t wc)
23{
24 uint32_t shift1 = ((const uint32_t *) table)[0];
25 uint32_t index1 = wc >> shift1;
26 uint32_t bound = ((const uint32_t *) table)[1];
27 if (index1 < bound)
28 {
29 uint32_t lookup1 = ((const uint32_t *) table)[5 + index1];
30 if (lookup1 != 0)
31 {
32 uint32_t shift2 = ((const uint32_t *) table)[2];
33 uint32_t mask2 = ((const uint32_t *) table)[3];
34 uint32_t index2 = (wc >> shift2) & mask2;
35 uint32_t lookup2 = ((const uint32_t *)(table + lookup1))[index2];
36 if (lookup2 != 0)
37 {
38 uint32_t mask3 = ((const uint32_t *) table)[4];
39 uint32_t index3 = wc & mask3;
40 int32_t lookup3 = ((const int32_t *)(table + lookup2))[index3];
41
42 return lookup3;
43 }
44 }
45 }
46 return 0;
47}
48
49
50/* Lookup in a table of uint32_t, with default value 0xffffffff. */
51uint32_t
52__collseq_table_lookup (const char *table, uint32_t wc)
53{
54 uint32_t shift1 = ((const uint32_t *) table)[0];
55 uint32_t index1 = wc >> shift1;
56 uint32_t bound = ((const uint32_t *) table)[1];
57 if (index1 < bound)
58 {
59 uint32_t lookup1 = ((const uint32_t *) table)[5 + index1];
60 if (lookup1 != 0)
61 {
62 uint32_t shift2 = ((const uint32_t *) table)[2];
63 uint32_t mask2 = ((const uint32_t *) table)[3];
64 uint32_t index2 = (wc >> shift2) & mask2;
65 uint32_t lookup2 = ((const uint32_t *)(table + lookup1))[index2];
66 if (lookup2 != 0)
67 {
68 uint32_t mask3 = ((const uint32_t *) table)[4];
69 uint32_t index3 = wc & mask3;
70 uint32_t lookup3 = ((const uint32_t *)(table + lookup2))[index3];
71
72 return lookup3;
73 }
74 }
75 }
76 return ~((uint32_t) 0);
77}
78

source code of glibc/locale/coll-lookup.c