xref: /haiku/src/system/libroot/posix/glibc/locale/coll-lookup.c (revision 21258e2674226d6aa732321b6f8494841895af5f)
1 /* Copyright (C) 2000, 2003 Free Software Foundation, Inc.
2    This file is part of the GNU C Library.
3    Contributed by Bruno Haible <haible@clisp.cons.org>, 2000.
4 
5    The GNU C Library is free software; you can redistribute it and/or
6    modify it under the terms of the GNU Lesser General Public
7    License as published by the Free Software Foundation; either
8    version 2.1 of the License, or (at your option) any later version.
9 
10    The GNU C Library 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
16    License along with the GNU C Library; if not, write to the Free
17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18    02111-1307 USA.  */
19 
20 #include <stdint.h>
21 
22 #ifndef internal_function
23 #	define internal_function
24 #endif
25 
26 /* Lookup in a table of int32_t, with default value 0.  */
27 int32_t
28 internal_function
29 __collidx_table_lookup (const char *table, uint32_t wc)
30 {
31   uint32_t shift1 = ((const uint32_t *) table)[0];
32   uint32_t index1 = wc >> shift1;
33   uint32_t bound = ((const uint32_t *) table)[1];
34   if (index1 < bound)
35     {
36       uint32_t lookup1 = ((const uint32_t *) table)[5 + index1];
37       if (lookup1 != 0)
38 	{
39 	  uint32_t shift2 = ((const uint32_t *) table)[2];
40 	  uint32_t mask2 = ((const uint32_t *) table)[3];
41 	  uint32_t index2 = (wc >> shift2) & mask2;
42 	  uint32_t lookup2 = ((const uint32_t *)(table + lookup1))[index2];
43 	  if (lookup2 != 0)
44 	    {
45 	      uint32_t mask3 = ((const uint32_t *) table)[4];
46 	      uint32_t index3 = wc & mask3;
47 	      int32_t lookup3 = ((const int32_t *)(table + lookup2))[index3];
48 
49 	      return lookup3;
50 	    }
51 	}
52     }
53   return 0;
54 }
55 
56 
57 /* Lookup in a table of uint32_t, with default value 0xffffffff.  */
58 uint32_t
59 internal_function
60 __collseq_table_lookup (const char *table, uint32_t wc)
61 {
62   uint32_t shift1 = ((const uint32_t *) table)[0];
63   uint32_t index1 = wc >> shift1;
64   uint32_t bound = ((const uint32_t *) table)[1];
65   if (index1 < bound)
66     {
67       uint32_t lookup1 = ((const uint32_t *) table)[5 + index1];
68       if (lookup1 != 0)
69 	{
70 	  uint32_t shift2 = ((const uint32_t *) table)[2];
71 	  uint32_t mask2 = ((const uint32_t *) table)[3];
72 	  uint32_t index2 = (wc >> shift2) & mask2;
73 	  uint32_t lookup2 = ((const uint32_t *)(table + lookup1))[index2];
74 	  if (lookup2 != 0)
75 	    {
76 	      uint32_t mask3 = ((const uint32_t *) table)[4];
77 	      uint32_t index3 = wc & mask3;
78 	      uint32_t lookup3 = ((const uint32_t *)(table + lookup2))[index3];
79 
80 	      return lookup3;
81 	    }
82 	}
83     }
84   return ~((uint32_t) 0);
85 }
86