1/* Copyright (C) 1996-2018 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Written by Ulrich Drepper, <drepper@cygnus.com>.
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, see
17 <http://www.gnu.org/licenses/>. */
18
19#ifndef _WEIGHTWC_H_
20#define _WEIGHTWC_H_ 1
21
22#include <libc-diag.h>
23
24/* Find index of weight. */
25static inline int32_t __attribute__ ((always_inline))
26findidx (const int32_t *table,
27 const int32_t *indirect,
28 const wint_t *extra,
29 const wint_t **cpp, size_t len)
30{
31 wint_t ch = *(*cpp)++;
32 int32_t i = __collidx_table_lookup ((const char *) table, ch);
33
34 if (i >= 0)
35 /* This is an index into the weight table. Cool. */
36 return i;
37
38 /* Oh well, more than one sequence starting with this byte.
39 Search for the correct one. */
40 const int32_t *cp = (const int32_t *) &extra[-i];
41 --len;
42 while (1)
43 {
44 size_t nhere;
45 const int32_t *usrc = (const int32_t *) *cpp;
46
47 /* The first thing is the index. */
48 i = *cp++;
49
50 /* Next is the length of the byte sequence. These are always
51 short byte sequences so there is no reason to call any
52 function (even if they are inlined). */
53 nhere = *cp++;
54
55 if (i >= 0)
56 {
57 /* It is a single character. If it matches we found our
58 index. Note that at the end of each list there is an
59 entry of length zero which represents the single byte
60 sequence. The first (and here only) byte was tested
61 already. */
62 size_t cnt;
63
64 /* With GCC 5.3 when compiling with -Os the compiler warns
65 that seq2.back_us, which becomes usrc, might be used
66 uninitialized. This can't be true because we pass a length
67 of -1 for len at the same time which means that this loop
68 never executes. */
69 DIAG_PUSH_NEEDS_COMMENT;
70 DIAG_IGNORE_Os_NEEDS_COMMENT (5, "-Wmaybe-uninitialized");
71 for (cnt = 0; cnt < nhere && cnt < len; ++cnt)
72 if (cp[cnt] != usrc[cnt])
73 break;
74 DIAG_POP_NEEDS_COMMENT;
75
76 if (cnt == nhere)
77 {
78 /* Found it. */
79 *cpp += nhere;
80 return i;
81 }
82
83 /* Up to the next entry. */
84 cp += nhere;
85 }
86 else
87 {
88 /* This is a range of characters. First decide whether the
89 current byte sequence lies in the range. */
90 size_t cnt;
91 size_t offset;
92
93 for (cnt = 0; cnt < nhere - 1 && cnt < len; ++cnt)
94 if (cp[cnt] != usrc[cnt])
95 break;
96
97 if (cnt < nhere - 1)
98 {
99 cp += 2 * nhere;
100 continue;
101 }
102
103 if (cp[nhere - 1] > usrc[nhere -1])
104 {
105 cp += 2 * nhere;
106 continue;
107 }
108
109 if (cp[2 * nhere - 1] < usrc[nhere -1])
110 {
111 cp += 2 * nhere;
112 continue;
113 }
114
115 /* This range matches the next characters. Now find
116 the offset in the indirect table. */
117 offset = usrc[nhere - 1] - cp[nhere - 1];
118 *cpp += nhere;
119
120 return indirect[-i + offset];
121 }
122 }
123
124 /* NOTREACHED */
125 return 0x43219876;
126}
127
128#endif /* weightwc.h */
129