1 | /* Copyright (C) 1996-2016 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 _WEIGHT_H_ |
20 | #define _WEIGHT_H_ 1 |
21 | |
22 | /* Find index of weight. */ |
23 | static inline int32_t __attribute__ ((always_inline)) |
24 | findidx (const int32_t *table, |
25 | const int32_t *indirect, |
26 | const unsigned char *, |
27 | const unsigned char **cpp, size_t len) |
28 | { |
29 | int_fast32_t i = table[*(*cpp)++]; |
30 | const unsigned char *cp; |
31 | const unsigned char *usrc; |
32 | |
33 | if (i >= 0) |
34 | /* This is an index into the weight table. Cool. */ |
35 | return i; |
36 | |
37 | /* Oh well, more than one sequence starting with this byte. |
38 | Search for the correct one. */ |
39 | cp = &extra[-i]; |
40 | usrc = *cpp; |
41 | --len; |
42 | while (1) |
43 | { |
44 | size_t nhere; |
45 | |
46 | /* The first thing is the index. */ |
47 | i = *((const int32_t *) cp); |
48 | cp += sizeof (int32_t); |
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 | for (cnt = 0; cnt < nhere && cnt < len; ++cnt) |
65 | if (cp[cnt] != usrc[cnt]) |
66 | break; |
67 | |
68 | if (cnt == nhere) |
69 | { |
70 | /* Found it. */ |
71 | *cpp += nhere; |
72 | return i; |
73 | } |
74 | |
75 | /* Up to the next entry. */ |
76 | cp += nhere; |
77 | if (!LOCFILE_ALIGNED_P (1 + nhere)) |
78 | cp += LOCFILE_ALIGN - (1 + nhere) % LOCFILE_ALIGN; |
79 | } |
80 | else |
81 | { |
82 | /* This is a range of characters. First decide whether the |
83 | current byte sequence lies in the range. */ |
84 | size_t cnt; |
85 | size_t offset = 0; |
86 | |
87 | for (cnt = 0; cnt < nhere && cnt < len; ++cnt) |
88 | if (cp[cnt] != usrc[cnt]) |
89 | break; |
90 | |
91 | if (cnt != nhere) |
92 | { |
93 | if (cnt == len || cp[cnt] > usrc[cnt]) |
94 | { |
95 | /* Cannot be in this range. */ |
96 | cp += 2 * nhere; |
97 | if (!LOCFILE_ALIGNED_P (1 + 2 * nhere)) |
98 | cp += (LOCFILE_ALIGN |
99 | - (1 + 2 * nhere) % LOCFILE_ALIGN); |
100 | continue; |
101 | } |
102 | |
103 | /* Test against the end of the range. */ |
104 | for (cnt = 0; cnt < nhere; ++cnt) |
105 | if (cp[nhere + cnt] != usrc[cnt]) |
106 | break; |
107 | |
108 | if (cnt != nhere && cp[nhere + cnt] < usrc[cnt]) |
109 | { |
110 | /* Cannot be in this range. */ |
111 | cp += 2 * nhere; |
112 | if (!LOCFILE_ALIGNED_P (1 + 2 * nhere)) |
113 | cp += (LOCFILE_ALIGN |
114 | - (1 + 2 * nhere) % LOCFILE_ALIGN); |
115 | continue; |
116 | } |
117 | |
118 | /* This range matches the next characters. Now find |
119 | the offset in the indirect table. */ |
120 | for (cnt = 0; cp[cnt] == usrc[cnt]; ++cnt); |
121 | |
122 | do |
123 | { |
124 | offset <<= 8; |
125 | offset += usrc[cnt] - cp[cnt]; |
126 | } |
127 | while (++cnt < nhere); |
128 | } |
129 | |
130 | *cpp += nhere; |
131 | return indirect[-i + offset]; |
132 | } |
133 | } |
134 | |
135 | /* NOTREACHED */ |
136 | return 0x43219876; |
137 | } |
138 | |
139 | #endif /* weight.h */ |
140 | |