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8690e634 | 1 | /* Optimized string comparison. |
7a6dbc2f | 2 | Copyright (C) 2001-2002, 2007, 2009-2018 Free Software Foundation, Inc. |
8690e634 JK |
3 | |
4 | This program is free software: you can redistribute it and/or modify it | |
5 | under the terms of the GNU General Public License as published | |
6 | by the Free Software Foundation; either version 3 of the License, or | |
7 | (at your option) any later version. | |
8 | ||
9 | This program 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 | General Public License for more details. | |
13 | ||
14 | You should have received a copy of the GNU General Public License | |
7a6dbc2f | 15 | along with this program. If not, see <https://www.gnu.org/licenses/>. */ |
8690e634 JK |
16 | |
17 | /* Written by Bruno Haible <bruno@clisp.org>. */ | |
18 | ||
19 | #ifndef _GL_STREQ_H | |
20 | #define _GL_STREQ_H | |
21 | ||
22 | #include <string.h> | |
23 | ||
24 | /* STREQ_OPT allows to optimize string comparison with a small literal string. | |
25 | STREQ_OPT (s, "EUC-KR", 'E', 'U', 'C', '-', 'K', 'R', 0, 0, 0) | |
26 | is semantically equivalent to | |
27 | strcmp (s, "EUC-KR") == 0 | |
28 | just faster. */ | |
29 | ||
30 | /* Help GCC to generate good code for string comparisons with | |
31 | immediate strings. */ | |
32 | #if defined (__GNUC__) && defined (__OPTIMIZE__) | |
33 | ||
34 | static inline int | |
35 | streq9 (const char *s1, const char *s2) | |
36 | { | |
37 | return strcmp (s1 + 9, s2 + 9) == 0; | |
38 | } | |
39 | ||
40 | static inline int | |
41 | streq8 (const char *s1, const char *s2, char s28) | |
42 | { | |
43 | if (s1[8] == s28) | |
44 | { | |
45 | if (s28 == 0) | |
46 | return 1; | |
47 | else | |
48 | return streq9 (s1, s2); | |
49 | } | |
50 | else | |
51 | return 0; | |
52 | } | |
53 | ||
54 | static inline int | |
55 | streq7 (const char *s1, const char *s2, char s27, char s28) | |
56 | { | |
57 | if (s1[7] == s27) | |
58 | { | |
59 | if (s27 == 0) | |
60 | return 1; | |
61 | else | |
62 | return streq8 (s1, s2, s28); | |
63 | } | |
64 | else | |
65 | return 0; | |
66 | } | |
67 | ||
68 | static inline int | |
69 | streq6 (const char *s1, const char *s2, char s26, char s27, char s28) | |
70 | { | |
71 | if (s1[6] == s26) | |
72 | { | |
73 | if (s26 == 0) | |
74 | return 1; | |
75 | else | |
76 | return streq7 (s1, s2, s27, s28); | |
77 | } | |
78 | else | |
79 | return 0; | |
80 | } | |
81 | ||
82 | static inline int | |
83 | streq5 (const char *s1, const char *s2, char s25, char s26, char s27, char s28) | |
84 | { | |
85 | if (s1[5] == s25) | |
86 | { | |
87 | if (s25 == 0) | |
88 | return 1; | |
89 | else | |
90 | return streq6 (s1, s2, s26, s27, s28); | |
91 | } | |
92 | else | |
93 | return 0; | |
94 | } | |
95 | ||
96 | static inline int | |
97 | streq4 (const char *s1, const char *s2, char s24, char s25, char s26, char s27, char s28) | |
98 | { | |
99 | if (s1[4] == s24) | |
100 | { | |
101 | if (s24 == 0) | |
102 | return 1; | |
103 | else | |
104 | return streq5 (s1, s2, s25, s26, s27, s28); | |
105 | } | |
106 | else | |
107 | return 0; | |
108 | } | |
109 | ||
110 | static inline int | |
111 | streq3 (const char *s1, const char *s2, char s23, char s24, char s25, char s26, char s27, char s28) | |
112 | { | |
113 | if (s1[3] == s23) | |
114 | { | |
115 | if (s23 == 0) | |
116 | return 1; | |
117 | else | |
118 | return streq4 (s1, s2, s24, s25, s26, s27, s28); | |
119 | } | |
120 | else | |
121 | return 0; | |
122 | } | |
123 | ||
124 | static inline int | |
125 | streq2 (const char *s1, const char *s2, char s22, char s23, char s24, char s25, char s26, char s27, char s28) | |
126 | { | |
127 | if (s1[2] == s22) | |
128 | { | |
129 | if (s22 == 0) | |
130 | return 1; | |
131 | else | |
132 | return streq3 (s1, s2, s23, s24, s25, s26, s27, s28); | |
133 | } | |
134 | else | |
135 | return 0; | |
136 | } | |
137 | ||
138 | static inline int | |
139 | streq1 (const char *s1, const char *s2, char s21, char s22, char s23, char s24, char s25, char s26, char s27, char s28) | |
140 | { | |
141 | if (s1[1] == s21) | |
142 | { | |
143 | if (s21 == 0) | |
144 | return 1; | |
145 | else | |
146 | return streq2 (s1, s2, s22, s23, s24, s25, s26, s27, s28); | |
147 | } | |
148 | else | |
149 | return 0; | |
150 | } | |
151 | ||
152 | static inline int | |
153 | streq0 (const char *s1, const char *s2, char s20, char s21, char s22, char s23, char s24, char s25, char s26, char s27, char s28) | |
154 | { | |
155 | if (s1[0] == s20) | |
156 | { | |
157 | if (s20 == 0) | |
158 | return 1; | |
159 | else | |
160 | return streq1 (s1, s2, s21, s22, s23, s24, s25, s26, s27, s28); | |
161 | } | |
162 | else | |
163 | return 0; | |
164 | } | |
165 | ||
166 | #define STREQ_OPT(s1,s2,s20,s21,s22,s23,s24,s25,s26,s27,s28) \ | |
167 | streq0 (s1, s2, s20, s21, s22, s23, s24, s25, s26, s27, s28) | |
168 | ||
169 | #else | |
170 | ||
171 | #define STREQ_OPT(s1,s2,s20,s21,s22,s23,s24,s25,s26,s27,s28) \ | |
172 | (strcmp (s1, s2) == 0) | |
173 | ||
174 | #endif | |
175 | ||
176 | #endif /* _GL_STREQ_H */ |