1 | /* Optimized string comparison. |
2 | Copyright (C) 2001-2002, 2007, 2009-2019 Free Software Foundation, Inc. |
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 |
15 | along with this program. If not, see <https://www.gnu.org/licenses/>. */ |
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 */ |
177 | |