1 : /* Optimized string comparison.
2 : Copyright (C) 2001-2002, 2007, 2009-2011 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 <http://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 allows to optimize string comparison with a small literal string.
25 : STREQ (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 0 : 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 0 : if (s1[8] == s28)
44 : {
45 0 : if (s28 == 0)
46 0 : return 1;
47 : else
48 0 : return streq9 (s1, s2);
49 : }
50 : else
51 0 : return 0;
52 : }
53 :
54 : static inline int
55 : streq7 (const char *s1, const char *s2, char s27, char s28)
56 : {
57 0 : if (s1[7] == s27)
58 : {
59 0 : if (s27 == 0)
60 0 : return 1;
61 : else
62 0 : return streq8 (s1, s2, s28);
63 : }
64 : else
65 0 : return 0;
66 : }
67 :
68 : static inline int
69 : streq6 (const char *s1, const char *s2, char s26, char s27, char s28)
70 : {
71 0 : if (s1[6] == s26)
72 : {
73 0 : if (s26 == 0)
74 0 : return 1;
75 : else
76 0 : return streq7 (s1, s2, s27, s28);
77 : }
78 : else
79 0 : 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 0 : if (s1[5] == s25)
86 : {
87 0 : if (s25 == 0)
88 0 : return 1;
89 : else
90 0 : return streq6 (s1, s2, s26, s27, s28);
91 : }
92 : else
93 0 : 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 0 : if (s1[4] == s24)
100 : {
101 0 : if (s24 == 0)
102 0 : return 1;
103 : else
104 0 : return streq5 (s1, s2, s25, s26, s27, s28);
105 : }
106 : else
107 0 : 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 0 : if (s1[3] == s23)
114 : {
115 0 : if (s23 == 0)
116 0 : return 1;
117 : else
118 0 : return streq4 (s1, s2, s24, s25, s26, s27, s28);
119 : }
120 : else
121 0 : 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 0 : if (s1[2] == s22)
128 : {
129 0 : if (s22 == 0)
130 0 : return 1;
131 : else
132 0 : return streq3 (s1, s2, s23, s24, s25, s26, s27, s28);
133 : }
134 : else
135 0 : 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 0 : if (s1[1] == s21)
142 : {
143 0 : if (s21 == 0)
144 0 : return 1;
145 : else
146 0 : return streq2 (s1, s2, s22, s23, s24, s25, s26, s27, s28);
147 : }
148 : else
149 0 : 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 1498 : {
155 1498 : if (s1[0] == s20)
156 : {
157 0 : if (s20 == 0)
158 0 : return 1;
159 : else
160 0 : return streq1 (s1, s2, s21, s22, s23, s24, s25, s26, s27, s28);
161 : }
162 : else
163 1498 : return 0;
164 : }
165 :
166 : #define STREQ(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(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 */
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