xref: /dragonfly/contrib/grep/lib/c-strcaseeq.h (revision 2b7dbe20)
1 /* Optimized case-insensitive string comparison in C locale.
2    Copyright (C) 2001-2002, 2007, 2009-2020 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 #include "c-strcase.h"
20 #include "c-ctype.h"
21 
22 /* STRCASEEQ allows to optimize string comparison with a small literal string.
23      STRCASEEQ (s, "UTF-8", 'U','T','F','-','8',0,0,0,0)
24    is semantically equivalent to
25      c_strcasecmp (s, "UTF-8") == 0
26    just faster.  */
27 
28 /* Help GCC to generate good code for string comparisons with
29    immediate strings. */
30 #if defined (__GNUC__) && defined (__OPTIMIZE__)
31 
32 /* Case insensitive comparison of ASCII characters.  */
33 # if C_CTYPE_ASCII
34 #  define CASEEQ(other,upper) \
35      (c_isupper (upper) ? ((other) & ~0x20) == (upper) : (other) == (upper))
36 # else
37 #  define CASEEQ(other,upper) \
38      (c_toupper (other) == (upper))
39 # endif
40 
41 static inline int
42 strcaseeq9 (const char *s1, const char *s2)
43 {
44   return c_strcasecmp (s1 + 9, s2 + 9) == 0;
45 }
46 
47 static inline int
48 strcaseeq8 (const char *s1, const char *s2, char s28)
49 {
50   if (CASEEQ (s1[8], s28))
51     {
52       if (s28 == 0)
53         return 1;
54       else
55         return strcaseeq9 (s1, s2);
56     }
57   else
58     return 0;
59 }
60 
61 static inline int
62 strcaseeq7 (const char *s1, const char *s2, char s27, char s28)
63 {
64   if (CASEEQ (s1[7], s27))
65     {
66       if (s27 == 0)
67         return 1;
68       else
69         return strcaseeq8 (s1, s2, s28);
70     }
71   else
72     return 0;
73 }
74 
75 static inline int
76 strcaseeq6 (const char *s1, const char *s2, char s26, char s27, char s28)
77 {
78   if (CASEEQ (s1[6], s26))
79     {
80       if (s26 == 0)
81         return 1;
82       else
83         return strcaseeq7 (s1, s2, s27, s28);
84     }
85   else
86     return 0;
87 }
88 
89 static inline int
90 strcaseeq5 (const char *s1, const char *s2, char s25, char s26, char s27, char s28)
91 {
92   if (CASEEQ (s1[5], s25))
93     {
94       if (s25 == 0)
95         return 1;
96       else
97         return strcaseeq6 (s1, s2, s26, s27, s28);
98     }
99   else
100     return 0;
101 }
102 
103 static inline int
104 strcaseeq4 (const char *s1, const char *s2, char s24, char s25, char s26, char s27, char s28)
105 {
106   if (CASEEQ (s1[4], s24))
107     {
108       if (s24 == 0)
109         return 1;
110       else
111         return strcaseeq5 (s1, s2, s25, s26, s27, s28);
112     }
113   else
114     return 0;
115 }
116 
117 static inline int
118 strcaseeq3 (const char *s1, const char *s2, char s23, char s24, char s25, char s26, char s27, char s28)
119 {
120   if (CASEEQ (s1[3], s23))
121     {
122       if (s23 == 0)
123         return 1;
124       else
125         return strcaseeq4 (s1, s2, s24, s25, s26, s27, s28);
126     }
127   else
128     return 0;
129 }
130 
131 static inline int
132 strcaseeq2 (const char *s1, const char *s2, char s22, char s23, char s24, char s25, char s26, char s27, char s28)
133 {
134   if (CASEEQ (s1[2], s22))
135     {
136       if (s22 == 0)
137         return 1;
138       else
139         return strcaseeq3 (s1, s2, s23, s24, s25, s26, s27, s28);
140     }
141   else
142     return 0;
143 }
144 
145 static inline int
146 strcaseeq1 (const char *s1, const char *s2, char s21, char s22, char s23, char s24, char s25, char s26, char s27, char s28)
147 {
148   if (CASEEQ (s1[1], s21))
149     {
150       if (s21 == 0)
151         return 1;
152       else
153         return strcaseeq2 (s1, s2, s22, s23, s24, s25, s26, s27, s28);
154     }
155   else
156     return 0;
157 }
158 
159 static inline int
160 strcaseeq0 (const char *s1, const char *s2, char s20, char s21, char s22, char s23, char s24, char s25, char s26, char s27, char s28)
161 {
162   if (CASEEQ (s1[0], s20))
163     {
164       if (s20 == 0)
165         return 1;
166       else
167         return strcaseeq1 (s1, s2, s21, s22, s23, s24, s25, s26, s27, s28);
168     }
169   else
170     return 0;
171 }
172 
173 #define STRCASEEQ(s1,s2,s20,s21,s22,s23,s24,s25,s26,s27,s28) \
174   strcaseeq0 (s1, s2, s20, s21, s22, s23, s24, s25, s26, s27, s28)
175 
176 #else
177 
178 #define STRCASEEQ(s1,s2,s20,s21,s22,s23,s24,s25,s26,s27,s28) \
179   (c_strcasecmp (s1, s2) == 0)
180 
181 #endif
182