1/* Optimized case-insensitive string comparison in C locale.
2   Copyright (C) 2001-2002, 2007, 2009-2012 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#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# elif C_CTYPE_CONSECUTIVE_UPPERCASE && C_CTYPE_CONSECUTIVE_LOWERCASE
37#  define CASEEQ(other,upper) \
38     (c_isupper (upper) ? (other) == (upper) || (other) == (upper) - 'A' + 'a' : (other) == (upper))
39# else
40#  define CASEEQ(other,upper) \
41     (c_toupper (other) == (upper))
42# endif
43
44static inline int
45strcaseeq9 (const char *s1, const char *s2)
46{
47  return c_strcasecmp (s1 + 9, s2 + 9) == 0;
48}
49
50static inline int
51strcaseeq8 (const char *s1, const char *s2, char s28)
52{
53  if (CASEEQ (s1[8], s28))
54    {
55      if (s28 == 0)
56        return 1;
57      else
58        return strcaseeq9 (s1, s2);
59    }
60  else
61    return 0;
62}
63
64static inline int
65strcaseeq7 (const char *s1, const char *s2, char s27, char s28)
66{
67  if (CASEEQ (s1[7], s27))
68    {
69      if (s27 == 0)
70        return 1;
71      else
72        return strcaseeq8 (s1, s2, s28);
73    }
74  else
75    return 0;
76}
77
78static inline int
79strcaseeq6 (const char *s1, const char *s2, char s26, char s27, char s28)
80{
81  if (CASEEQ (s1[6], s26))
82    {
83      if (s26 == 0)
84        return 1;
85      else
86        return strcaseeq7 (s1, s2, s27, s28);
87    }
88  else
89    return 0;
90}
91
92static inline int
93strcaseeq5 (const char *s1, const char *s2, char s25, char s26, char s27, char s28)
94{
95  if (CASEEQ (s1[5], s25))
96    {
97      if (s25 == 0)
98        return 1;
99      else
100        return strcaseeq6 (s1, s2, s26, s27, s28);
101    }
102  else
103    return 0;
104}
105
106static inline int
107strcaseeq4 (const char *s1, const char *s2, char s24, char s25, char s26, char s27, char s28)
108{
109  if (CASEEQ (s1[4], s24))
110    {
111      if (s24 == 0)
112        return 1;
113      else
114        return strcaseeq5 (s1, s2, s25, s26, s27, s28);
115    }
116  else
117    return 0;
118}
119
120static inline int
121strcaseeq3 (const char *s1, const char *s2, char s23, char s24, char s25, char s26, char s27, char s28)
122{
123  if (CASEEQ (s1[3], s23))
124    {
125      if (s23 == 0)
126        return 1;
127      else
128        return strcaseeq4 (s1, s2, s24, s25, s26, s27, s28);
129    }
130  else
131    return 0;
132}
133
134static inline int
135strcaseeq2 (const char *s1, const char *s2, char s22, char s23, char s24, char s25, char s26, char s27, char s28)
136{
137  if (CASEEQ (s1[2], s22))
138    {
139      if (s22 == 0)
140        return 1;
141      else
142        return strcaseeq3 (s1, s2, s23, s24, s25, s26, s27, s28);
143    }
144  else
145    return 0;
146}
147
148static inline int
149strcaseeq1 (const char *s1, const char *s2, char s21, char s22, char s23, char s24, char s25, char s26, char s27, char s28)
150{
151  if (CASEEQ (s1[1], s21))
152    {
153      if (s21 == 0)
154        return 1;
155      else
156        return strcaseeq2 (s1, s2, s22, s23, s24, s25, s26, s27, s28);
157    }
158  else
159    return 0;
160}
161
162static inline int
163strcaseeq0 (const char *s1, const char *s2, char s20, char s21, char s22, char s23, char s24, char s25, char s26, char s27, char s28)
164{
165  if (CASEEQ (s1[0], s20))
166    {
167      if (s20 == 0)
168        return 1;
169      else
170        return strcaseeq1 (s1, s2, s21, s22, s23, s24, s25, s26, s27, s28);
171    }
172  else
173    return 0;
174}
175
176#define STRCASEEQ(s1,s2,s20,s21,s22,s23,s24,s25,s26,s27,s28) \
177  strcaseeq0 (s1, s2, s20, s21, s22, s23, s24, s25, s26, s27, s28)
178
179#else
180
181#define STRCASEEQ(s1,s2,s20,s21,s22,s23,s24,s25,s26,s27,s28) \
182  (c_strcasecmp (s1, s2) == 0)
183
184#endif
185