Linux kernel mirror (for testing)
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linux
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * arch/arm/boot/compressed/string.c
4 *
5 * Small subset of simple string routines
6 */
7
8#include <linux/string.h>
9
10void *memcpy(void *__dest, __const void *__src, size_t __n)
11{
12 int i = 0;
13 unsigned char *d = (unsigned char *)__dest, *s = (unsigned char *)__src;
14
15 for (i = __n >> 3; i > 0; i--) {
16 *d++ = *s++;
17 *d++ = *s++;
18 *d++ = *s++;
19 *d++ = *s++;
20 *d++ = *s++;
21 *d++ = *s++;
22 *d++ = *s++;
23 *d++ = *s++;
24 }
25
26 if (__n & 1 << 2) {
27 *d++ = *s++;
28 *d++ = *s++;
29 *d++ = *s++;
30 *d++ = *s++;
31 }
32
33 if (__n & 1 << 1) {
34 *d++ = *s++;
35 *d++ = *s++;
36 }
37
38 if (__n & 1)
39 *d++ = *s++;
40
41 return __dest;
42}
43
44void *memmove(void *__dest, __const void *__src, size_t count)
45{
46 unsigned char *d = __dest;
47 const unsigned char *s = __src;
48
49 if (__dest == __src)
50 return __dest;
51
52 if (__dest < __src)
53 return memcpy(__dest, __src, count);
54
55 while (count--)
56 d[count] = s[count];
57 return __dest;
58}
59
60size_t strlen(const char *s)
61{
62 const char *sc = s;
63
64 while (*sc != '\0')
65 sc++;
66 return sc - s;
67}
68
69size_t strnlen(const char *s, size_t count)
70{
71 const char *sc;
72
73 for (sc = s; count-- && *sc != '\0'; ++sc)
74 /* nothing */;
75 return sc - s;
76}
77
78int memcmp(const void *cs, const void *ct, size_t count)
79{
80 const unsigned char *su1 = cs, *su2 = ct, *end = su1 + count;
81 int res = 0;
82
83 while (su1 < end) {
84 res = *su1++ - *su2++;
85 if (res)
86 break;
87 }
88 return res;
89}
90
91int strcmp(const char *cs, const char *ct)
92{
93 unsigned char c1, c2;
94 int res = 0;
95
96 do {
97 c1 = *cs++;
98 c2 = *ct++;
99 res = c1 - c2;
100 if (res)
101 break;
102 } while (c1);
103 return res;
104}
105
106void *memchr(const void *s, int c, size_t count)
107{
108 const unsigned char *p = s;
109
110 while (count--)
111 if ((unsigned char)c == *p++)
112 return (void *)(p - 1);
113 return NULL;
114}
115
116char *strchr(const char *s, int c)
117{
118 while (*s != (char)c)
119 if (*s++ == '\0')
120 return NULL;
121 return (char *)s;
122}
123
124char *strrchr(const char *s, int c)
125{
126 const char *last = NULL;
127 do {
128 if (*s == (char)c)
129 last = s;
130 } while (*s++);
131 return (char *)last;
132}
133
134#undef memset
135
136void *memset(void *s, int c, size_t count)
137{
138 char *xs = s;
139 while (count--)
140 *xs++ = c;
141 return s;
142}