arch/arm/boot/compressed/string.c

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