mirror of
https://github.com/torvalds/linux.git
synced 2024-12-25 12:21:37 +00:00
df4879fa26
This is a small subset of string functions needed by commits to come. Except for memcpy() which is unchanged from its original location, their implementation is meant to be small, and -Os is enforced to prevent gcc from doing pointless loop unrolling. Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org> Tested-by: Shawn Guo <shawn.guo@linaro.org> Tested-by: Dave Martin <dave.martin@linaro.org> Tested-by: Thomas Abraham <thomas.abraham@linaro.org>
128 lines
1.8 KiB
C
128 lines
1.8 KiB
C
/*
|
|
* arch/arm/boot/compressed/string.c
|
|
*
|
|
* Small subset of simple string routines
|
|
*/
|
|
|
|
#include <linux/string.h>
|
|
|
|
void *memcpy(void *__dest, __const void *__src, size_t __n)
|
|
{
|
|
int i = 0;
|
|
unsigned char *d = (unsigned char *)__dest, *s = (unsigned char *)__src;
|
|
|
|
for (i = __n >> 3; i > 0; i--) {
|
|
*d++ = *s++;
|
|
*d++ = *s++;
|
|
*d++ = *s++;
|
|
*d++ = *s++;
|
|
*d++ = *s++;
|
|
*d++ = *s++;
|
|
*d++ = *s++;
|
|
*d++ = *s++;
|
|
}
|
|
|
|
if (__n & 1 << 2) {
|
|
*d++ = *s++;
|
|
*d++ = *s++;
|
|
*d++ = *s++;
|
|
*d++ = *s++;
|
|
}
|
|
|
|
if (__n & 1 << 1) {
|
|
*d++ = *s++;
|
|
*d++ = *s++;
|
|
}
|
|
|
|
if (__n & 1)
|
|
*d++ = *s++;
|
|
|
|
return __dest;
|
|
}
|
|
|
|
void *memmove(void *__dest, __const void *__src, size_t count)
|
|
{
|
|
unsigned char *d = __dest;
|
|
const unsigned char *s = __src;
|
|
|
|
if (__dest == __src)
|
|
return __dest;
|
|
|
|
if (__dest < __src)
|
|
return memcpy(__dest, __src, count);
|
|
|
|
while (count--)
|
|
d[count] = s[count];
|
|
return __dest;
|
|
}
|
|
|
|
size_t strlen(const char *s)
|
|
{
|
|
const char *sc = s;
|
|
|
|
while (*sc != '\0')
|
|
sc++;
|
|
return sc - s;
|
|
}
|
|
|
|
int memcmp(const void *cs, const void *ct, size_t count)
|
|
{
|
|
const unsigned char *su1 = cs, *su2 = ct, *end = su1 + count;
|
|
int res = 0;
|
|
|
|
while (su1 < end) {
|
|
res = *su1++ - *su2++;
|
|
if (res)
|
|
break;
|
|
}
|
|
return res;
|
|
}
|
|
|
|
int strcmp(const char *cs, const char *ct)
|
|
{
|
|
unsigned char c1, c2;
|
|
int res = 0;
|
|
|
|
do {
|
|
c1 = *cs++;
|
|
c2 = *ct++;
|
|
res = c1 - c2;
|
|
if (res)
|
|
break;
|
|
} while (c1);
|
|
return res;
|
|
}
|
|
|
|
void *memchr(const void *s, int c, size_t count)
|
|
{
|
|
const unsigned char *p = s;
|
|
|
|
while (count--)
|
|
if ((unsigned char)c == *p++)
|
|
return (void *)(p - 1);
|
|
return NULL;
|
|
}
|
|
|
|
char *strchr(const char *s, int c)
|
|
{
|
|
while (*s != (char)c)
|
|
if (*s++ == '\0')
|
|
return NULL;
|
|
return (char *)s;
|
|
}
|
|
|
|
#undef memset
|
|
|
|
void *memset(void *s, int c, size_t count)
|
|
{
|
|
char *xs = s;
|
|
while (count--)
|
|
*xs++ = c;
|
|
return s;
|
|
}
|
|
|
|
void __memzero(void *s, size_t count)
|
|
{
|
|
memset(s, 0, count);
|
|
}
|