mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-20 02:34:23 +08:00
33 lines
722 B
C
33 lines
722 B
C
#include <linux/string.h>
|
|
#include <linux/export.h>
|
|
|
|
char *strstr(const char *cs, const char *ct)
|
|
{
|
|
int d0, d1;
|
|
register char *__res;
|
|
__asm__ __volatile__(
|
|
"movl %6,%%edi\n\t"
|
|
"repne\n\t"
|
|
"scasb\n\t"
|
|
"notl %%ecx\n\t"
|
|
"decl %%ecx\n\t" /* NOTE! This also sets Z if searchstring='' */
|
|
"movl %%ecx,%%edx\n"
|
|
"1:\tmovl %6,%%edi\n\t"
|
|
"movl %%esi,%%eax\n\t"
|
|
"movl %%edx,%%ecx\n\t"
|
|
"repe\n\t"
|
|
"cmpsb\n\t"
|
|
"je 2f\n\t" /* also works for empty string, see above */
|
|
"xchgl %%eax,%%esi\n\t"
|
|
"incl %%esi\n\t"
|
|
"cmpb $0,-1(%%eax)\n\t"
|
|
"jne 1b\n\t"
|
|
"xorl %%eax,%%eax\n\t"
|
|
"2:"
|
|
: "=a" (__res), "=&c" (d0), "=&S" (d1)
|
|
: "0" (0), "1" (0xffffffff), "2" (cs), "g" (ct)
|
|
: "dx", "di");
|
|
return __res;
|
|
}
|
|
EXPORT_SYMBOL(strstr);
|