https://github.com/torvalds/linux
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Tip revision: 15c03dd4859ab16f9212238f29dd315654aa94f6 authored by Linus Torvalds on 29 September 2013, 22:02:38 UTC
Linux 3.12-rc3
Tip revision: 15c03dd
strstr_32.c
#include <linux/string.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;
}

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