xref: /linux/arch/x86/lib/strstr_32.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 #include <linux/string.h>
2 
3 char *strstr(const char *cs, const char *ct)
4 {
5 int	d0, d1;
6 register char *__res;
7 __asm__ __volatile__(
8 	"movl %6,%%edi\n\t"
9 	"repne\n\t"
10 	"scasb\n\t"
11 	"notl %%ecx\n\t"
12 	"decl %%ecx\n\t"	/* NOTE! This also sets Z if searchstring='' */
13 	"movl %%ecx,%%edx\n"
14 	"1:\tmovl %6,%%edi\n\t"
15 	"movl %%esi,%%eax\n\t"
16 	"movl %%edx,%%ecx\n\t"
17 	"repe\n\t"
18 	"cmpsb\n\t"
19 	"je 2f\n\t"		/* also works for empty string, see above */
20 	"xchgl %%eax,%%esi\n\t"
21 	"incl %%esi\n\t"
22 	"cmpb $0,-1(%%eax)\n\t"
23 	"jne 1b\n\t"
24 	"xorl %%eax,%%eax\n\t"
25 	"2:"
26 	: "=a" (__res), "=&c" (d0), "=&S" (d1)
27 	: "0" (0), "1" (0xffffffff), "2" (cs), "g" (ct)
28 	: "dx", "di");
29 return __res;
30 }
31 
32