1#include <linux/string.h>
 
 2
 3char *strstr(const char *cs, const char *ct)
 4{
 5int	d0, d1;
 6register 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");
29return __res;
30}
31

 1// SPDX-License-Identifier: GPL-2.0
 2#include <linux/string.h>
 3#include <linux/export.h>
 4
 5char *strstr(const char *cs, const char *ct)
 6{
 7int	d0, d1;
 8register char *__res;
 9__asm__ __volatile__(
10	"movl %6,%%edi\n\t"
11	"repne\n\t"
12	"scasb\n\t"
13	"notl %%ecx\n\t"
14	"decl %%ecx\n\t"	/* NOTE! This also sets Z if searchstring='' */
15	"movl %%ecx,%%edx\n"
16	"1:\tmovl %6,%%edi\n\t"
17	"movl %%esi,%%eax\n\t"
18	"movl %%edx,%%ecx\n\t"
19	"repe\n\t"
20	"cmpsb\n\t"
21	"je 2f\n\t"		/* also works for empty string, see above */
22	"xchgl %%eax,%%esi\n\t"
23	"incl %%esi\n\t"
24	"cmpb $0,-1(%%eax)\n\t"
25	"jne 1b\n\t"
26	"xorl %%eax,%%eax\n\t"
27	"2:"
28	: "=a" (__res), "=&c" (d0), "=&S" (d1)
29	: "0" (0), "1" (0xffffffff), "2" (cs), "g" (ct)
30	: "dx", "di");
31return __res;
32}
33EXPORT_SYMBOL(strstr);