| Kyle Swenson | 8d8f654 | 2021-03-15 11:02:55 -0600 | [diff] [blame^] | 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 | |