Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 | 2 | #include <linux/string.h> |
784d5699 | 3 | #include <linux/export.h> |
1da177e4 | 4 | |
f73920cd | 5 | char *strstr(const char *cs, const char *ct) |
1da177e4 LT |
6 | { |
7 | int d0, d1; | |
f73920cd | 8 | register char *__res; |
1da177e4 LT |
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:" | |
209b580f PC |
28 | : "=a" (__res), "=&c" (d0), "=&S" (d1) |
29 | : "0" (0), "1" (0xffffffff), "2" (cs), "g" (ct) | |
30 | : "dx", "di"); | |
1da177e4 LT |
31 | return __res; |
32 | } | |
784d5699 | 33 | EXPORT_SYMBOL(strstr); |