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13#include <linux/string.h>
14#include <linux/module.h>
15
16#ifdef __HAVE_ARCH_STRCPY
17char *strcpy(char *dest, const char *src)
18{
19 int d0, d1, d2;
20 asm volatile("1:\tlodsb\n\t"
21 "stosb\n\t"
22 "testb %%al,%%al\n\t"
23 "jne 1b"
24 : "=&S" (d0), "=&D" (d1), "=&a" (d2)
25 : "0" (src), "1" (dest) : "memory");
26 return dest;
27}
28EXPORT_SYMBOL(strcpy);
29#endif
30
31#ifdef __HAVE_ARCH_STRNCPY
32char *strncpy(char *dest, const char *src, size_t count)
33{
34 int d0, d1, d2, d3;
35 asm volatile("1:\tdecl %2\n\t"
36 "js 2f\n\t"
37 "lodsb\n\t"
38 "stosb\n\t"
39 "testb %%al,%%al\n\t"
40 "jne 1b\n\t"
41 "rep\n\t"
42 "stosb\n"
43 "2:"
44 : "=&S" (d0), "=&D" (d1), "=&c" (d2), "=&a" (d3)
45 : "0" (src), "1" (dest), "2" (count) : "memory");
46 return dest;
47}
48EXPORT_SYMBOL(strncpy);
49#endif
50
51#ifdef __HAVE_ARCH_STRCAT
52char *strcat(char *dest, const char *src)
53{
54 int d0, d1, d2, d3;
55 asm volatile("repne\n\t"
56 "scasb\n\t"
57 "decl %1\n"
58 "1:\tlodsb\n\t"
59 "stosb\n\t"
60 "testb %%al,%%al\n\t"
61 "jne 1b"
62 : "=&S" (d0), "=&D" (d1), "=&a" (d2), "=&c" (d3)
63 : "0" (src), "1" (dest), "2" (0), "3" (0xffffffffu) : "memory");
64 return dest;
65}
66EXPORT_SYMBOL(strcat);
67#endif
68
69#ifdef __HAVE_ARCH_STRNCAT
70char *strncat(char *dest, const char *src, size_t count)
71{
72 int d0, d1, d2, d3;
73 asm volatile("repne\n\t"
74 "scasb\n\t"
75 "decl %1\n\t"
76 "movl %8,%3\n"
77 "1:\tdecl %3\n\t"
78 "js 2f\n\t"
79 "lodsb\n\t"
80 "stosb\n\t"
81 "testb %%al,%%al\n\t"
82 "jne 1b\n"
83 "2:\txorl %2,%2\n\t"
84 "stosb"
85 : "=&S" (d0), "=&D" (d1), "=&a" (d2), "=&c" (d3)
86 : "0" (src), "1" (dest), "2" (0), "3" (0xffffffffu), "g" (count)
87 : "memory");
88 return dest;
89}
90EXPORT_SYMBOL(strncat);
91#endif
92
93#ifdef __HAVE_ARCH_STRCMP
94int strcmp(const char *cs, const char *ct)
95{
96 int d0, d1;
97 int res;
98 asm volatile("1:\tlodsb\n\t"
99 "scasb\n\t"
100 "jne 2f\n\t"
101 "testb %%al,%%al\n\t"
102 "jne 1b\n\t"
103 "xorl %%eax,%%eax\n\t"
104 "jmp 3f\n"
105 "2:\tsbbl %%eax,%%eax\n\t"
106 "orb $1,%%al\n"
107 "3:"
108 : "=a" (res), "=&S" (d0), "=&D" (d1)
109 : "1" (cs), "2" (ct)
110 : "memory");
111 return res;
112}
113EXPORT_SYMBOL(strcmp);
114#endif
115
116#ifdef __HAVE_ARCH_STRNCMP
117int strncmp(const char *cs, const char *ct, size_t count)
118{
119 int res;
120 int d0, d1, d2;
121 asm volatile("1:\tdecl %3\n\t"
122 "js 2f\n\t"
123 "lodsb\n\t"
124 "scasb\n\t"
125 "jne 3f\n\t"
126 "testb %%al,%%al\n\t"
127 "jne 1b\n"
128 "2:\txorl %%eax,%%eax\n\t"
129 "jmp 4f\n"
130 "3:\tsbbl %%eax,%%eax\n\t"
131 "orb $1,%%al\n"
132 "4:"
133 : "=a" (res), "=&S" (d0), "=&D" (d1), "=&c" (d2)
134 : "1" (cs), "2" (ct), "3" (count)
135 : "memory");
136 return res;
137}
138EXPORT_SYMBOL(strncmp);
139#endif
140
141#ifdef __HAVE_ARCH_STRCHR
142char *strchr(const char *s, int c)
143{
144 int d0;
145 char *res;
146 asm volatile("movb %%al,%%ah\n"
147 "1:\tlodsb\n\t"
148 "cmpb %%ah,%%al\n\t"
149 "je 2f\n\t"
150 "testb %%al,%%al\n\t"
151 "jne 1b\n\t"
152 "movl $1,%1\n"
153 "2:\tmovl %1,%0\n\t"
154 "decl %0"
155 : "=a" (res), "=&S" (d0)
156 : "1" (s), "0" (c)
157 : "memory");
158 return res;
159}
160EXPORT_SYMBOL(strchr);
161#endif
162
163#ifdef __HAVE_ARCH_STRLEN
164size_t strlen(const char *s)
165{
166 int d0;
167 int res;
168 asm volatile("repne\n\t"
169 "scasb\n\t"
170 "notl %0\n\t"
171 "decl %0"
172 : "=c" (res), "=&D" (d0)
173 : "1" (s), "a" (0), "0" (0xffffffffu)
174 : "memory");
175 return res;
176}
177EXPORT_SYMBOL(strlen);
178#endif
179
180#ifdef __HAVE_ARCH_MEMCHR
181void *memchr(const void *cs, int c, size_t count)
182{
183 int d0;
184 void *res;
185 if (!count)
186 return NULL;
187 asm volatile("repne\n\t"
188 "scasb\n\t"
189 "je 1f\n\t"
190 "movl $1,%0\n"
191 "1:\tdecl %0"
192 : "=D" (res), "=&c" (d0)
193 : "a" (c), "0" (cs), "1" (count)
194 : "memory");
195 return res;
196}
197EXPORT_SYMBOL(memchr);
198#endif
199
200#ifdef __HAVE_ARCH_MEMSCAN
201void *memscan(void *addr, int c, size_t size)
202{
203 if (!size)
204 return addr;
205 asm volatile("repnz; scasb\n\t"
206 "jnz 1f\n\t"
207 "dec %%edi\n"
208 "1:"
209 : "=D" (addr), "=c" (size)
210 : "0" (addr), "1" (size), "a" (c)
211 : "memory");
212 return addr;
213}
214EXPORT_SYMBOL(memscan);
215#endif
216
217#ifdef __HAVE_ARCH_STRNLEN
218size_t strnlen(const char *s, size_t count)
219{
220 int d0;
221 int res;
222 asm volatile("movl %2,%0\n\t"
223 "jmp 2f\n"
224 "1:\tcmpb $0,(%0)\n\t"
225 "je 3f\n\t"
226 "incl %0\n"
227 "2:\tdecl %1\n\t"
228 "cmpl $-1,%1\n\t"
229 "jne 1b\n"
230 "3:\tsubl %2,%0"
231 : "=a" (res), "=&d" (d0)
232 : "c" (s), "1" (count)
233 : "memory");
234 return res;
235}
236EXPORT_SYMBOL(strnlen);
237#endif
238
