Commit | Line | Data |
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b520b85a AK |
1 | /* |
2 | * Most of the string-functions are rather heavily hand-optimized, | |
3 | * see especially strsep,strstr,str[c]spn. They should work, but are not | |
4 | * very easy to understand. Everything is done entirely within the register | |
5 | * set, making the functions fast and clean. String instructions have been | |
6 | * used through-out, making for "slightly" unclear code :-) | |
7 | * | |
8 | * AK: On P4 and K7 using non string instruction implementations might be faster | |
9 | * for large memory blocks. But most of them are unlikely to be used on large | |
10 | * strings. | |
11 | */ | |
12 | ||
13 | #include <linux/string.h> | |
14 | #include <linux/module.h> | |
15 | ||
16 | #ifdef __HAVE_ARCH_STRCPY | |
17 | char *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 | } | |
28 | EXPORT_SYMBOL(strcpy); | |
29 | #endif | |
30 | ||
31 | #ifdef __HAVE_ARCH_STRNCPY | |
32 | char *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 | } | |
48 | EXPORT_SYMBOL(strncpy); | |
49 | #endif | |
50 | ||
51 | #ifdef __HAVE_ARCH_STRCAT | |
52 | char *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 | } | |
66 | EXPORT_SYMBOL(strcat); | |
67 | #endif | |
68 | ||
69 | #ifdef __HAVE_ARCH_STRNCAT | |
70 | char *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 | } | |
90 | EXPORT_SYMBOL(strncat); | |
91 | #endif | |
92 | ||
93 | #ifdef __HAVE_ARCH_STRCMP | |
94 | int 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 | } | |
113 | EXPORT_SYMBOL(strcmp); | |
114 | #endif | |
115 | ||
116 | #ifdef __HAVE_ARCH_STRNCMP | |
117 | int 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 | } | |
138 | EXPORT_SYMBOL(strncmp); | |
139 | #endif | |
140 | ||
141 | #ifdef __HAVE_ARCH_STRCHR | |
142 | char *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 | } | |
160 | EXPORT_SYMBOL(strchr); | |
161 | #endif | |
162 | ||
163 | #ifdef __HAVE_ARCH_STRRCHR | |
164 | char *strrchr(const char * s, int c) | |
165 | { | |
166 | int d0, d1; | |
167 | char * res; | |
168 | asm volatile( "movb %%al,%%ah\n" | |
169 | "1:\tlodsb\n\t" | |
170 | "cmpb %%ah,%%al\n\t" | |
171 | "jne 2f\n\t" | |
172 | "leal -1(%%esi),%0\n" | |
173 | "2:\ttestb %%al,%%al\n\t" | |
174 | "jne 1b" | |
175 | :"=g" (res), "=&S" (d0), "=&a" (d1) | |
176 | :"0" (0),"1" (s),"2" (c) | |
177 | :"memory"); | |
178 | return res; | |
179 | } | |
180 | EXPORT_SYMBOL(strrchr); | |
181 | #endif | |
182 | ||
183 | #ifdef __HAVE_ARCH_STRLEN | |
184 | size_t strlen(const char * s) | |
185 | { | |
186 | int d0; | |
187 | int res; | |
188 | asm volatile( "repne\n\t" | |
189 | "scasb\n\t" | |
190 | "notl %0\n\t" | |
191 | "decl %0" | |
192 | :"=c" (res), "=&D" (d0) | |
193 | :"1" (s),"a" (0), "0" (0xffffffffu) | |
194 | :"memory"); | |
195 | return res; | |
196 | } | |
197 | EXPORT_SYMBOL(strlen); | |
198 | #endif | |
199 | ||
200 | #ifdef __HAVE_ARCH_MEMCHR | |
201 | void *memchr(const void *cs,int c,size_t count) | |
202 | { | |
203 | int d0; | |
204 | void *res; | |
205 | if (!count) | |
206 | return NULL; | |
207 | asm volatile( "repne\n\t" | |
208 | "scasb\n\t" | |
209 | "je 1f\n\t" | |
210 | "movl $1,%0\n" | |
211 | "1:\tdecl %0" | |
212 | :"=D" (res), "=&c" (d0) | |
213 | :"a" (c),"0" (cs),"1" (count) | |
214 | :"memory"); | |
215 | return res; | |
216 | } | |
217 | EXPORT_SYMBOL(memchr); | |
218 | #endif | |
219 | ||
220 | #ifdef __HAVE_ARCH_MEMSCAN | |
221 | void *memscan(void * addr, int c, size_t size) | |
222 | { | |
223 | if (!size) | |
224 | return addr; | |
225 | asm volatile("repnz; scasb\n\t" | |
226 | "jnz 1f\n\t" | |
227 | "dec %%edi\n" | |
228 | "1:" | |
229 | : "=D" (addr), "=c" (size) | |
230 | : "0" (addr), "1" (size), "a" (c) | |
231 | : "memory"); | |
232 | return addr; | |
233 | } | |
234 | EXPORT_SYMBOL(memscan); | |
235 | #endif | |
236 | ||
237 | #ifdef __HAVE_ARCH_STRNLEN | |
238 | size_t strnlen(const char *s, size_t count) | |
239 | { | |
240 | int d0; | |
241 | int res; | |
242 | asm volatile( "movl %2,%0\n\t" | |
243 | "jmp 2f\n" | |
244 | "1:\tcmpb $0,(%0)\n\t" | |
245 | "je 3f\n\t" | |
246 | "incl %0\n" | |
247 | "2:\tdecl %1\n\t" | |
248 | "cmpl $-1,%1\n\t" | |
249 | "jne 1b\n" | |
250 | "3:\tsubl %2,%0" | |
251 | :"=a" (res), "=&d" (d0) | |
252 | :"c" (s),"1" (count) | |
253 | :"memory"); | |
254 | return res; | |
255 | } | |
256 | EXPORT_SYMBOL(strnlen); | |
257 | #endif |