1 #include "types.h"
2 #include "x86.h"
3
4 void*
memset(void * dst,int c,uint n)5 memset(void *dst, int c, uint n)
6 {
7 if ((int)dst%4 == 0 && n%4 == 0){
8 c &= 0xFF;
9 stosl(dst, (c<<24)|(c<<16)|(c<<8)|c, n/4);
10 } else
11 stosb(dst, c, n);
12 return dst;
13 }
14
15 int
memcmp(const void * v1,const void * v2,uint n)16 memcmp(const void *v1, const void *v2, uint n)
17 {
18 const uchar *s1, *s2;
19
20 s1 = v1;
21 s2 = v2;
22 while(n-- > 0){
23 if(*s1 != *s2)
24 return *s1 - *s2;
25 s1++, s2++;
26 }
27
28 return 0;
29 }
30
31 void*
memmove(void * dst,const void * src,uint n)32 memmove(void *dst, const void *src, uint n)
33 {
34 const char *s;
35 char *d;
36
37 s = src;
38 d = dst;
39 if(s < d && s + n > d){
40 s += n;
41 d += n;
42 while(n-- > 0)
43 *--d = *--s;
44 } else
45 while(n-- > 0)
46 *d++ = *s++;
47
48 return dst;
49 }
50
51 // memcpy exists to placate GCC. Use memmove.
52 void*
memcpy(void * dst,const void * src,uint n)53 memcpy(void *dst, const void *src, uint n)
54 {
55 return memmove(dst, src, n);
56 }
57
58 int
strncmp(const char * p,const char * q,uint n)59 strncmp(const char *p, const char *q, uint n)
60 {
61 while(n > 0 && *p && *p == *q)
62 n--, p++, q++;
63 if(n == 0)
64 return 0;
65 return (uchar)*p - (uchar)*q;
66 }
67
68 char*
strncpy(char * s,const char * t,int n)69 strncpy(char *s, const char *t, int n)
70 {
71 char *os;
72
73 os = s;
74 while(n-- > 0 && (*s++ = *t++) != 0)
75 ;
76 while(n-- > 0)
77 *s++ = 0;
78 return os;
79 }
80
81 // Like strncpy but guaranteed to NUL-terminate.
82 char*
safestrcpy(char * s,const char * t,int n)83 safestrcpy(char *s, const char *t, int n)
84 {
85 char *os;
86
87 os = s;
88 if(n <= 0)
89 return os;
90 while(--n > 0 && (*s++ = *t++) != 0)
91 ;
92 *s = 0;
93 return os;
94 }
95
96 int
strlen(const char * s)97 strlen(const char *s)
98 {
99 int n;
100
101 for(n = 0; s[n]; n++)
102 ;
103 return n;
104 }
105
106