Last change
on this file since 473 was 389, checked in by coas-nagasima, 5 years ago |
ビルドが通るよう更新
|
-
Property svn:eol-style
set to
native
-
Property svn:mime-type
set to
text/x-csrc;charset=UTF-8
|
File size:
619 bytes
|
Rev | Line | |
---|
[388] | 1 | #include <string.h>
|
---|
| 2 | #include <stdint.h>
|
---|
| 3 | #include <limits.h>
|
---|
| 4 |
|
---|
| 5 | #define SS (sizeof(size_t))
|
---|
| 6 | #define ALIGN (sizeof(size_t)-1)
|
---|
| 7 | #define ONES ((size_t)-1/UCHAR_MAX)
|
---|
| 8 | #define HIGHS (ONES * (UCHAR_MAX/2+1))
|
---|
| 9 | #define HASZERO(x) ((x)-ONES & ~(x) & HIGHS)
|
---|
| 10 |
|
---|
| 11 | void *memchr(const void *src, int c, size_t n)
|
---|
| 12 | {
|
---|
| 13 | const unsigned char *s = src;
|
---|
| 14 | c = (unsigned char)c;
|
---|
| 15 | for (; ((uintptr_t)s & ALIGN) && n && *s != c; s++, n--);
|
---|
| 16 | if (n && *s != c) {
|
---|
| 17 | const size_t *w;
|
---|
| 18 | size_t k = ONES * c;
|
---|
| 19 | for (w = (const void *)s; n>=SS && !HASZERO(*w^k); w++, n-=SS);
|
---|
| 20 | for (s = (const void *)w; n && *s != c; s++, n--);
|
---|
| 21 | }
|
---|
| 22 | return n ? (void *)s : 0;
|
---|
| 23 | }
|
---|
Note:
See
TracBrowser
for help on using the repository browser.