Index: fusl/src/string/memccpy.c |
diff --git a/fusl/src/string/memccpy.c b/fusl/src/string/memccpy.c |
new file mode 100644 |
index 0000000000000000000000000000000000000000..7c233d5e90571f20ed06819575343657495b8246 |
--- /dev/null |
+++ b/fusl/src/string/memccpy.c |
@@ -0,0 +1,31 @@ |
+#include <string.h> |
+#include <stdint.h> |
+#include <limits.h> |
+ |
+#define ALIGN (sizeof(size_t)-1) |
+#define ONES ((size_t)-1/UCHAR_MAX) |
+#define HIGHS (ONES * (UCHAR_MAX/2+1)) |
+#define HASZERO(x) ((x)-ONES & ~(x) & HIGHS) |
+ |
+void *memccpy(void *restrict dest, const void *restrict src, int c, size_t n) |
+{ |
+ unsigned char *d = dest; |
+ const unsigned char *s = src; |
+ size_t *wd, k; |
+ const size_t *ws; |
+ |
+ c = (unsigned char)c; |
+ if (((uintptr_t)s & ALIGN) == ((uintptr_t)d & ALIGN)) { |
+ for (; ((uintptr_t)s & ALIGN) && n && (*d=*s)!=c; n--, s++, d++); |
+ if ((uintptr_t)s & ALIGN) goto tail; |
+ k = ONES * c; |
+ wd=(void *)d; ws=(const void *)s; |
+ for (; n>=sizeof(size_t) && !HASZERO(*ws^k); |
+ n-=sizeof(size_t), ws++, wd++) *wd = *ws; |
+ d=(void *)wd; s=(const void *)ws; |
+ } |
+ for (; n && (*d=*s)!=c; n--, s++, d++); |
+tail: |
+ if (*s==c) return d+1; |
+ return 0; |
+} |