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-rw-r--r--src/string/strchrnul.c26
1 files changed, 23 insertions, 3 deletions
diff --git a/src/string/strchrnul.c b/src/string/strchrnul.c
index 5e0c1a1a..ceae4d45 100644
--- a/src/string/strchrnul.c
+++ b/src/string/strchrnul.c
@@ -1,7 +1,27 @@
#include <string.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <limits.h>
+#include "libc.h"
-char *strchrnul(const char *s, int c)
+#define ALIGN (sizeof(size_t))
+#define ONES ((size_t)-1/UCHAR_MAX)
+#define HIGHS (ONES * (UCHAR_MAX/2+1))
+#define HASZERO(x) ((x)-ONES & ~(x) & HIGHS)
+
+char *__strchrnul(const char *s, int c)
{
- char *p = strchr(s, c);
- return p ? p : (char *)s + strlen(s);
+ size_t *w, k;
+
+ c = (unsigned char)c;
+ if (!c) return (char *)s + strlen(s);
+
+ for (; (uintptr_t)s % ALIGN; s++)
+ if (!*s || *(unsigned char *)s == c) return (char *)s;
+ k = ONES * c;
+ for (w = (void *)s; !HASZERO(*w) && !HASZERO(*w^k); w++);
+ for (s = (void *)w; *s && *(unsigned char *)s != c; s++);
+ return (char *)s;
}
+
+weak_alias(__strchrnul, strchrnul);