optimize strchrnul/strcspn not to scan string twice on no-match

[musl] / src / string / strchr.c

diff --git a/src/string/strchr.c b/src/string/strchr.c
index d3563f1..bfae8f9 100644 (file)
--- a/src/string/strchr.c
+++ b/src/string/strchr.c
@@ -1,26 +1,9 @@
 #include <string.h>
 #include <string.h>

-#include <stdlib.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)
+char *__strchrnul(const char *, int);

 
 char *strchr(const char *s, int c)
 {
 
 char *strchr(const char *s, int c)
 {

-       size_t *w, k;
-
-       c = (unsigned char)c;
-       if (!c) return (char *)s + strlen(s);
-
-       for (; ((uintptr_t)s & ALIGN); s++)
-               if (*(unsigned char *)s == c) return (char *)s;
-               else if (!*s) return 0;
-       k = ONES * c;
-       for (w = (void *)s; !HASZERO(*w) && !HASZERO(*w^k); w++);
-       for (s = (void *)w; *s; s++)
-               if (*(unsigned char *)s == c) return (char *)s;
-       return 0;
+       char *r = __strchrnul(s, c);
+       return *(unsigned char *)r == (unsigned char)c ? r : 0;

 }
 }