Compact memnrcmp, just for fun

diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index ad08e9db3e5090c101f80a79aca817975c615860..f89f46b753d3d43fa912b2898b5632a95ae22598 100644 (file)
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -346,25 +346,19 @@ memncmp(const void *s1, size_t n1, const void *s2, size_t n2)
 static int
 memnrcmp(const void *s1, size_t n1, const void *s2, size_t n2)
 {
-       const unsigned char     *p1;
-       const unsigned char     *p2;
-
-       if (n1 == 0)
-               return n2 == 0 ? 0 : -1;
+       const unsigned char     *p1, *p2, *p1_lim;
 
        if (n2 == 0)
-               return n1 == 0 ? 0 : 1;
+               return n1 != 0;
+       if (n1 == 0)
+               return -1;
 
        p1 = (const unsigned char *)s1 + n1 - 1;
        p2 = (const unsigned char *)s2 + n2 - 1;
 
-       while (*p1 == *p2) {
-               if (p1 == s1)
-                       return (p2 == s2) ? 0 : -1;
-               if (p2 == s2)
-                       return (p1 == p2) ? 0 : 1;
-               p1--;
-               p2--;
+       for (p1_lim = (n1 <= n2 ? s1 : s2);  *p1 == *p2;  p1--, p2--) {
+               if (p1 == p1_lim)
+                       return (p1 != s1) ? (p1 != p2) : (p2 != s2) ? -1 : 0;
        }
        return *p1 - *p2;
 }