Compact memnrcmp, just for fun

This commit is contained in:
Hallvard B Furuseth 2011-06-29 19:17:31 +02:00
parent ab0d6fa05e
commit aed36f5780

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@ -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;
}