|
|
|
|
#include "byte.h"
|
|
|
|
|
|
|
|
|
|
/* byte_diff returns negative, 0, or positive, depending on whether the
|
|
|
|
|
* string one[0], one[1], ..., one[len-1] is lexicographically smaller
|
|
|
|
|
* than, equal to, or greater than the string one[0], one[1], ...,
|
|
|
|
|
* one[len-1]. When the strings are different, byte_diff does not read
|
|
|
|
|
* bytes past the first difference. */
|
|
|
|
|
int byte_diff(const void* a, size_t len, const void* b) {
|
|
|
|
|
#if 0
|
|
|
|
|
/* this gets miscompiled by gcc 4.3.2 on x86_64 */
|
|
|
|
|
register const unsigned char* s=a;
|
|
|
|
|
register const unsigned char* t=b;
|
|
|
|
|
register const unsigned char* u=t+len;
|
|
|
|
|
register int j;
|
|
|
|
|
j=0;
|
|
|
|
|
for (;;) {
|
|
|
|
|
if (t==u) break; if ((j=((unsigned int)*s-*t))) break; ++s; ++t;
|
|
|
|
|
if (t==u) break; if ((j=((unsigned int)*s-*t))) break; ++s; ++t;
|
|
|
|
|
if (t==u) break; if ((j=((unsigned int)*s-*t))) break; ++s; ++t;
|
|
|
|
|
if (t==u) break; if ((j=((unsigned int)*s-*t))) break; ++s; ++t;
|
|
|
|
|
}
|
|
|
|
|
return j;
|
|
|
|
|
#else
|
|
|
|
|
size_t i;
|
|
|
|
|
for (i=0; i<len; ++i) {
|
|
|
|
|
int r=((unsigned char*)a)[i] - ((unsigned char*)b)[i];
|
|
|
|
|
if (r) return r;
|
|
|
|
|
}
|
|
|
|
|
return 0;
|
|
|
|
|
#endif
|
|
|
|
|
}
|
