7 May
2011
7 May
'11
5:11 a.m.
On May 6, 2011, at 8:53 PM, Robert Ransom wrote:
int memcmp(const void *m1, const void *m2, size_t n) { /*XXX I don't know if this is even right; I haven't tested it at all */ const uint8_t *b1 = m1, *b2 = m2; int retval = 0;
while (n--) { const uint8_t v1 = b1[n], v2 = b2[n]; int diff = (int)v1 - (int)v2; retval = (v1 == v2) * retval + diff; }
return retval; }
GCC is likely to turn (v1 == v2) into a backdoor.
Can you explain what you mean?