Technically you could get by with 5 bytes for "mov ebp, 0". Another reason why it was faster was that the processor recognized it and avoided partial flags sta

Technically you could get by with 5 bytes for "mov ebp, 0". Another reason why it was faster was that the processor recognized it and avoided partial flags stalls after an "inc". But in 64-bit code you rarely have "inc" at all, so it matters less. On the other hand, a few years ago XOR had a false dependency on the register you're clearing; I'm not sure it is still that way on more recent processors.