The obvious answer is that XOR is faster. To do a subtract, you have to propagate the carry bit from the least-significant bit to the most-significant bit. In XOR you don't have to do that because the output of every bit is independent of the other adjacent bits.
Probably, there are ALU pipeline designs where you don't pay an explicit penalty. But not all, and so XOR is faster.
Surely, someone as awesome as Raymond Chen knows that. The answer is so obvious and basic I must be missing something myself?
Probably, there are ALU pipeline designs where you don't pay an explicit penalty. But not all, and so XOR is faster.
Surely, someone as awesome as Raymond Chen knows that. The answer is so obvious and basic I must be missing something myself?