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SubjectRe: [patch 1/13] Qsort
Date
On 23 Jan 2005, at 03:39, Andi Kleen wrote:

> Felipe Alfaro Solana <lkml@mac.com> writes:
>>
>> AFAIK, XOR is quite expensive on IA32 when compared to simple MOV
>> operatings. Also, since the original patch uses 3 MOVs to perform the
>> swapping, and your version uses 3 XOR operations, I don't see any
>> gains.
>
> Both are one cycle latency for register<->register on all x86 cores
> I've looked at. What makes you think differently?

I thought XOR was more expensie. Anyways, I still don't see any
advantage in replacing 3 MOVs with 3 XORs.

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