Messages in this thread | | | From | Felipe Alfaro Solana <> | Subject | Re: [patch 1/13] Qsort | Date | Sun, 23 Jan 2005 05:58:00 +0100 |
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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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