Re: [patch 1/13] Qsort

[Andi Kleen]

Felipe Alfaro Solana <lkml@xxxxxxx> 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?

-Andi (who thinks the glibc qsort is vast overkill for kernel purposes
where there are only small data sets and it would be better to use a 
simpler one optimized for code size)

-
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