Messages in this thread | | | Date | Mon, 24 Aug 2015 19:11:48 +0530 | From | Afzal Mohammed <> | Subject | Re: [RFC] fbdev/riva:change to use generice function to implement reverse_order() |
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Hi,
On Mon, Aug 24, 2015 at 04:31:13PM +0800, yalin wang wrote: > > i only submit the bit reverse patch for arm / arm64 arch,
yes, saw later git blaming it on you :)
> > Not for this case, but once measured on ARM, iirc, a 32-bit asm bit > > reversal as compared to doing it in C was taking 1 cycle as opposed to > > ~225 cycles!, of course writing optimized C could have made it fare > > better, but still would reach no-way near asm bit reversal.
The above measurement was done not in Linux, rather on a baremetal code, but seeing the efficient Kernel C implementation, realized that the gain would not be that much, it would be good to know if there are measurements for Kernel bitreversal in C & asm (on supported arch)
Regards afzal
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