[FFmpeg-devel] [PATCH] split-radix FFT

Måns Rullgård mans
Tue Aug 5 20:10:12 CEST 2008

matthieu castet <castet.matthieu at free.fr> writes:

> Siarhei Siamashka wrote:
>> On Mon, Aug 4, 2008 at 10:27 PM, matthieu castet
>> <castet.matthieu at free.fr> wrote:
>>> M?ns Rullg?rd wrote:
>>>> Loren Merritt <lorenm at u.washington.edu> writes:
>> Modern arm cores have hardware fpu which is reasonably fast, so it is
>> quite questionable if fixed point decoder would be better for such
>> cores. The same happened for x86 in the past and floating point audio
>> decoders are now better for modern x86 cores.
> Do you have some number for fixed-point vs fpu ?
> I was beveling that arm fpu were quite slow, but may be new hardware are 
> better.

Cortex-A8 can do two single-precision floating-point ops per cycle.
Double-precision operations are not pipelined, and take mostly 9-17
cycles.  Cortex-A9 supposedly has a fully pipelined FPU.

M?ns Rullg?rd
mans at mansr.com

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