[Speex-dev] Performance and Optimization

[Greger Burman]

Ok. Will look out for alloca().
cheers

If you define _USE_SSE, CELT is already able to use SSE instructions. You
> must
> be careful on Windows though because it doesn't support C99 var-arrays and
> alloca() isn't properly aligned for SSE, so you have to make sure that
> alloca()
> isn't used.
>
> > 2) To maybe learn from someone with previous experience in optimizing
> Speex
> > for moderns x86 architectures before I set off trying all kinds of things
> on
> > my own.
>
> Can't think of anything else you need to know.
>
>   Jean-Marc
>
> >
> > See answers inline:
> > 2009/6/15 Tom Grandgent <tom at grandgent.com>
> >
> > > Why haven't you tried using release build with compiler optimizations?
> >
> > I just haven't started with optimizing... yet.
> >
> >
> > >
> > > It's quite possible that the performance picture could be substantially
> > > different.  You might end up wasting a lot of time if you do much
> > > performance analysis or optimization on a debug build.
> >
> > Yes, you are right and that is not what I'm doing.
> >
> >
> > > Debug build
> > > not only has no optimization - it also has extra checks that may have a
> > > significant performance impact depending on the code.
> >
> > Possibly, but I have identified the most expensive functions. They are
> all
> > from the Speex dll. I believe these will remain the most interesting ones
> > also in release build with some O-flags.
> > Someone who is knowledgeable in these functions might know if their
> impact
> > can be reduced and what the best practices are.
> >
> > >
> > >
> > > If you want to profile with symbols, you know you can compile a release
> > > build with symbols, right?  The CodeAnalyst documentation describes
> > > how to do that with Visual Studio.  (I've done it.)
> >
> > Ok. thx.
> >
> > >
> > >
> > > Tom
> > >
> > > Greger Burman <greger at mobile-robotics.com> wrote:
> > > >
> > > > I have a question about the overall performance of Speex and what I
> can
> > > do
> > > > to improve it. I'm running Speex Windows x86, Visual C++ EE compiler.
> I
> > > will
> > > > say right away that I've only compiled debug so far and used no
> compiler
> > > > optimizations at all.
> > > > I use the uwb-mode, preprocessing, denoising and echo cancellation.
> > > > I've noticed that speex consumes a lot of cpu resources. When I run
> this
> > > on
> > > > a Celeron 2,6GHz I have to disable EC in order to not overload the
> cpu.
> > > Am I
> > > > correct to assume that there are massive floating point calculations
> > > > happening?
> > > > I did a quick profile with CodeAnalyst and identified the most
> expensive
> > > > functions as (in order):
> > > > CPU Clocks, Function
> > > > 4657, kiss_fft_stride
> > > > 4456, speex_echo_cancellation
> > > > 2494, split_cb_search_shape_sign
> > > > 1490, fir_mem16
> > > > 1419, speex_preprocess_run
> > > > I'm looking for advise on how to boost the performance with as little
> > > code
> > > > rewrite as possible. The architecture for release build will be
> SSE/SSE2
> > > > capable.
> > > > 1) Compiler optimizations: Recommended options?
> > > > 2) SIMD. Is Speex written to take advantage of SIMD architectures?
> What
> > > must
> > > > I do to take advantage of this?
> > > > --
> > > > Greger Burman
> > >
> > >
> >
>
>
>
>
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