Re: [Discuss-gnuradio] ANCI-C vs Gnuradio/C++ speeeed

[Achilleas Anastasopoulos]

Ilia,

you can find the relevant code here:

http://www.eecs.umich.edu/~anastas/gnuradio/

looking forward to your comments.
Achilleas

Ilia Mirkin wrote:
> Would you care to share your C++ implementation (e.g. post a link) so 
> that it
> might be critiqued rather than say things like "C++ is slower than C"?
>
>  -Ilia
>
> Quoting Achilleas Anastasopoulos <address@hidden>:
>
> > I have some new data on this.
> >
> > Going from ANSI-C to C++ (NO Gnuradio) using
> > STL vectors results in a 5-fold speed reduction!
> >
> > So Gnuradio seems to be responsible for the remaining
> > 4-fold reduction (for an overall 20-fold as I reported earlier).
> >
> > I am OK with Gnuradio resulting in this 4-fold speed reduction,
> > but I cannot swallow the fact that STL sucks that bad :-(  !!!
> >
> > I believe that this is not specific to my application, but should be 
> > true for any algorithm that uses vectors/matrices.
> > I wonder if anyone can corroborate this.
> >
> > Achilleas
> >
> >
> > Robert W McGwier wrote:
> >
> > > Yes.  I was comparing Phil Karn's native code to it and it runs at 
> > > least 20 times faster.
> > >
> > > Bob
> > >
> > >
> > >
> > > Achilleas Anastasopoulos wrote:
> > >
> > > > I have noticed a huge speed dissadvantage when comparing my
> > > > ANSI-C implementation of a Viterbi decoder with my Gnuradio 
> > > > implementation. The core code is pretty much the same, except
> > > > that in the Gnuradio implementation I am using STL vectors.
> > > >
> > > > It seems that Gnuradio is about 20 times SLOWER than ANSI-C!!!
> > > > I was wondering if this has to do with Gnuradio itself (buffering +
> > > > python + other fat), or with the fact that I had to translate all
> > > > my ANCI-C code to C++ and use STL.
> > > >
> > > > Does anyone have similar experiences?
> > > >
> > > > Achilleas
> >
> >
> >
> > _______________________________________________
> > Discuss-gnuradio mailing list
> > address@hidden
> > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio

--
_______________________________________________________
Achilleas Anastasopoulos                        
Associate Professor
EECS Department               Voice : (734)615-4024
UNIVERSITY OF MICHIGAN        Fax   : (734)763-8041
Ann Arbor, MI 48109-2122      E-mail: address@hidden
URL: http://www-personal.engin.umich.edu/~anastas/      
_______________________________________________________