Re: [LAD] vectorization

From: Jens M Andreasen <jens.andreasen@email-addr-hidden>
Date: Tue May 06 2008 - 00:32:56 EEST

On Mon, 2008-05-05 at 22:33 +0200, Fons Adriaensen wrote:
> > ...
> > #define N 1024
> > ...
> > int n = 1000000;
> > ...
>
> Looping a million times over the same small data vector
> is _not_ very realistic.

OK, good point!

#define N (1024 * 1024 ) // flood the level 2 cache ...
...
int n = 1000; // we need to loop for clock() to take notice
...

with icc I am then getting these numbers:

> clock: 4020 ms (_Complex)
> clock: 1550 ms (cvec_t)
> clock: 70000 ms (original float array[N][2])

... which supports the notion that the shape of the data structure is an
important factor, not only for the vectorization but also for data
thruput.

(With gcc results for all versions were in the 50 - 60 000 ms range.)

_______________________________________________
Linux-audio-dev mailing list
Linux-audio-dev@email-addr-hidden
http://lists.linuxaudio.org/mailman/listinfo/linux-audio-dev
Received on Tue May 6 04:15:02 2008

This archive was generated by hypermail 2.1.8 : Tue May 06 2008 - 04:15:02 EEST