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Message
From: Matjaz Breskvar<phoenix@o...>
Date: Wed Feb 16 01:45:21 CET 2005
Subject: [openrisc] or1ksim stable_0_1_0
* György 'nog' Jeney (nog@s...) wrote:
> > > Regarding FAST_SIM i'd really be interested in some numbers. Does it
> > > really speed up execution by some meaningful margin (As far as i know
> > > faster simulation time is the only it exists) ? If it's
> > > negligable i'm all for throwing that one out.
> >
> > If I can get a working simulator with --enable-fsim, I'll do some benchmarks.
> > If we actually want to keep FAST_SIM, then we'll need to rethink the peripheral
> > cleanups. FAST_SIM is based on the assumption that all the configuration is
> > static and the compiler will remove always true or always false conditions.
> > With the peripheral cleanups however, everything became dynamic...
>
> I've done some benchmarks. The results are surpising to such an extent that I'm
> sure I'm doing something wrong. I am useing stock cvs. I have attached a copy
> of fast_config.c which has been generated from the attached sim.cfg (sim
> --output-cfg). I have also attached my `hack' to linux to prevent it from
> recalibrating its delay loop (just to make it boot faster).
>
> +-----+-------------------------+----------------------------+
> | Run | Real with --enable-fsim | Real without --enable-fsim |
> +-----+-------------------------+----------------------------+
> | 1 | 3m35.566s | 2m55.641s |
> | 2 | 3m24.519s | 3m8.849s |
> | 3 | 2m45.621s | 3m32.061s |
> | 4 | 3m34.219s | 3m33.546s |
> +-----+-------------------------+----------------------------+
>
> I have pasted the output of the time commands below.
So you're saying that --enable-fsim is actually --enable-slowsim ;)...
(for all but one misterious case)...
Just to make sure, are you running this on otherwise idle machine ? Do you
have any daemon that renices processes hard on cpu or similar ?
Please give me a few days to confirm this (or anybody else if you want
to help) and if it turns out our results are consistent it's bye-bye
"FAST_SIM"... Agreed ?
best regards,
p.
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