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[ts-7000] Re: TS-7200 / ARM9 speed issue - question

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Subject: [ts-7000] Re: TS-7200 / ARM9 speed issue - question
From: "charliem_1216" <>
Date: Thu, 07 Jun 2007 12:34:53 -0000
Hi --

I did some simple whetstone tests earlier this year: With softfloat
and eabi, I saw a factor of 15 speedup compared to the kernel-emulated
hardfp that you get with oabi.

With crunch instructions (and softfloat / eabi), I saw a factor of
about 19.  

So, it looks like you can get a _significant_ FP speedup
just by moving to eabi and using softfloat.  You can get this on any
Arm9 core, no FP hardware needed!  Crunch is harder, as
there is still some question of upstrream gcc support properly working
around chip errata.  Although crunch support is in modern gcc's,
Cirrus implies it does not have all the fixes.

So I'd suggest you try to do some eabi testing with your app, and if
that's not fast enough, then work on using crunch.

Regards, .......... Charlie

--- In  Jason Stahls <> wrote:
>
> Well the big problem is that it assumes a FPU, sends the
instructions to 
> the FPU (which is does have but isn't supported by default), those 
> instructions fail, causing the kernel to have to re-issue instructions 
> to emulate a FPU.  This whole thing takes _forever_, if the distro was 
> built with softfloat it wouldn't be as bad, and if built with Mavric 
> Crunch would be even better.  You can of course, rebuild the distro
with 
> EABI  or softfloat if you want, there's a few people on here working on 
> that.
> 
> Jason
> 
> David Topper wrote:
> > Yeah, it uses floats all over the place.  Interesting,
> > that would explain why I had to fall back to a two
> > year old version of the app (less use of floats).
> >
> > So the processor emulates FP math?  How can I get the
> > FPU to work?
> >
> > Thanks,
> >
> > DT
> >
> > --- "Breton M. Saunders"
> > <> wrote:
> >
> >   
> >> Check that it doesn't use floating point math.
> >> If it does, you are in trouble.  You could try
> >> getting the FPU on the
> >> ARM9 to work, but that won't be easy.
> >>
> >>     -Brett
> >>
> >>
> >> djtopper wrote:
> >>     
> >>> Hi folks,
> >>>
> >>> I've been working getting an audio app
> >>>       
> >> (www.rtcmix.org) to compile for
> >>     
> >>> the TS-7xx boards.  I think I've finally got it
> >>>       
> >> working, using the
> >>     
> >>> ALSA libraries, etc...  I can definitely play
> >>>       
> >> soundfiles through my
> >>     
> >>> little USB dongle.
> >>>
> >>> I'm noticing, however, that for basic synthesis
> >>>       
> >> (eg., making a sine
> >>     
> >>> wave) the board is far too slow).  I mean, I can
> >>>       
> >> barely get one
> >>     
> >>> oscillator going.
> >>>
> >>> I used to be able to get about a dozen or so on my
> >>>       
> >> old 90 mhz Pentium.
> >>     
> >>> What's the deal with the ARM processor and speed?
> >>>
> >>> Thanks,
> >>>
> >>> DT
> >>>
> >>>
> >>>
> >>>  
> >>> Yahoo! Groups Links
> >>>
> >>>
> >>>
> >>>   
> >>>       
> >>     
> >
> >
> >
> >  
> >
____________________________________________________________________________________
> > It's here! Your new message!  
> > Get new email alerts with the free Yahoo! Toolbar.
> > http://tools.search.yahoo.com/toolbar/features/mail/
> >
> >
> >  
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
>



 
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