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Re: [ts-7000] Re: What is needed to have floating point capabilities on

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Subject: Re: [ts-7000] Re: What is needed to have floating point capabilities on 7250?
From: Eddie Dawydiuk <>
Date: Thu, 26 Jul 2007 12:12:41 -0700
Hello,

> --- In  Pat Farrell <> wrote:
>> Jim Jackson wrote:
>>> My advice would be to first figure out if you really need FP. 
> I've seen a
>>> lot of code use FP for no good reason - it could have been done 
> with fixed
>>> point (integer) quite simply. Maybe it's a symptom of my age - I 
> remember
>>> a time when the norm was for FP to be a large overhead you used 
> only if
>>> you had to.
>> Floating point is evil. Fixed Point (integers with implied decimal 
>> points) are often enough, search the archives for some links to 
> clever 
>> FFT code using fixed point.
>>
>> If I had a nickel for every rookie programmer who used floating 
> point to 
>> store and manipulate money, and then screwed up the arithmetic, 
> I'd retire.
>> -- 
>> Pat Farrell                  
>> www.bioinformatx.com
>>
> 
> thanks Pat. I know fixed point can often be sufficient but my 
> intention was to run gnuplot to process my data into svg and serve it 
> up with apache since I already have this coded.
> 
> gnuplot requires fp. 
> 
> Now if I could install softfloat without too much pain this would be 
> a good option.
> 
> The other route is to dump what I've got and find another way to do 
> LR curve fitting, replace simple log expressions with a whole bunch 
> of lookup tables, do some complicated preprocessing and then code the 
> plotting routines using something like GD.
> 
> Using the 30 or so lines of code that I already have to do all this 
> with one gnuplot file also appeals.
> 
> So my basic question remains:
> What is needed to have floating point capabilities on 7250?

My last answer to this question was pretty short, I should have been 
more verbose or pointed to passed discussion on this topic. Anyway you'd 
need a kernel that supports Maverick Crunch(the current shipping 2.4 
kernel does not), you'd also need a toolchain that supports the crunch 
instructions(I believe gcc 4.x has this support), and libs/userland code 
that has compiled with a crunch enabled toolchain.

-- 
Best Regards,
________________________________________________________________
  Eddie Dawydiuk, Technologic Systems | voice:  (480) 837-5200
  16610 East Laser Drive Suite 10     | fax:    (480) 837-5300
  Fountain Hills, AZ 85268            | web: www.embeddedARM.com


 
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