Date:	Sat, 13 Mar 1999 18:07:43 +0100
To:	pgcc AT delorie DOT com
Subject:	Re: amd and float
Message-ID:	<19990313180743.G620@cerebro.laendle>
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References:	<19990312235917 DOT K9148 AT cerebro DOT laendle> <Pine DOT GSO DOT 4 DOT 05 DOT 9903130019520 DOT 18710-100000 AT legolas DOT mdh DOT se>
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In-Reply-To:	<Pine.GSO.4.05.9903130019520.18710-100000@legolas.mdh.se>; from Henrik Berglund SdU on Sat, Mar 13, 1999 at 12:24:20AM +0100
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From:	Marc Lehmann <pcg AT goof DOT com>
Reply-To:	pgcc AT delorie DOT com
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On Sat, Mar 13, 1999 at 12:24:20AM +0100, Henrik Berglund SdU wrote:
> On 12 Mar 1999, Marc Lehmann wrote:
> 
> > The biggest probelm I see is that 3dnow uses different float formats than the
> > x86 fpu. even worse, you probably won't get improvements in the common case
> > anyway (doubles). also, the interoperability between the x86 fpu and 3dnow is
> > very bad.
> > 
> > the good thing is that, finally, its a sane design. a very sane design. if we
> > only had this design from the very beginning (and no x86 fpu).
> 
> Is it possible to just use 3dnow instead of the fpu does 3dnow have all
> the required instructions? if so it would be great if it only used the
> 3dnow for fpu operations when typing -march=3dnow or something :) 

Unfortunately, its not, as 3dnow does not support all dataformats and
instructions neccessary for this, so we still need the x86 fpu.

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