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Re: [f-cpu] dynamic code reuse



Le Dimanche 7 Décembre 2003 16:36, Michael Riepe a écrit :
> On Sun, Dec 07, 2003 at 04:19:58PM +0000, Nicolas Boulay wrote:
> > There is a branch of studies concerning the reuse of soon calculated
> > value in code.
> >
> > http://citeseer.nj.nec.com/sodani97dynamic.html
> >
> > The idea from the paper is that there is always some result in the code
> > that have been soon calculated. The idea is to reuse the result instead
> > of recalulate it. Increase speed could reach 20%.
> >
> > This gave me an idea but with software support.
> >
> > This is a kind of jump instruction. The jump take some register and one
> > adresse. If the content of the r register + the PC match a internal
> > specific cache the result of 2w register is set and the jump occur.
>
> Sounds a lot like `speculative execution' to me.
> Disclaimer: I didn't read the paper yet.
>

nop this is a specultative reuse of a previous calculated result.

> > To fill the cache, some thing "watch" the result calculated  where the
> > instruction is supposed to jump. In case of interrupt, this is lost to
> > avoid confusion and to stay stateless.
> >
> > This instruction needed to be handle carrefully by the compiler. So
> > what's up in the area ?
>
> Rien, I suppose.

Devik ? what's your opinion about this feature to implemented in the compiler 
?

nicO

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