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Re: [PATCH] improve index register recognition


Hi,

On Thu, 2 Sep 2004, Richard Henderson wrote:

> On Tue, Aug 10, 2004 at 01:19:35AM +0200, Roman Zippel wrote:
> > (plus (sign_extract ((mult (reg %d0) 2)) 17 15) (reg %a0))
> > 
> > which corresponds to (%a0,%d0.w*2).
> 
> Hum, I guess.  I'd rather not add codes at random here.  I think
> we can safely characterize the index as !OBJECT_P though.

I don't understand, how OBJECT_P helps here.
The problem is that (reg %d0) is not recognized as index register, 
regalloc prefers to put it into an address register and sometimes 
generating worse code and reload/regrename assumes both registers are 
equal and sometimes tries to use a data register as base register.

bye, Roman


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