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Re: Feature request: ability to describe x86 register halves as contraints.
- To: Alan Modra <alan at spri dot levels dot unisa dot edu dot au>
- Subject: Re: Feature request: ability to describe x86 register halves as contraints.
- From: Andreas Kleen <ak at muc dot de>
- Date: Wed, 1 Jul 1998 04:39:16 +0200
- Cc: ak at muc dot de, egcs at cygnus dot com
- References: <19980630135032.22058@kali.lrz-muenchen.de> <Pine.LNX.3.96.980701100534.29344A-100000@mullet.Levels.UniSA.Edu.Au>
On Wed, Jul 01, 1998 at 02:44:02AM +0200, Alan Modra wrote:
>
> On Tue, 30 Jun 1998 ak@muc.de wrote:
>
> > > asm ("# %0 %b0 %h0 %w0 %k0" : : "q"(x));
> > >
> > > yields
> > >
> > > # %eax %al %ah %ax %eax
> >
> > Ok, I feel stupid now, but to my defense I must say that this is not
> > documented in the info pages.
>
> Yes, you have to dig into i386.md
>
> Colin Plumb <colin@nyx.net> wrote a really good, tutorial style,
> description of x86 constraints. If you ask him, I guess he'd be happy to
> send it to you. His tutorial really ought to be part of egcs
> documentation.
I have his tutorial, but I didn't look there (mea culpa)
-Andi