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Re: trouble emilinating redundant compares


On Mon, 23 Jan 2012, Paul S wrote:
> Thanks Dave,
>
> I would never have guessed from gccinternals.pdf that it is possible to use
> mode iterators to select predicates & constraints ...

Really?  If you but if you have suggestions for improving the
documentation, that'd be welcome.

> I think I have a use for
> this today :-)
>
> Cheers, Paul.
>
> On 20/01/12 10:26, Dave Korn wrote:
> > On 17/01/2012 21:16, Paul S wrote:
> >
> >
> > > For example the i386 seems to use predicates and constraints of the form
> > > <*_operand>  and<m/r/i>  for the reload versions of these instructions -
> > > and I haven't been able to find definitions of these or a mention in
> > > gcc_internals.pdf of any special meaning assigned to the<>  notation.
> > >
> >    See http://gcc.gnu.org/onlinedocs/gccint/Substitutions.html, and take a
> > look
> > for the define_[code/mode]_[attr/iterator] definitions around line ~650ish
> > of
> > i386.md
> >
> >      cheers,
> >        DaveK
> >
> >
> >
> >
> >


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