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Re: Paradoxical subreg in compare
- To: Jeffrey A Law <law at cygnus dot com>
- Subject: Re: Paradoxical subreg in compare
- From: Bernd Schmidt <bernds at pasanda dot cygnus dot co dot uk>
- Date: Tue, 30 May 2000 13:12:31 +0100 (BST)
- cc: Alexandre Oliva <aoliva at cygnus dot com>, gcc-patches at gcc dot gnu dot org
On Mon, 29 May 2000, Jeffrey A Law wrote:
> In message <oraeh92ord.fsf@saci.lsd.ic.unicamp.br>you write:
> > On May 29, 2000, Jeffrey A Law <law@cygnus.com> wrote:
> >
> > > In message <orsnv245h7.fsf@saci.lsd.ic.unicamp.br>you write:
> >
> > > Then you need to be looking to fix reload inheritance, not combine.
> > > Combine's actions are OK given the current state of register_operand
> > > and friends.
> >
> > Ok, so, of the three relevant steps in my message, which one do you
> > think is the wrong one?
> I do not know, I havne't looked into them in detail. I do know that the
> code combine created is reasonable. Thus the fix isn't in combine, but
> in whatever code is not handling the paradoxical subreg correctly.
IMO the real problem is that SUBREG has too many different meanings. If
we want zero extension, why don't we say ZERO_EXTEND? That would be lots
cleaner.
Bernd