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Re: RFC -- update_equiv_regs and friends
- To: Bernd Schmidt <bernds at cambridge dot redhat dot com>
- Subject: Re: RFC -- update_equiv_regs and friends
- From: Jeffrey A Law <law at redhat dot com>
- Date: Wed, 28 Feb 2001 08:37:12 -0700
- cc: gcc at gcc dot gnu dot org
- Reply-To: law at redhat dot com
In message <Pine.LNX.4.30.0102281118330.1311-100000@host140.cambridge.redhat.
com>you write:
> On Tue, 27 Feb 2001, Jeffrey A Law wrote:
> Shouldn't the equivalences be restricted to function invariant expressions?
> That should rule out pseudos.
Generally they are. In this particular case we do not kick out the
lo_sum due to code which special cases the first argument of a lo_sum
(because we know it's the high part of the expression and is constant).
> It seems that the problem may be the special handling of LO_SUM in
> rtx_varies_p. Maybe we want to change the equivalence to be
> (mem (symbol_ref)) if we detect this case.
>
> > F. Don't consider the first argument of a LO_SUM as special in
> > rtx_varies_p.
>
> Or maybe do that.
:-)
jeff