Steven Bosscher wrote:
> On Tue, Mar 20, 2012 at 8:54 PM, Georg-Johann Lay <a...@gjlay.de> wrote:
>> Dropping the first patch which does not work because at expand-time there
>> must not be pre-/post-modify addressing :-(
> Have you tried to fix that, instead? Or at least ask around a bit to
> see what people would think about that idea? The reasons why things
> are the way they are, may not be applicable anymore.
No, I didn't try to fix it. I am not experienced enough in that field.
Moreover, at least as far as avr is concerned, using post-inc would
just be a hack, too.
> For example, perhaps the only reason for not having pre-/post-modify
> addressing modes earlier is that the old "flow" dataflow frame work
> didn't handle them. And it doesn't seem to be so black-and-white: The
> very pass you ran into problems with first, cprop, does handle
> pre-/post-modify addresses in local cprop. Some other passes simply
> take the conservative path and drop pre-/post-modify (like CSE, which
The problems were not only in cprop but also in cselib.
> doesn't record values from them). It may be a relatively small job to
> make everything accept them, and you may be something that's also
> helpful for other targets.