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Date: Tue, 14 Jun 2011 09:10:00 -0000
From: Richard Guenther <rguenther@suse.de>
To: Jason Merrill <jason@redhat.com>
Cc: Richard Guenther <richard.guenther@gmail.com>,	gcc-patches List <gcc-patches@gcc.gnu.org>, GCC <gcc@gcc.gnu.org>
Subject: Re: RFA (fold): PATCH for c++/49290 (folding *(T*)(ar+10))
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On Mon, 13 Jun 2011, Jason Merrill wrote:

> On 06/13/2011 06:51 AM, Richard Guenther wrote:
> > But I suppose you want the array-ref be folded to a constant eventually?
> 
> Right.
> 
> I'm not going to keep arguing about VIEW_CONVERT_EXPR, but that brings me back
> to my original question: is it OK to add a permissive mode to the function, or
> should I copy the whole thing into the front end?

I think you should copy the whole thing into the front end for now.

Note that we want to arrive at a point where our constant folding
can handle the MEM_REF case for arbitrary constant constructors.
See fold_const_aggregate_ref in gimple-fold.c - probably not usable
from the frontend directly though.  And it doesn't yet handle
non-array constructors without having a component-ref tree.
But if we eventually have all the code in that routine you might
switch to it instead.

Richard.