This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [PATCH] Fix PR41317, wrong code with folding conversions
- From: "H.J. Lu" <hjl dot tools at gmail dot com>
- To: Richard Guenther <rguenther at suse dot de>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Mon, 3 Jan 2011 14:38:47 -0800
- Subject: Re: [PATCH] Fix PR41317, wrong code with folding conversions
- References: <alpine.LNX.2.00.0909091622350.28140@zhemvz.fhfr.qr>
On Wed, Sep 9, 2009 at 7:24 AM, Richard Guenther <rguenther@suse.de> wrote:
>
> We are currently folding (T *) ptr into all sorts of addresses of
> component accesses of *ptr. ?This is bogus as propagating these
> addresses into dereferences can expose accesses that were not in
> the original program and that violate strict aliasing rules.
>
> Bootstrapped and tested on x86_64-unknown-linux-gnu, I'll install
> this momentarily.
>
> Richard.
>
> 2009-09-09 ?Richard Guenther ?<rguenther@suse.de>
>
> ? ? ? ?PR middle-end/41317
> ? ? ? ?* tree-ssa-ccp.c (maybe_fold_offset_to_component_ref): Remove
> ? ? ? ?code dealing with plain pointer bases.
> ? ? ? ?(maybe_fold_offset_to_reference): Likewise.
> ? ? ? ?(maybe_fold_stmt_addition): Adjust.
>
This caused:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47053
--
H.J.