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Re: [PATCH] Fix missed VRP with unhandled operations
- 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: Wed, 20 Aug 2008 16:06:49 -0700
- Subject: Re: [PATCH] Fix missed VRP with unhandled operations
- References: <alpine.LNX.1.10.0808201759150.3427@zhemvz.fhfr.qr>
On Wed, Aug 20, 2008 at 9:01 AM, Richard Guenther <rguenther@suse.de> wrote:
>
> VRP doesn't do range propagation on all operations but instead of
> falling back to varying in all cases it should at least do what CCP
> does, namely constant folding if all operands are single valued
> ranges and constants. Noted while removing the last DOM pass.
>
> Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to the
> trunk.
>
> Richard.
>
> 2008-08-20 Richard Guenther <rguenther@suse.de>
>
> * tree-vrp.c (op_with_constant_singleton_value_range): New function.
> (extract_range_from_binary_expr): Fall back to constant propagation.
> (extract_range_from_unary_expr): Likewise.
>
> * gcc.dg/tree-ssa/pr21829.c: Scan optimized and cddce2 dumps
> instead of phicprop2. Make sure all is fine after cddce2,
> add an XFAILed scan for merging the two remaining ifs.
>
This patch may have caused
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37181
--
H.J.