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Re: [PATCH] Fix PR58459
- From: Jakub Jelinek <jakub at redhat dot com>
- To: Richard Biener <rguenther at suse dot de>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Thu, 26 Sep 2013 16:00:27 +0200
- Subject: Re: [PATCH] Fix PR58459
- Authentication-results: sourceware.org; auth=none
- References: <alpine dot LNX dot 2 dot 00 dot 1309261548240 dot 29411 at zhemvz dot fhfr dot qr>
- Reply-to: Jakub Jelinek <jakub at redhat dot com>
On Thu, Sep 26, 2013 at 03:54:19PM +0200, Richard Biener wrote:
>
> After much thinking I settled on removing the restriction from
> forwprop that avoids propagating non-invariant addresses into
> loops. As forwprop is mainly seen as a way to canonicalize the IL
> and simplify it for further passes this seems like the correct thing
> to do. LIM and IVOPTs should undo any harm this causes, otherwise
> I'll find another way to fix the fallout.
But, aren't some forwprop passes run after LIM and IVOPTs, so while
LIM and IVOPTs undo that harm, forwprop4 pass adds it there again?
I guess it is just fine to remove the restriction for forwprop{1,2,3},
but for forwprop4 I'm not that sure. You are then hoping RTL optimizations
will undo the harm, but if they don't, ...
Jakub