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Re: [PATCH] Fix PR56426
On Mon, Feb 25, 2013 at 09:01:17PM +0100, Steven Bosscher wrote:
> On Mon, Feb 25, 2013 at 8:53 PM, Marek Polacek wrote:
> > This fixes PR56426. We were ICEing during the loop pipeline,
> > because copyprop changed an irreducible region into a reducible - thus
> > the number_of_loops grew.
>
> We've seen that kind of thing happen before with the tracer pass. It
> makes me worried a bit about the robustness of preserving loops...
>
> Is there anything in the loop maintenance frame work that catches and
> handles new loops if they are "spontaneously" created from previously
> irreducible regions?
Well - flow_loops_find now works incrementally on an existing loop
tree, so when the new loops appear, this function is able to detect
them. When passing the NULL parameter, loops are computed from
scratch. It is what e.g. fix_loop_structure now uses.
Marek