[Bug tree-optimization/93439] [9/10 Regression] ICE in gimple_duplicate_bb, at tree-cfg.c:6277

[rguenther at suse dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93439

--- Comment #7 from rguenther at suse dot de <rguenther at suse dot de> ---
On Tue, 28 Jan 2020, jakub at gcc dot gnu.org wrote:

> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93439
> 
> --- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
> (In reply to Richard Biener from comment #5)
> > OK, so the reason is that when we actually create the parallel decl
> > last_clique
> > is not yet up to its maximum since we later loop_version another loop in the
> > source function.  The solution is to move the last clique setting to
> > function outlining I guess.
> > 
> > Testing patch.
> 
> I guess that doesn't hurt, but do we really want to parallelize inner loops of
> loops that we've parallelized already?
> I mean, that is nested parallelism and won't always be very beneficial
> (especially when in OpenMP 4.5 and earlier dynamic parallelism is disabled by
> default and needs to be explicitly enabled).

Sure, but that's a separate issue...