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Re: [PATCH] Fix PR18754: add early loop pass, 2nd try
> >>(Richard Guenther wrote in
> >>>I did experiments with scheduling a second SRA pass after
> >>>loop optimization, but that doesn't help ivopts - we'd need
> >>>another loop pass after the second SRA this way.
> >>Maybe adding this extra ivopts pass isn't that bad? If that would allow
> >>scheduling vectorization then loop-unrolling then SRA I think that would
> >extra ivopts pass is not a good idea (ivopts are quite slow just now).
> >The right fix seems to be to add the second SRA pass in the middle of loop
> >optimizations (just immediately after cunroll). You would also need to
> >schedule constant propagation pass there (which should just work)
> >and preferably also cfg_cleanup (the variation from tcb branch that
> >preserves loop structures).
> Yes, I tried this - actually just adding SRA and redphi after cunroll,
> but this caused verify failures about not the right ssa form or so. So
> I guessed SRA may be not ready to preserve invariants the loop
> optimizers need.
you probably need to rerun the loop closed ssa form creation afterwards