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Re: postreload-gcse heuristics broken?





Mostafa Hagog/Haifa/IBM wrote on 01/25/2005 06:05:27 PM:

> "insns deleted" is wrong, this is due to a bug in the dumps of
> postreload-gcse. We have two places in which we delete instructions and
> only one of them is reported.

OK, I see.

> I have prepared a patch to prevent postreload-gcse to split critical
> edges (as Ayal suggested to me) - this should do the trick for you.
> The patch also includes the fix for the dumps bug.
>
> postreload-gcse didn't cause any degradation in G5 so I cannot test
> if the patch fixes your problem.  can you test it?

Crashes because of NULL 'occr' in:
!           print_rtl_single (dump_file, occr->insn);
I guess this should be just 'insn'.

With this fixed, the loop back-edge of my testcase is indeed no longer
split, so this should fix the problem I was seeing ...

Thanks for taking care of this!


Mit freundlichen Gruessen / Best Regards

Ulrich Weigand

--
  Dr. Ulrich Weigand
  Linux for S/390 Design & Development
  IBM Deutschland Entwicklung GmbH, Schoenaicher Str. 220, 71032 Boeblingen
  Phone: +49-7031/16-3727   ---   Email: Ulrich.Weigand@de.ibm.com


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