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Re: postreload-gcse heuristics broken?
- From: Ulrich Weigand <Ulrich dot Weigand at de dot ibm dot com>
- To: Mostafa Hagog <MUSTAFA at il dot ibm dot com>
- Cc: Ayal Zaks <ZAKS at il dot ibm dot com>, gcc at gcc dot gnu dot org
- Date: Tue, 25 Jan 2005 21:45:39 +0100
- Subject: 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
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