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Re: Loop unrolling-related SPEC regressions?

Paolo Carlini <> writes:

> Andreas Jaeger wrote:
>>Paolo Carlini <> writes:
>>>Perhaps we could ask Andreas to help by running an exceptional SPEC test with
>>>-funroll-loops instead (ideally, 2 different runs, pre- and post- the unroller
>>Sorry for joining in late, I've been travelling.
>>Tell me exactly which patch I should revert and which compiler flags I
>>should use and I'll bootstrap two GCCs and run one SPECint run using
>>the different compilers for base and peak.
> Thank you very much for your feedback Andreas.
> With your help we could try to understand the following: RTH patch
> affects negatively SPEC runs (*) for a PEAK setup identical to that
> which you currently use *but* with -funroll-loops (instead of
> -funroll-all-loops) or not? In the process, we could also understand
> more of the issue itself -funroll-all-loops vs. -funroll-loops.
> Therefore, if you agree, this is the patch which should be tentatively
> reverted:
> Thanks,
> Paolo.
> (*) When I say "affect negatively" I really mean the following: there
> is a good amount of evidence that due to that patch the following
> tests loose many points: 164.gzip, 186.crafty, 200.sixtrack.

I have some scripts [1] that bootstrap GCC and automatically run SPEC.
I'll try to setup some tests tomorrow and send the results,


[1]  If anybody likes to have my scripts, just ask me.

 Andreas Jaeger
  SuSE Labs

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