Re: Re: ROOT 5.22 with gcc 4.4 (.1)

From: Fons Rademakers <Fons.Rademakers_at_cern.ch>
Date: Mon, 17 Aug 2009 18:52:05 +0200

My gripe is that the behavior of the compiler should not change between -O and -O2. With -O they obviously can generate these inline instantiations, but at -O2 not anymore. Not good.

• Fons

Christophe Saout wrote:
> Hi,
>

>>    this R__EXPLICIT_FUNCTION_INSTANTIATION is needed to work around a bug 
>> in the -O2 mode of gcc 4.4.0. The bug was reported to the developers, but 
>> obviously not yet fixed in the 4.4.1 release. I'll update to Module.mk to 
>> also include the 4.4.1 release. Not that e.g. with -O there is no problem.

>
> I believe this is not a bug, but valid behaviour.
>
> Andrew Pinski seems to think so as well.
>
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40056
>
> I would not call this a regression. New gcc optimisations just lead gcc
> to another decision in that particular case, I am sure that you could
> also trick gcc to perform a similar decision in older versions.
>
> Christophe
>
>

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Received on Mon Aug 17 2009 - 18:52:08 CEST