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Re: Koji stuck?



On 09-12-19 17:19:37, Orcan Ogetbil wrote:
 ...
> There is a -O2 flag issue that causes some builds to hang. Maybe 
> those emacs hangs are related to this bug in gcc
> It happened to 2 of my packages. Removing -O2 makes things compile in
> my packages. (No I didn't do official builds without -O2 flag)
> 
> Someone filed a bug about this a while ago but unfortunately gcc
> maintainers don't seem to care much. Anything we can do about this?
> Can we use -O1 instead? The fact is these packages will not compile 
> if there will be a mass rebuild. And this needs to be fixed at some 
> point before F-13 is out.

`man gcc` suggests that one can find out the differences between -On 
levels with:

    $ gcc -c -Q -O2 --help=optimizers > /tmp/O2-opts
    $ gcc -c -Q -O1 --help=optimizers > /tmp/O1-opts
    $ diff /tmp/O{1,2}-opts | grep enabled

(and the man page also lists differences).

Perhaps only one of the added optimizations is the problem and 
disabling that one will fix it.  A bug report about that particular 
optimization on a particular file might get better results.  I suppose 
I'd disable half of the added optimizations at a time on a problem file 
until I found the one that causes the hangs.

-- 
____________________________________________________________________
TonyN.:'                       <mailto:tonynelson georgeanelson com>
      '                              <http://www.georgeanelson.com/>


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