[Bug c/50254] gcc-4.5 -fstrict-aliasing -fschedule-insns optimization produces wrong code

["vzapolskiy at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50254

Vladimir Zapolskiy <vzapolskiy at gmail dot com> changed:

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--- Comment #2 from Vladimir Zapolskiy <vzapolskiy at gmail dot com> 2011-09-01 09:37:00 UTC ---
Created attachment 25157
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25157
test code

(In reply to comment #1)
>         qentry->next      = (void *)qhead;
> 
> is voiolating strict aliasing rules if you ever end up loading/storing
> qentry->next->{prev,next}.

Thank you very much for the quick response.

I managed to reduce a test case and hopefully understand strict aliasing rules.