> Hi,
>
> using -fno-semantic-interposition has been reported by various people
> to bring about considerable speed up at the cost of strict compliance
> to the ELF symbol interposition rules See for example
> https://fedoraproject.org/wiki/Changes/PythonNoSemanticInterpositionSpeedup
>
> As such I believe it should be implied by our -Ofast optimization
> level, not only so that benchmarks that can benefit run faster, but
> also so that people looking at -Ofast documentation for options that
> could speed their programs find it.
>
> I have verified that with the following patch IPA-CP sees
> flag_semantic_interposition set to zero at Ofast and that info and pdf
> manual builds fine with the documentation change. I am bootstrapping
> and testing it now in order to comply with submission criteria but I
> don't think an Ofast change gets much tested.
>
> Assuming it passes, is the patch OK? (If it is, I will also add a note
> about it in the "Caveats" section in gcc-12/changes.html of wwwdocs
> after I commit the patch.)
>
> Thanks,
>
> Martin
>
>
> gcc/ChangeLog:
>
> 2021-11-12 Martin Jambor <mjam...@suse.cz>
>
> * opts.c (default_options_table): Switch off
> flag_semantic_interposition at Ofast.
> * doc/invoke.texi (Optimize Options): Document that Ofast switches off
> -fsemantic-interposition.
OK,
thanks!
Honza
