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Re: changing "configure" to default to "gcc -g -O2 -fwrapv ..."


"Daniel Berlin" <dberlin@dberlin.org> writes:

>> http://www.suse.de/~gcctest/SPEC/CFP/sb-vangelis-head-64/recent.html
>> and
>> http://www.suse.de/~gcctest/SPEC/CINT/sb-vangelis-head-64/recent.html
>>
> Note the distinct drop in performance across almost all the benchmarks
> on Dec 30, including popular programs like bzip2 and gzip.

That benchmark isn't that relevant, as it's using -O3, as is typical
for SPEC benchmarks.

This discussion is talking about -O2, not -O3.  The proposed change
(i.e., having -O2 imply -fwrapv) would not affect -O3 benchmark
scores.


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