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Subject: Re: [Boost-build] B2 C++ engine development.
From: Fabien Chêne (fabien.chene_at_[hidden])
Date: 2018-10-26 12:44:37


Hi,

Le ven. 26 oct. 2018 à 04:47, Rene Rivera via Boost-build
<boost-build_at_[hidden]> a écrit :
[...]
>> I think the speedup is from the stricter type rules of C++, probably constness and aliasing. But it would take way more investigation and looking at assembly to truly figure that out. And I'm not going to bother doing that :-) I don't prevent linking of the C++ runtime. But since it's not used yet I suspect it's just linked away anyway. My suspicion for size increase would be of the slightly different optimization behavior. In that it might prefer slightly larger code that performs better in many small instances.
>
>
> While adding the "--debug" option for building I added LTO to the release build. And that gives an overall 11% perf improvement (with xcode 10 clang).

Sorry for disrupting this thread with an unrelated remark, but can we
imagine a built-in feature <link-time-optimization> or the like doing
all the magic incantations for us ?

--
Fabien

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