Re: [Boost-build] B2 C++ engine development.

Subject: Re: [Boost-build] B2 C++ engine development.
From: Rene Rivera (grafikrobot_at_[hidden])
Date: 2018-10-26 13:58:40

On Fri, Oct 26, 2018 at 7:57 AM Stefan Seefeld via Boost-build <
boost-build_at_[hidden]> wrote:

> On 2018-10-25 10:46 p.m., Rene Rivera via Boost-build wrote:
>
>
> 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).
>
> That's quite impressive. I'd be curious to see a heat map showing where
> the time is spent. I was expecting most of the time being spent in running
> subprocesses (the actual commands), rather than within b2 itself. So an
> overall performance improvement of 11% based on work on b2 itself suggests
> that assumption is wrong.
>
I should have mentioned that I don't measure with build times. The
improvements are *only* the b2 parsing and make generation. What I do is
run a fake build on the Boost tree like this:

time ../../bfgroup/b2-c --build-type=complete -n -d0 --layout=versioned

I run it multiple times so it's mostly hot code already. And the config
checks are all cached.

-- 
-- Rene Rivera
-- Grafik - Don't Assume Anything
-- Robot Dreams - http://robot-dreams.net