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

Subject: Re: [Boost-build] B2 C++ engine development.
From: Stefan Seefeld (stefan_at_[hidden])
Date: 2018-10-26 14:06:06

On 2018-10-26 9:58 a.m., Rene Rivera wrote:
> On Fri, Oct 26, 2018 at 7:57 AM Stefan Seefeld via Boost-build 
> <boost-build_at_[hidden] <mailto: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.

Ah, OK, that puts things into perspective. :-)

Still, 11% is huge. Congrats !

Stefan

--
       ...ich hab' noch einen Koffer in Berlin...