Re: [boost] Measuring compile time performance

Subject: Re: [boost] Measuring compile time performance
From: David Abrahams (dave_at_[hidden])
Date: 2008-10-17 18:46:47

on Fri Oct 17 2008, dan marsden <danmarsden-AT-yahoo.co.uk> wrote:

> Steven Watanabe wrote:
>>Joel de Guzman wrote:
>>> time is good enough for benchmarking. OTOH, Steven's perl sript
>>> is nice because it can (as he says) actually gather info when
>>> templates are being instantiated. I haven't used it yet, but it
>>> seems to be just the tool we need for profiling templates.
>>> Steven, please tell us more about your script.
>>
>>The scripts are actually a combination of bjam + perl + C++.
>>
>>At the moment, the only thing that it does reliably is to
>>count the number of times each template is instantiated.
>>
>>A month or two ago, I tried to make it produce a gprof-like
>>call graph by parsing the instantiation backtraces, but it
>>doesn't really work, and I broke gcc support in the process.
>>Hmmm, I'll try to fix this over fall break.
>
> Thanks Steven, that would be great. We'd certainly be interested
> in trying what you've got on Fusions compile time performance
> tests.
>
> Thanks to everyone else that provided ideas on this.

Remember that although the number of template instantiations is
important, it doesn't necessarily have a linear relationship to compile
times.  I think measuring time is still important, and probably more
important.

-- 
Dave Abrahams
BoostPro Computing
http://www.boostpro.com