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Re: g++ spent lots of user time

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wij@totalbb.net.tw writes:
> On Wednesday, March 1, 2017 at 10:50:14 PM UTC+8, Lew Pitcher wrote:

[...]

>> > -----------------
>> > $g++ --version
>> > g++ (GCC) 6.3.1 20161221 (Red Hat 6.3.1-1)
>> > ...
>> > 
>> > $time g++ -c -Wall -pthread -fPIC dsmain.cpp
>> > 
>> > real	6m10.623s
>> > user	6m8.142s
>> > sys	0m0.099s
>> 
>> > Why did the compilation took so long in user time?

[...]

>> Your compilation tool a long time because the compiler was doing lots of 
>> complicated things that didn't require any system calls.

[...]

> Currently, almost every object files in the Makefile takes nearly 10 more
> minutes to compile. So I think it should be mostly the 'feature' of newer g++

This strongly suggests that you're keeping the compiler busy with doing
and re-doing loads of avoidable things. Considering that this is C++,
that's almost certainly template-related.

It should be possible to detemine the exact cause using #if 0
... #endif to neutralize all of the code in this file and than
re-activate it bit by bit until the problematic part has been found.

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g++ spent lots of user time wij@totalbb.net.tw - 2017-03-01 06:05 -0800
  Re: g++ spent lots of user time Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2017-03-01 09:50 -0500
    Re: g++ spent lots of user time wij@totalbb.net.tw - 2017-03-01 17:12 -0800
      Re: g++ spent lots of user time Rainer Weikusat <rweikusat@talktalk.net> - 2017-03-02 15:33 +0000
  Re: g++ spent lots of user time Johann Klammer <klammerj@NOSPAM.a1.net> - 2017-03-01 17:18 +0100
    Re: g++ spent lots of user time wij@totalbb.net.tw - 2017-03-01 17:29 -0800

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