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Subject: Re: [boost] [offtopic] C++11 useful trick
From: Mathias Gaunard (mathias.gaunard_at_[hidden])
Date: 2012-07-03 14:29:24


On 07/03/2012 08:19 PM, Larry Evans wrote:

> Anyone know why, in this particular case, -O3 is faster than
> with no optimization?

Without optimizations

Execution times (seconds)
  phase setup : 0.01
  phase parsing : 0.10
  phase lang. deferred : 0.54
  phase cgraph : 3.50
  phase generate : 4.04
  |name lookup : 0.08
  |overload resolution : 0.30

With optimizations

Execution times (seconds)
  phase setup : 0.01
  phase parsing : 0.09
  phase lang. deferred : 0.52
  phase cgraph : 0.40
  phase generate : 0.92
  |name lookup : 0.03
  |overload resolution : 0.34

Optimizations done by the frontend resulted in much less symbols to
compute the call graph for.


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