[Boost-bugs] [Boost C++ Libraries] #8994: Design complexity prevents compiler optimizations

Subject: [Boost-bugs] [Boost C++ Libraries] #8994: Design complexity prevents compiler optimizations
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2013-08-14 10:29:14

#8994: Design complexity prevents compiler optimizations
------------------------------+---------------------
 Reporter:  andysem           |      Owner:  theller
     Type:  Bugs              |     Status:  new
Milestone:  To Be Determined  |  Component:  phoenix
  Version:  Boost 1.53.0      |   Severity:  Problem
 Keywords:                    |
------------------------------+---------------------
 While debugging my application I discovered that the compiler (gcc 4.6
 with -O3) fails to optimize even the simplest Boost.Phoenix v3
 expressions. For example, the following function object:

 {{{
 phoenix::bind(&media_session::set_local_description, &session(),
 boost::cref(sdp))
 }}}

 when invoked, generates 7 (seven) nested operator()/eval calls before
 actually reaching the media_session::set_local_description method. This
 doesn't take into account any other possible overhead that I'm not seeing
 in the stack backtrace. Changing phoenix::bind to boost::bind reduces this
 backtrace to only 3 operator() calls before
 media_session::set_local_description is reached.

 Please, simplify the library to improve its efficiency. As a side note,
 the complicated design of the library also increases compile times and
 possibly resulting binary sizes (I haven't done any research on the
 latter, but I was suggested that in ticket #8820).

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/8994>
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