Re: [Boost-bugs] [Boost C++ Libraries] #3030: [crc] optimization of crc_optimal::process_block

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #3030: [crc] optimization of crc_optimal::process_block
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2011-12-16 22:18:01

#3030: [crc] optimization of crc_optimal::process_block
-------------------------------+--------------------------------------------
  Reporter:  qehgt0@…          |       Owner:  dlwalker    
      Type:  Patches           |      Status:  new         
 Milestone:  Boost 1.40.0      |   Component:  crc         
   Version:  Boost 1.39.0      |    Severity:  Optimization
Resolution:                    |    Keywords:  crc         
-------------------------------+--------------------------------------------

Comment (by Vasily Titskiy <qehgt0@…>):

 I made a (quick-and-dirty) test. Just two source files, to measure time of
 original and optimized version of crc32 calculation.

 http://pastebin.com/BQDyBmNx

 http://pastebin.com/ZUmLB9Cc


 And run this test on four platforms: linux-amd64 with gcc 4.6, linux-x86
 with gcc 4.6, armv7 with gcc 4.6, win32 with msvc 2008. On Linux "-O3"
 optimization option was used, on win32 "-O2 -EHsc -MD" options were used.

 Results:
   - linux-amd64 with gcc 4.6: same time (no difference),
   - linux-x86 with gcc 4.6: 105 ms before optimization, 93 ms after (12%
 better)
   - armv7 with gcc 4.6: 360 ms before optimization, 305 ms after (18%
 better)
   - win32 with msvc 2008: 173 ms before optimization, 87 ms after (98%
 better)

 Pretty good results for just changing few lines of code.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/3030#comment:5>
Boost C++ Libraries <http://www.boost.org/>
Boost provides free peer-reviewed portable C++ source libraries.