> -----Original Message----- > From: Etienne Sandré-Chardonnal [mailto:[email protected]] > Sent: Wednesday, March 27, 2013 3:12 PM > To: [email protected] > Subject: [Mingw-w64-public] Performance changes when switching to 4.8.0 > > Dear all, > > Until a few days ago, I was using: > - Old mingw32 shipped with Qt (gcc 4.4.0) for 32bit builds > - Mingw-w64 x86_64 rubenvb build (gcc 4.7.1) > > My code (an intensive calculation) was running at similar speed with 32-bit > and 64-bit build (speed index : 510-520, only a few % difference between > both) > > I just switched to 4.8.0 rubenvb builds for both 32bit and 64bit builds
> Here are the results: > - 32bits : speed index around 420 (strong decrease) > - 64bits : speed index around 630 (Wow! That's a good surprise!) > > Besides the fact that 4.8.0 has fantastic performances in 64bit (now it beats > MSVC fingers in the nose), do you have an idea why the 32bit build is > significantly slower? Are you using sjlj or dw2 as exception handling for 32 bit? It's a known issue that the sjlj exception handling model has much worse performance, see also https://bugreports.qt-project.org/browse/QTBUG-29653 . Give gcc-4.8-dw2-release/ a try. Regards Kai ------------------------------------------------------------------------------ Own the Future-Intel® Level Up Game Demo Contest 2013 Rise to greatness in Intel's independent game demo contest. Compete for recognition, cash, and the chance to get your game on Steam. $5K grand prize plus 10 genre and skill prizes. Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d _______________________________________________ Mingw-w64-public mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/mingw-w64-public
