Hi Michael Hope <michael.h...@linaro.org> > On 30 October 2012 22:11, Mans Rullgard <mans.rullg...@linaro.org> wrote: > > On 29 October 2012 16:28, "Frank Müller" <franky1...@gmx.net> wrote: > >> Mans Rullgard <mans.rullg...@linaro.org> wrote: > >>> On 28 October 2012 18:08, "Frank Müller" <franky1...@gmx.net> wrote: > >>> > For easier maintenance, we are now switching to Linaro. The image is > set > >>> up and I can compile, however I notice a peculiar fact: the binary > >>> distribution of Linaro's gcc > >>> > (https://launchpad.net/linaro-toolchain-binaries/trunk/2012.10/+download/gcc-linaro-arm-linux-gnueabihf-4.7-2012.10-20121022_linux.tar.bz2) > >>> has a significantly larger compilation speed than a version of > >>> arm-linux-gnueabihf-gcc that is shipping with Ubuntu. In our > particular case, using > >>> Ubuntu's version it takes less than 6 minutes to compile our software, > but 10 > >>> minutes when we use Linaro's version. The makefiles and source are > exactly > >>> the same, only the compiler is different. I also tried an older > version > >>> (4.6) of Linaro's gcc to match the Ubuntu one (tested the 12.04 > shipped > >>> version), with no significant difference. > >>> > > >>> > Compiler flags for the system are -march=armv7-a -mtune=cortex-a8 > >>> -mfpu=neon -mfloat-abi=hard > >>> > >>> Could you please show us the full output from compiling one of your > >>> source files adding -v to the flags with both compilers? This will > >>> reveal any differences in how they were configured. > >> > >> Of course. I've also updated to the Ubuntu 12.10 > g++-arm-linux-gnueabihf_4.7.2 version so it matches a bit better. For better > readability I've > added "=====" lines between the outputs. > > > > Your Linaro compiler is a 32-bit build, the Ubuntu one 64-bit. That > > might explain at least part of the difference. > > Hi Frank. I had a quick play and built a 64 bit version of the > current release. See: > > http://people.linaro.org/~michaelh/incoming/gcc-linaro-arm-linux-gnueabihf-4.7-2012.10-20121015_linux64.tar.xz > > Could you give it a try under Ubuntu Precise and see if the > compilation speed changes? If not we can look further.
I tried your 64 bit version and got a compilation time of 11m5.699s. So the updated "benchmark" overview is now 6m24s/4.6mb gcc version 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5) 7m2s/4.0mb gcc version 4.7.2 (Ubuntu/Linaro 4.7.2-1ubuntu1) 10m51s/4.0mb gcc version 4.7.3 20121001 (prerelease) 32 bit 11m3s/4.2mb same (4.7.3/Linaro) but with -mtune=cortex-a9 11m5s/4.0mb gcc version 4.7.3 20121001 (prerelease) 64 bit Has anybody done any performance comparisons with the two compilers (Ubuntu vs Linaro)? Should I try to make an example project that exhibits this "problem"? Frank _______________________________________________ linaro-toolchain mailing list linaro-toolchain@lists.linaro.org http://lists.linaro.org/mailman/listinfo/linaro-toolchain
