On 30 October 2012 22:11, Mans Rullgard mans.rullgard@linaro.org wrote:
On 29 October 2012 16:28, "Frank Müller" franky1976@gmx.net wrote:
Mans Rullgard mans.rullgard@linaro.org wrote:
On 28 October 2012 18:08, "Frank Müller" franky1976@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-...) 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...
Could you give it a try under Ubuntu Precise and see if the compilation speed changes? If not we can look further.
-- Michael