On Tue, Apr 7, 2015 at 7:45 AM, Ilya Palachev <i.palac...@samsung.com> wrote: > Hi, > > Here are some questions about AutoFDO. > > On 08.05.2014 02:55, Dehao Chen wrote: >> >> We have open-sourced AutoFDO profile toolchain in: >> >> https://github.com/google/autofdo >> >> For GCC developers, the most important tool is create_gcov, which >> converts sampling based profile to GCC-readable profile. Please refer >> to the readme file >> (https://raw.githubusercontent.com/google/autofdo/master/README) for >> more details. > > > In the mentioned README file it is said that " In order to collect this > profile, you will need to have an Intel CPU that have last branch record > (LBR) support." Is this information obsolete? Chrome Canary builds use > AutoFDO for ARMv7l > (https://code.google.com/p/chromium/issues/detail?id=434587) > > What about Aarch64 support? Is it supported?
As mentioned by Sebastian, the current solution is to collect profile on Intel platform (with LBR support) and cross optimize arm/aarch64 target. AutoFDO support with other PMU events (cycles, retired instructions etc) still needs more tuning to match FDO performance. > >> To use the profile, one need to checkout >> https://gcc.gnu.org/svn/gcc/branches/google/gcc-4_8. We are working on >> porting AutoFDO to trunk >> (http://gcc.gnu.org/ml/gcc-patches/2014-05/msg00438.html). > > > For now AutoFDO was merged into gcc-5.0 (trunk) branch. > Is it possible to backport it to 4.9 branch? Can you estimate required > efforts for that? The google gcc49 branch has the autofdo support. David > >> >> We have limited doc inside the open-sourced package, and we are >> planning to add more content to the wiki page >> (https://github.com/google/autofdo/wiki). Feel free to send me emails >> or discuss on github if you have any questions. >> >> Cheers, >> Dehao > > > -- > Best regards, > Ilya
