On Tue, May 2, 2023 at 5:38 PM Kito Cheng via Gcc-patches <gcc-patches@gcc.gnu.org> wrote: > > > >>> Pushed to trunk, thanks for catching that, that's definitely should > > >>> use log2 no matter C++03 or C++11, > > >>> but I think GCC allows the usage of C++11 according to > > >>> https://gcc.gnu.org/install/prerequisites.html :P > > >> Yes, we should be able to use C++11. I'd like to get that to C++17 at > > >> some point, but I think the biggest problem is the desire to support > > >> bootstrapping on something like centos7/rhel7. > > > > > > At least we have auto and range based for loop, I am satisfied with > > > that enough. > > > > Indeed, gcc 4.9 already support C++11 but for some reason std::log2 fail > > with > > it. Probably because gcc 4.9 is the last gcc release with C++03 used by > > default. > > I wasn't able to reproduce the build issue (without my patch) with gcc 10 > > or 11. > > Anyway I think your fix is reasonable since we include math.h not cmath.h > here, > so use without std:: is rightway, but don't know why it is build-able > with newer GCC, > I guess that might be included by some other header indirectly.
No libstdc++ was specifically fixed in GCC 6 to do the correct thing, see PR 60401 and PR 14608 (r6-6392-g96e19adabc80146648825). Thanks, Andrew Pinski > > > I'm fine with new prerequisites for the next gcc release, I checked the > > release > > note about that. I noticed that all toolchains I've built with gcc 13.1 for > > other cpu target where successful with the same setup (docker image). > > > > Thanks! > > > > Best regards, > > Romain > > > > > > > > > > >> > > >> jeff > >
