On Wed, 2019-01-23 at 16:18 -0800, Khem Raj wrote: > tune files which inherit the arch definitions already define > appropriate > -mcpu option, which is equivalent of right -march and -mtune > combination > and is preferred since gcc is getting stricter and stricter with > option > check semantics and can now find incompatible -march and -mcpu > options > better with every release. It does internal feature consistency check > and if it finds out discrepency between what -mcpu would expand to as > compared to -march it will flag the options to be incompatible, for > naked eye it sounds wrong but gcc would translate -mcpu to a given > -march internally and it might not match to what we set in these arch > files. > > The effects are quite subtle, where this can result in configure test > failing to compile due to these incompatible options and a feature > option getting disabled for a recipe for no reason. > > e.g. with gcc9 which can now detect that -mcpu=cortex-a5 and > -march=armv7-a are incompatible, many features in libstdc++ ends up > disabled due to configure check failures e.g. size_t size, ptrdiff_t > sizes, which inturn results in compiling libstdc++ with unwanted > disabled features. > > If user has machine definitions which do not inherit the arm tune > files > then they can still use the -march switch as such > > Signed-off-by: Khem Raj <[email protected]> > --- > v2: Only delete -march if -mcpu is set
I suspect this might cause: https://autobuilder.yoctoproject.org/typhoon/#/builders/46/builds/212 Cheers, Richard -- _______________________________________________ Openembedded-core mailing list [email protected] http://lists.openembedded.org/mailman/listinfo/openembedded-core
