https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100799
--- Comment #13 from Segher Boessenkool <segher at gcc dot gnu.org> --- (In reply to Alexander Grund from comment #11) > Some more experiments with GCC 10.3, OpenBLAS 0.3.15 and FlexiBLAS 3.0.4: > > Baseline: Broken at -O1, working at -Og > > I got it to break with "-Og -fmove-loop-invariants". > Then it worked again by adding "-fstack-protector-all". Both are great info! > But that is > seemingly not advisable: > https://developers.redhat.com/blog/2020/05/22/stack-clash-mitigation-in-gcc- > part-3 -fstack-protector-strong is cheap enough that you can (and perhaps should) enable it almost always. Some distributions do this even? -fstack-check= is an Ada thing. -fstack-clash-protection is a different thing as well (that's what that article is about). Enabling ssp is not a great workaround of course, it is much to roundabout; and I suspect the only reason it works is because it changes the stack layout. Still, useful info, thanks :-)
