On Fri, 30 Jul 2021, 15:37 Marc Glisse, <marc.glisse@xxxxxxxx> wrote: > On Fri, 30 Jul 2021, Mahmood Naderan via Gcc-help wrote: > > > I have noticed that my program with -O1 receives segmentation fault > > while if I manually specify all 45 O1 switches described in [1], the > > programs runs without problem. The gcc version is 9.3.0. I wonder if -O1 > > do something more than those switches. > > > https://gcc.gnu.org/wiki/FAQ#Is_-O1_.28-O2.2C-O3.2C_-Os_or_-Og.29_equivalent_to_individual_-foptimization_options.3F That's why what you tried doesn't work. Instead of trying to disable all the optimization passes, have you tried building your program with -fsanitize=undefined instead? >
