https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88662
--- Comment #19 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to Vincent Lefèvre from comment #17) > (In reply to Joseph S. Myers from comment #16) > > It's for the psABI to document the valid representations of bool on a given > > platform. > > But GCC does not honor the psABI for the AMD64 (x86-64) architecture. Or > should this be regarded as a bug? Plus I have been fixing up issues recently related to bools inside unions at optimization levels so I am curious if you have more testcases?