https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98425
Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Keywords| |ABI --- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Actually this is an abi issue. The upper 32bits of the register is undefined by the x86_64 ABI iirc. If this is true then clang has a bug.