https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96306
--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Most targets don't have 128-bit GPR instructions, either none at all, or most of them. That doesn't mean it isn't easy to support it, for the simpler operations like basic arithmetics, if there is no optab for those, the middle-end (well, expander) should DTRT and expand those already, and for more complex stuff there is always libgcc that has the double word support in there. I think the backend needs to have at least movti optab. Of course, it helps if the backend tries to help a little bit, e.g. for TImode plus/minus it is nice to have some carry into the second addition or similar. For the omp_depend_kind itself, even no arithmetic support is probably needed.
