https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96306
--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Only by slowing down all 64-bit targets in OpenMP for Fortran by using the
indirection (and make it incompatible with C/C++ too, which is even worse).
I wasn't aware that gcn is BITS_PER_WORD 32 target, that makes it indeed
harder, but for an offloading target that wants to support 64-bit host targets
I'm afraid the extra work is needed, because user can use the kind=16 or
__int128_t types in their code.
It can be minimal support, e.g. just have addti3, subti3, {and,ior,xor}ti3,
shifts and a few others just as expanders that lower it immediately to DImode
code, and for other operations defer to library.
libgcc2.[ch] I think can be convinced through macros to emit code for TImode
implementation using DImode, or you have e.g. config/gcn/lib2-divmod.c that
could be adjusted into lib2-divmodti.c.
