No reason you can't compile C down to that. It's just that there will be less of a clear performance advantage for C as some of the semantics will be slightly a

No reason you can't compile C down to that. It's just that there will be less of a clear performance advantage for C as some of the semantics will be slightly awkward to map to that instruction set. You might still get a speedup by writing C in some areas, but I think the real reason for supporting it is that you have a bunch of legacy software and drivers written in C, and it's easier to get a C compiler working on that platform than to port all that software.