There is no way to express that in C, but the x86 DIV instruction will
do exactly that. It sounds like adding some inline assembly functions
(which needs to go into include/asm-* and need equivalents for all
architectures) probably is in order.
Furthermore, it might be worthwhile to provide the equivalent of
libgcc in the kernel.
-hpa
-- Not speaking for Transmeta in any way, shape or form.