routing socket rouding?

[Mouse <mouse%Rodents-Montreal.ORG@localhost>]

I recently had occasion to figure out the routing socket interface.

There is a macro, historically ROUNDUP defined in various .c files,
RT_ROUNDUP in <net/route.h> in 5.1 and presumably later, which appears
to be designed around the undocumented (even in comments) assumption
that sizeof(long) is a power of two.

So, I'm curious: does anyone know what this macro turned into on a
system with sizeof(long) not a power of two but with anything like the
BSD routing socket, if such a system exists?

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