Performance and transparency to the underlying system. Int would be whatever the instruction set of the platform supports by default for most of its arithmetic

Performance and transparency to the underlying system. Int would be whatever the instruction set of the platform supports by default for most of its arithmetic and memory operations. C would be sitting a layer above assembly but not try to hide what is going on behind the scene I guess. Much later on languages like java would bring the concept of virtual machines where the types are unified across different instructions set.