The INT32 API provides a way to perform optimal raw 32-bit arithmetic. Note that, unlike Lisp integer types, this is modulo 2^32 like the C int type.
The INT32 symbols are all in the system package.
The Lisp type
, but the data is in int32 format for use with the INT32 API.
LispWorks User Guide and Reference Manual - 21 Dec 2011