




 
The FLI provides several different immediate types for the representation of floating point numbers. They consist of the following: :float, :double, :lisp-double-float, 
:lisp-float,
 and :lisp-single-float. The floating types all associate equivalent Lisp and C types, except the 
:lisp-float
, which can take a modifier to cause an associations between different floating types. A 
:lisp-float
 associates a Lisp 
float
 with a C 
float
 by default, but a declaration of 
(:lisp-float :double)
 corresponds to a C 
double
, for example.
Note: be sure to use 
:language :ansi-c
 when passing float arguments to and from C using define-foreign-function and so on.