ALLOCATE-FIXNUM-RANGE.html -- ACL2 Version 6.3

### ALLOCATE-FIXNUM-RANGE

set aside fixnums in GCL

    Major Section:  ACL2-BUILT-INS

`(Allocate-fixnum-range fixnum-lo fixnum-hi)` causes Gnu Common Lisp (GCL) to create a persistent table for the integers between `fixnum-lo` and `fixnum-hi` (both bounds inclusive). This table is referenced first when any integer is boxed and the existing box in the table is used if the integer is in bounds. This can speed up GCL considerably by avoiding wasteful fixnum boxing. Here, `fixnum-lo` and `fixnum-hi` should be fixnums. On 32-bit machines it would be good for them to be of type `(signed-byte 30)`, with `fixnum-lo <= fixnum-hi`.

When this function is executed in a Lisp implementation other than GCL, it has no side effect. This function always returns `nil`.