constant-function

[John Williams <johnw%cvaxa.sussex.ac.uk@NSS.Cs.Ucl.AC.UK>]

A CONSTANT-FUNCTION declaration might save an indirection on 
function call. Also, it would enable the compiler to make use
of information about a function that it (the compiler) has 
worked out for itself. For example, in my Common Lisp, more 
efficient function calling code can be planted if the compiler
knows how many results a function will return. For many function
definitions, the compiler can deduce the number of results. But 
without some kind of CONSTANT-FUNCTION declaration, this information
can not be acted upon. 

john