3 Optimizing Lisp Programs

3.5 Development mode optimizations

In development mode, which is the default mode, the Compiler performs only the following optimizations on the compiled code:

It obeysspecial,notinline,arglist, andignore declarations.
It obeysinline proclamations.
It obeyssafety optimization proclamations.
It performs tail call optimization if you request it by setting thespeed optimization level to 3 or by setting the:tail-merge keyword argument to for the functionscompile,compile-file, orcompiler-options.
It usesdefsubst anddef-compiler-macro definitions.

All other optimizations described in this chapter are ignored. In particular, the Compiler does not perform the following optimizations:

It does not replace generic operations with type-specific operations. Thus, type declarations are ignored.
It does not perform constant folding on constant numerical expressions. Thus, the Compiler does not perform constant folding on the following expressions:

(+ 1 2)
(* 2.0 pi)
(aref \#(a b c) 1)
(car '(a b))

When you want to use these optimizations, you must select the production mode of the Compiler.

The Advanced User's Guide - 9 SEP 1996