optimize (original) (raw)

ANSI Common Lisp 3 Evaluation and Compilation 3.8 Dictionary Evaluation and Compilation

Syntax:

(optimize {quality | (quality value)}*)

Arguments:

quality - an optimize quality.

value - one of the integers 0, 1, 2, or 3.

Valid Context:

declaration or proclamation

Description:

Advises the compiler that each quality should be given attention according to the specified corresponding value. Each quality must be a symbol naming an optimize quality; the names and meanings of the standard optimize qualities are shown in the next figure.

Optimize qualities

There may be other, implementation-defined optimize qualities.

A value 0 means that the corresponding quality is totally unimportant, and 3 that the quality is extremely important;1 and 2 are intermediate values, with 1 the neutral value.(quality 3) can be abbreviated to quality.

Note that code which has the optimization (safety 3), or just safety, is called safe code.

The consequences are unspecified if a quality appears more than once with different values.

Examples:

(defun often-used-subroutine (x y) (declare (optimize (safety 2))) (error-check x y) (hairy-setup x) (do ((i 0 (+ i 1)) (z x (cdr z))) ((null z)) ;; This inner loop really needs to burn. (declare (optimize speed)) (declare (fixnum i)) ))

See Also:

declare,declaim,proclaim, Section 3.3.4 Declaration Scope

Notes:

An optimize declaration never applies to either a variable or a function binding. An optimize declaration can only be a free declaration. For more information, see Section 3.3.4 Declaration Scope.

Allegro CL Implementation Details:

None.