<html lang="en"> <head> <title>Equiv - Using as</title> <meta http-equiv="Content-Type" content="text/html"> <meta name="description" content="Using as"> <meta name="generator" content="makeinfo 4.7"> <link title="Top" rel="start" href="index.html#Top"> <link rel="up" href="Pseudo-Ops.html#Pseudo-Ops" title="Pseudo Ops"> <link rel="prev" href="Equ.html#Equ" title="Equ"> <link rel="next" href="Eqv.html#Eqv" title="Eqv"> <link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> <!-- This file documents the GNU Assembler "as". Copyright (C) 1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000, 2001, 2002, 2006, 2007 Free Software Foundation, Inc. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the license is included in the section entitled ``GNU Free Documentation License''. man end--> <meta http-equiv="Content-Style-Type" content="text/css"> <style type="text/css"><!-- pre.display { font-family:inherit } pre.format { font-family:inherit } pre.smalldisplay { font-family:inherit; font-size:smaller } pre.smallformat { font-family:inherit; font-size:smaller } pre.smallexample { font-size:smaller } pre.smalllisp { font-size:smaller } span.sc { font-variant:small-caps } span.roman { font-family: serif; font-weight: normal; } --></style> </head> <body> <div class="node"> <p> <a name="Equiv"></a>Next: <a rel="next" accesskey="n" href="Eqv.html#Eqv">Eqv</a>, Previous: <a rel="previous" accesskey="p" href="Equ.html#Equ">Equ</a>, Up: <a rel="up" accesskey="u" href="Pseudo-Ops.html#Pseudo-Ops">Pseudo Ops</a> <hr><br> </div> <h3 class="section">7.45 <code>.equiv </code><var>symbol</var><code>, </code><var>expression</var></h3> <p><a name="index-_0040code_007bequiv_007d-directive-320"></a>The <code>.equiv</code> directive is like <code>.equ</code> and <code>.set</code>, except that the assembler will signal an error if <var>symbol</var> is already defined. Note a symbol which has been referenced but not actually defined is considered to be undefined. <p>Except for the contents of the error message, this is roughly equivalent to <pre class="smallexample"> .ifdef SYM .err .endif .equ SYM,VAL </pre> <p>plus it protects the symbol from later redefinition. </body></html>