1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
2<html>
3<!-- This file documents the GNU Assembler "as".
4
5Copyright (C) 1991-2021 Free Software Foundation, Inc.
6
7Permission is granted to copy, distribute and/or modify this document
8under the terms of the GNU Free Documentation License, Version 1.3
9or any later version published by the Free Software Foundation;
10with no Invariant Sections, with no Front-Cover Texts, and with no
11Back-Cover Texts.  A copy of the license is included in the
12section entitled "GNU Free Documentation License".
13 -->
14<!-- Created by GNU Texinfo 5.1, http://www.gnu.org/software/texinfo/ -->
15<head>
16<title>Using as: Previous</title>
17
18<meta name="description" content="Using as: Previous">
19<meta name="keywords" content="Using as: Previous">
20<meta name="resource-type" content="document">
21<meta name="distribution" content="global">
22<meta name="Generator" content="makeinfo">
23<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
24<link href="index.html#Top" rel="start" title="Top">
25<link href="AS-Index.html#AS-Index" rel="index" title="AS Index">
26<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
27<link href="Pseudo-Ops.html#Pseudo-Ops" rel="up" title="Pseudo Ops">
28<link href="Print.html#Print" rel="next" title="Print">
29<link href="PopSection.html#PopSection" rel="previous" title="PopSection">
30<style type="text/css">
31<!--
32a.summary-letter {text-decoration: none}
33blockquote.smallquotation {font-size: smaller}
34div.display {margin-left: 3.2em}
35div.example {margin-left: 3.2em}
36div.indentedblock {margin-left: 3.2em}
37div.lisp {margin-left: 3.2em}
38div.smalldisplay {margin-left: 3.2em}
39div.smallexample {margin-left: 3.2em}
40div.smallindentedblock {margin-left: 3.2em; font-size: smaller}
41div.smalllisp {margin-left: 3.2em}
42kbd {font-style:oblique}
43pre.display {font-family: inherit}
44pre.format {font-family: inherit}
45pre.menu-comment {font-family: serif}
46pre.menu-preformatted {font-family: serif}
47pre.smalldisplay {font-family: inherit; font-size: smaller}
48pre.smallexample {font-size: smaller}
49pre.smallformat {font-family: inherit; font-size: smaller}
50pre.smalllisp {font-size: smaller}
51span.nocodebreak {white-space:nowrap}
52span.nolinebreak {white-space:nowrap}
53span.roman {font-family:serif; font-weight:normal}
54span.sansserif {font-family:sans-serif; font-weight:normal}
55ul.no-bullet {list-style: none}
56-->
57</style>
58
59
60</head>
61
62<body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000">
63<a name="Previous"></a>
64<div class="header">
65<p>
66Next: <a href="Print.html#Print" accesskey="n" rel="next">Print</a>, Previous: <a href="PopSection.html#PopSection" accesskey="p" rel="previous">PopSection</a>, Up: <a href="Pseudo-Ops.html#Pseudo-Ops" accesskey="u" rel="up">Pseudo Ops</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="AS-Index.html#AS-Index" title="Index" rel="index">Index</a>]</p>
67</div>
68<hr>
69<a name="g_t_002eprevious"></a>
70<h3 class="section">7.73 <code>.previous</code></h3>
71
72<a name="index-previous-directive"></a>
73<a name="index-Section-Stack-1"></a>
74<p>This is one of the ELF section stack manipulation directives.  The others are
75<code>.section</code> (see <a href="Section.html#Section">Section</a>), <code>.subsection</code> (see <a href="SubSection.html#SubSection">SubSection</a>),
76<code>.pushsection</code> (see <a href="PushSection.html#PushSection">PushSection</a>), and <code>.popsection</code>
77(see <a href="PopSection.html#PopSection">PopSection</a>).
78</p>
79<p>This directive swaps the current section (and subsection) with most recently
80referenced section/subsection pair prior to this one.  Multiple
81<code>.previous</code> directives in a row will flip between two sections (and their
82subsections).  For example:
83</p>
84<div class="smallexample">
85<pre class="smallexample">.section A
86 .subsection 1
87  .word 0x1234
88 .subsection 2
89  .word 0x5678
90.previous
91 .word 0x9abc
92</pre></div>
93
94<p>Will place 0x1234 and 0x9abc into subsection 1 and 0x5678 into subsection 2 of
95section A.  Whilst:
96</p>
97<div class="smallexample">
98<pre class="smallexample">.section A
99.subsection 1
100  # Now in section A subsection 1
101  .word 0x1234
102.section B
103.subsection 0
104  # Now in section B subsection 0
105  .word 0x5678
106.subsection 1
107  # Now in section B subsection 1
108  .word 0x9abc
109.previous
110  # Now in section B subsection 0
111  .word 0xdef0
112</pre></div>
113
114<p>Will place 0x1234 into section A, 0x5678 and 0xdef0 into subsection 0 of
115section B and 0x9abc into subsection 1 of section B.
116</p>
117<p>In terms of the section stack, this directive swaps the current section with
118the top section on the section stack.
119</p>
120
121
122
123</body>
124</html>
125