You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
115 lines
5.5 KiB
HTML
115 lines
5.5 KiB
HTML
4 years ago
|
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
||
|
|
<html>
|
||
|
|
<!-- This file documents the GNU Assembler "as".
|
||
|
|
|
||
|
|
Copyright (C) 1991-2019 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 1.3
|
||
|
|
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".
|
||
|
|
-->
|
||
|
|
<!-- Created by GNU Texinfo 6.4, http://www.gnu.org/software/texinfo/ -->
|
||
|
|
<head>
|
||
|
|
<title>P2align (Using as)</title>
|
||
|
|
|
||
|
|
<meta name="description" content="P2align (Using as)">
|
||
|
|
<meta name="keywords" content="P2align (Using as)">
|
||
|
|
<meta name="resource-type" content="document">
|
||
|
|
<meta name="distribution" content="global">
|
||
|
|
<meta name="Generator" content="makeinfo">
|
||
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
|
||
|
|
<link href="index.html#Top" rel="start" title="Top">
|
||
|
|
<link href="AS-Index.html#AS-Index" rel="index" title="AS Index">
|
||
|
|
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
|
||
|
|
<link href="Pseudo-Ops.html#Pseudo-Ops" rel="up" title="Pseudo Ops">
|
||
|
|
<link href="PopSection.html#PopSection" rel="next" title="PopSection">
|
||
|
|
<link href="Org.html#Org" rel="prev" title="Org">
|
||
|
|
<style type="text/css">
|
||
|
|
<!--
|
||
|
|
a.summary-letter {text-decoration: none}
|
||
|
|
blockquote.indentedblock {margin-right: 0em}
|
||
|
|
blockquote.smallindentedblock {margin-right: 0em; font-size: smaller}
|
||
|
|
blockquote.smallquotation {font-size: smaller}
|
||
|
|
div.display {margin-left: 3.2em}
|
||
|
|
div.example {margin-left: 3.2em}
|
||
|
|
div.lisp {margin-left: 3.2em}
|
||
|
|
div.smalldisplay {margin-left: 3.2em}
|
||
|
|
div.smallexample {margin-left: 3.2em}
|
||
|
|
div.smalllisp {margin-left: 3.2em}
|
||
|
|
kbd {font-style: oblique}
|
||
|
|
pre.display {font-family: inherit}
|
||
|
|
pre.format {font-family: inherit}
|
||
|
|
pre.menu-comment {font-family: serif}
|
||
|
|
pre.menu-preformatted {font-family: serif}
|
||
|
|
pre.smalldisplay {font-family: inherit; font-size: smaller}
|
||
|
|
pre.smallexample {font-size: smaller}
|
||
|
|
pre.smallformat {font-family: inherit; font-size: smaller}
|
||
|
|
pre.smalllisp {font-size: smaller}
|
||
|
|
span.nolinebreak {white-space: nowrap}
|
||
|
|
span.roman {font-family: initial; font-weight: normal}
|
||
|
|
span.sansserif {font-family: sans-serif; font-weight: normal}
|
||
|
|
ul.no-bullet {list-style: none}
|
||
|
|
-->
|
||
|
|
</style>
|
||
|
|
|
||
|
|
|
||
|
|
</head>
|
||
|
|
|
||
|
|
<body lang="en">
|
||
|
|
<a name="P2align"></a>
|
||
|
|
<div class="header">
|
||
|
|
<p>
|
||
|
|
Next: <a href="PopSection.html#PopSection" accesskey="n" rel="next">PopSection</a>, Previous: <a href="Org.html#Org" accesskey="p" rel="prev">Org</a>, Up: <a href="Pseudo-Ops.html#Pseudo-Ops" accesskey="u" rel="up">Pseudo Ops</a> [<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>
|
||
|
|
</div>
|
||
|
|
<hr>
|
||
|
|
<a name="g_t_002ep2align_005bwl_005d-abs_002dexpr_002c-abs_002dexpr_002c-abs_002dexpr"></a>
|
||
|
|
<h3 class="section">7.69 <code>.p2align[wl] <var>abs-expr</var>, <var>abs-expr</var>, <var>abs-expr</var></code></h3>
|
||
|
|
|
||
|
|
<a name="index-padding-the-location-counter-given-a-power-of-two"></a>
|
||
|
|
<a name="index-p2align-directive"></a>
|
||
|
|
<p>Pad the location counter (in the current subsection) to a particular
|
||
|
|
storage boundary. The first expression (which must be absolute) is the
|
||
|
|
number of low-order zero bits the location counter must have after
|
||
|
|
advancement. For example ‘<samp>.p2align 3</samp>’ advances the location
|
||
|
|
counter until it a multiple of 8. If the location counter is already a
|
||
|
|
multiple of 8, no change is needed.
|
||
|
|
</p>
|
||
|
|
<p>The second expression (also absolute) gives the fill value to be stored in the
|
||
|
|
padding bytes. It (and the comma) may be omitted. If it is omitted, the
|
||
|
|
padding bytes are normally zero. However, on most systems, if the section is
|
||
|
|
marked as containing code and the fill value is omitted, the space is filled
|
||
|
|
with no-op instructions.
|
||
|
|
</p>
|
||
|
|
<p>The third expression is also absolute, and is also optional. If it is present,
|
||
|
|
it is the maximum number of bytes that should be skipped by this alignment
|
||
|
|
directive. If doing the alignment would require skipping more bytes than the
|
||
|
|
specified maximum, then the alignment is not done at all. You can omit the
|
||
|
|
fill value (the second argument) entirely by simply using two commas after the
|
||
|
|
required alignment; this can be useful if you want the alignment to be filled
|
||
|
|
with no-op instructions when appropriate.
|
||
|
|
</p>
|
||
|
|
<a name="index-p2alignw-directive"></a>
|
||
|
|
<a name="index-p2alignl-directive"></a>
|
||
|
|
<p>The <code>.p2alignw</code> and <code>.p2alignl</code> directives are variants of the
|
||
|
|
<code>.p2align</code> directive. The <code>.p2alignw</code> directive treats the fill
|
||
|
|
pattern as a two byte word value. The <code>.p2alignl</code> directives treats the
|
||
|
|
fill pattern as a four byte longword value. For example, <code>.p2alignw
|
||
|
|
2,0x368d</code> will align to a multiple of 4. If it skips two bytes, they will be
|
||
|
|
filled in with the value 0x368d (the exact placement of the bytes depends upon
|
||
|
|
the endianness of the processor). If it skips 1 or 3 bytes, the fill value is
|
||
|
|
undefined.
|
||
|
|
</p>
|
||
|
|
<hr>
|
||
|
|
<div class="header">
|
||
|
|
<p>
|
||
|
|
Next: <a href="PopSection.html#PopSection" accesskey="n" rel="next">PopSection</a>, Previous: <a href="Org.html#Org" accesskey="p" rel="prev">Org</a>, Up: <a href="Pseudo-Ops.html#Pseudo-Ops" accesskey="u" rel="up">Pseudo Ops</a> [<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>
|
||
|
|
</div>
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
</body>
|
||
|
|
</html>
|