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.
121 lines
4.8 KiB
HTML
121 lines
4.8 KiB
HTML
<!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>AArch64-Relocations (Using as)</title>
|
|
|
|
<meta name="description" content="AArch64-Relocations (Using as)">
|
|
<meta name="keywords" content="AArch64-Relocations (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="AArch64-Syntax.html#AArch64-Syntax" rel="up" title="AArch64 Syntax">
|
|
<link href="AArch64-Floating-Point.html#AArch64-Floating-Point" rel="next" title="AArch64 Floating Point">
|
|
<link href="AArch64_002dRegs.html#AArch64_002dRegs" rel="prev" title="AArch64-Regs">
|
|
<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="AArch64_002dRelocations"></a>
|
|
<div class="header">
|
|
<p>
|
|
Previous: <a href="AArch64_002dRegs.html#AArch64_002dRegs" accesskey="p" rel="prev">AArch64-Regs</a>, Up: <a href="AArch64-Syntax.html#AArch64-Syntax" accesskey="u" rel="up">AArch64 Syntax</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="Relocations"></a>
|
|
<h4 class="subsubsection">9.1.3.3 Relocations</h4>
|
|
|
|
<a name="index-relocations_002c-AArch64"></a>
|
|
<a name="index-AArch64-relocations"></a>
|
|
<a name="index-MOVN_002c-MOVZ-and-MOVK-group-relocations_002c-AArch64"></a>
|
|
<p>Relocations for ‘<samp>MOVZ</samp>’ and ‘<samp>MOVK</samp>’ instructions can be generated
|
|
by prefixing the label with ‘<samp>#:abs_g2:</samp>’ etc.
|
|
For example to load the 48-bit absolute address of <var>foo</var> into x0:
|
|
</p>
|
|
<div class="smallexample">
|
|
<pre class="smallexample"> movz x0, #:abs_g2:foo // bits 32-47, overflow check
|
|
movk x0, #:abs_g1_nc:foo // bits 16-31, no overflow check
|
|
movk x0, #:abs_g0_nc:foo // bits 0-15, no overflow check
|
|
</pre></div>
|
|
|
|
<a name="index-ADRP_002c-ADD_002c-LDR_002fSTR-group-relocations_002c-AArch64"></a>
|
|
<p>Relocations for ‘<samp>ADRP</samp>’, and ‘<samp>ADD</samp>’, ‘<samp>LDR</samp>’ or ‘<samp>STR</samp>’
|
|
instructions can be generated by prefixing the label with
|
|
‘<samp>:pg_hi21:</samp>’ and ‘<samp>#:lo12:</samp>’ respectively.
|
|
</p>
|
|
<p>For example to use 33-bit (+/-4GB) pc-relative addressing to
|
|
load the address of <var>foo</var> into x0:
|
|
</p>
|
|
<div class="smallexample">
|
|
<pre class="smallexample"> adrp x0, :pg_hi21:foo
|
|
add x0, x0, #:lo12:foo
|
|
</pre></div>
|
|
|
|
<p>Or to load the value of <var>foo</var> into x0:
|
|
</p>
|
|
<div class="smallexample">
|
|
<pre class="smallexample"> adrp x0, :pg_hi21:foo
|
|
ldr x0, [x0, #:lo12:foo]
|
|
</pre></div>
|
|
|
|
<p>Note that ‘<samp>:pg_hi21:</samp>’ is optional.
|
|
</p>
|
|
<div class="smallexample">
|
|
<pre class="smallexample"> adrp x0, foo
|
|
</pre></div>
|
|
|
|
<p>is equivalent to
|
|
</p>
|
|
<div class="smallexample">
|
|
<pre class="smallexample"> adrp x0, :pg_hi21:foo
|
|
</pre></div>
|
|
|
|
|
|
|
|
|
|
</body>
|
|
</html>
|