111 lines
5.3 KiB
HTML
111 lines
5.3 KiB
HTML
<html lang="en">
|
|
<head>
|
|
<title>CR16 Operand Qualifiers - Using as</title>
|
|
<meta http-equiv="Content-Type" content="text/html">
|
|
<meta name="description" content="Using as">
|
|
<meta name="generator" content="makeinfo 4.13">
|
|
<link title="Top" rel="start" href="index.html#Top">
|
|
<link rel="up" href="CR16_002dDependent.html#CR16_002dDependent" title="CR16-Dependent">
|
|
<link rel="next" href="CR16-Syntax.html#CR16-Syntax" title="CR16 Syntax">
|
|
<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage">
|
|
<!--
|
|
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''.
|
|
|
|
-->
|
|
<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; }
|
|
span.sansserif { font-family:sans-serif; font-weight:normal; }
|
|
--></style>
|
|
</head>
|
|
<body>
|
|
<div class="node">
|
|
<a name="CR16-Operand-Qualifiers"></a>
|
|
<p>
|
|
Next: <a rel="next" accesskey="n" href="CR16-Syntax.html#CR16-Syntax">CR16 Syntax</a>,
|
|
Up: <a rel="up" accesskey="u" href="CR16_002dDependent.html#CR16_002dDependent">CR16-Dependent</a>
|
|
<hr>
|
|
</div>
|
|
|
|
<h4 class="subsection">9.8.1 CR16 Operand Qualifiers</h4>
|
|
|
|
<p><a name="index-CR16-Operand-Qualifiers-872"></a>
|
|
The National Semiconductor CR16 target of <code>as</code> has a few machine dependent operand qualifiers.
|
|
|
|
<p>Operand expression type qualifier is an optional field in the instruction operand, to determines the type of the expression field of an operand. The <code>@</code> is required. CR16 architecture uses one of the following expression qualifiers:
|
|
|
|
<dl>
|
|
<dt><code>s</code><dd>- <code>Specifies expression operand type as small</code>
|
|
<br><dt><code>m</code><dd>- <code>Specifies expression operand type as medium</code>
|
|
<br><dt><code>l</code><dd>- <code>Specifies expression operand type as large</code>
|
|
<br><dt><code>c</code><dd>- <code>Specifies the CR16 Assembler generates a relocation entry for the operand, where pc has implied bit, the expression is adjusted accordingly. The linker uses the relocation entry to update the operand address at link time.</code>
|
|
<br><dt><code>got/GOT</code><dd>- <code>Specifies the CR16 Assembler generates a relocation entry for the operand, offset from Global Offset Table. The linker uses this relocation entry to update the operand address at link time</code>
|
|
<br><dt><code>cgot/cGOT</code><dd>- <code>Specifies the CompactRISC Assembler generates a relocation entry for the operand, where pc has implied bit, the expression is adjusted accordingly. The linker uses the relocation entry to update the operand address at link time.</code>
|
|
</dl>
|
|
|
|
<p>CR16 target operand qualifiers and its size (in bits):
|
|
|
|
<dl>
|
|
<dt>‘<samp><span class="samp">Immediate Operand: s</span></samp>’<dd>4 bits.
|
|
|
|
<br><dt>‘<samp><span class="samp">Immediate Operand: m</span></samp>’<dd>16 bits, for movb and movw instructions.
|
|
|
|
<br><dt>‘<samp><span class="samp">Immediate Operand: m</span></samp>’<dd>20 bits, movd instructions.
|
|
|
|
<br><dt>‘<samp><span class="samp">Immediate Operand: l</span></samp>’<dd>32 bits.
|
|
|
|
<br><dt>‘<samp><span class="samp">Absolute Operand: s</span></samp>’<dd>Illegal specifier for this operand.
|
|
|
|
<br><dt>‘<samp><span class="samp">Absolute Operand: m</span></samp>’<dd>20 bits, movd instructions.
|
|
|
|
<br><dt>‘<samp><span class="samp">Displacement Operand: s</span></samp>’<dd>8 bits.
|
|
|
|
<br><dt>‘<samp><span class="samp">Displacement Operand: m</span></samp>’<dd>16 bits.
|
|
|
|
<br><dt>‘<samp><span class="samp">Displacement Operand: l</span></samp>’<dd>24 bits.
|
|
|
|
</dl>
|
|
|
|
<p>For example:
|
|
<pre class="example"> 1 <code>movw $_myfun@c,r1</code>
|
|
|
|
This loads the address of _myfun, shifted right by 1, into r1.
|
|
|
|
2 <code>movd $_myfun@c,(r2,r1)</code>
|
|
|
|
This loads the address of _myfun, shifted right by 1, into register-pair r2-r1.
|
|
|
|
3 <code>_myfun_ptr:</code>
|
|
<code>.long _myfun@c</code>
|
|
<code>loadd _myfun_ptr, (r1,r0)</code>
|
|
<code>jal (r1,r0)</code>
|
|
|
|
This .long directive, the address of _myfunc, shifted right by 1 at link time.
|
|
|
|
4 <code>loadd _data1@GOT(r12), (r1,r0)</code>
|
|
|
|
This loads the address of _data1, into global offset table (ie GOT) and its offset value from GOT loads into register-pair r2-r1.
|
|
|
|
5 <code>loadd _myfunc@cGOT(r12), (r1,r0)</code>
|
|
|
|
This loads the address of _myfun, shifted right by 1, into global offset table (ie GOT) and its offset value from GOT loads into register-pair r1-r0.
|
|
</pre>
|
|
</body></html>
|
|
|