visus
/
toolchain-gcc-arm-embedded


			
							<!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) 1991-2020 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 6.5, http://www.gnu.org/software/texinfo/ -->
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>CRIS-Expand (Using as)</title>

<meta name="description" content="CRIS-Expand (Using as)">
<meta name="keywords" content="CRIS-Expand (Using as)">
<meta name="resource-type" content="document">
<meta name="distribution" content="global">
<meta name="Generator" content="makeinfo">
<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="CRIS_002dDependent.html#CRIS_002dDependent" rel="up" title="CRIS-Dependent">
<link href="CRIS_002dSymbols.html#CRIS_002dSymbols" rel="next" title="CRIS-Symbols">
<link href="CRIS_002dOpts.html#CRIS_002dOpts" rel="prev" title="CRIS-Opts">
<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="CRIS_002dExpand"></a>
<div class="header">
<p>
Next: <a href="CRIS_002dSymbols.html#CRIS_002dSymbols" accesskey="n" rel="next">CRIS-Symbols</a>, Previous: <a href="CRIS_002dOpts.html#CRIS_002dOpts" accesskey="p" rel="prev">CRIS-Opts</a>, Up: <a href="CRIS_002dDependent.html#CRIS_002dDependent" accesskey="u" rel="up">CRIS-Dependent</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>
</div>
<hr>
<a name="Instruction-expansion"></a>
<h4 class="subsection">9.9.2 Instruction expansion</h4>

<a name="index-instruction-expansion_002c-CRIS"></a>
<a name="index-CRIS-instruction-expansion"></a>
<p><code>as</code> will silently choose an instruction that fits
the operand size for &lsquo;<samp>[register+constant]</samp>&rsquo; operands.  For
example, the offset <code>127</code> in <code>move.d [r3+127],r4</code> fits
in an instruction using a signed-byte offset.  Similarly,
<code>move.d [r2+32767],r1</code> will generate an instruction using a
16-bit offset.  For symbolic expressions and constants that do
not fit in 16 bits including the sign bit, a 32-bit offset is
generated.
</p>
<p>For branches, <code>as</code> will expand from a 16-bit branch
instruction into a sequence of instructions that can reach a
full 32-bit address.  Since this does not correspond to a single
instruction, such expansions can optionally be warned about.
See <a href="CRIS_002dOpts.html#CRIS_002dOpts">CRIS-Opts</a>.
</p>
<p>If the operand is found to fit the range, a <code>lapc</code> mnemonic
will translate to a <code>lapcq</code> instruction.  Use <code>lapc.d</code>
to force the 32-bit <code>lapc</code> instruction.
</p>
<p>Similarly, the <code>addo</code> mnemonic will translate to the
shortest fitting instruction of <code>addoq</code>, <code>addo.w</code> and
<code>addo.d</code>, when used with a operand that is a constant known
at assembly time.
</p>


</body>
</html>