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.
102 lines
4.4 KiB
HTML
102 lines
4.4 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>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">
|
||
|
|
<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="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> [<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">9.8.2 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 ‘<samp>[register+constant]</samp>’ 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>
|