| <!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) 1991-2015 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 5.2, http://www.gnu.org/software/texinfo/ --> |
| <head> |
| <title>Using as: ARM Opcodes</title> |
| |
| <meta name="description" content="Using as: ARM Opcodes"> |
| <meta name="keywords" content="Using as: ARM Opcodes"> |
| <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="ARM_002dDependent.html#ARM_002dDependent" rel="up" title="ARM-Dependent"> |
| <link href="ARM-Mapping-Symbols.html#ARM-Mapping-Symbols" rel="next" title="ARM Mapping Symbols"> |
| <link href="ARM-Directives.html#ARM-Directives" rel="prev" title="ARM Directives"> |
| <style type="text/css"> |
| <!-- |
| a.summary-letter {text-decoration: none} |
| blockquote.smallquotation {font-size: smaller} |
| div.display {margin-left: 3.2em} |
| div.example {margin-left: 3.2em} |
| div.indentedblock {margin-left: 3.2em} |
| div.lisp {margin-left: 3.2em} |
| div.smalldisplay {margin-left: 3.2em} |
| div.smallexample {margin-left: 3.2em} |
| div.smallindentedblock {margin-left: 3.2em; font-size: smaller} |
| 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.nocodebreak {white-space:nowrap} |
| span.nolinebreak {white-space:nowrap} |
| span.roman {font-family:serif; font-weight:normal} |
| span.sansserif {font-family:sans-serif; font-weight:normal} |
| ul.no-bullet {list-style: none} |
| --> |
| </style> |
| |
| |
| </head> |
| |
| <body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000"> |
| <a name="ARM-Opcodes"></a> |
| <div class="header"> |
| <p> |
| Next: <a href="ARM-Mapping-Symbols.html#ARM-Mapping-Symbols" accesskey="n" rel="next">ARM Mapping Symbols</a>, Previous: <a href="ARM-Directives.html#ARM-Directives" accesskey="p" rel="prev">ARM Directives</a>, Up: <a href="ARM_002dDependent.html#ARM_002dDependent" accesskey="u" rel="up">ARM-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="Opcodes-3"></a> |
| <h4 class="subsection">9.4.5 Opcodes</h4> |
| |
| <a name="index-ARM-opcodes"></a> |
| <a name="index-opcodes-for-ARM"></a> |
| <p><code>as</code> implements all the standard ARM opcodes. It also |
| implements several pseudo opcodes, including several synthetic load |
| instructions. |
| </p> |
| <dl compact="compact"> |
| <dd> |
| <a name="index-NOP-pseudo-op_002c-ARM"></a> |
| </dd> |
| <dt><code>NOP</code></dt> |
| <dd><div class="smallexample"> |
| <pre class="smallexample"> nop |
| </pre></div> |
| |
| <p>This pseudo op will always evaluate to a legal ARM instruction that does |
| nothing. Currently it will evaluate to MOV r0, r0. |
| </p> |
| <a name="index-LDR-reg_002c_003d_003clabel_003e-pseudo-op_002c-ARM"></a> |
| </dd> |
| <dt><code>LDR</code></dt> |
| <dd><div class="smallexample"> |
| <pre class="smallexample"> ldr <register> , = <expression> |
| </pre></div> |
| |
| <p>If expression evaluates to a numeric constant then a MOV or MVN |
| instruction will be used in place of the LDR instruction, if the |
| constant can be generated by either of these instructions. Otherwise |
| the constant will be placed into the nearest literal pool (if it not |
| already there) and a PC relative LDR instruction will be generated. |
| </p> |
| <a name="index-ADR-reg_002c_003clabel_003e-pseudo-op_002c-ARM"></a> |
| </dd> |
| <dt><code>ADR</code></dt> |
| <dd><div class="smallexample"> |
| <pre class="smallexample"> adr <register> <label> |
| </pre></div> |
| |
| <p>This instruction will load the address of <var>label</var> into the indicated |
| register. The instruction will evaluate to a PC relative ADD or SUB |
| instruction depending upon where the label is located. If the label is |
| out of range, or if it is not defined in the same file (and section) as |
| the ADR instruction, then an error will be generated. This instruction |
| will not make use of the literal pool. |
| </p> |
| <a name="index-ADRL-reg_002c_003clabel_003e-pseudo-op_002c-ARM"></a> |
| </dd> |
| <dt><code>ADRL</code></dt> |
| <dd><div class="smallexample"> |
| <pre class="smallexample"> adrl <register> <label> |
| </pre></div> |
| |
| <p>This instruction will load the address of <var>label</var> into the indicated |
| register. The instruction will evaluate to one or two PC relative ADD |
| or SUB instructions depending upon where the label is located. If a |
| second instruction is not needed a NOP instruction will be generated in |
| its place, so that this instruction is always 8 bytes long. |
| </p> |
| <p>If the label is out of range, or if it is not defined in the same file |
| (and section) as the ADRL instruction, then an error will be generated. |
| This instruction will not make use of the literal pool. |
| </p> |
| </dd> |
| </dl> |
| |
| <p>For information on the ARM or Thumb instruction sets, see <cite>ARM |
| Software Development Toolkit Reference Manual</cite>, Advanced RISC Machines |
| Ltd. |
| </p> |
| <hr> |
| <div class="header"> |
| <p> |
| Next: <a href="ARM-Mapping-Symbols.html#ARM-Mapping-Symbols" accesskey="n" rel="next">ARM Mapping Symbols</a>, Previous: <a href="ARM-Directives.html#ARM-Directives" accesskey="p" rel="prev">ARM Directives</a>, Up: <a href="ARM_002dDependent.html#ARM_002dDependent" accesskey="u" rel="up">ARM-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> |
| |
| |
| |
| </body> |
| </html> |