| <!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: Sparc-Size-Translations</title> |
| |
| <meta name="description" content="Using as: Sparc-Size-Translations"> |
| <meta name="keywords" content="Using as: Sparc-Size-Translations"> |
| <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="Sparc_002dSyntax.html#Sparc_002dSyntax" rel="up" title="Sparc-Syntax"> |
| <link href="Sparc_002dFloat.html#Sparc_002dFloat" rel="next" title="Sparc-Float"> |
| <link href="Sparc_002dRelocs.html#Sparc_002dRelocs" rel="prev" title="Sparc-Relocs"> |
| <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="Sparc_002dSize_002dTranslations"></a> |
| <div class="header"> |
| <p> |
| Previous: <a href="Sparc_002dRelocs.html#Sparc_002dRelocs" accesskey="p" rel="prev">Sparc-Relocs</a>, Up: <a href="Sparc_002dSyntax.html#Sparc_002dSyntax" accesskey="u" rel="up">Sparc-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="Size-Translations"></a> |
| <h4 class="subsubsection">9.42.3.5 Size Translations</h4> |
| <a name="index-Sparc-size-translations"></a> |
| <a name="index-size_002c-translations_002c-Sparc"></a> |
| |
| <p>Often it is desirable to write code in an operand size agnostic |
| manner. <code>as</code> provides support for this via |
| operand size opcode translations. Translations are supported |
| for loads, stores, shifts, compare-and-swap atomics, and the |
| ‘<samp>clr</samp>’ synthetic instruction. |
| </p> |
| <p>If generating 32-bit code, <code>as</code> will generate the |
| 32-bit opcode. Whereas if 64-bit code is being generated, |
| the 64-bit opcode will be emitted. For example <code>ldn</code> |
| will be transformed into <code>ld</code> for 32-bit code and |
| <code>ldx</code> for 64-bit code. |
| </p> |
| <p>Here is an example meant to demonstrate all the supported |
| opcode translations: |
| </p> |
| <div class="example"> |
| <pre class="example">ldn [%o0], %o1 |
| ldna [%o0] %asi, %o2 |
| stn %o1, [%o0] |
| stna %o2, [%o0] %asi |
| slln %o3, 3, %o3 |
| srln %o4, 8, %o4 |
| sran %o5, 12, %o5 |
| casn [%o0], %o1, %o2 |
| casna [%o0] %asi, %o1, %o2 |
| clrn %g1 |
| </pre></div> |
| |
| <p>In 32-bit mode <code>as</code> will emit: |
| </p> |
| <div class="example"> |
| <pre class="example">ld [%o0], %o1 |
| lda [%o0] %asi, %o2 |
| st %o1, [%o0] |
| sta %o2, [%o0] %asi |
| sll %o3, 3, %o3 |
| srl %o4, 8, %o4 |
| sra %o5, 12, %o5 |
| cas [%o0], %o1, %o2 |
| casa [%o0] %asi, %o1, %o2 |
| clr %g1 |
| </pre></div> |
| |
| <p>And in 64-bit mode <code>as</code> will emit: |
| </p> |
| <div class="example"> |
| <pre class="example">ldx [%o0], %o1 |
| ldxa [%o0] %asi, %o2 |
| stx %o1, [%o0] |
| stxa %o2, [%o0] %asi |
| sllx %o3, 3, %o3 |
| srlx %o4, 8, %o4 |
| srax %o5, 12, %o5 |
| casx [%o0], %o1, %o2 |
| casxa [%o0] %asi, %o1, %o2 |
| clrx %g1 |
| </pre></div> |
| |
| <p>Finally, the ‘<samp>.nword</samp>’ translating directive is supported |
| as well. It is documented in the section on Sparc machine |
| directives. |
| </p> |
| |
| |
| |
| </body> |
| </html> |