<!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) 1991-2021 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 5.1, http://www.gnu.org/software/texinfo/ -->
|
<head>
|
<title>Using as: MIPS FP ABI Variants</title>
|
|
<meta name="description" content="Using as: MIPS FP ABI Variants">
|
<meta name="keywords" content="Using as: MIPS FP ABI Variants">
|
<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="MIPS-FP-ABIs.html#MIPS-FP-ABIs" rel="up" title="MIPS FP ABIs">
|
<link href="MIPS-FP-ABI-Selection.html#MIPS-FP-ABI-Selection" rel="next" title="MIPS FP ABI Selection">
|
<link href="MIPS-FP-ABI-History.html#MIPS-FP-ABI-History" rel="previous" title="MIPS FP ABI History">
|
<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="MIPS-FP-ABI-Variants"></a>
|
<div class="header">
|
<p>
|
Next: <a href="MIPS-FP-ABI-Selection.html#MIPS-FP-ABI-Selection" accesskey="n" rel="next">MIPS FP ABI Selection</a>, Previous: <a href="MIPS-FP-ABI-History.html#MIPS-FP-ABI-History" accesskey="p" rel="previous">MIPS FP ABI History</a>, Up: <a href="MIPS-FP-ABIs.html#MIPS-FP-ABIs" accesskey="u" rel="up">MIPS FP ABIs</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="Supported-FP-ABIs"></a>
|
<h4 class="subsubsection">9.27.9.2 Supported FP ABIs</h4>
|
<p>The supported floating-point ABI variants are:
|
</p>
|
<dl compact="compact">
|
<dt><code>0 - No floating-point</code></dt>
|
<dd><p>This variant is used to indicate that floating-point is not used within
|
the module at all and therefore has no impact on the ABI. This is the
|
default.
|
</p>
|
</dd>
|
<dt><code>1 - Double-precision</code></dt>
|
<dd><p>This variant indicates that double-precision support is used. For 64-bit
|
ABIs this means that 64-bit wide floating-point registers are required.
|
For 32-bit ABIs this means that 32-bit wide floating-point registers are
|
required and double-precision operations use pairs of registers.
|
</p>
|
</dd>
|
<dt><code>2 - Single-precision</code></dt>
|
<dd><p>This variant indicates that single-precision support is used. Double
|
precision operations will be supported via soft-float routines.
|
</p>
|
</dd>
|
<dt><code>3 - Soft-float</code></dt>
|
<dd><p>This variant indicates that although floating-point support is used all
|
operations are emulated in software. This means the ABI is modified to
|
pass all floating-point data in general-purpose registers.
|
</p>
|
</dd>
|
<dt><code>4 - Deprecated</code></dt>
|
<dd><p>This variant existed as an initial attempt at supporting 64-bit wide
|
floating-point registers for O32 ABI on a MIPS32r2 CPU. This has been
|
superseded by 5, 6 and 7.
|
</p>
|
</dd>
|
<dt><code>5 - Double-precision 32-bit CPU, 32-bit or 64-bit FPU</code></dt>
|
<dd><p>This variant is used by 32-bit ABIs to indicate that the floating-point
|
code in the module has been designed to operate correctly with either
|
32-bit wide or 64-bit wide floating-point registers. Double-precision
|
support is used. Only O32 currently supports this variant and requires
|
a minimum architecture of MIPS II.
|
</p>
|
</dd>
|
<dt><code>6 - Double-precision 32-bit FPU, 64-bit FPU</code></dt>
|
<dd><p>This variant is used by 32-bit ABIs to indicate that the floating-point
|
code in the module requires 64-bit wide floating-point registers.
|
Double-precision support is used. Only O32 currently supports this
|
variant and requires a minimum architecture of MIPS32r2.
|
</p>
|
</dd>
|
<dt><code>7 - Double-precision compat 32-bit FPU, 64-bit FPU</code></dt>
|
<dd><p>This variant is used by 32-bit ABIs to indicate that the floating-point
|
code in the module requires 64-bit wide floating-point registers.
|
Double-precision support is used. This differs from the previous ABI
|
as it restricts use of odd-numbered single-precision registers. Only
|
O32 currently supports this variant and requires a minimum architecture
|
of MIPS32r2.
|
</p></dd>
|
</dl>
|
|
<hr>
|
<div class="header">
|
<p>
|
Next: <a href="MIPS-FP-ABI-Selection.html#MIPS-FP-ABI-Selection" accesskey="n" rel="next">MIPS FP ABI Selection</a>, Previous: <a href="MIPS-FP-ABI-History.html#MIPS-FP-ABI-History" accesskey="p" rel="previous">MIPS FP ABI History</a>, Up: <a href="MIPS-FP-ABIs.html#MIPS-FP-ABIs" accesskey="u" rel="up">MIPS FP ABIs</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>
|
