638 lines
25 KiB
HTML
638 lines
25 KiB
HTML
|
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
||
|
|
<html>
|
||
|
|
<!-- Copyright (C) 1988-2016 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 the
|
||
|
|
Invariant Sections being "Funding Free Software", the Front-Cover
|
||
|
|
Texts being (a) (see below), and with the Back-Cover Texts being (b)
|
||
|
|
(see below). A copy of the license is included in the section entitled
|
||
|
|
"GNU Free Documentation License".
|
||
|
|
|
||
|
|
(a) The FSF's Front-Cover Text is:
|
||
|
|
|
||
|
|
A GNU Manual
|
||
|
|
|
||
|
|
(b) The FSF's Back-Cover Text is:
|
||
|
|
|
||
|
|
You have freedom to copy and modify this GNU Manual, like GNU
|
||
|
|
software. Copies published by the Free Software Foundation raise
|
||
|
|
funds for GNU development. -->
|
||
|
|
<!-- Created by GNU Texinfo 5.2, http://www.gnu.org/software/texinfo/ -->
|
||
|
|
<head>
|
||
|
|
<title>GNU Compiler Collection (GCC) Internals: Machine Modes</title>
|
||
|
|
|
||
|
|
<meta name="description" content="GNU Compiler Collection (GCC) Internals: Machine Modes">
|
||
|
|
<meta name="keywords" content="GNU Compiler Collection (GCC) Internals: Machine Modes">
|
||
|
|
<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="Option-Index.html#Option-Index" rel="index" title="Option Index">
|
||
|
|
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
|
||
|
|
<link href="RTL.html#RTL" rel="up" title="RTL">
|
||
|
|
<link href="Constants.html#Constants" rel="next" title="Constants">
|
||
|
|
<link href="Flags.html#Flags" rel="prev" title="Flags">
|
||
|
|
<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="Machine-Modes"></a>
|
||
|
|
<div class="header">
|
||
|
|
<p>
|
||
|
|
Next: <a href="Constants.html#Constants" accesskey="n" rel="next">Constants</a>, Previous: <a href="Flags.html#Flags" accesskey="p" rel="prev">Flags</a>, Up: <a href="RTL.html#RTL" accesskey="u" rel="up">RTL</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p>
|
||
|
|
</div>
|
||
|
|
<hr>
|
||
|
|
<a name="Machine-Modes-1"></a>
|
||
|
|
<h3 class="section">13.6 Machine Modes</h3>
|
||
|
|
<a name="index-machine-modes"></a>
|
||
|
|
|
||
|
|
<a name="index-machine_005fmode"></a>
|
||
|
|
<p>A machine mode describes a size of data object and the representation used
|
||
|
|
for it. In the C code, machine modes are represented by an enumeration
|
||
|
|
type, <code>machine_mode</code>, defined in <samp>machmode.def</samp>. Each RTL
|
||
|
|
expression has room for a machine mode and so do certain kinds of tree
|
||
|
|
expressions (declarations and types, to be precise).
|
||
|
|
</p>
|
||
|
|
<p>In debugging dumps and machine descriptions, the machine mode of an RTL
|
||
|
|
expression is written after the expression code with a colon to separate
|
||
|
|
them. The letters ‘<samp>mode</samp>’ which appear at the end of each machine mode
|
||
|
|
name are omitted. For example, <code>(reg:SI 38)</code> is a <code>reg</code>
|
||
|
|
expression with machine mode <code>SImode</code>. If the mode is
|
||
|
|
<code>VOIDmode</code>, it is not written at all.
|
||
|
|
</p>
|
||
|
|
<p>Here is a table of machine modes. The term “byte” below refers to an
|
||
|
|
object of <code>BITS_PER_UNIT</code> bits (see <a href="Storage-Layout.html#Storage-Layout">Storage Layout</a>).
|
||
|
|
</p>
|
||
|
|
<dl compact="compact">
|
||
|
|
<dd><a name="index-BImode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>BImode</code></dt>
|
||
|
|
<dd><p>“Bit” mode represents a single bit, for predicate registers.
|
||
|
|
</p>
|
||
|
|
<a name="index-QImode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>QImode</code></dt>
|
||
|
|
<dd><p>“Quarter-Integer” mode represents a single byte treated as an integer.
|
||
|
|
</p>
|
||
|
|
<a name="index-HImode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>HImode</code></dt>
|
||
|
|
<dd><p>“Half-Integer” mode represents a two-byte integer.
|
||
|
|
</p>
|
||
|
|
<a name="index-PSImode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>PSImode</code></dt>
|
||
|
|
<dd><p>“Partial Single Integer” mode represents an integer which occupies
|
||
|
|
four bytes but which doesn’t really use all four. On some machines,
|
||
|
|
this is the right mode to use for pointers.
|
||
|
|
</p>
|
||
|
|
<a name="index-SImode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>SImode</code></dt>
|
||
|
|
<dd><p>“Single Integer” mode represents a four-byte integer.
|
||
|
|
</p>
|
||
|
|
<a name="index-PDImode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>PDImode</code></dt>
|
||
|
|
<dd><p>“Partial Double Integer” mode represents an integer which occupies
|
||
|
|
eight bytes but which doesn’t really use all eight. On some machines,
|
||
|
|
this is the right mode to use for certain pointers.
|
||
|
|
</p>
|
||
|
|
<a name="index-DImode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>DImode</code></dt>
|
||
|
|
<dd><p>“Double Integer” mode represents an eight-byte integer.
|
||
|
|
</p>
|
||
|
|
<a name="index-TImode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>TImode</code></dt>
|
||
|
|
<dd><p>“Tetra Integer” (?) mode represents a sixteen-byte integer.
|
||
|
|
</p>
|
||
|
|
<a name="index-OImode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>OImode</code></dt>
|
||
|
|
<dd><p>“Octa Integer” (?) mode represents a thirty-two-byte integer.
|
||
|
|
</p>
|
||
|
|
<a name="index-XImode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>XImode</code></dt>
|
||
|
|
<dd><p>“Hexadeca Integer” (?) mode represents a sixty-four-byte integer.
|
||
|
|
</p>
|
||
|
|
<a name="index-QFmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>QFmode</code></dt>
|
||
|
|
<dd><p>“Quarter-Floating” mode represents a quarter-precision (single byte)
|
||
|
|
floating point number.
|
||
|
|
</p>
|
||
|
|
<a name="index-HFmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>HFmode</code></dt>
|
||
|
|
<dd><p>“Half-Floating” mode represents a half-precision (two byte) floating
|
||
|
|
point number.
|
||
|
|
</p>
|
||
|
|
<a name="index-TQFmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>TQFmode</code></dt>
|
||
|
|
<dd><p>“Three-Quarter-Floating” (?) mode represents a three-quarter-precision
|
||
|
|
(three byte) floating point number.
|
||
|
|
</p>
|
||
|
|
<a name="index-SFmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>SFmode</code></dt>
|
||
|
|
<dd><p>“Single Floating” mode represents a four byte floating point number.
|
||
|
|
In the common case, of a processor with IEEE arithmetic and 8-bit bytes,
|
||
|
|
this is a single-precision IEEE floating point number; it can also be
|
||
|
|
used for double-precision (on processors with 16-bit bytes) and
|
||
|
|
single-precision VAX and IBM types.
|
||
|
|
</p>
|
||
|
|
<a name="index-DFmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>DFmode</code></dt>
|
||
|
|
<dd><p>“Double Floating” mode represents an eight byte floating point number.
|
||
|
|
In the common case, of a processor with IEEE arithmetic and 8-bit bytes,
|
||
|
|
this is a double-precision IEEE floating point number.
|
||
|
|
</p>
|
||
|
|
<a name="index-XFmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>XFmode</code></dt>
|
||
|
|
<dd><p>“Extended Floating” mode represents an IEEE extended floating point
|
||
|
|
number. This mode only has 80 meaningful bits (ten bytes). Some
|
||
|
|
processors require such numbers to be padded to twelve bytes, others
|
||
|
|
to sixteen; this mode is used for either.
|
||
|
|
</p>
|
||
|
|
<a name="index-SDmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>SDmode</code></dt>
|
||
|
|
<dd><p>“Single Decimal Floating” mode represents a four byte decimal
|
||
|
|
floating point number (as distinct from conventional binary floating
|
||
|
|
point).
|
||
|
|
</p>
|
||
|
|
<a name="index-DDmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>DDmode</code></dt>
|
||
|
|
<dd><p>“Double Decimal Floating” mode represents an eight byte decimal
|
||
|
|
floating point number.
|
||
|
|
</p>
|
||
|
|
<a name="index-TDmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>TDmode</code></dt>
|
||
|
|
<dd><p>“Tetra Decimal Floating” mode represents a sixteen byte decimal
|
||
|
|
floating point number all 128 of whose bits are meaningful.
|
||
|
|
</p>
|
||
|
|
<a name="index-TFmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>TFmode</code></dt>
|
||
|
|
<dd><p>“Tetra Floating” mode represents a sixteen byte floating point number
|
||
|
|
all 128 of whose bits are meaningful. One common use is the
|
||
|
|
IEEE quad-precision format.
|
||
|
|
</p>
|
||
|
|
<a name="index-QQmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>QQmode</code></dt>
|
||
|
|
<dd><p>“Quarter-Fractional” mode represents a single byte treated as a signed
|
||
|
|
fractional number. The default format is “s.7”.
|
||
|
|
</p>
|
||
|
|
<a name="index-HQmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>HQmode</code></dt>
|
||
|
|
<dd><p>“Half-Fractional” mode represents a two-byte signed fractional number.
|
||
|
|
The default format is “s.15”.
|
||
|
|
</p>
|
||
|
|
<a name="index-SQmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>SQmode</code></dt>
|
||
|
|
<dd><p>“Single Fractional” mode represents a four-byte signed fractional number.
|
||
|
|
The default format is “s.31”.
|
||
|
|
</p>
|
||
|
|
<a name="index-DQmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>DQmode</code></dt>
|
||
|
|
<dd><p>“Double Fractional” mode represents an eight-byte signed fractional number.
|
||
|
|
The default format is “s.63”.
|
||
|
|
</p>
|
||
|
|
<a name="index-TQmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>TQmode</code></dt>
|
||
|
|
<dd><p>“Tetra Fractional” mode represents a sixteen-byte signed fractional number.
|
||
|
|
The default format is “s.127”.
|
||
|
|
</p>
|
||
|
|
<a name="index-UQQmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>UQQmode</code></dt>
|
||
|
|
<dd><p>“Unsigned Quarter-Fractional” mode represents a single byte treated as an
|
||
|
|
unsigned fractional number. The default format is “.8”.
|
||
|
|
</p>
|
||
|
|
<a name="index-UHQmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>UHQmode</code></dt>
|
||
|
|
<dd><p>“Unsigned Half-Fractional” mode represents a two-byte unsigned fractional
|
||
|
|
number. The default format is “.16”.
|
||
|
|
</p>
|
||
|
|
<a name="index-USQmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>USQmode</code></dt>
|
||
|
|
<dd><p>“Unsigned Single Fractional” mode represents a four-byte unsigned fractional
|
||
|
|
number. The default format is “.32”.
|
||
|
|
</p>
|
||
|
|
<a name="index-UDQmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>UDQmode</code></dt>
|
||
|
|
<dd><p>“Unsigned Double Fractional” mode represents an eight-byte unsigned
|
||
|
|
fractional number. The default format is “.64”.
|
||
|
|
</p>
|
||
|
|
<a name="index-UTQmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>UTQmode</code></dt>
|
||
|
|
<dd><p>“Unsigned Tetra Fractional” mode represents a sixteen-byte unsigned
|
||
|
|
fractional number. The default format is “.128”.
|
||
|
|
</p>
|
||
|
|
<a name="index-HAmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>HAmode</code></dt>
|
||
|
|
<dd><p>“Half-Accumulator” mode represents a two-byte signed accumulator.
|
||
|
|
The default format is “s8.7”.
|
||
|
|
</p>
|
||
|
|
<a name="index-SAmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>SAmode</code></dt>
|
||
|
|
<dd><p>“Single Accumulator” mode represents a four-byte signed accumulator.
|
||
|
|
The default format is “s16.15”.
|
||
|
|
</p>
|
||
|
|
<a name="index-DAmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>DAmode</code></dt>
|
||
|
|
<dd><p>“Double Accumulator” mode represents an eight-byte signed accumulator.
|
||
|
|
The default format is “s32.31”.
|
||
|
|
</p>
|
||
|
|
<a name="index-TAmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>TAmode</code></dt>
|
||
|
|
<dd><p>“Tetra Accumulator” mode represents a sixteen-byte signed accumulator.
|
||
|
|
The default format is “s64.63”.
|
||
|
|
</p>
|
||
|
|
<a name="index-UHAmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>UHAmode</code></dt>
|
||
|
|
<dd><p>“Unsigned Half-Accumulator” mode represents a two-byte unsigned accumulator.
|
||
|
|
The default format is “8.8”.
|
||
|
|
</p>
|
||
|
|
<a name="index-USAmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>USAmode</code></dt>
|
||
|
|
<dd><p>“Unsigned Single Accumulator” mode represents a four-byte unsigned
|
||
|
|
accumulator. The default format is “16.16”.
|
||
|
|
</p>
|
||
|
|
<a name="index-UDAmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>UDAmode</code></dt>
|
||
|
|
<dd><p>“Unsigned Double Accumulator” mode represents an eight-byte unsigned
|
||
|
|
accumulator. The default format is “32.32”.
|
||
|
|
</p>
|
||
|
|
<a name="index-UTAmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>UTAmode</code></dt>
|
||
|
|
<dd><p>“Unsigned Tetra Accumulator” mode represents a sixteen-byte unsigned
|
||
|
|
accumulator. The default format is “64.64”.
|
||
|
|
</p>
|
||
|
|
<a name="index-CCmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>CCmode</code></dt>
|
||
|
|
<dd><p>“Condition Code” mode represents the value of a condition code, which
|
||
|
|
is a machine-specific set of bits used to represent the result of a
|
||
|
|
comparison operation. Other machine-specific modes may also be used for
|
||
|
|
the condition code. These modes are not used on machines that use
|
||
|
|
<code>cc0</code> (see <a href="Condition-Code.html#Condition-Code">Condition Code</a>).
|
||
|
|
</p>
|
||
|
|
<a name="index-BLKmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>BLKmode</code></dt>
|
||
|
|
<dd><p>“Block” mode represents values that are aggregates to which none of
|
||
|
|
the other modes apply. In RTL, only memory references can have this mode,
|
||
|
|
and only if they appear in string-move or vector instructions. On machines
|
||
|
|
which have no such instructions, <code>BLKmode</code> will not appear in RTL.
|
||
|
|
</p>
|
||
|
|
<a name="index-VOIDmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>VOIDmode</code></dt>
|
||
|
|
<dd><p>Void mode means the absence of a mode or an unspecified mode.
|
||
|
|
For example, RTL expressions of code <code>const_int</code> have mode
|
||
|
|
<code>VOIDmode</code> because they can be taken to have whatever mode the context
|
||
|
|
requires. In debugging dumps of RTL, <code>VOIDmode</code> is expressed by
|
||
|
|
the absence of any mode.
|
||
|
|
</p>
|
||
|
|
<a name="index-QCmode"></a>
|
||
|
|
<a name="index-HCmode"></a>
|
||
|
|
<a name="index-SCmode"></a>
|
||
|
|
<a name="index-DCmode"></a>
|
||
|
|
<a name="index-XCmode"></a>
|
||
|
|
<a name="index-TCmode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>QCmode, HCmode, SCmode, DCmode, XCmode, TCmode</code></dt>
|
||
|
|
<dd><p>These modes stand for a complex number represented as a pair of floating
|
||
|
|
point values. The floating point values are in <code>QFmode</code>,
|
||
|
|
<code>HFmode</code>, <code>SFmode</code>, <code>DFmode</code>, <code>XFmode</code>, and
|
||
|
|
<code>TFmode</code>, respectively.
|
||
|
|
</p>
|
||
|
|
<a name="index-CQImode"></a>
|
||
|
|
<a name="index-CHImode"></a>
|
||
|
|
<a name="index-CSImode"></a>
|
||
|
|
<a name="index-CDImode"></a>
|
||
|
|
<a name="index-CTImode"></a>
|
||
|
|
<a name="index-COImode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>CQImode, CHImode, CSImode, CDImode, CTImode, COImode</code></dt>
|
||
|
|
<dd><p>These modes stand for a complex number represented as a pair of integer
|
||
|
|
values. The integer values are in <code>QImode</code>, <code>HImode</code>,
|
||
|
|
<code>SImode</code>, <code>DImode</code>, <code>TImode</code>, and <code>OImode</code>,
|
||
|
|
respectively.
|
||
|
|
</p>
|
||
|
|
<a name="index-BND32mode"></a>
|
||
|
|
<a name="index-BND64mode"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>BND32mode BND64mode</code></dt>
|
||
|
|
<dd><p>These modes stand for bounds for pointer of 32 and 64 bit size respectively.
|
||
|
|
Mode size is double pointer mode size.
|
||
|
|
</p></dd>
|
||
|
|
</dl>
|
||
|
|
|
||
|
|
<p>The machine description defines <code>Pmode</code> as a C macro which expands
|
||
|
|
into the machine mode used for addresses. Normally this is the mode
|
||
|
|
whose size is <code>BITS_PER_WORD</code>, <code>SImode</code> on 32-bit machines.
|
||
|
|
</p>
|
||
|
|
<p>The only modes which a machine description <i>must</i> support are
|
||
|
|
<code>QImode</code>, and the modes corresponding to <code>BITS_PER_WORD</code>,
|
||
|
|
<code>FLOAT_TYPE_SIZE</code> and <code>DOUBLE_TYPE_SIZE</code>.
|
||
|
|
The compiler will attempt to use <code>DImode</code> for 8-byte structures and
|
||
|
|
unions, but this can be prevented by overriding the definition of
|
||
|
|
<code>MAX_FIXED_MODE_SIZE</code>. Alternatively, you can have the compiler
|
||
|
|
use <code>TImode</code> for 16-byte structures and unions. Likewise, you can
|
||
|
|
arrange for the C type <code>short int</code> to avoid using <code>HImode</code>.
|
||
|
|
</p>
|
||
|
|
<a name="index-mode-classes"></a>
|
||
|
|
<p>Very few explicit references to machine modes remain in the compiler and
|
||
|
|
these few references will soon be removed. Instead, the machine modes
|
||
|
|
are divided into mode classes. These are represented by the enumeration
|
||
|
|
type <code>enum mode_class</code> defined in <samp>machmode.h</samp>. The possible
|
||
|
|
mode classes are:
|
||
|
|
</p>
|
||
|
|
<dl compact="compact">
|
||
|
|
<dd><a name="index-MODE_005fINT"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>MODE_INT</code></dt>
|
||
|
|
<dd><p>Integer modes. By default these are <code>BImode</code>, <code>QImode</code>,
|
||
|
|
<code>HImode</code>, <code>SImode</code>, <code>DImode</code>, <code>TImode</code>, and
|
||
|
|
<code>OImode</code>.
|
||
|
|
</p>
|
||
|
|
<a name="index-MODE_005fPARTIAL_005fINT"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>MODE_PARTIAL_INT</code></dt>
|
||
|
|
<dd><p>The “partial integer” modes, <code>PQImode</code>, <code>PHImode</code>,
|
||
|
|
<code>PSImode</code> and <code>PDImode</code>.
|
||
|
|
</p>
|
||
|
|
<a name="index-MODE_005fFLOAT"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>MODE_FLOAT</code></dt>
|
||
|
|
<dd><p>Floating point modes. By default these are <code>QFmode</code>,
|
||
|
|
<code>HFmode</code>, <code>TQFmode</code>, <code>SFmode</code>, <code>DFmode</code>,
|
||
|
|
<code>XFmode</code> and <code>TFmode</code>.
|
||
|
|
</p>
|
||
|
|
<a name="index-MODE_005fDECIMAL_005fFLOAT"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>MODE_DECIMAL_FLOAT</code></dt>
|
||
|
|
<dd><p>Decimal floating point modes. By default these are <code>SDmode</code>,
|
||
|
|
<code>DDmode</code> and <code>TDmode</code>.
|
||
|
|
</p>
|
||
|
|
<a name="index-MODE_005fFRACT"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>MODE_FRACT</code></dt>
|
||
|
|
<dd><p>Signed fractional modes. By default these are <code>QQmode</code>, <code>HQmode</code>,
|
||
|
|
<code>SQmode</code>, <code>DQmode</code> and <code>TQmode</code>.
|
||
|
|
</p>
|
||
|
|
<a name="index-MODE_005fUFRACT"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>MODE_UFRACT</code></dt>
|
||
|
|
<dd><p>Unsigned fractional modes. By default these are <code>UQQmode</code>, <code>UHQmode</code>,
|
||
|
|
<code>USQmode</code>, <code>UDQmode</code> and <code>UTQmode</code>.
|
||
|
|
</p>
|
||
|
|
<a name="index-MODE_005fACCUM"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>MODE_ACCUM</code></dt>
|
||
|
|
<dd><p>Signed accumulator modes. By default these are <code>HAmode</code>,
|
||
|
|
<code>SAmode</code>, <code>DAmode</code> and <code>TAmode</code>.
|
||
|
|
</p>
|
||
|
|
<a name="index-MODE_005fUACCUM"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>MODE_UACCUM</code></dt>
|
||
|
|
<dd><p>Unsigned accumulator modes. By default these are <code>UHAmode</code>,
|
||
|
|
<code>USAmode</code>, <code>UDAmode</code> and <code>UTAmode</code>.
|
||
|
|
</p>
|
||
|
|
<a name="index-MODE_005fCOMPLEX_005fINT"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>MODE_COMPLEX_INT</code></dt>
|
||
|
|
<dd><p>Complex integer modes. (These are not currently implemented).
|
||
|
|
</p>
|
||
|
|
<a name="index-MODE_005fCOMPLEX_005fFLOAT"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>MODE_COMPLEX_FLOAT</code></dt>
|
||
|
|
<dd><p>Complex floating point modes. By default these are <code>QCmode</code>,
|
||
|
|
<code>HCmode</code>, <code>SCmode</code>, <code>DCmode</code>, <code>XCmode</code>, and
|
||
|
|
<code>TCmode</code>.
|
||
|
|
</p>
|
||
|
|
<a name="index-MODE_005fFUNCTION"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>MODE_FUNCTION</code></dt>
|
||
|
|
<dd><p>Algol or Pascal function variables including a static chain.
|
||
|
|
(These are not currently implemented).
|
||
|
|
</p>
|
||
|
|
<a name="index-MODE_005fCC"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>MODE_CC</code></dt>
|
||
|
|
<dd><p>Modes representing condition code values. These are <code>CCmode</code> plus
|
||
|
|
any <code>CC_MODE</code> modes listed in the <samp><var>machine</var>-modes.def</samp>.
|
||
|
|
See <a href="Jump-Patterns.html#Jump-Patterns">Jump Patterns</a>,
|
||
|
|
also see <a href="Condition-Code.html#Condition-Code">Condition Code</a>.
|
||
|
|
</p>
|
||
|
|
<a name="index-MODE_005fPOINTER_005fBOUNDS"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>MODE_POINTER_BOUNDS</code></dt>
|
||
|
|
<dd><p>Pointer bounds modes. Used to represent values of pointer bounds type.
|
||
|
|
Operations in these modes may be executed as NOPs depending on hardware
|
||
|
|
features and environment setup.
|
||
|
|
</p>
|
||
|
|
<a name="index-MODE_005fRANDOM"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>MODE_RANDOM</code></dt>
|
||
|
|
<dd><p>This is a catchall mode class for modes which don’t fit into the above
|
||
|
|
classes. Currently <code>VOIDmode</code> and <code>BLKmode</code> are in
|
||
|
|
<code>MODE_RANDOM</code>.
|
||
|
|
</p></dd>
|
||
|
|
</dl>
|
||
|
|
|
||
|
|
<p>Here are some C macros that relate to machine modes:
|
||
|
|
</p>
|
||
|
|
<dl compact="compact">
|
||
|
|
<dd><a name="index-GET_005fMODE"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>GET_MODE (<var>x</var>)</code></dt>
|
||
|
|
<dd><p>Returns the machine mode of the RTX <var>x</var>.
|
||
|
|
</p>
|
||
|
|
<a name="index-PUT_005fMODE"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>PUT_MODE (<var>x</var>, <var>newmode</var>)</code></dt>
|
||
|
|
<dd><p>Alters the machine mode of the RTX <var>x</var> to be <var>newmode</var>.
|
||
|
|
</p>
|
||
|
|
<a name="index-NUM_005fMACHINE_005fMODES"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>NUM_MACHINE_MODES</code></dt>
|
||
|
|
<dd><p>Stands for the number of machine modes available on the target
|
||
|
|
machine. This is one greater than the largest numeric value of any
|
||
|
|
machine mode.
|
||
|
|
</p>
|
||
|
|
<a name="index-GET_005fMODE_005fNAME"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>GET_MODE_NAME (<var>m</var>)</code></dt>
|
||
|
|
<dd><p>Returns the name of mode <var>m</var> as a string.
|
||
|
|
</p>
|
||
|
|
<a name="index-GET_005fMODE_005fCLASS"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>GET_MODE_CLASS (<var>m</var>)</code></dt>
|
||
|
|
<dd><p>Returns the mode class of mode <var>m</var>.
|
||
|
|
</p>
|
||
|
|
<a name="index-GET_005fMODE_005fWIDER_005fMODE"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>GET_MODE_WIDER_MODE (<var>m</var>)</code></dt>
|
||
|
|
<dd><p>Returns the next wider natural mode. For example, the expression
|
||
|
|
<code>GET_MODE_WIDER_MODE (QImode)</code> returns <code>HImode</code>.
|
||
|
|
</p>
|
||
|
|
<a name="index-GET_005fMODE_005fSIZE"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>GET_MODE_SIZE (<var>m</var>)</code></dt>
|
||
|
|
<dd><p>Returns the size in bytes of a datum of mode <var>m</var>.
|
||
|
|
</p>
|
||
|
|
<a name="index-GET_005fMODE_005fBITSIZE"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>GET_MODE_BITSIZE (<var>m</var>)</code></dt>
|
||
|
|
<dd><p>Returns the size in bits of a datum of mode <var>m</var>.
|
||
|
|
</p>
|
||
|
|
<a name="index-GET_005fMODE_005fIBIT"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>GET_MODE_IBIT (<var>m</var>)</code></dt>
|
||
|
|
<dd><p>Returns the number of integral bits of a datum of fixed-point mode <var>m</var>.
|
||
|
|
</p>
|
||
|
|
<a name="index-GET_005fMODE_005fFBIT"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>GET_MODE_FBIT (<var>m</var>)</code></dt>
|
||
|
|
<dd><p>Returns the number of fractional bits of a datum of fixed-point mode <var>m</var>.
|
||
|
|
</p>
|
||
|
|
<a name="index-GET_005fMODE_005fMASK"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>GET_MODE_MASK (<var>m</var>)</code></dt>
|
||
|
|
<dd><p>Returns a bitmask containing 1 for all bits in a word that fit within
|
||
|
|
mode <var>m</var>. This macro can only be used for modes whose bitsize is
|
||
|
|
less than or equal to <code>HOST_BITS_PER_INT</code>.
|
||
|
|
</p>
|
||
|
|
<a name="index-GET_005fMODE_005fALIGNMENT"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>GET_MODE_ALIGNMENT (<var>m</var>)</code></dt>
|
||
|
|
<dd><p>Return the required alignment, in bits, for an object of mode <var>m</var>.
|
||
|
|
</p>
|
||
|
|
<a name="index-GET_005fMODE_005fUNIT_005fSIZE"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>GET_MODE_UNIT_SIZE (<var>m</var>)</code></dt>
|
||
|
|
<dd><p>Returns the size in bytes of the subunits of a datum of mode <var>m</var>.
|
||
|
|
This is the same as <code>GET_MODE_SIZE</code> except in the case of complex
|
||
|
|
modes. For them, the unit size is the size of the real or imaginary
|
||
|
|
part.
|
||
|
|
</p>
|
||
|
|
<a name="index-GET_005fMODE_005fNUNITS"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>GET_MODE_NUNITS (<var>m</var>)</code></dt>
|
||
|
|
<dd><p>Returns the number of units contained in a mode, i.e.,
|
||
|
|
<code>GET_MODE_SIZE</code> divided by <code>GET_MODE_UNIT_SIZE</code>.
|
||
|
|
</p>
|
||
|
|
<a name="index-GET_005fCLASS_005fNARROWEST_005fMODE"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>GET_CLASS_NARROWEST_MODE (<var>c</var>)</code></dt>
|
||
|
|
<dd><p>Returns the narrowest mode in mode class <var>c</var>.
|
||
|
|
</p></dd>
|
||
|
|
</dl>
|
||
|
|
|
||
|
|
<p>The following 3 variables are defined on every target. They can be
|
||
|
|
used to allocate buffers that are guaranteed to be large enough to
|
||
|
|
hold any value that can be represented on the target. The first two
|
||
|
|
can be overridden by defining them in the target’s mode.def file,
|
||
|
|
however, the value must be a constant that can determined very early
|
||
|
|
in the compilation process. The third symbol cannot be overridden.
|
||
|
|
</p>
|
||
|
|
<dl compact="compact">
|
||
|
|
<dd><a name="index-BITS_005fPER_005fUNIT"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>BITS_PER_UNIT</code></dt>
|
||
|
|
<dd><p>The number of bits in an addressable storage unit (byte). If you do
|
||
|
|
not define this, the default is 8.
|
||
|
|
</p>
|
||
|
|
<a name="index-MAX_005fBITSIZE_005fMODE_005fANY_005fINT"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>MAX_BITSIZE_MODE_ANY_INT</code></dt>
|
||
|
|
<dd><p>The maximum bitsize of any mode that is used in integer math. This
|
||
|
|
should be overridden by the target if it uses large integers as
|
||
|
|
containers for larger vectors but otherwise never uses the contents to
|
||
|
|
compute integer values.
|
||
|
|
</p>
|
||
|
|
<a name="index-MAX_005fBITSIZE_005fMODE_005fANY_005fMODE"></a>
|
||
|
|
</dd>
|
||
|
|
<dt><code>MAX_BITSIZE_MODE_ANY_MODE</code></dt>
|
||
|
|
<dd><p>The bitsize of the largest mode on the target.
|
||
|
|
</p></dd>
|
||
|
|
</dl>
|
||
|
|
|
||
|
|
<a name="index-byte_005fmode"></a>
|
||
|
|
<a name="index-word_005fmode"></a>
|
||
|
|
<p>The global variables <code>byte_mode</code> and <code>word_mode</code> contain modes
|
||
|
|
whose classes are <code>MODE_INT</code> and whose bitsizes are either
|
||
|
|
<code>BITS_PER_UNIT</code> or <code>BITS_PER_WORD</code>, respectively. On 32-bit
|
||
|
|
machines, these are <code>QImode</code> and <code>SImode</code>, respectively.
|
||
|
|
</p>
|
||
|
|
<hr>
|
||
|
|
<div class="header">
|
||
|
|
<p>
|
||
|
|
Next: <a href="Constants.html#Constants" accesskey="n" rel="next">Constants</a>, Previous: <a href="Flags.html#Flags" accesskey="p" rel="prev">Flags</a>, Up: <a href="RTL.html#RTL" accesskey="u" rel="up">RTL</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p>
|
||
|
|
</div>
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
</body>
|
||
|
|
</html>
|