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diff --git a/share/doc/gcc/Fixed_002dPoint.html b/share/doc/gcc/Fixed_002dPoint.html new file mode 100644 index 0000000..abe6a10 --- /dev/null +++ b/share/doc/gcc/Fixed_002dPoint.html @@ -0,0 +1,226 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<html> +<!-- This file documents the use of the GNU compilers. + +Copyright (C) 1988-2023 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). 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Copies published by the Free Software Foundation raise + funds for GNU development. --> +<!-- Created by GNU Texinfo 5.1, http://www.gnu.org/software/texinfo/ --> +<head> +<title>Using the GNU Compiler Collection (GCC): Fixed-Point</title> + +<meta name="description" content="Using the GNU Compiler Collection (GCC): Fixed-Point"> +<meta name="keywords" content="Using the GNU Compiler Collection (GCC): Fixed-Point"> +<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="Indices.html#Indices" rel="index" title="Indices"> +<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> +<link href="C-Extensions.html#C-Extensions" rel="up" title="C Extensions"> +<link href="Named-Address-Spaces.html#Named-Address-Spaces" rel="next" title="Named Address Spaces"> +<link href="Hex-Floats.html#Hex-Floats" rel="previous" title="Hex Floats"> +<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_US" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000"> +<a name="Fixed_002dPoint"></a> +<div class="header"> +<p> +Next: <a href="Named-Address-Spaces.html#Named-Address-Spaces" accesskey="n" rel="next">Named Address Spaces</a>, Previous: <a href="Hex-Floats.html#Hex-Floats" accesskey="p" rel="previous">Hex Floats</a>, Up: <a href="C-Extensions.html#C-Extensions" accesskey="u" rel="up">C Extensions</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Indices.html#Indices" title="Index" rel="index">Index</a>]</p> +</div> +<hr> +<a name="Fixed_002dPoint-Types"></a> +<h3 class="section">6.16 Fixed-Point Types</h3> +<a name="index-fixed_002dpoint-types"></a> +<a name="index-_005fFract-data-type"></a> +<a name="index-_005fAccum-data-type"></a> +<a name="index-_005fSat-data-type"></a> +<a name="index-hr-fixed_002dsuffix"></a> +<a name="index-r-fixed_002dsuffix"></a> +<a name="index-lr-fixed_002dsuffix"></a> +<a name="index-llr-fixed_002dsuffix"></a> +<a name="index-uhr-fixed_002dsuffix"></a> +<a name="index-ur-fixed_002dsuffix"></a> +<a name="index-ulr-fixed_002dsuffix"></a> +<a name="index-ullr-fixed_002dsuffix"></a> +<a name="index-hk-fixed_002dsuffix"></a> +<a name="index-k-fixed_002dsuffix"></a> +<a name="index-lk-fixed_002dsuffix"></a> +<a name="index-llk-fixed_002dsuffix"></a> +<a name="index-uhk-fixed_002dsuffix"></a> +<a name="index-uk-fixed_002dsuffix"></a> +<a name="index-ulk-fixed_002dsuffix"></a> +<a name="index-ullk-fixed_002dsuffix"></a> +<a name="index-HR-fixed_002dsuffix"></a> +<a name="index-R-fixed_002dsuffix"></a> +<a name="index-LR-fixed_002dsuffix"></a> +<a name="index-LLR-fixed_002dsuffix"></a> +<a name="index-UHR-fixed_002dsuffix"></a> +<a name="index-UR-fixed_002dsuffix"></a> +<a name="index-ULR-fixed_002dsuffix"></a> +<a name="index-ULLR-fixed_002dsuffix"></a> +<a name="index-HK-fixed_002dsuffix"></a> +<a name="index-K-fixed_002dsuffix"></a> +<a name="index-LK-fixed_002dsuffix"></a> +<a name="index-LLK-fixed_002dsuffix"></a> +<a name="index-UHK-fixed_002dsuffix"></a> +<a name="index-UK-fixed_002dsuffix"></a> +<a name="index-ULK-fixed_002dsuffix"></a> +<a name="index-ULLK-fixed_002dsuffix"></a> + +<p>As an extension, GNU C supports fixed-point types as +defined in the N1169 draft of ISO/IEC DTR 18037. Support for fixed-point +types in GCC will evolve as the draft technical report changes. +Calling conventions for any target might also change. Not all targets +support fixed-point types. +</p> +<p>The fixed-point types are +<code>short _Fract</code>, +<code>_Fract</code>, +<code>long _Fract</code>, +<code>long long _Fract</code>, +<code>unsigned short _Fract</code>, +<code>unsigned _Fract</code>, +<code>unsigned long _Fract</code>, +<code>unsigned long long _Fract</code>, +<code>_Sat short _Fract</code>, +<code>_Sat _Fract</code>, +<code>_Sat long _Fract</code>, +<code>_Sat long long _Fract</code>, +<code>_Sat unsigned short _Fract</code>, +<code>_Sat unsigned _Fract</code>, +<code>_Sat unsigned long _Fract</code>, +<code>_Sat unsigned long long _Fract</code>, +<code>short _Accum</code>, +<code>_Accum</code>, +<code>long _Accum</code>, +<code>long long _Accum</code>, +<code>unsigned short _Accum</code>, +<code>unsigned _Accum</code>, +<code>unsigned long _Accum</code>, +<code>unsigned long long _Accum</code>, +<code>_Sat short _Accum</code>, +<code>_Sat _Accum</code>, +<code>_Sat long _Accum</code>, +<code>_Sat long long _Accum</code>, +<code>_Sat unsigned short _Accum</code>, +<code>_Sat unsigned _Accum</code>, +<code>_Sat unsigned long _Accum</code>, +<code>_Sat unsigned long long _Accum</code>. +</p> +<p>Fixed-point data values contain fractional and optional integral parts. +The format of fixed-point data varies and depends on the target machine. +</p> +<p>Support for fixed-point types includes: +</p><ul> +<li> prefix and postfix increment and decrement operators (<code>++</code>, <code>--</code>) +</li><li> unary arithmetic operators (<code>+</code>, <code>-</code>, <code>!</code>) +</li><li> binary arithmetic operators (<code>+</code>, <code>-</code>, <code>*</code>, <code>/</code>) +</li><li> binary shift operators (<code><<</code>, <code>>></code>) +</li><li> relational operators (<code><</code>, <code><=</code>, <code>>=</code>, <code>></code>) +</li><li> equality operators (<code>==</code>, <code>!=</code>) +</li><li> assignment operators (<code>+=</code>, <code>-=</code>, <code>*=</code>, <code>/=</code>, +<code><<=</code>, <code>>>=</code>) +</li><li> conversions to and from integer, floating-point, or fixed-point types +</li></ul> + +<p>Use a suffix in a fixed-point literal constant: +</p><ul> +<li> ‘<samp>hr</samp>’ or ‘<samp>HR</samp>’ for <code>short _Fract</code> and +<code>_Sat short _Fract</code> +</li><li> ‘<samp>r</samp>’ or ‘<samp>R</samp>’ for <code>_Fract</code> and <code>_Sat _Fract</code> +</li><li> ‘<samp>lr</samp>’ or ‘<samp>LR</samp>’ for <code>long _Fract</code> and +<code>_Sat long _Fract</code> +</li><li> ‘<samp>llr</samp>’ or ‘<samp>LLR</samp>’ for <code>long long _Fract</code> and +<code>_Sat long long _Fract</code> +</li><li> ‘<samp>uhr</samp>’ or ‘<samp>UHR</samp>’ for <code>unsigned short _Fract</code> and +<code>_Sat unsigned short _Fract</code> +</li><li> ‘<samp>ur</samp>’ or ‘<samp>UR</samp>’ for <code>unsigned _Fract</code> and +<code>_Sat unsigned _Fract</code> +</li><li> ‘<samp>ulr</samp>’ or ‘<samp>ULR</samp>’ for <code>unsigned long _Fract</code> and +<code>_Sat unsigned long _Fract</code> +</li><li> ‘<samp>ullr</samp>’ or ‘<samp>ULLR</samp>’ for <code>unsigned long long _Fract</code> +and <code>_Sat unsigned long long _Fract</code> +</li><li> ‘<samp>hk</samp>’ or ‘<samp>HK</samp>’ for <code>short _Accum</code> and +<code>_Sat short _Accum</code> +</li><li> ‘<samp>k</samp>’ or ‘<samp>K</samp>’ for <code>_Accum</code> and <code>_Sat _Accum</code> +</li><li> ‘<samp>lk</samp>’ or ‘<samp>LK</samp>’ for <code>long _Accum</code> and +<code>_Sat long _Accum</code> +</li><li> ‘<samp>llk</samp>’ or ‘<samp>LLK</samp>’ for <code>long long _Accum</code> and +<code>_Sat long long _Accum</code> +</li><li> ‘<samp>uhk</samp>’ or ‘<samp>UHK</samp>’ for <code>unsigned short _Accum</code> and +<code>_Sat unsigned short _Accum</code> +</li><li> ‘<samp>uk</samp>’ or ‘<samp>UK</samp>’ for <code>unsigned _Accum</code> and +<code>_Sat unsigned _Accum</code> +</li><li> ‘<samp>ulk</samp>’ or ‘<samp>ULK</samp>’ for <code>unsigned long _Accum</code> and +<code>_Sat unsigned long _Accum</code> +</li><li> ‘<samp>ullk</samp>’ or ‘<samp>ULLK</samp>’ for <code>unsigned long long _Accum</code> +and <code>_Sat unsigned long long _Accum</code> +</li></ul> + +<p>GCC support of fixed-point types as specified by the draft technical report +is incomplete: +</p> +<ul> +<li> Pragmas to control overflow and rounding behaviors are not implemented. +</li></ul> + +<p>Fixed-point types are supported by the DWARF debug information format. +</p> +<hr> +<div class="header"> +<p> +Next: <a href="Named-Address-Spaces.html#Named-Address-Spaces" accesskey="n" rel="next">Named Address Spaces</a>, Previous: <a href="Hex-Floats.html#Hex-Floats" accesskey="p" rel="previous">Hex Floats</a>, Up: <a href="C-Extensions.html#C-Extensions" accesskey="u" rel="up">C Extensions</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Indices.html#Indices" title="Index" rel="index">Index</a>]</p> +</div> + + + 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