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| author | alk3pInjection <webmaster@raspii.tech> | 2024-02-04 16:16:35 +0800 |
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| committer | alk3pInjection <webmaster@raspii.tech> | 2024-02-04 16:16:35 +0800 |
| commit | abdaadbcae30fe0c9a66c7516798279fdfd97750 (patch) | |
| tree | 00a54a6e25601e43876d03c1a4a12a749d4a914c /share/doc/gcc/Floating-point-implementation.html | |
https://developer.arm.com/downloads/-/arm-gnu-toolchain-downloads
Change-Id: I7303388733328cd98ab9aa3c30236db67f2e9e9c
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diff --git a/share/doc/gcc/Floating-point-implementation.html b/share/doc/gcc/Floating-point-implementation.html new file mode 100644 index 0000000..4ca3eaf --- /dev/null +++ b/share/doc/gcc/Floating-point-implementation.html @@ -0,0 +1,173 @@ +<!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). 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 5.1, http://www.gnu.org/software/texinfo/ --> +<head> +<title>Using the GNU Compiler Collection (GCC): Floating point implementation</title> + +<meta name="description" content="Using the GNU Compiler Collection (GCC): Floating point implementation"> +<meta name="keywords" content="Using the GNU Compiler Collection (GCC): Floating point implementation"> +<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-Implementation.html#C-Implementation" rel="up" title="C Implementation"> +<link href="Arrays-and-pointers-implementation.html#Arrays-and-pointers-implementation" rel="next" title="Arrays and pointers implementation"> +<link href="Integers-implementation.html#Integers-implementation" rel="previous" title="Integers implementation"> +<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="Floating-point-implementation"></a> +<div class="header"> +<p> +Next: <a href="Arrays-and-pointers-implementation.html#Arrays-and-pointers-implementation" accesskey="n" rel="next">Arrays and pointers implementation</a>, Previous: <a href="Integers-implementation.html#Integers-implementation" accesskey="p" rel="previous">Integers implementation</a>, Up: <a href="C-Implementation.html#C-Implementation" accesskey="u" rel="up">C Implementation</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="Floating-Point"></a> +<h3 class="section">4.6 Floating Point</h3> + +<ul> +<li> <cite>The accuracy of the floating-point operations and of the library +functions in <code><math.h></code> and <code><complex.h></code> that return floating-point +results (C90, C99 and C11 5.2.4.2.2).</cite> + +<p>The accuracy is unknown. +</p> +</li><li> <cite>The rounding behaviors characterized by non-standard values +of <code>FLT_ROUNDS</code> +(C90, C99 and C11 5.2.4.2.2).</cite> + +<p>GCC does not use such values. +</p> +</li><li> <cite>The evaluation methods characterized by non-standard negative +values of <code>FLT_EVAL_METHOD</code> (C99 and C11 5.2.4.2.2).</cite> + +<p>GCC does not use such values. +</p> +</li><li> <cite>The direction of rounding when an integer is converted to a +floating-point number that cannot exactly represent the original +value (C90 6.2.1.3, C99 and C11 6.3.1.4).</cite> + +<p>C99 Annex F is followed. +</p> +</li><li> <cite>The direction of rounding when a floating-point number is +converted to a narrower floating-point number (C90 6.2.1.4, C99 and C11 +6.3.1.5).</cite> + +<p>C99 Annex F is followed. +</p> +</li><li> <cite>How the nearest representable value or the larger or smaller +representable value immediately adjacent to the nearest representable +value is chosen for certain floating constants (C90 6.1.3.1, C99 and C11 +6.4.4.2).</cite> + +<p>C99 Annex F is followed. +</p> +</li><li> <cite>Whether and how floating expressions are contracted when not +disallowed by the <code>FP_CONTRACT</code> pragma (C99 and C11 6.5).</cite> + +<p>Expressions are currently only contracted if <samp>-ffp-contract=fast</samp>, +<samp>-funsafe-math-optimizations</samp> or <samp>-ffast-math</samp> are used. +This is subject to change. +</p> +</li><li> <cite>The default state for the <code>FENV_ACCESS</code> pragma (C99 and C11 +7.6.1).</cite> + +<p>This pragma is not implemented, but the default is to “off” unless +<samp>-frounding-math</samp> is used and <samp>-fno-trapping-math</samp> is not +in which case it is “on”. +</p> +</li><li> <cite>Additional floating-point exceptions, rounding modes, environments, +and classifications, and their macro names (C99 and C11 7.6, C99 and +C11 7.12).</cite> + +<p>This is dependent on the implementation of the C library, and is not +defined by GCC itself. +</p> +</li><li> <cite>The default state for the <code>FP_CONTRACT</code> pragma (C99 and C11 +7.12.2).</cite> + +<p>This pragma is not implemented. Expressions are currently only +contracted if <samp>-ffp-contract=fast</samp>, +<samp>-funsafe-math-optimizations</samp> or <samp>-ffast-math</samp> are used. +This is subject to change. +</p> +</li><li> <cite>Whether the “inexact” floating-point exception can be raised +when the rounded result actually does equal the mathematical result +in an IEC 60559 conformant implementation (C99 F.9).</cite> + +<p>This is dependent on the implementation of the C library, and is not +defined by GCC itself. +</p> +</li><li> <cite>Whether the “underflow” (and “inexact”) floating-point +exception can be raised when a result is tiny but not inexact in an +IEC 60559 conformant implementation (C99 F.9).</cite> + +<p>This is dependent on the implementation of the C library, and is not +defined by GCC itself. +</p> +</li></ul> + +<hr> +<div class="header"> +<p> +Next: <a href="Arrays-and-pointers-implementation.html#Arrays-and-pointers-implementation" accesskey="n" rel="next">Arrays and pointers implementation</a>, Previous: <a href="Integers-implementation.html#Integers-implementation" accesskey="p" rel="previous">Integers implementation</a>, Up: <a href="C-Implementation.html#C-Implementation" accesskey="u" rel="up">C Implementation</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> + + + +</body> +</html> |