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diff --git a/share/doc/gdb/Decimal-Floating-Point.html b/share/doc/gdb/Decimal-Floating-Point.html new file mode 100644 index 0000000..9afaa04 --- /dev/null +++ b/share/doc/gdb/Decimal-Floating-Point.html @@ -0,0 +1,100 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<html> +<!-- 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 "Free Software" and "Free Software Needs +Free Documentation", with the Front-Cover Texts being "A GNU Manual," +and with the Back-Cover Texts as in (a) below. + +(a) The FSF's Back-Cover Text is: "You are free to copy and modify +this GNU Manual. Buying copies from GNU Press supports the FSF in +developing GNU and promoting software freedom." --> +<!-- Created by GNU Texinfo 5.1, http://www.gnu.org/software/texinfo/ --> +<head> +<title>Debugging with GDB: Decimal Floating Point</title> + +<meta name="description" content="Debugging with GDB: Decimal Floating Point"> +<meta name="keywords" content="Debugging with GDB: Decimal Floating 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="Concept-Index.html#Concept-Index" rel="index" title="Concept Index"> +<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> +<link href="C.html#C" rel="up" title="C"> +<link href="D.html#D" rel="next" title="D"> +<link href="Debugging-C-Plus-Plus.html#Debugging-C-Plus-Plus" rel="previous" title="Debugging C Plus Plus"> +<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="Decimal-Floating-Point"></a> +<div class="header"> +<p> +Previous: <a href="Debugging-C-Plus-Plus.html#Debugging-C-Plus-Plus" accesskey="p" rel="previous">Debugging C Plus Plus</a>, Up: <a href="C.html#C" accesskey="u" rel="up">C</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p> +</div> +<hr> +<a name="Decimal-Floating-Point-format"></a> +<h4 class="subsubsection">15.4.1.8 Decimal Floating Point format</h4> +<a name="index-decimal-floating-point-format"></a> + +<p><small>GDB</small> can examine, set and perform computations with numbers in +decimal floating point format, which in the C language correspond to the +<code>_Decimal32</code>, <code>_Decimal64</code> and <code>_Decimal128</code> types as +specified by the extension to support decimal floating-point arithmetic. +</p> +<p>There are two encodings in use, depending on the architecture: BID (Binary +Integer Decimal) for x86 and x86-64, and DPD (Densely Packed Decimal) for +PowerPC and S/390. <small>GDB</small> will use the appropriate encoding for the +configured target. +</p> +<p>Because of a limitation in <samp>libdecnumber</samp>, the library used by <small>GDB</small> +to manipulate decimal floating point numbers, it is not possible to convert +(using a cast, for example) integers wider than 32-bit to decimal float. +</p> +<p>In addition, in order to imitate <small>GDB</small>’s behaviour with binary floating +point computations, error checking in decimal float operations ignores +underflow, overflow and divide by zero exceptions. +</p> +<p>In the PowerPC architecture, <small>GDB</small> provides a set of pseudo-registers +to inspect <code>_Decimal128</code> values stored in floating point registers. +See <a href="PowerPC.html#PowerPC">PowerPC</a> for more details. +</p> + + + +</body> +</html> |