1<html lang="en"> 2<head> 3<title>Floating Types - Using the GNU Compiler Collection (GCC)</title> 4<meta http-equiv="Content-Type" content="text/html"> 5<meta name="description" content="Using the GNU Compiler Collection (GCC)"> 6<meta name="generator" content="makeinfo 4.13"> 7<link title="Top" rel="start" href="index.html#Top"> 8<link rel="up" href="C-Extensions.html#C-Extensions" title="C Extensions"> 9<link rel="prev" href="Complex.html#Complex" title="Complex"> 10<link rel="next" href="Half_002dPrecision.html#Half_002dPrecision" title="Half-Precision"> 11<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> 12<!-- 13Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 141998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 152010 Free Software Foundation, Inc. 16 17Permission is granted to copy, distribute and/or modify this document 18under the terms of the GNU Free Documentation License, Version 1.3 or 19any later version published by the Free Software Foundation; with the 20Invariant Sections being ``Funding Free Software'', the Front-Cover 21Texts being (a) (see below), and with the Back-Cover Texts being (b) 22(see below). A copy of the license is included in the section entitled 23``GNU Free Documentation License''. 24 25(a) The FSF's Front-Cover Text is: 26 27 A GNU Manual 28 29(b) The FSF's Back-Cover Text is: 30 31 You have freedom to copy and modify this GNU Manual, like GNU 32 software. Copies published by the Free Software Foundation raise 33 funds for GNU development.--> 34<meta http-equiv="Content-Style-Type" content="text/css"> 35<style type="text/css"><!-- 36 pre.display { font-family:inherit } 37 pre.format { font-family:inherit } 38 pre.smalldisplay { font-family:inherit; font-size:smaller } 39 pre.smallformat { font-family:inherit; font-size:smaller } 40 pre.smallexample { font-size:smaller } 41 pre.smalllisp { font-size:smaller } 42 span.sc { font-variant:small-caps } 43 span.roman { font-family:serif; font-weight:normal; } 44 span.sansserif { font-family:sans-serif; font-weight:normal; } 45--></style> 46<link rel="stylesheet" type="text/css" href="../cs.css"> 47</head> 48<body> 49<div class="node"> 50<a name="Floating-Types"></a> 51<p> 52Next: <a rel="next" accesskey="n" href="Half_002dPrecision.html#Half_002dPrecision">Half-Precision</a>, 53Previous: <a rel="previous" accesskey="p" href="Complex.html#Complex">Complex</a>, 54Up: <a rel="up" accesskey="u" href="C-Extensions.html#C-Extensions">C Extensions</a> 55<hr> 56</div> 57 58<h3 class="section">6.11 Additional Floating Types</h3> 59 60<p><a name="index-additional-floating-types-2287"></a><a name="index-g_t_0040code_007b_005f_005ffloat80_007d-data-type-2288"></a><a name="index-g_t_0040code_007b_005f_005ffloat128_007d-data-type-2289"></a><a name="index-g_t_0040code_007bw_007d-floating-point-suffix-2290"></a><a name="index-g_t_0040code_007bq_007d-floating-point-suffix-2291"></a><a name="index-g_t_0040code_007bW_007d-floating-point-suffix-2292"></a><a name="index-g_t_0040code_007bQ_007d-floating-point-suffix-2293"></a> 61As an extension, the GNU C compiler supports additional floating 62types, <code>__float80</code> and <code>__float128</code> to support 80bit 63(<code>XFmode</code>) and 128 bit (<code>TFmode</code>) floating types. 64Support for additional types includes the arithmetic operators: 65add, subtract, multiply, divide; unary arithmetic operators; 66relational operators; equality operators; and conversions to and from 67integer and other floating types. Use a suffix ‘<samp><span class="samp">w</span></samp>’ or ‘<samp><span class="samp">W</span></samp>’ 68in a literal constant of type <code>__float80</code> and ‘<samp><span class="samp">q</span></samp>’ or ‘<samp><span class="samp">Q</span></samp>’ 69for <code>_float128</code>. You can declare complex types using the 70corresponding internal complex type, <code>XCmode</code> for <code>__float80</code> 71type and <code>TCmode</code> for <code>__float128</code> type: 72 73<pre class="smallexample"> typedef _Complex float __attribute__((mode(TC))) _Complex128; 74 typedef _Complex float __attribute__((mode(XC))) _Complex80; 75</pre> 76 <p>Not all targets support additional floating point types. <code>__float80</code> 77and <code>__float128</code> types are supported on i386, x86_64 and ia64 targets. 78The <code>__float128</code> type is supported on hppa HP-UX targets. 79 80 </body></html> 81 82